NEW FATTY ACID ESTERS OF SOLUBLE DIETARY FIBERS WITH EMULSIFYING PROPERTIES Petkova

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NEW FATTY ACID ESTERS OF SOLUBLE DIETARY FIBERS WITH EMULSIFYING PROPERTIES Petkova Powered By Docstoc
					                                                                                                                                                                                         NAROSSA® International Conference for Renewable Resources
                                                                                                                                                                                         and Plant Biotechnology                                                                                                                                                                                                                                                                                                                                                     O
            UNIVERSITY OF FOOD TECHNOLOGIES
            Bulgaria, 4002 Plovdiv, 26, bulv. “Maritza“                                                                                                                                  18th conference, NAROSSA® 2012 in Magdeburg, Germany,
                                                                                                                                                                                         June 4–5, 2012
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                                   NEW FATTY ACID ESTERS OF SOLUBLE DIETARY FIBERS WITH EMULSIFING                                                                                                                                                                                                                                                                                                                                                                                                                                                                       CH2
                                                             PROPERTIES                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  O
                                                                                                                          NADEZHDA PETKOVA*, MINA TODOROVA*, NIKOVSKA KREMENA**, PANTELEY DENEV*                                                                                                                                                                                                                                                                                                                                                             O
                                                                                                    *University of Food Technologies, Department of Organic Chemistry and Microbiology, 26 Maritza Blvd., Plovdiv, Bulgaria,
                                                                                                          **University of Food Technologies, Departament of Catering and Tourism, 26 Maritza Blvd., Plovdiv, Bulgaria,

                                                                                                                                        E-mail address: petkovanadejda@abv.bg, denev57@abv.bg
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             CH2

                                                                                                                                                                                                                                            FT-IR specta of inulin and inulin starate (DS 0,33)
                                                                                                                                                                                                                                                                                                                                                                                                                                                   C=O (ester groups)                                                                                                    O
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             O
     Abstract                                                                                                                                                              80


     Fatty esters of carbohydrates constitute an interesting group of non-ionic                                                                                                         –OH alcohol                                                                                                                                                11 0
                                                                                                                                                                           75

                                                                                                                                                                           70
                                                                                                                                                                                          groups                                                                                                                                                   10 0
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             CH 2




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    597.40
     surfactants. These compounds are environmentally friendly, with low toxicity and                                                                                      65




                                                                                                                                                                                                                                                                                                                                                             3773.05




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                936.76
                                                                                                                                                                                                                                                                                                                                                    90




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      1379.73
                                                                                                                                                                           60


     present interest in agriculture, pharmaceuticals, cosmetic and food industry.                                                                                         55                                                                                                                                                                       80

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         O




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           719.76
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       987.86
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     1171.58
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             O




                                                                                                                                                                                                                                                                                                                                                                                                                                                                              1421.21
                                                                                                                                                                           50




                                                                                                                                                                                                                                                                                                                                                                               3330.54
                                                                                                                                                                                                                                                                                                                            820.06
                                                                                                                                                                                                                                                                 1646.54
                                                                                                                                                                                                                                                                                                                                                    70

     Inulin and fructooligosaccharides esters were synthesized by reacting these                                                                                           45




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 1033.19
                                                                                                                                                                                                                                                                                                                                                                                                                                                   1742.63
                                                                                                                                                                                                                                                                                                                                                    60




                                                                                                                                                                                                                                                                                   1417.63




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  1197.86
                                                                                                                                                                     %T




                                                                                                                                                                                                                                                                                                                                              %T
                                                                                                                                                                           40




                                                                                                                                                                                                                                                                                                                                                                                                                                                                            1439.03
     carbohydrates with methyl esters of saturated fatty acids (C12 to С18). The




                                                                                                                                                                                                                                                                                                                                     599.31
                                                                                                                                                                           35                                                                                                                                                                       50




                                                                                                                                                                                                                    2930.43




                                                                                                                                                                                                                                                                                                                   936.09
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             CH 2
                                                                                                                                                                           30




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                1215.49
     esterification reaction was performed in presence of catalyst NaOMe and




                                                                                                                                                                                                                                                                                                                                                                                                                                                              1556.80
                                                                                                                                                                                                                                                                                                                                                    40




                                                                                                                                                                                                                                                                                                                                                                                                                                                                        1469.80
                                                                                                                                                                           25                                                                                                                                                                             free –OH groups
                                                                                                                                                                           20                                                                                                                                                                       30


     absence of solvent. A new method for synthesis with the ultrasonic influence has




                                                                                                                                                                                                                                                                                                                                                                                                           2849.52
                                                                                                                                                                           15
                                                                                                                                                                                                                                                                                                                                                    20




                                                                                                                                                                                                                                                                                             1132.31
     been developed and applied. The fructooligosaccharides esters and modified
                                                                                                                                                                           10
                                                                                                                                                                                                                                                                                                                                                                                                                     Successful esterification                                                                                                                           O




                                                                                                                                                                                                                                                                                                         1031.20
                                                                                                                                                                                                                                                                                                                                                    10




                                                                                                                                                                                                  3373.58




                                                                                                                                                                                                                                                                                                                                                                                                 2917.17
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             O
                                                                                                                                                                            5

                                                                                                                                                                            0                                                                                                                                                                        0

     inulin have been characterized by measurement of melting point, water activity,                                                                                        40 00         35 00             30 00             25 00              20 00
                                                                                                                                                                                                                                  W aven umb ers (c m-1)
                                                                                                                                                                                                                                                                           15 00                       10 00                           50 0          40 00             35 00             30 00                       25 00              20 00
                                                                                                                                                                                                                                                                                                                                                                                                                         W aven umb ers (c m-1)
                                                                                                                                                                                                                                                                                                                                                                                                                                                             15 00                                             10 00                                  50 0




     thin-layer chromatography (TLC) and FT-IR. A preliminary study of their                                                                                                            Figure 3. FT-IR spectrum of inulin                                                                                                                         Figure 4. FT-IR spectrum of synthesized inulin stearate
     emulsifying and stabilizing properties was analyzed. The rheological properties,                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        CH2
     dispersion and emulsion stability of oil-in-water emulsions (O/W) prepared with
     different concentration of inulin esters as emulsifier were investigated.
                                                                                                                                                                                    Emulsion study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             O O
                                                                                                                                                                                                                                                                                                                                                                                 inulin backbone
 Introduction
 Fatty esters of carbohydrates constitute an interesting group of non-ionic surfactants. These compounds
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      water
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             CH2
 present a good biodegradability and a low toxicity, which confer to them a particular interest in
 pharmaceutical, cosmetic, food industry and agriculture. Polymeric surfactants attract considerable                                                                                                                                                                                                                                                                                                                                                                                                                                                                     O
                                                                                                                                                                                                                                                                                                                                                                                                                                                  oil                                                                                                        O
 attention as dispersants for solid in liquid medium and as emulsifiers. In recent years, the interest to
                                                                                                                                                                                    a                                                                        b
 surfactants that are based on polysaccharides via the grafting of alkyl chains increased dramatically.                                                                                                                                                                                                                                                                                                                       water
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                alkyl chains
Inulin is a polydisperse linear polysaccharide, member of fructan                                                                                                                                                                                                                                                                                                                                                                                                                               (C16 –C18)                                                                   CH2
family and serves as a reserve carbohydrate in underground part of
the Compositae plants. Inulin consists mainly of β-(2→1) fructosyl
fructose units (Fm), and usually but not always the chain contains a                                                                                                                                                                                                                                                                                                           Figure 6. Inulin esters in O/W emulsion                                                                                                                                                   O
terminal α-glucopyranose unit (1→2) (GFn) at the reducing end
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             O
(Figure 1). A small percentage of inulin molecules have a terminal
fructoside unit found primarily in the pyranose form in aqueous                                                                                                                 Figure 5. Microphotographs of modeling emulsions
solution. The degree of polymerization (DP) of inulin varies from 2 to                                                                                                          prepared with 8 % (w/v) inulin palmitate (DS 0,28): a) 50                                                                                                                                                                                                                                                                                                                                     CH2
70 and depends on plant species, harvesting time and post-harvest                                                                                                               % oil phase; b) 70 % oil phase.
conditions. Molecules with DP<10 are called oligofructose or
fructooligosaccharides (FOSs) and is a subgroup of inulin. Inulin and                                                                                                            The rheological behaviors of investigated emulsions prepared with inulin esters characterized                                                                                                                                                                                                                                                                                               O
FOSs are classified as soluble dietary fiber.                                                                                                                                   them as Pseudoplastic fluids (Figure 7 ) with tendency to Nonideal plastic behavior – for                                                                                                                                                                                                                                                                                        O
                                                                                                                           Figure 1. Chemical structure of Inulin
                                                                                                                                                                                emulsions with high amount of oil phase and higher concentration of inulin stearate. The
 Several amphiphilic polymers obtained from inulin have been prepared by esterification, etherification                                                                         viscosity of emulsion increased with increasing of concentration of inulin stearate from 5 to 15                                                                                                                                                                                                                                                                                              CH2
 and carbamoulation. The esterification of inulin is performed by reaction with acid chlorides or                                                                               %. The obtained results showed that the increasing of inulin stearate concentration were
 anhydrides of suitable carboxylic acid (C2 to C22). As a solvent in esterification process usually are used                                                                    achieved more viscous emulsion systems due to more monodispersed oil phase and probably
 toxic solvent with bad smell as pyridine, dimethylformamide (DMF) or dimethylsulfoxide (DMSO). The                                                                                                                                                                                                                                                                                                                                                                                                                                                                      O
                                                                                                                                                                                to better structured continuous phase.                                                                                                                                                                                                                                                                                                                                           O
 esterification of inulin can be achived in absence of solvent using kneader or extruder. The obtained
 inulin esters with long alkyl chain can be used as surfactants in laundry and dishwashing detergent, in
 cosmetics, in pharmaceuticals, in textile industry.                                                                                                                                                                                                                                                                        A                                                                                                                                                                                                                       B
                                                                                                                                                                                                                                                                                                                                                    τ,Pa                                                                                                                                                                                                                     CH2
Aims:     Synthesis of dietary fiber esters of fatty acids on the base of inulin and FOSs. For
esterification process any toxic solvents was not used and an ultrasonic irradiation was                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     O
used to intensify transesterification reaction. Some of the obtained esters to could be used                                                                                                                                                                                                                                                                                                                                                                                                                                                                     O
as emulsifier for preparation of emulsions as eventual future candidate for emulsifier with
high biological activity and dietary effect.
Results                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       CH2
            OH                                                                            OH


                          O                                                                        O                                                                                                                                                                                                                                                                                                                                                                                                                                                                         O
 HO
  HO
                                                                                HO
                                                                                  HO
                                                                                                                                                                                                                                                                                                                    γ ,s-1
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 O
                          OH
                                                                    R                              OH                                                                                                                                                                                                                                                                                                                                                                                                                                    γ ,s-1
HO                                                                          C
                               O                                                 O                      O                                                                   Figure 7. Flow curves of modell emulsions: A - emulsion with 50 % (v/v) oil phase and 2 % (1) and 8 % (w/v)
                 O
                     HO
                                             x eq.CH 3OCOR
                                                                    O
                                                                                               O
                                                                                                   HO
                                                                                                                                                                            (2) inulin palmitate; B - emulsion with 70 % (v/v) oil phase and 8 % (w/v) inulin palmite.                                                                                                                                                                                                                                                                                                        CH 2
                                          NaOMe, t C, M.S. (U.S.)
                                                                        O                                                                                                                                                                            Table 2. Emulsion stability (in % separated phase) of modeling emulsion
                               CH 2
                                      n
                                                                                                        CH2
                                                                                                                                                                                                                                                     prepared with 5, 10 и 15 % inulin stearate and 30, 50 и 70 % oil phase                                                                                                                                                                                                                                                  O
  HO

                               O                                    R
                                                                            C         O

                                                                                                        O
                                                                                                               n
                                                                                                                                                                          The emulsions with 10
                                                                                                                                                                                                                                                              Oil                                                           Separated phase (oil/water) from emulsion with inulin stearate, %
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 O
  CH 2 OH
             O
                                                                                CH 2OH                                                                                    % concentration of
                                                                                               O
                     HO                                                                                                                                                   emulsifier       inulin                                                            phase,                                                                5                          10                        15
                                                                                                   OH
                                                                                                                                                                          stearate reached the                                                                 %                              O                                F     W     Е      O       F    W      Е     O      F     W                                                                                                                                                           Е
                                                                                                                     inulin palmitate     inulin stearate
                                   CH2 OH
                                               x = 0,1; 0,2
                                                                                                            CH2 OH                                                        maximum       stability.                                                             30                             6                               37     38   19       -     23    40    37      -    50 17                                                                                                                                                             33                           CH2
  HO                                           R= C9H19, C11H23, C13H27,         HO                                                                                       Increased emulsifiers
                                               C15H31, C17H35                                                                                                             concentration had no                                                                 50                             6                                -     38   56       -           31    69      -    35 24                                                                                                                                                             41
Figure 2. Transesterification of inulin and oligofructoses using fatty acid methyl esters (FAME)                                                                          influence   on     the                                                               70                             16                               -     17   67       -      -    13    87      -     8     -                                                                                                                                                          92
                                                                                                                                                                          emulsion and a foam                                                                                                                                                                                                                                                                                                                                                                                O
                                                                                                                                                                                                                                                           * O -oil, F -foam, W-water, Е-emulsion
Table 1. The physico-chemical characteristics of synthesized inulin and fructooligosaccharides
                                                                                                                                                                          formation began to
                                                                                                                                                                          observe.
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 O
( FOS) esters with saturated fatty acids
Ester                   Molar ratio      Reaction      Melting          aw         DS     HLB                                                                                                                                                                Conclusions
                        FAME/AFU temperature, point, °C                                                                                                                                                                                                      In conclusion, our results indicate that the transesterification of                                                                                                                                                                                                                                                 CH2
                                            °C                                                                                                                                                                                                               inulin and oligofructoses using fatty acid methyl ester could be
FOS caprinate U.S.          1:1             70           110      0,333±0,002 0,03       10,5                                                                                                                                                                achieved in presence of basic catalyst without presence of toxic
FOS caprinate M.S           1:1             70           120      0,441±0,002 0,01       10,6                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 O
FOS laurate MS              1:1             70          72-74     0,528±0,001 0,08       10,2
                                                                                                                                                                                                                                                             solvent. The esterification reaction could be intensified by ultrasonic                                                                                                                                                                                                                             O
                                                                                                                                                                                                                                                             irradiation process as we successfully obtained FOS caprinate ester
FOS myristate MS            1:1             70           135      0,434±0,003 0,01       10,6
                                                                                                                                                                                                                                                             (DS 0,03). The tested modified inulin showed emulsifying properties,
Inulin laurate              1:1            100           n.d.          n.d        0,17   16,5
Inulin myristate            1:2            100           n.d.          n.d        0,11   17,3
                                                                                                                                                                                                                                                             which make these dietary fiber fatty acid esters interesting in field                                                                                                                                                                                                                                               CH 2
Inulin myristate            1:1             70           132           n.d        0,45    7,6                                                                                                                                                                of surface-active agent for food purposes. Based on the results
                                                                                                                                                                                                                                                             obtained from the O/W emulsions prepared with inulin stearate we
FOS palmitate MS            1:1             70           n.d.         0,372       0,01    7,4
                                                                                                                                                                                                                                                             can conclude that this surface-active substance used in
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              O
Inulin palmitate            1:2             90        127-135         0,269       0,28   13,5                                                                                                                                                                                                                                                                                                                                                                                                                                                                    O
FOS stearate MS             1:1             70           105          0,338       0,02    7,0                                                                                                                                                                concentration 10 % can be excellent emulsifier for preparation of
Inulin Stearate             1:1            100        129-131         0,210       0,17   17,1                                                                                                                                                                O/W emulsions with 30-70 % oil phase. We suggest that the
Inulin Stearate             1:2             90        122-130         0,200       0,33   12,3                                                                                                                                                                application of inulin stearate as emulsifier in lower concentration
U.S.- ester synthesis by the ultrasonic irradiation; M.S. – ester synthesis by a magnetic stirrer; FAME – fatty                                                                                                                                              supposed combination with other hydrocolloias pectin,                                                                                                                                                                                                                                                               CH2
acid methyl ester; AFU – anhydrous fructose unit; aw –water activity; DS – degree of substitution; HLB –                                                                                                                                                     carrageenans, agar and other gums, but it is need of new additional
hydrophilic-lipophilic balance; n.d – not determinated
                                                                                                                                                                                                                                                             research that have to be done. Inulin palmitate also showed good
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              O
                                                                                                                                                                                                                                                             emulsifying capacity and could be used in stabilization and                                                                                                                                                                                                                                         O
                                                                                                                                                                                                                                                             preparation of emulsions.
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 CH2OH

				
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Description: Fatty esters of carbohydrates constitute an interesting group of non-ionic surfactants. These compounds are environmentally friendly, with low toxicity and present interest in agriculture, pharmaceutical, cosmetic and food industry. Inulin and fructooligosaccharides esters were synthesized by reacting these carbohydrates with methyl esters of saturated fatty acids (C12 to С18). The esterification reaction was performed in presence of catalyst NaOMe and absence of solvent. A new method for synthesis with the ultrasonic influence has been developed and applied. The fructooligosaccharides esters and modified inulin have been characterized by measurement of melting point, water activity, thin-layer chromatography (TLC) and FT-IR. A preliminary study of their emulsifying and stabilizing properties was analyzed. The rheological properties, dispersion and emulsion stability of oil-in-water emulsions (O/W) prepared with different concentration of inulin esters as emulsifier were investigated.