Recent Advances in Platinum Chemistry by ewghwehws

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									   Phenol profile of olives from
            fruit to oil
                          Curtis Mbulanyumba Kalua*


  School of Science & Technology, Farrer Centre, Charles Sturt University,
           Locked Bag 588, Wagga Wagga, NSW 2678, Australia


* The presenter is a second year PhD student at Charles Sturt University.
                        Project Overview

   Quality of extra-virgin olive oil.

   Phenols & volatiles relationship with taste, aroma, quality
    parameters & stability.

   The quality of olive oil is followed from fruit to oil taking into
    account:
     Fruit quality,
     Processing conditions &
     Storage conditions.

   Phenolics are responsible for the taste & stability of olive oil
    and can be followed from fruit to oil.
              Overview of Presentation

   Phenolic compounds in olives.

   Phenolic compounds & fruit maturity.

   Processing & retained phenolic compounds.

   Phenol profile changes during oil storage.

   Conclusion.
           Phenolic compounds in olives

   A small % of phenols are                            Phenol profile of olive paste
    transferred from fruit to oil.
                                                        Verbascoside
                                           Hydroxytyrosol
   Phenols are released &                                                 Oleuropein
                                                       Tyrosol
    partitioned into the oil during
    processing.

   Hydrolysis converts phenols
    into smaller lipid soluble
    molecules.                             Verbascoside

                                                                                        Oleuropein


   Phenol hydrolysis takes place
                                                 +
    during processing & as the                                                               + Elenolic acid
                                                                                                  glucoside
                                      Hydroxytyrosol      Caf f eic acid
    olive fruit matures.                        + Sugar
                                                                                 Hydroxytyrosol
        Phenolic compounds & fruit maturity

   Hydroxytyrosol increased                         Hydroxytyrosol vs fruit maturity in Mission
    with maturity for Mission,
    Barnea & Manzanillo.                           2000




                                 ppm (w/w)
                                                   1500

   Constant hydroxytyrosol                        1000
    for Paragon with maturity.                      500
                                                      0
                                                          Green      Spotted      Red       Black
   V-shape for Correggiolla &
    Leccino with minimum                             Hydroxytyrosol vs fruit maturity in Leccino
    before red fruit colour.
                                       ppm (w/w)    400
                                                    300
   Phenolic profile trends &
                                                    200
    levels are cutivar
    dependent.                                      100
                                                      0
                                                          Green     Spotted     Red       Black
    Processing & retained phenolic compounds
                                                                               Retained Hty & Oleur vs Temperature
   Hydroxytyrosol & oleuropein




                                                 % Retained phenol
                                                                     100
                                                                                                           Hydroxytyrosol
    retained (fruit to paste) differently                             80
    with processing temperature.                                      60
                                                                      40                                      Oleuropein
                                                                      20
   Hydroxytyrosol retained more                                       0
    than oleuropein.                                                       0          15        30       45          60     75
                                                                                            T (degrees celsius)

                                                                           Retained Verbasc &Tyr vs Temperature
   Verbascoside & tyrosol decrease                                  100




                                            % Retained phenol
    with temperature.                                                80                                   Verbascoscide

                                                                     60

                                                                     40
   Low temperature favours the                                                                                      Tyrosol
                                                                     20
    transfer of best available phenols
                                                                      0
    from fruit to oil.                                                     0          15        30       45          60     75
                                                                                            T (degrees celsius)
    Phenolic compounds changes during storage

   Fast decrease of caffeic
                                                    Caffeic acid vs weeks of storage - Light
    acid in light & dark.
                                                       20
   Slight change at low temp.                         15




                                             (w/w)
                                              ppm
                                                       10
                                                        5
   Decrease in oleuropein                              0
    derivative in light, dark & at                              0       8      16       24
    low temp.
                                                 Oleuropein derivative vs weeks of storage - LT

   Caffeic acid decreases                       200
    faster than oleuropein           ppm (w/w)
                                                 150
    derivatives.                                 100
                                                  50
   Olive oil storage conditions                   0
    affect levels of phenols in                             0       8         16         24
    different ways.
Phenol profile changes with oil storage

     Phenol profile - Time Zero                  Phenol profile - 6 months in light



                                         Light




         Low Temp



 Phenol profile - 6 months at low temp           Phenol profile - 6 months in dark
                           Conclusion

   The desired phenolic compounds in a cultivar can be targeted
    for transfer from fruit to oil by harvesting at a particular stage
    of maturity.

   Phenolic compounds in olive oil depend on processing
    conditions with different phenols responding differently to
    processing conditions.

   The phenols in olive oil change with storage time & the
    changes are a function of storage conditions.

   In general, a stable & premium quality olive oil is produced
    from olive fruit of high quality, with right processing parameters
    & the quality is maintained by favourable storage conditions.
                     Acknowledgements


   Funding: RIRDC, CSU


   Collaboration: Dr. Daniel Jardine, Flinders University;
                   NSW Primary Indusries, Wagga Wagga


   Supervisors: Bedgood, D.; Bishop, A. & Prenzler, P.
END OF PRESENTATION – THANK YOU

								
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