Increase of cholesterol oxidation and decrease of PUFA as a result of thermal processing and storage in eggs enriched with n-3 fatty acids by ProQuest


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									                                                                                              538        inform August 2009, Vol. 20 (8)

       palmitic acid, reduced linoleic acid content,   LR at low degrees of supercooling with          in the focus of research for three decades.
       and increased the amount of palmitic acid       increased k and SFC and decreased t1/2. The     Within the last decade, however, it became
       at the sn-2 position of the SL product. Even    characteristics of the blends may have cor-     evident that the lipolytic pathway is incom-
       though amaranth oil content of palmitic         relations with their properties in potential    pletely understood. Studies on the regula-
       acid (18.3%) was originally similar to that     meat applications.                              tion of lipolysis and the characterization
       in breast milk (18.3−25.9%), the structural                                                     of HSL-deficient mice indicated that addi-
       changes induced through enzymatic modi-         Increase of cholesterol                         tional previously unrecognized factors that
       fication resulted in a SL closely resembling                                                    contribute to fat catabolism must exist. This
       breast milk fat and hence its possible appli-   oxidation and decrease of                       led to the discovery of the perilipin, adipo-
       cation as a fat substitute for infant nutri-    PUFA as a result of thermal                     philin, Tip47 (PAT) family of lipid drop-
       tion. A second-order polynomial model was       processing and storage in eggs                  let-binding proteins and the identification
       developed to predict the amount of total                                                        of a novel TAG hydrolase named adipose
       palmitic acid incorporated when reaction        enriched with n-3 fatty acids                   triglyceride lipase (ATGL). This review
       time and substrate level were manipulated,      Mazalli, M.R., and N. Bragagnolo, J. Agric.     focuses on the importance of ATGL as TG
       and to optimize the combination of param-       Food Chem. 57:5028–5034, 2009.                  lipase within the “lipolytic machinery” and
       eters to achieve specific palmitic acid con-         In this work, cholesterol oxide forma-     the current knowledge of molecular mecha-
       tents in amaranth oil. The resulting model      tion and alteration of fatty acid composition   nisms that regulate ATGL activity.
       is useful to develop an SL from amaranth        were analyzed in n-3 enriched eggs under
       oil enriched with palmitic acid specifically    different storage periods and two temper-       Fast method for monitoring
       at the sn-2 position for possible application   atures. The eggs enriched with n-3 fatty
       in infant formulas                              acids were stored at 5 or 25°C for 45 days      phospholipase A 2 activity by
                                                       and subsequently boiled or fried. For each      liquid chromatography–
       Physical characterization of                    treatment, 12 yolks were analyzed every         electrospray ionization mass
                                                       15 days including time zero. The concen-
       lard partial acylglycerols and                  trations of the cholesterol oxides 7-keto-      spectrometry
       their effects on melting and                    cholesterol, 7β-hydroxycholesterol, and         Schebb, N.H., D. Falck, H. Faber, E.-M.
       crystallization properties of                   7α-hydroxycholesterol increased during          Hein, U. Karst, and H. Hayen, J. Chro-
                                                       the storage period and were higher in           matogr. A 1216:5249–5255, 2009.
       blends with rapeseed oil                        fried eggs. Only the 7-ketocholesterol was           A new liquid chromatography–elec-
       Cheong, L.-Z., H. Zhang, Y. Xu, and X.          affected by the storage temperature, and its    trospray ionization mass spectrometry
       Xu, J. Agric. Food
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