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