Characterization of main physicochemical parameters of milk obtained fromgoats supplemented with sunflower and fish oils

DOME, C.; CARRIÓN SAD, Y.; GAGLIOSTRO, G.; ANTONACCI, L.; MEDICI, S.; CABEZAS, D.M.; PEREYRA, A.; MIGNINO, L.

Congreso; 2021 AOCS Annual Meeting & Expo; 2021

American Oil Chemists' Society

Milk is a complete food containing bioactive fatty acids (FA) like the cis-9, trans-11C 18:2(CLA) isomer of the linoleic acid and its precursor, the trans-11C 18:1 or vaccenic acid (VA) that showed promising cardioprotective and antitumoral properties. Supplementing goats with polyunsaturated fatty acids(PUFA) is an effective way to increase CLA and VA and reduce saturated fat contents but the effects on milk physicochemical parameters and protein profile are poorly explored. Moreover, Milk fat(MF) and protein content determine the technological properties of the obtained cheese. This work focused on the effects of supplementary PUFA feeding on milk FA profile, casein (CN) composition and other parameters of technological interest of milk obtained from PUFA supplemented goats (PUFA-M)compared to unsupplemented control goats (Control-M). To obtain the PUFA-M, goats were supplemented with sunflower and fish oils at a 5:1 ratio. Proximal analysis, Milk FA composition, fat globule (FG), and CN fractions were analyzed together with density, pH, and acidity. MF content (g.L -1) resulted higher (P< 0.05) in PUFA-M (59.67) compared to Control-M (43.82). The same results were observed for lactose (46.85 versus 43.82 g.L -1) and total solids (144.41 versus 134.22 g.L -1). Feeding supplementary PUFA significantly reduced (42.5%) the atherogenic index of milk (P< 0.05), with an increase in VA and CLA. FG size was not affected, averaging 5 μm diameter. Although milk protein and total CN were not affected, the PUFA-M showed a higher (P< 0.05) percentage of α-1CN fraction, potentially improving coagulation properties coupled to a higher pH (6.79 versus 6.63, P< 0.05) and lower acidity (0.137 versus 0.182 mL NaOH/mL milk, P< 0.05). Results obtained confirmed that feeding supplementary PUFA is a useful tool to increase bioactive FA content in goat milk reducing its atherogenic index. Also, these milk physicochemical characteristics could improve the cheese-making process and quality.