Métodos analíticos para determinação de ácidos graxos em leite equinos e ruminantes

Abstract

The amy of the study was to compare methods of qualitative evaluation of the fatty acid (FA) profile of equine and ruminant milk and to identify the most appropriate methodology for mares and donkeys' milk. Also, determine the best FA profile for human consumption between equine and ruminant milks. Samples of mare, donkey, cow and goat milk were used, ruminant milk was used as a control. The FA of the milks were identified by gas chromatography after three different methylation methodologies, Kramer (1997), acid/base catalysis; O'Fallon (2007) acid/base catalyzes in aqueous medium, and Liu (2020) base catalyzes. No significant differences were observed between the methylation methods for the identified FAs. The mean values of short-chain FA and medium-chain FA contents differed significantly between the methods, and the identification of these FA groups is an important factor in choosing the methodology for each milk. In the qualitative evaluation of the FA profile of milk from mares, donkeys and ruminants, the methylation methods used were similar, indicating that the milks of mares and donkeys can be analyzed by the three methods evaluated in the present study. Short chain FA (C4:0, C6:0 and C8:0) contents were similar, and medium chain FA (C10:0, C12:0 and C14:0) were higher in donkey milk. The mare's milk had the highest content of C18:3n3, which influenced the ∑n3 (C18:3n3, C20:5n3 and C22:6n3), this group with the highest content in mare's milk, 12 times higher than in cow's milk and 8 times that in donkey's milk. ∑n6 (C18:2 n6 and C20:4 n6) were higher in donkey milk (17.75%), followed by mare's milk (12.64%), and 15 times lower in cow's milk (2.55%), when compared to donkey milk. When compared to cow's milk, equid milk has higher levels of n3 and n6; therefore, it has the best FA profile for human consumption. Concluded that the milk of mares and donkeys has a better FA profile for the promotion of human health and can be methylated for the three methods studied without prejudice in the identification.