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Fatty acid compositions of low-fat goat milk ice creams formulated with commercial ice cream mix and 3 different levels of caprine milk fat
Low-fat ice cream has been a popular frozen dairy food among the consumers due mainly to health concerns. However, scientific research on nutritional quality of caprine milk ice cream has been very scarce. The objective of this study was to determine fatty acid compositions of three types of low-fat goat milk ice creams. Three batches of three different low-fat caprine milk ice creams were manufactured using skim (0.46%; SIC), 2.0% (2IC) and whole (3.65%; WIC) goat milk by addition of a commercial ice cream mix (0.25% fat) in fluid goat milk. The soft serve goat ice creams were made using Sani Serv ice cream machine (A5223P, Mooresville, IN), and all experimental fresh ice creams were stored at -18oC in a freezer for 0, 2, 4 and 8 weeks. Fatty acids compositions of all experimental ice cream samples were analyzed using a GC-MS (Thermo Electronic TRACE GC Ultra, Austin, TX) equipped with an automatic sampler (Thermo Electronic AS-3000) and a fused silica capillary column (0.25 mm i.d. x 0.25µm x 60 m; SP-2380 Supelco, Bellefonte, PA). The results showed that concentrations of fatty acids C4:0, C6:0, C8:0, C12:0, C14:0, C16:0, C16:1, C18:0, C18:1, C18:3, C24:0 in the ice creams were significantly (P<0.05 or 0.01) affected by the 3 different levels of fat treatments, while those of C10:0, C14:1, C18:2, C20:0, C22:0 acids were not influenced by the fat treatment. The C12:0, C16:0 and C18:1 acids were the most abundant fatty acids in the experimental goat ice creams, while C12:0 (lauric acid) revealed the highest concentration among all 16 fatty acids. There were no differences in levels of individual fatty acid between storage periods, where the same trend of storage effect occurred in all 16 fatty acids. The fat level x storage interaction effects were also not significant on fatty acid contents of all three goat ice creams. It was concluded that the highest content of lauric acid among all fatty acids was probably due to the existence of coconut oil in the commercial ice cream mix, which was used in the manufacture of goat milk ice creams in this study.
Keywords: Goat milk, ice cream, fatty acids