No abstract

Effects of frozen-storage on fatty acids profiles and basic nutrient contents of two types of low-fat caprine milk ice creams were investigated during 0, 2, 4, 8 weeks of storage at −18˚C. Two types of the experimental low-fat soft-serve goat ice creams were manufactured using whole (full-fat) milk and 2% fat goat milk with addition of commercial powdered vanilla flavor pre-mix containing 0.25% fat (Alpha Freeze, D466-A9047, Tampa, FL, USA). Fatty acid concentrations were quantified using a Thermo Electronic gas chromatography (GC)-MS (Model TRACE GC Ultra, Austin, TX, USA) equiped with an automatic sampler (Model AS-3000, Thermo Electronic Co.). The results showed that fat content was the only basic nutrient component exhibited the difference between the two types of ice creams, while no other components have shown differences between the two low-fat ice creams during the storage periods. The level of lauric acid (C12:0) was the highest among all 16 fatty acids, followed by palmitic (C16:0), linoleic (C18:1), and myristic acid (C14:0). The high levels of the medium chain fatty acids (C12:0 and C14:0) might have been derived from the goat milk as well as the palm oil asa part of the ingredients in the commercial ice cream premix. Among long chain fatty acids, palmitic acid (C16:0) was the highest, followed by oleic acid (C18:1) and stearic acid (C18:0). All of the long chain fatty acids contents were significantly higher (P < 0.05 or 0.01) in whole milk ice cream than those in 2% fat ice cream, except for the C22:0 and C24:00 acids. It was concluded that mean levels of the individual fatty acids in the caprine ice creams were significantly influenced by the types of milk fat used in the ice creams, but not by storage periods and storage × fat type interaction effects.