Abstract:In this study, macadamia nut yoghurt was developed with macadamia nut pulp as the main raw material. Through the single factor combined with response surface optimization test, the effects of sucrose addition, fermentation temperature and fermentation time on the sensory and acidity of the product were studied, and the best process was determined. The results showed that the best fermentation strain of Macadamia yoghurt was the combination of Lactobacillus bulgaricus and Streptococcus thermophilus, the ratio of which was 1:2 (0.33%: 0.67%), the sensory score was 85.5, and the taste was the best; The ratio of macadamia nut kernel to liquid was 1:3, the heat treatment temperature was 65~75 ℃, the secondary homogenization was adopted (20 MPa homogenization for 5 min for the first time and 40 MPa homogenization for 10 min for the second time), the optimum fermentation temperature was 41.5 ℃, the fermentation time was 7.5 h, and the addition amount of sucrose was 6.27%. Under these conditions, the hardness was 323.10g and the viscosity was 53.04 mPa•s. The water holding capacity is 1.53%, the pH value is 3.91, the acidity is 76.12 °T, the protein content is 4.98%, the fat content is 11.80%, and the number of viable lactic acid bacteria is 1.65×109 CFU/g, coliform group, total number of colonies, mold, yeast and pathogenic bacteria (Staphylococcus aureus, Escherichia coli and Salmonella) were not detected. Macadamia yogurt contains 15 fatty acids, mainly unsaturated fatty acids (67.77%). The developed macadamia nut yogurt has a mellow taste, moderate sweet and sour taste, delicate taste and uniform texture, it is a pure plant-based yogurt with high protein and good flavor, which enriches the category of yogurt to a certain extent, improves the deep processing level of macadamia nuts, and has a positive role in promoting the healthy development of the macadamia nut industry.
