To compare the quality of goat milk by different concentrated methods, this paper explored the effect of vacuum combined heating or frozen concentrated methods on the physicochemical quality of goat milk (pH value, turbidity, color value, particle size, and secondary structure of casein and fat globule). The results showed that when the total solids were 25%, the pH value, turbidity, color value, particle size and casein secondary structure of three concentrated goat milk changed significantly (P<0.05). The fat globules of heated and vacuum heated concentrated goat milk became larger, while the fat globules of vacuum frozen concentrated goat milk did not change significantly. Particle size, fat globules, casein secondary structure and turbidity of vacuum frozen concentrated goat milk changed significantly compared with heating and vacuum heating concentrated goat milk(P<0.05), and vacuum frozen concentrated method had the least effect on goat milk color difference. When the total solids were 35%, the turbidity, color difference and pH value of the three concentrated goat milk changed significantly (P<0.05). The particle size of heated concentrated goat milk increased by 33.90% compared to fresh goat milk (P<0.05), but there was no significant change in the other two concentrated goat milk (P>0.05). There was no significant changed in casein secondary structure of vacuum heated concentrated goat milk(P>0.05). The turbidity, color difference, particle size and casein secondary structure of vacuum frozen concentrated goat milk were changed significantly compared with the other two types of goat milk(P<0.05), and fat globules less than the other two goat milk. Therefore, the quality of with goat milk of 25% total solids was better than that of 35% total solids, and the vacuum frozen condensed goat milk with 25% total solids concentrated level was better than other concentrated goat milk.
[1] 史怀平, 罗军, 党立峰, 等.山羊奶的营养成分及营养价值的提高途径[J].黑龙江畜牧兽医, 2017(9):118-122.
SHI H P, LUO J, DANG L F, et al.Review on improvement approaches of nutrition composition and nutritional value in goat milk[J].Heilongjiang Animal Science and Veterinary Medicine, 2017(9):118-122.
[2] 高佳媛, 邵玉宇, 王毕妮, 等.羊奶及其制品的研究进展[J].中国乳品工业, 2017, 45(1):34-38.
GAO J Y, SHAO Y Y, WANG B N, et al.Research development of goat milk and its products[J].China Dairy Industry, 2017, 45(1):34-38.
[3] BALDE A, AIDER M.Impact of sterilization and storage on the properties of concentrated skim milk by cryoconcentration in comparison with vacuum evaporation and reverse osmosis concentration[J].Journal of Food Process Engineering, 2019, 42(5):e13130.
[4] GRAF B, HEHNKE S, NEUWIRTH M, et al.Continuous microwave heating to inactivate thermophilic spores in heating-sensitive skim milk concentrate[J].International Dairy Journal, 2021, 113:104894.
[5] 步营, 胡显杰, 刘瑛楠, 等.两种浓缩方式对扇贝蒸煮液色泽及挥发性风味物质的影响[J].中国调味品, 2019, 44(12):12-17.
BU Y, HU X J, LIU Y N, et al.Effects of two concentration methods on the color and volatile flavor compounds of scallop cooking liquor[J].China Condiment, 2019, 44(12):12-17.
[6] PETZOLD G, ORELLANA P, MORENO J, et al.Vacuum-assisted block freeze concentration applied to wine[J].Innovative Food Science & Emerging Technologies, 2016, 36:330-335.
[7] 秦贯丰, 丁中祥, 原姣姣, 等.苹果汁冷冻浓缩与真空蒸发浓缩效果的对比[J].食品科学, 2020, 41(7):102-109.
QIN G F, DING Z X, YUAN J J, et al.Comparative experimental study on freeze concentration and vacuum evaporation concentration of apple juice[J].Food Science, 2020, 41(7):102-109.
[8] ZHAO L L, ZHANG S W, LU J, et al.Effects of heat treatment and stabilizing salts supplementation on the physicochemical properties, protein structure and salts balance of goat milk[J].LWT, 2020, 132:109878.
[9] ZHAO X, CHENG M, ZHANG X X, et al.The effect of heat treatment on the microstructure and functional properties of whey protein from goat milk[J].Journal of Dairy Science, 2020, 103(2):1 289-1 302.
[10] TRIBST A A L, FALCADE L T P, CARVALHO N S, et al.Using physical processes to improve physicochemical and structural characteristics of fresh and frozen/thawed sheep milk[J].Innovative Food Science & Emerging Technologies, 2020, 59:102247.
[11] MARKOSKA T, HUPPERTZ T, GREWAL M K, et al.FTIR analysis of physiochemical changes in raw skim milk upon concentration[J].LWT, 2019, 102:64-70.
[12] 孙静丽. 不同热处理对乳蛋白理化性状影响[D].西安:陕西师范大学, 2018.
SUN J L.Effects of different heat treatment on the physicochemical properties of milk protein[D].Xi’an:Shaanxi Normal University, 2018.
[13] YU Z Z, QIAO C Y, ZHANG X R, et al.Screening of frozen-thawed conditions for keeping nutritive compositions and physicochemical characteristics of goat milk[J].Journal of Dairy Science, 2021, 104(4):4 108-4 118.
[14] PARMAR P, SINGH A K, MEENA G S, et al.Application of ohmic heating for concentration of milk[J].Journal of Food Science and Technology, 2018, 55(12):4 956-4 963.
[15] 陈聪, 胡长利, 谢晶.浓缩与冻结方式对牛乳品质的影响[J].食品与发酵工业, 2021, 47(1):214-221.
CHEN C, HU C L, XIE J.Effects of concentrating and freezing methods on milk quality[J].Food and Fermentation Industries, 2021, 47(1):214-221.
[16] VASBINDER A J, DE KRUIF C G.Casein-whey protein interactions in heated milk:The influence of pH[J].International Dairy Journal, 2003, 13(8):669-677.
[17] 刘永峰, 鱼喆喆, 申倩, 等.冻融对牛奶酸度、色泽与营养成分的变化研究[J].陕西师范大学学报(自然科学版), 2021, 49(3):51-59.
LIU Y F, YU Z Z, SHEN Q, et al.The changes of acidity, color and nutritional composition in frozen-thawed raw milk[J].Journal of Shaanxi Normal University (Natural Science Edition), 2021, 49(3):51-59.
[18] SOLAH V A, STAINES V, HONDA S, et al.Measurement of milk color and composition:Effect of dietary intervention on western Australian Holstein-Friesian cow’s milk quality[J].Journal of Food Science, 2007, 72(8):S560-S566.
[19] RAGAB E S, LU J, PANG X Y, et al.Effect of thermosonication process on physicochemical properties and microbial load of goat’s milk[J].Journal of Food Science and Technology, 2019, 56(12):5 309-5 316.
[20] 迟雪露, 仝令君, 潘明慧, 等.乳脂肪含量对牛乳理化性质的影响[J].食品科学, 2018, 39(4):26-31.
CHI X L, TONG L J, PAN M H, et al.Effect of fat content on physicochemical properties of milk[J].Food Science, 2018, 39(4):26-31.
[21] 赵悦, 李林强, 牛鹏飞.牛奶中5-HMF的RP-HPLC测定方法优化[J].江苏农业学报, 2020, 36(3):798-800.
ZHAO Y, LI L Q, NIU P F.Optimization of reverse-phase high-performance liquid chromatography(RP-HPLC) method for determination of 5-hydroxymethylfurfural in milk[J].Jiangsu Journal of Agricultural Sciences, 2020, 36(3):798-800.
[22] 孙佳悦, 钱方, 姜淑娟, 等.基于红外光谱分析热处理对牛乳蛋白质二级结构的影响[J].食品科学, 2017, 38(23):82-86.
SUN J Y, QIAN F, JIANG S J, et al.Effect of heat treatments on the secondary structure of milk proteins analyzed by Fourier transform infrared spectroscopy[J].Food Science, 2017, 38(23):82-86.
[23] YE M P, ZHOU R, SHI Y R, et al.Effects of heating on the secondary structure of proteins in milk powders using mid-infrared spectroscopy[J].Journal of Dairy Science, 2017, 100(1):89-95.
[24] 杨静洁, 张波, 张影全, 等.冷冻温度对非发酵面团蛋白质结构及面团特性的影响[J].中国粮油学报, 2020, 35(5):11-17.
YANG J J, ZHANG B, ZHANG Y Q, et al.Effect of freezing temperature on protein structure and dough properties of non-fermented dough[J].Journal of the Chinese Cereals and Oils Association, 2020, 35(5):11-17.
[25] WIKING L, STAGSTED J, BJÖRCK L, et al.Milk fat globule size is affected by fat production in dairy cows[J].International Dairy Journal, 2004, 14(10):909-913.
