陕西生鲜羊奶及其加工羊奶粉品质调研分析及相关性研究

Quality investigation and correlational study of fresh goat milk and goat milk powder in Shaanxi province

为调查陕西省生鲜羊奶及羊奶粉品质随月份的变化规律,明确生鲜羊奶和羊奶粉品质之间的相关关系,该研究以2020年4月至11月某乳品企业在陕西不同地区的奶站收购的生鲜羊奶及其加工羊奶粉为试验样品,对其感官、理化和安全指标进行分析。结果表明,生鲜羊奶和羊奶粉在感官指标方面均符合国家标准要求;在理化指标方面,生鲜羊奶脂肪含量为3.40%~3.68%,蛋白质含量为2.99%~3.19%,非脂乳固体含量为8.08%~8.48%,冰点为-0.509~-0.561℃,酸度为8.10~11.24°T;羊奶粉的脂肪含量为27.87%~29.87%,蛋白质含量为25.15%~27.65%,酸度为6.57~9.79°T,水分含量为1.62%~3.07%;在安全指标方面,生鲜羊奶和羊奶粉中的抗生素和β-内酰胺酶均为阴性,邻苯二甲酸二丁酯含量均低于0.3 mg/kg;聚类结果显示,相邻月份间生鲜羊奶与羊奶粉的质量相近;相关性分析结果显示,羊奶粉与生鲜羊奶的脂肪含量、蛋白含量、酸度间为极显著正相关(P<0.01),而羊奶粉水分含量与生鲜羊奶所有理化指标均呈负相关。综上,陕西不同区域的生鲜羊奶和羊奶粉的质量均符合国家标准要求;生鲜羊奶与羊奶粉在蛋白质含量、非脂乳固体含量、酸度含量与冰点指标上随月份呈现夏季较低,秋冬季较高的变化趋势;生鲜羊奶的质量对羊奶粉的质量起决定性作用。该研究为羊奶及羊奶粉品质的提升提供了理论支持。

The sensory,physicochemical and safety indexes of fresh goat milk and goat milk powder obtained from different milk stations of Shaanxi(from April to November 2020)were measured to investigate the quality law of fresh goat milk and powder with month and to clarify the correlation between fresh goat milk and powder.The results showed that the sensory indicators of both fresh goat milk and powder were within the national standard.In terms of physicochemical indicators,the fat content of fresh goat milk was 3.40%-3.68%,the protein content was 2.99%-3.19%,the non-fat milk solids was 8.08%-8.48%,the freezing point was-0.509--0.561℃,the acidity was 8.10-11.24°T.Moreover,the fat,protein and moisture content of goat milk powder was 27.87%-29.87%,25.15%-27.65%,1.62%-3.07%,respectively,and the acidity was 6.57-9.79°T.For safety indexes,the antibiotics andβ-lactamase of fresh goat milk and goat milk powder were all negative,and the DBP content was lower than 0.3 mg/kg.The clustering results showed that fresh goat milk quality was similar to that of goat milk powder in adjacent months.The correlation analysis results showed that the fat,protein and acidity of goat milk powder and fresh goat milk were significantly positive correlated(P<0.01),while the moisture content of goat milk powder was negatively correlated with physicochemical indexes of fresh goat milk.In conclusion,the quality of fresh goat milk and goat milk powder from different regions of Shaanxi met the requirements of national standards,and the protein,non-fat milk solids,acidity and freezing point of fresh goat milk and goat milk powder were lower in summer but higher in autumn and winter.The quality of fresh goat milk plays a decisive role in the quality of goat milk powder,and this work provided theoretical support for improving the quality of goat milk and powder during the production and processing process.