Camacho L, Sierra C, Jarpa J, Retamal E
Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago.
Arch Latinoam Nutr. 1991 Mar;41(1):79-91.
The purpose of this study was to increase the microbiological quality and yields of goat cheese prepared at farm level. For this purpose, appropriate technologies for the cheese-making process were designed, using a curd tank heated by gas, and cheese knives adjusted to the tank dimensions. Moreover, a low-cost table for whey draining and PVC moulds, were designed. Variables assayed were milk pasteurization, utilization of lactic acid starter by direct application, substitution of the kid rennet by commercial calf rennet, and cheese maturation for a one-month period. The control sample was goat cheese traditionally made by the small farmers. Processing and variables were evaluated by proximate chemical analysis, microbiological counts of aerobic mesophilic bacteria, total and fecal coliforms, and S. aureus; as well as by sensory evaluation of quality and acceptability. It was found that the cutting of curd with cheese knives significantly decreased solid losses in the whey. The addition of the starter and then the cheese maturation, as well as the use of the equipment previously described, increased the microbiological quality of cheese to standard sanitary regulation. Although pasteurization was the most effective treatment in decreasing bacteria contamination, this thermal treatment was difficult to be done under arid zones conditions. Commercial calf rennet did not differ significantly from kid rennet in the characteristics analyzed in this assay. Variables studied did not affect the normal sensory quality of goat cheese.
本研究的目的是提高农场制作的山羊奶酪的微生物质量和产量。为此,设计了适合奶酪制作过程的技术,使用燃气加热的凝乳罐,并根据罐的尺寸调整奶酪刀。此外,还设计了一个低成本的乳清沥干桌和PVC模具。测定的变量包括牛奶巴氏杀菌、直接使用乳酸发酵剂、用商业小牛凝乳酶替代羔羊凝乳酶以及奶酪成熟一个月。对照样品是小农户传统制作的山羊奶酪。通过近似化学分析、需氧嗜温菌、总大肠菌群和粪大肠菌群以及金黄色葡萄球菌的微生物计数来评估加工过程和变量;同时通过对质量和可接受性的感官评估来进行评估。结果发现,用奶酪刀切凝乳可显著减少乳清中的固体损失。添加发酵剂然后进行奶酪成熟,以及使用上述设备,可使奶酪的微生物质量提高到标准卫生规定水平。虽然巴氏杀菌是减少细菌污染最有效的处理方法,但在干旱地区条件下难以进行这种热处理。在本试验分析的特性方面,商业小牛凝乳酶与羔羊凝乳酶没有显著差异。所研究的变量并未影响山羊奶酪的正常感官质量。