Gil Pilar F, Conde Socorro, Albisu Marta, Pérez-Elortondo Francisco J, Etayo Iñaki, Virto Mailo, de Renobales Mertxe
Nutrición y Bromatología, Facultad de Farmacia, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Aptdo, 450 E-01080 Vitoria-Gasteiz, Spain.
J Dairy Res. 2007 Aug;74(3):329-35. doi: 10.1017/S0022029907002440. Epub 2007 Apr 30.
The use of artisan-produced lamb rennet pastes, but not any of the other commercial animal rennets, imparts a characteristic flavour to the cheese, so most Mediterranean ewes' milk cheeses are coagulated with this kind of rennet paste. In contrast to the advantages of using lamb or kid rennet pastes from the sensory point of view, questions are still raised as to their hygienic quality. The goal was to examine the microbiological and enzymic quality of lamb rennet pastes prepared by cheese manufacturers for their own use, and evaluate the hygienic quality of raw sheeps' milk cheeses made with them, using Idiazabal cheese as a model. Lamb rennet pastes prepared by artisan cheese makers from the Basque region of Spain (27), and Italy (8) were evaluated. For cheese making experiments 5 different lamb rennet pastes were selected among the 27 samples from the Basque Country region of Spain. Microbiological analyses were carried out on samples from rennet pastes, rennet extracts, milks and cheeses during ripening. Enzymic activities studied in rennet paste were: total coagulating strength and lipase. Analysis of variance and Student's t-tests was performed. The results show that the artisan-produced rennet pastes contain high levels of a variety of microorganisms. After 60 ripening days, which is the minimum ripening period required for Idiazabal cheese prior to its commercialization, no Eschericia coli, Clostridium, Salmonella spp. or Listeria monocytogenes were detected, and levels for the rest of the microorganisms were below the limits of the European legislative standards for cheese manufactured with raw milk. We can conclude that the use of artisan-produced lamb rennet pastes of questionable hygienic quality for the manufacture of raw milk hard cheeses yields products of good hygienic quality.
使用手工制作的羔羊凝乳酶糊剂，而不是其他任何商业动物凝乳酶，能赋予奶酪独特的风味，因此大多数地中海地区的母羊乳奶酪都用这种凝乳酶糊剂凝固。与从感官角度使用羔羊或小山羊凝乳酶糊剂的优点形成对比的是，其卫生质量仍存在问题。目标是以伊迪亚扎巴尔奶酪为模型，检测奶酪制造商自行制备的羔羊凝乳酶糊剂的微生物和酶质量，并评估用其制作的生羊乳奶酪的卫生质量。对西班牙巴斯克地区（27份）和意大利（8份）的手工奶酪制造商制备的羔羊凝乳酶糊剂进行了评估。在奶酪制作实验中，从西班牙巴斯克地区的27个样本中挑选了5种不同的羔羊凝乳酶糊剂。在凝乳酶糊剂、凝乳酶提取物、牛奶和成熟过程中的奶酪样本上进行了微生物分析。研究的凝乳酶糊剂中的酶活性有：总凝固强度和脂肪酶。进行了方差分析和学生t检验。结果表明，手工制作的凝乳酶糊剂含有大量各种微生物。在伊迪亚扎巴尔奶酪商业化前所需的最短成熟期60天后，未检测到大肠杆菌、梭菌、沙门氏菌属或单核细胞增生李斯特菌，其余微生物的含量低于欧洲生乳奶酪立法标准的限值。我们可以得出结论，使用卫生质量存疑的手工制作的羔羊凝乳酶糊剂来制造生乳硬质奶酪，能生产出卫生质量良好的产品。
