Leclercq-Perlat M N, Oumer A, Buono F, Bergere J L, Spinnler H E, Corrieu G
Institut National de la Recherche Agronomique (INRA), Laboratoire de Génie et de Microbiologie des Procédés Alimentaires (LGMPA), Thiverval-Grignon, France.
J Dairy Sci. 2000 Aug;83(8):1674-83. doi: 10.3168/jds.S0022-0302(00)75036-3.
Model smear soft cheeses, prepared with Debaryomyces hansenii and Brevibacterium linens as ripening starters, were ripened under aseptic conditions. Results of the cheese-making trials, in triplicate, were similar and showed similar patterns of protein degradation. In all of the trials, the acid-soluble nitrogen and nonprotein nitrogen (NPN) indexes and NH3 concentrations of the rind were low until d 10. The acid-soluble nitrogen and NPN of the rind then increased to 100 and 18% of total nitrogen, respectively, at d 76. The NH3 concentrations remained low until d 24 and increased until d 70, reaching about 1.8 g of NH3/kg of DM, and then remained constant. The acid-soluble nitrogen and NPN indexes and NH3 concentrations in the inner cheese mass were lower than in the rind. They showed the same evolution, reaching about 18% for acid-soluble nitrogen, 10% for NPN, and 1.5 g of NH3/kg of DM. It was shown that the inner cheese pH and populations of D. hansenii and B. linens have an effect on proteolysis. Viable cell counts of D. hansenii and B. linens were correlated with the environmental conditions and with proteolytic products. The determining role of carbon source and NH3 diffusions on the cheese ripening process were confirmed.
以汉逊德巴利酵母和林登短杆菌作为成熟发酵剂制备的模拟涂抹软质奶酪，在无菌条件下进行成熟。三次重复的奶酪制作试验结果相似，且显示出相似的蛋白质降解模式。在所有试验中，直到第10天，奶酪外皮的酸溶性氮、非蛋白氮（NPN）指标和NH₃浓度都很低。然后，在第76天时，外皮的酸溶性氮和NPN分别增加到总氮的100%和18%。NH₃浓度直到第24天一直很低，然后增加到第70天，达到约1.8 g NH₃/kg干物质，然后保持稳定。奶酪内部的酸溶性氮、NPN指标和NH₃浓度低于外皮。它们呈现相同的变化趋势，酸溶性氮达到约18%，NPN达到10%，NH₃为1.5 g NH₃/kg干物质。结果表明，奶酪内部的pH值以及汉逊德巴利酵母和林登短杆菌的数量对蛋白水解有影响。汉逊德巴利酵母和林登短杆菌的活菌数与环境条件和蛋白水解产物相关。证实了碳源和NH₃扩散在奶酪成熟过程中的决定性作用。
