Sodini I, Boquien C Y, Corrieu G, Lacroix C
Laboratoire de Génie et Microbiologie des Procédés Alimentaires, INRA, Thiverval-Grignon, France.
J Ind Microbiol Biotechnol. 1997 Jan;18(1):56-61. doi: 10.1038/sj.jim.2900362.
A system was developed to continuously acidify and inoculate skim milk for the production of fresh cheese. Four strains of mesophilic lactic acid bacteria were entrapped separately in kappa-carrageenan/locust bean gum gel beads and used in a stirred bioreactor operated at 26 degrees C with a 25% (v/v) gel load. The pH in the reactor was controlled at 6.0 by adding fresh milk using proportional integrated derived regulation. The bioreactor was operated during 8-h daily cycles for up to 7 weeks with different milks (heat treatment, dry matter content) and differing starting procedures. The heat treatment of the milk was an important factor for process performance: a dilution rate increase of 57% and an inoculation level decrease of 63% were observed with sterilized UHT skim milk (142 degrees C - 7.5 s) compared with pasteurized skim milk (72 degrees C - 15 s). The dry matter content of the milk (8-13% w/w) had no detectable effect on these parameters. A convenient starting procedure of the system was tested; steady-state was reached in less than 40 min following an interruption period of 16-60 h. These results combined with our published data on process performance show the feasibility of using an integrated immobilized cell bioreactor for milk prefermentation in cheese manufacture.
开发了一种用于连续酸化和接种脱脂乳以生产新鲜奶酪的系统。将四株嗜温乳酸菌分别包埋在κ-卡拉胶/刺槐豆胶凝胶珠中，并用于在26℃下运行、凝胶负载量为25%（v/v）的搅拌式生物反应器中。通过使用比例积分微分调节添加新鲜牛奶，将反应器中的pH控制在6.0。该生物反应器在长达7周的时间内，每天以8小时的周期运行，使用不同的牛奶（热处理、干物质含量）和不同的启动程序。牛奶的热处理是影响工艺性能的一个重要因素：与巴氏杀菌脱脂乳（72℃-15秒）相比，超高温灭菌脱脂乳（142℃-7.5秒）的稀释率提高了57%，接种水平降低了63%。牛奶的干物质含量（8-13% w/w）对这些参数没有可检测到的影响。测试了该系统的一种简便启动程序；在16-60小时的中断期后，不到40分钟即可达到稳态。这些结果与我们发表的关于工艺性能的数据相结合，表明了在奶酪制造中使用集成固定化细胞生物反应器进行牛奶预发酵的可行性。
