To investigate how antibodies influence the fermentation of Lactobacillus GG and how Lactobacillus GG influences the biological properties of antibodies during the fermentation and storage periods. Methods Anti-caries immune colostrum powder (IP) and control colostrum powder (CP), skimmed milk powder (SP) at concentrations of 1%, 2.5%, 5% and 10% (w/v) were added to MRS and 50mM Hepes buffer system was used in the milk, the growth curves of Lactobacillus GG including viable cells, lactic acid concentatrion and pH, and also the titer of specific antibodies were determined during the fermentation and storage periods. Results In MRS, SP could improve the growth of Lactobacillus GG in all periods of fermentation, especially at the concentrations of 5% and 10%. CP at the concentrations of 1% and 2.5% had a good initial velocity at the beginning and CP(1%, 2.5%, 5%, 10%) in all the groups could reach a high viable cell concentration at the end of fermentation, which suggested that there were some growth factors for Lactobacillus GG in CP overcoming the inhibition of unspecific antibodies. IP at 1%, 2.5%, 5% and 10% could inhibit the growth of Lactobacillus GG in all the fermentation periods, the critical concentration point was between 2.5%-5%, and there was a competition between growth factors and the inhibition of specific antibodies. In pasteurized milk, the influence of Hepes could help the fermentation start quickly and reach the log phase earlier than in the control group; however, when combined with 5% IP, the growth of Lactobacillus GG was strongly inhibited during all the fermentation periods. The fermentation of Lactobacillus GG had no significant effect on the titer change of anti-caries antibodies during the fermentation and storage periods. Conclusion SP and CP is beneficial to the growth of Lactobacillus GG in MRS, whereas there is a competition between growth factors and the inhibition of specific antibodies to the growth of Lactobacillus GG, the critical concentration of IP is 2.5%-5%. Hepes could influence the titer of antibodies through buffering Ph, thus influence the fermentation of. Lactobacillus GG. The fermentation of Lactobacillus GG with IP or CP could be used for the development of functionally fermented immune milk in the future.

The effects of cold and warm, chlorinated water as well as warm water without chlorination for pre-washing trimmed, cored iceberg lettuce heads was assessed regarding the shelf-life and physiological properties of the resulting ready-to-use (RTU) produce. On a pilot-plant scale, lettuce heads were shredded with or without pre-washing (50℃, no chlorine; 4 and 50℃, 200 mg/l free chlorine; 60s). After shredding, lettuce was washed for 90s (tap water, 4℃), spin-dried, packaged in 200g consumer-sized bags, and stored at 4℃ for ≦9 days. Samples were analyzed for their headspace O2 and CO2 levels, sensory properties, microbiological status, and phenylalanine ammonia-lyase (PAL) activity at regular intervals throughout processing and storage. Parallelly, instrumental color and texture measurements were performed. All pre-washing procedures of lettuce heads lowered the initial counts of total aerobic bacteria, pseudomonades, and Enterobacteriaceae by≧1.63, ≧1.55, and ≧1.85 log10 cfu/g, respectively, while the single-wash of shredded lettuce in tap water without any pre-washing resulted in significantly smaller reduction rates (0.23, 0.11, and 0.71 log10 cfu/g, respectively). During storage, all prewashing procedures had a persistent effect on bacterial counts of the RTU lettuce. Furthermore, all pre-washing procedures delayed vascular tissue browning at cut edges and retarded the decline in the overall visual quality of the samples. Whereas wound-induced PAL synthesis was reduced by the use of warm water (±chlorine), O2 depletion and CO2 evolution in the corresponding bags were slightly enhanced, thus proving that processing kept the food as a living tissue.

本文研究乳酸及其代谢产物对幽门螺杆菌繁殖的影响。采用平板活菌计数法，测定乳酸、乙酸的不同浓度、酸性或中性环境条件下，混合酸，乳酸菌代谢产物上清液以及干酪乳杆菌鼠李糖亚种的代谢活动对幽门螺杆菌的抑制作用。结果表明:乳酸和乙酸对幽门螺杆菌的抑制存在协同作用。干酪乳杆菌鼠李糖亚种发酵上清液对幽门螺杆菌作用不仅取决于乳酸，还依赖于其热敏感的成分；乳酸菌可竞争抑制幽门螺杆菌的繁殖。

目的对保加利亚乳杆菌、嗜热链球菌的微囊化工艺进行摸索.方法采用喷雾干燥方法.结果以C胶（13.3ml）+B胶（20g）微囊化对乳酸菌的保护效果较好，菌体存活率达34.6%，而C胶（75ml）+A胶（50g）微囊化对乳酸菌的保护效果最佳，菌体存活率达78%，冷冻干燥工艺结合微囊化技术，可获得较高存活率的乳酸菌活性.结论微囊化技术可提高菌体的抗热性.