Search

Fermented dairy products have been recognized as the best carriers for the administration of probiotics. Because one of the potential probiotic strains, Lactobacillus plantarum, has poor proteolytic ability and weak acidifying capacity in milk fermentation, the aim of this study was to preliminarily investigate the stimulation effect of plant-based meals on L. plantarum CCFM8661 growth in milk, and subsequently develop a yogurt or yogurt drinks containing probiotic strain L. plantarum CCFM8661. Milk supplemented with different concentrations (5 to 10%, wt/wt) of oat extract and malt extract, inoculated with 2.5 × 107 cfu/mL of L. plantarum CCFM8661, and then incubated at 35°C. The pH value, titration acidity, and viable cell counts during 48-h fermentation at 35°C and 25-d storage at 4°C, were determined at different intervals. The results showed that the promotion effects of oat extract and malt extract on L. plantarum CCFM8661 growth rate in milk were much stronger than almond, walnut, sweet corn, peanut, and soybean meals. In addition, the stimulation effect of oat extract was associated with its concentration, and was much stronger than that of malt extract. Furthermore, viable counts and titration acidity of yogurt were gradually increased in the oat extract group, whereas viable counts were gradually decreased and titration acidity were slightly increased in the malt extract group during the 25-d storage at 4°C.

The screw rod is widely used in the oil drilling, chemical industry, light industry and so on. Its machining accuracy affects directly the quality and efficiency of instruments. Thus a deep research on the machining process of the screw rod is urgently needed. The fitting method of the spiral surface cross-section is one of the key issues. It was proposed that cubic spline and parametric cubic spline interpolation function were taken to approximate the spiral surface cross-section by comparing different methods of curve fitting. Coefficients of them were derived, fitting equations were presented and examples were taken to verify the fitting results .At the same time, key issues on the skewness, tangent vectors of ends and so on were involved both in the process of cubic spline and in parametric cubic spline fittings. Corresponding fitting function can be chosen on the basis of foregone data points, so as to provide smooth curves to generate accurate tool path. (4 pages)