This study was carried out to investigate the quality characteristics of fermented milk containing Rhus verniciflua seed (RVS) extracts (0.0%, 0.1%, 0.3% and 0.5%) and antioxidant activity of RVS extracts. The proximate composition of RVS was moisture (4.76%), crude ash (1.40%), crude fat (5.33%) and crude protein (11.10%). A total polyphenol content of 70% ethanol extract of RVS (554±2.64 mg/g) was higher than that of RVS water extract (145±3.47 mg/g). 70% ethanol extract (1103±6.42 mg/g) of RVS showed higher content in the total flavonoids (37±2.30 mg/g) and activities on DPPH free radical scavenging (73.23%) and ABTS free radical scavenging (83.47%) when compared with water extracted of RVS. The quality characteristics, such as pH, titratable acidity, and the number of lactic acid producing bacteria were not remarkably different between the fermented milk samples subjected to treatments with and without the addition of RVS extracts.

This study was conducted to investigate the antibacterial activity of lactic acid bacteria isolated from traditional fermented foods and to develop a new starter for fermented milk. The isolates were identified using 16S rDNA sequencing and named Lactobacillus plantarum A, Leuconostoc lactis B and L. acidophilus C. The activity of these strains to inhibit the growth of food-borne human pathogens (Escherichia coli NCTC 12923, Salmonella Typhimurium NCTC 12023, Listeria monocytogenes NCTC 11994) was measured using the paper disc method. All these strains showed strong antibacterial activity against Li. monocytogenes NCTC 11994. The experiment groups were the fermented milks with these strains, and the control group was the fermented milk with the commercial starter (ABT 5). The change of pH, acidity and viable cell counts were measured during their aging time. All the experiment groups showed a significant difference in their aging times compared to the control group. However, the sensory test showed that the experiment groups can be used as useful starters for fermented milk. This result suggests that L. plantarum A, Leu. lactis B and L. acidophilus C have the potential to be developed as new starters for fermented milk.

This experiment was conducted to determine the effect of increasing the dietary levels of nattokinase (NK) addi-tives on milk production and composition, and blood metabolites in dairy cows. NK additives with high fibrinolytic activity were produced by the strain with similarity to the Bacillus amyloliquefacines. A total 20 mid-lactating Holstein cows (average body weight 652.00 ± 4.38 kg; average 2.25 ± 0.35 parity; average milk yield 24.4 ± 0.38 kg/d) were randomly assigned to three treatments (5 animals per treatment). Cows were fed TMR supplemented with DDGS 100 g for control, NK additives 100 g and 200 g for T1 and T2 treatment, respectively for 4 weeks. By the increases of NK additives, milk yield increased for T1 (1.35 kg/d) and T2 (0.98 kg/d) at the final period than at the initial period (p < 0.05). But milk protein content decreased for T1 (3.20%) and T2 (3.24%) than for control (3.56%) (p < 0.05). Blood triglyceride, T-CHO and BUN levels in T1 decreased compared with that in control and T2 (p < 0.05). This finding showed that 100g of NK additives could possibly have a positive effect in lactation performance of mid-lactation Holstein cows by increasing milk yield, improving protein metabolism and decreasing cholesterol in blood.