Protamine is a basic protein that is combined with DNA in the vertebrate sperm nucleus. It was reported that protamine purified from chum salmon milt has pancreas lipase inhibition activity (IC₅₀=1.2μg/mL). In the case of rats, protamine administration (100mg/rat) showed a suppressive effect on the blood plasma triglyceride (TG) levels in the corn oil tolerance test. Here, we investigated the suppressive effect of our developed protamine, “Proserve”, on lipid absorption in humans.
The oral fat tolerance test (OFTT) was performed on normal adult male subjects as a single-blind test. The subjects were fed a high-fat meal containing 56.0g of lipid and 500mg of protamine. Before and 2, 3, 4, 6h after ingestion, TG and free fatty acid levels in blood were measured. Protamine significantly suppressed the elevations of the TG and free fatty acid levels in blood after ingestion of the high fat meal compared with the placebo group. When 300mg of protamine was administered, no significant suppressive effect was confirmed, but TG and free fatty acid levels in the blood tended to be suppressed. In the digestive resistance test, the lipase inhibition activity of protamine was maintained after the reaction in the stomach. Therefore, we propose that protamine is an anti-obesity material.

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In order to utilize efficiently discharged tofu refuse (Okara), a tofu refuse-enriched cake (TREC) was prepared by addition of tofu refuse, sugar, egg, margarine, edible vegetable oil, salt, baking powder and vanilla essence, and its approximate compositions, hypoglycemic effect in vivo and sensory attributes were compared with those of wheat-based cake as a control. According to approximate composition analysis, dietary fiber was higher in TREC than in the control, in which the content of insoluble dietary fiber was extremely high. Single-dose oral administration of TREC significantly lowered blood glucose 30min after loading of 50g of sugars in healthy subjects (p<0.05). Glycemic index was 39.1% lower in TREC than in the control. The results of sensory evaluation revealed that texture, easiness of swallowing and overall taste of TREC were more agreeable than those of the control (p<0.05). There was no significant difference of external appearance or smell between TREC and the control (p>0.05). The acceptability of TREC was also significantly higher than that of the control (p<0.001). These results suggest that TREC may not only prevent increases in postprandial glucose level but also have good palatability.

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This study investigated the ameliorative effect of dietary apple antlered form of Ganoderma lucidum (AAFGL) in mice with carbon tetrachloride (CCl₄)-induced liver injury. Male ICR mice (6 weeks, n=6-7per group) were divided into control and 1% AAFGL groups. Mice were given test diets for 11 days before intraperitoneal injection with CCl₄ (40μL/kg). Dietary AAFGL inhibited the abnormal increase of GOT, GPT, and LDH in serum. The serum TNF-α and the liver triglyceride levels tended to be lower in the AAFGL-fed group than in the control. The liver TBARS level was significantly lower in the AAFGL-fed group than in the control, however, the liver tocopherol level was significantly higher in AAFGL-fed group than in the control. Moreover, the erythrocytic catalase and glutathione peroxidase activities in AAFG-fed group were higher than those in the control. Thus, dietary AAFGL may exert protective function against liver damage and modulation of antioxidant system induced by CCl₄.

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The safety of oral administration of an extract prepared from the leaves of Tsubaki (Camellia japonica) was studied in CD rats by single dosing and repetitive dosing for 28 days. Doses of 500 and 2000mg/kg of Tsubaki extract were used for evaluation. Consumption of both dose levels by rats showed no abnormalities, indicating the safety of the extract by oral administration. Additionally, the extract was tested by a reverse mutation test using Salmonella typhimurium and Escherichia coli. The number of revertants of all bacteria treated with the extract was below the numerical double of the negative control. No mutagenicity of the Tsubaki extract was detected under these experimental conditions.

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The aroma of ground roasted sesame seeds, which is characterized by high volatility and instability, has not been thoroughly investigated in detail.
The aroma components of these seeds were concentrated using methods previously reported, and analyzed by Gas Chromatography-Olfactometry (GC-O) to elucidate precisely which components contribute to the characteristic aroma.
The components that contributed to the aroma were found to have low boiling points with two or more peaks described as the roast and the sulfur odors. In addition, the one of the sulfur odor, the catty odor peaks was identified as 2-mercapto-3-pentanone, an odor component of coffee and cooked meat. This study is the first to detect the catty odor in sesame seeds.

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In a previous study, we established a method for discrimination of the original natto starter strain, KA-145, of Marumiya Co. Ltd. using IS4Bsu1, though discrimination of commercial natto starter strains was not accomplished. Therefore, we examined a method to discriminate three commercial strains, Miyagino, Naruse and Takahashi strains, as well as the KA-145 strain. Southern blot analysis revealed that Naruse and Takahashi strains have some specific insertion sites of IS4Bsu1 copies. Inverse PCR and sequence analysis further revealed that one of the insertion sites of IS4Bsu1 copy is specific to each strain. Based on the specific IS4Bsu1 locus three primer pairs were designed and PCR was performed to discriminate the four different strains. We also confirmed that one-step multiplex PCR using a mixture of all three primer pairs can easily identify each of the four strains, Miyagino, Naruse, Takahashi and KA-145.

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