Deodorant activities of several saccharides though heat treatment to methylmercaptane were assayed. The non-heated saccharides (glucose, fructose, sucrose, maltose and palatinose) did not show the deodorant activities. When heat at 160°C for 30 minutes, however, these saccharides turned to have deodorant activities, especially heated palatinose showed the highest activity. From relationship between heating time and activity, it was suggested that the active compounds in heated palatinose were produced in early stage of heating. Two active compounds were separated from heated palatinose with HPLC. They were identified to 5-[(α-D-glucopyranosyloxy)methyl]-2-furancarboxaldehyde and 6-(α-D-glucopyranosyloxy)-1, 3, 4-trihydroxyhexa-5-en-2-one.

View full abstract

In recent years, a lot of aseptic products are sold in the market around the world. It is important to supply good taste and flavor products to consumers. In this research, L-ascorbic acid contents in model solutions, which contained citric acid in de-ionized water, was measured in aseptic filling and in conventional hot-packed products with different oxygen contents. A quantitative analysis was conducted in oxygen and L-ascorbic acid contents during processing and storage. It was important to remove dissolved oxygen before aseptic filling to maintain the initial amount of L-ascorbic acid, because oxygen in model solutions did not have chances to escape into the atmosphere during processing. There were two stages in decreasing velocity of L-ascorbic acid. The first stage was fast, because a model solution had a lot of oxygen. The second stage was slow because it had consumed oxygen. The best way to maintain the amount of L-ascorbic acid level in model solution was to remove dissolved oxygen from the solution before processing, and to make aseptic filling in cans, which has good gas-barrier and light-protection.

View full abstract

Detection of cells of Escherichia coli injured by high hydrostatic pressure treatment on Desoxycholate Agar (DESO) was investigated. Cell suspensions were treated by high hydrostatic pressure at 100 to 400MPa, 25°C for 10 to 30min. As pressure and pressurization period increased, surviving cells decreased. Colonies were detected on nonselective Tryptic Soy Agar (TSA) under all tested conditions. However, surviving cells on DESO were significantly lower than on TSA, and colonies could not be detected on DESO when the cells were pressurized at 300 to 400MPa for 20 to 30min. The cells that could grow only on TSA were regarded as injured cells, and were sensitive to desoxycholic acid and neutral red in DESO. A Double layer method (DESO overlaid on TSA) was effective for detecting the injured cells compared with DESO alone.

View full abstract

The whitening of meat caused by the interaction of pressure and temperature during pressure processing was analyzed using minced beef, pork, and chicken. L-Values of the meat heated from 45°C to 75°C for 1min followed a sigmoid curve. The whiteness of the meat pressured with 400MPa for 10min was evaluated to the heattreatments of approximately 60°C by the linear equation transformed from the heat-curves.
From the relationship between the calculated temperature/pressure and processing temperatures, the temperature sensitivity in pressure processing differed with the type of meat. It was suggested that the increase of whiteness with temperature during pressure processing was dependent on the myoglobin concentration.

View full abstract

The deodorizing activity of various kinds of plant extracts on allylmethylsulfide (AMS) in the breath after eating garlic was measured by gas chromatography. Among these extracts, water extract of Rubus suavissimus (RSW) showed the highest deodorizing activity against AMS. The active components of R. suavissimus were considered to be a mixture of polyphenolic compounds, because of positive correlation with deodorizing activity and polyphenol content in RSW. As a result of the separation of RSW in guidance with deodorizing activity by column chromatography of Diaion HP20 and Sephadex LH-20, the fraction RSW-24 possessed the highest deodorizing effect. And allylmethylsulfoxide was detected in the reaction mixture of AMS and RSW-24. The deodorizing activity of RSW-24 was disappeared under anaerobic conditions. It was suggested that the reaction mechanism of RSW against AMS was the oxidative reaction by polyphenolic compounds.

View full abstract

The microbial transformation of genistein by nongerminating spores of fungi from the Aspergillus strains was investigated. The spores of A. saitoi effectively transformed genistein into 8-hydroxygenistein (8-OHG) in the pH range 3-5 at 30-35°C. The column chromatography using immobilized spores by Ca-alginate gel showed the possibility of successive production of potent antioxidative 8-OHG. It is noteworthy that this sporemediated transformation of genistein was also performed with the majority of the A. oryzae strains (6 out of 7).

View full abstract