In this study, we report the purification and characterization of the extracellular protease BPP-B from the zein-utilizing Bacillus pumilus strain MS-1. The purified BPP-B exhibited glutamyl endopeptidase activity. The Optimum pHs for the cleavage of casein and Suc-Ala-Ala-Pro-Glu-pNA were 11.0 and 8.0, respectively. The bppB gene encoded a 303-amino-acid pre-pro form of BPP-B, and mature BPP-B contained 215-amino-acid residues. BPP-B had three V8 serine protease family signatures (amino acid residues 96-113, 120-137, and 211-224), a serine protease (trypsin or chymotrypsin) family signature (amino acid residues 120-136), and the catalytic triad of serine proteases (His135, Asp186 and Ser259). These results indicate that BPP-B is a glutamyl endopeptidase belonging to peptidase family S2B. This is the first report on a glutamyl endopeptidase from a Bacillus pumilus strain. Although we have recently reported a subtilisin-like protease (BPP-A) playing a major part in zein degradation by Bacillus pumilus strain MS-1, it is possible that BPP-B is also involved in the further digestion of zein.

View full abstract

There has been increasing concern about the “safety of food” among consumers in recent years. Various regulations regarding the dosages of agricultural chemicals and food additives, transparency in labeling genetically modified organisms, and the display of shelf-life have been institutionalized. The labeling system for food containing allergens is one of the newest regulations. In this report, the outline of this system is presented. Moreover, the methods of labeling, detection, and judgment and the risk communication are discussed.

View full abstract

To apply partial seal packaging, which is a new method of modified atmosphere packaging (MAP), to flower buds of rape, packaging materials and sealing forms were studied. A bundle (100 g) of rape buds was placed in an OPP film bag (25μm thick, 150mm×220mm). The sealing types used in this experiment were Pattern 1 (form with 4 mm width of vertically sealed line, 0.4 mm width of fused part and 0.6 mm width of nonfused part) and Pattern 2 (form with 3 mm width of obliquely sealed lane, 7.6 mm width of fused part, and 2.4 mm width of nonfused part). Off-odor was generated from the rape buds due to insufficient gas permeability for both patterns of sealing of the OPP film bags. On the other hand, when an OPS film (40μm thick) with the same bag size and sealing type was used, insufficient gas permeability was observed in Pattern 2 sealing; however, in Pattern 1 sealing, offodor was not generated and components, such as chlorophyll, sugar and ascorbic acid, were maintained at high concentrations in the rape buds. Observation of the cross sections sealed parts of the OPS film revealed that the vertical seal of Pattern 1 maintained a wide airspace in the nonfused part, while the oblique seal of Pattern 2 maintained a narrow airspace. Consequently partial seal packaging (Pattern 1) using an OPS film is suitable for maintaining the freshness of rape buds.

View full abstract

Shiikuwasa (Citrus depressa Hayata) is cultivated in the northern areas of the Okinawa main island, Japan. Whole shiikuwasas were extracted for juice processing using extractors. The polymethoxylated flavone nobiletin is a characteristic component of shiikuwasa, and its various biological activities have been extensively reported. In this study, nobiletin concentration in shiikuwasa juice samples was quantitatively determined by high-performance liquid chromatography (HPLC), and the change in nobiletin concentration in shiikuwasa juice during processing was analyzed. Shiikuwasa juice was concentrated with a centrifugal evaporator, and some extraction solvents were examined by HPLC. The optimum extraction solvent was found to be methanol. Nobiletin concentration was determined to be 0.1mg/100g, with a coefficient of variation of 1.8%. A juice sample extracted from only the edible part of the fruit contained a very low nobiletin concentration (0.2mg/100g). Therefore, it was suggested that nobiletin in juice extracted from whole shiikuwasas is from peel tissues. Also, it was indicated that centrifugation during juice processing markedly affects nobiletin concentration in shiikuwasa juice.

View full abstract