The γ-aminobutyric acid (GABA) is the amino acid which is known to have an antihypertensive effect and to have a stress reduction effect. It is known to be able to produce GABA high component food by using a lactic acid bacterium accumulating GABA, however, in many cases, sodium glutamate was added to substrate. We tried the production of GABA-enriched food or feed material without adding sodium glutamate by choosing a cultivar kind of the rice and the kind of the lactic acid bacterium. First, we selected the plant origin lactic acid bacterium Lactococcus lactis RO50 which GABA accumulate in large quantities to rice. Next, we considered whether a cultivar kind and a fertilization condition of the rice influenced GABA accumulation. The additional nitrogen fertilization to rice did not have a big influence on GABA accumulation by the lactic fermentation, but the GABA accumulation greatly varied according to a cultivar kind of the rice. We succeeded in producing the GABA-enriched food or feed material rice flour which accumulated GABA 120-150mg/100g (per dry weight) by high-yielding rice Momiroman cultivated a lot of nitrogen basal fertilizer and using lactic acid bacterium RO50.

Gel permeation chromatography (GPC) patterns of wheat starch on a Toyopearl HW-75F column changed from two peaks to one peak following heat treatment at 200°C Although both amylose and amylopectin in the starch granule were largely decomposed, the molecular size of both components converged to some extent. Therefore, we surmised that hydrolysis of amylopectin occurred in the amorphous regions of the starch granule.

The present study aimed to clarify the effect of steaming temperature on ascorbic acid (AsA) contents and the characteristics of low temperature steaming (LTS) method, compared to LTS under vacuum and boiling as cooking methods. We analyzed the total AsA contents in sweet potato, broccoli and potato subjected to 60-90°C steaming conditions. The results showed that steaming at low temperature resulted in low AsA loss. In addition, we analyzed the total/reduced AsA and antioxidant properties in the three vegetables treated with LTS, LTS under vacuum and boiling. These analyses demonstrate that LTS is able to achieve low AsA loss and has greater utility than boiling.

Human norovirus (HuNV) infects humans through the consumption of contaminated food, contact with the excrement or vomit of an infected person, and via airborne droplets. Being highly infectious and highly viable in the environment, inactivation of norovirus requires an extremely effective inactivating agent. In this study, we characterized the norovirus-inactivating effects of thermally denatured lysozyme. We observed that lysozymes heat-treated for 40 min at 100°C caused a 4.5 log reduction in the infectivity of norovirus. Transmission electron microscope analysis showed that viral particles exposed to heat-denatured lysozymes were expanded compared to those before exposure. Moreover, we confirmed breaking of the capsid proteins of murine norovirus and HuNV by real-time PCR combined with propidium monoazide.

The emulsification properties of various phospholipids in egg yolk lecithin were evaluated using emulsion droplet size and surface potential (zeta potential). Five different phospholipids (phosphatidylcholine, lysophosphatidylcholine, phosphatidylethanolamine, phosphatidic acid and sphingomyelin) were assessed in this study. Also, cholesterol was employed as a co-emulsifier of phosphatidylcholine. Based on the results of mean diameter of oil droplets in emulsion, lysophosphatidylcholine and phosphatidylcholine showed excellent properties as emulsifiers. The results of zeta potential measurement identified phosphatidylcholine and phosphatidylethanolamine as excellent emulsifiers for the preparation of stable emulsions compared to the other phospholipids. Further, the addition of cholesterol to phosphatidylcholine resulted in increased stability of the emulsion.