Selection of lactic acid bacterium lactococcus lactis RO50 which produced high γ-aminobutyric acid (GABA) to rice flour fermentation and method for producing of GABA-enriched rice flour using RO50

Abstract

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 120-150 mg/100 g (per dry weight) by high-yielding rice Momiroman cultivated a lot of nitrogen basal fertilizer and using lactic acid bacterium RO50.