Influence of low O₂ and high CO₂ environment on changes in metabolite concentrations in harvested vegetable soybeans

Influence of atmosphere and storage period on the physicochemical and biological properties of harvested vegetable soybeans stored for 10 d at 25 °C was investigated. Storing vegetable soybeans under modified atmosphere (low O₂ and high CO₂), was more effective in maintaining its green color and mass than storing them under normoxia. Principal component 1 (PC1; contribution rate: 25%) was related to the atmospheres, whereas PC2 (contribution rate: 19%) was related to storage period. Cluster analysis showed that some types of sugars decreased, whereas some types of organic and amino acids increased with deterioration. Alanine, an indicator of low O₂ stress, was maintained for 3 d under modified atmospheres, whereas alanine significantly decreased under normoxia. The concentrations of inositol and niacinamide (functional ingredients) under the modified atmospheres were significantly higher than those under normoxia. Thus, storage under modified atmospheres was effective in maintaining freshness and increasing the nutritional content of vegetable soybeans.