Improvement of the antioxidative activity of soluble phenolic compounds in chickpea by germination

Authors: XU, MINWEI - North Dakota State University; JIN, ZHAO - North Dakota State University; Ohm, Jae-Bom; SCHWARZ, PAUL - North Dakota State University; RAO, JIAJIA - North Dakota State University; CHEN, BINGCAN - North Dakota State University

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/3/2018
Publication Date: 6/4/2018
Citation: Xu, M., Jin, Z., Ohm, J., Schwarz, P., Rao, J., Chen, B. 2018. Improvement of the antioxidative activity of soluble phenolic compounds in chickpea by germination. Journal of Agricultural and Food Chemistry. p. 6179-6187.

Interpretive Summary: Antioxidants are known to have beneficial effects on human health, preventing some diseases. One of the main antioxidants found in foods are phenolic compounds, which are mainly composed of phenolic acids and flavonoids. The results of our recent study showed that germination boosted antioxidant activity of phenolic compounds for chickpea. The purpose of the current study was to elucidate how chickpea germination impacts the phenolic composition to enhance antioxidant activity. Two forms of phenolic compounds, including insoluble and soluble, are present in chickpea seeds. The soluble phenolic compounds that were extracted from chickpea seed 6 days after germination were analyzed for their chemical composition, and this led to the identification of biochemical components that played important roles in boosting antioxidant activity for soluble phenolic compounds in germinated chickpea. These findings improve our understanding of the mechanisms associated with increased antioxidant activity in germinated chickpea seeds, and may lead to the production of healthier foods.

Technical Abstract: Our recent study found that antioxidative activity of phenolic compounds extracted from germinated chickpea was boosted both in vitro and in oil-in-water emulsion. The purpose of this study was to elucidate the mechanism by which chickpea germination impacts the composition of phenolic compounds to enhance its antioxidative activity. LC-ESI-QTOF-MS and SEC-MALS-RI were employed to evaluate the phenolic composition of soluble phenolic compounds (free and bound) and molar mass of soluble bound phenolic compounds, respectively, over the period of 6 days germination. With principal component analysis of the interrelationship between germination time and phenolic composition, it is revealed that protocatechuic acid 4-O-glucoside and 6-hydroxydaidzein played a pivotal role in the soluble free phenolic compounds, while gentisic acid and 7,3',4'-trihydroxyflavone were important in the soluble bound phenolic compounds. Molar masses of soluble bound phenolic compounds were increased after 6 days germination. Protective and co-antioxidative principle were proposed to explicate how antioxidative activity of soluble bound phenolic compounds in oil-in-water emulsion system was improved with germination.