Effect of supplemental Ca2+ on yield and quality characteristics of soybean sprouts

•CaCl2 were added during soybean sprout production by three ways.•Soybean sprout length and yield were improved by supplemental CaCl2.•CaCl2 improved Zn, Fe and Ca bioavailability by decreasing phytic acid content.•Free amino acid, GABA and isoflavone content of CaCl2-treated sprouts were improved. Effects of supplemental Ca2+ on growth and selected qualities of soybean sprout were investigated. Ca2+-treated sprouts had 40∼47% higher length and 31∼39% higher yield than water-treated ones. Increment of endogenous indoleacetic acid and gibberellin in Ca2+-treated soybean sprouts possibly contributed to the improved growth. Metabolism of selected anti-nutritional factor and bioactive substances in soybean sprouts was strengthened by Ca2+. Phytic acid content of Ca2+-treated soybean sprouts was 33∼49% lower than that of the control. Supplemental Ca2+ increased content of gamma-aminobutyric acid and isoflavone by improving activity of diamine oxidase and isoflavone synthetase, respectively. Soybean sprouts produced by soaking Ca2+ and spraying Ca2+ contained more ascorbic acid and phenolics and hence exhibited enhanced antioxidant capacity compared to the control. Besides, no adverse change on protein content and amino acid composition was observed in Ca2+-treated sprouts. These findings indicate that supplemental Ca2+ can increase soybean sprout yield and improve its nutrition qualities.