A novel strategy for β-glucan enrichment during oat germination: Low temperature stress combined with slightly acidic electrolyzed water

The treatment of germinating seeds with slightly acidic electrolyzed water (SAEW) is a promising sustainable agricultural technology, but there is limited research on its effect on enriching β-glucan in germinating oat seeds. In this study, the effects of SAEW treatments at two different temperatures (25°C and 4°C) on the β-glucan content in germinating oat seeds were investigated by assessing morphological indicators, as well as changes in substances related to the β-glucan content, functional characteristics, and the structural characteristics of β-glucan during germination. Although the β-glucan content in germinating oat seeds continued to increase at 36 h, 24 h was selected as the optimal interval for comparing treatment effects. The results showed that the enrichment of β-glucan in germinating oat seeds was highest with the 4°C + SAEW treatment. At 24 h of germination after 4°C + SAEW treatment, the β-glucan content was 9.69 ± 0.30 mg/g, the β-glucanase activity was 24003.22 ± 242.52 U/mL, the soluble sugars content was 40.46 ± 0.72 mg/g, the reducing sugars content was 5.25 ± 0.01 mg/g, the total saponin content was 186.48 ± 7.01 mg/g, the glucose content (indicative of monosaccharide composition) was 14.22 mg/L, and the molecular weight of β-glucan was 163.10 kDa. These index values in the 4°C + SAEW treatment group were significantly different from those in the tap water (TW) control group and the 25°C + SAEW treatment group ( p < 0.05), indicating that the 4°C + SAEW treatment was the most effective. We also evaluated the ability of extracts from oat seeds in the different groups to adsorb glucose, inhibit glucose diffusion, inhibit α-glucosidase activity, and inhibit pancreatic amylase activity. The extract from oat seeds under the 4°C + SAEW treatment had significantly stronger effects on these factors compared with extracts from oat seeds in the TW control group and the 25°C + SAEW treatment group ( p < 0.05). Treatment with SAEW at low temperature is a novel strategy for the efficient enrichment of oat β-glucan. • Slightly acidic electrolyzed water (SAEW) is convenient to prepare and environmentally friendly. • A novel SAEW and low-temperature synergy optimally enriches β-glucan in germinating oats. • The accumulated β-glucan has higher molecular weight and enhanced bioactivity. • SAEW is repurposed from a sterilant to a metabolic elicitor for biofortification.