Buckwheat possesses significant nutritional content and contains different bioactive compounds, such as total flavonoids, which enhance its appeal to consumers. This study employed single-factor experiments and the response surface methodology to identify the optimal germination conditions for enhancing the total flavonoid content in buckwheat sprouts through ultraviolet-B treatment. The research showed that buckwheat sprouts germinated for 3 days at a temperature of 28.7 °C while being exposed to ultraviolet-B radiation at an intensity of 30.0 μmol·m⁻²·s⁻¹ for 7.6 h per day during the germination period resulted in the highest total flavonoid content of 1872.84 μg/g fresh weight. Under these specified conditions, ultraviolet-B treatment significantly elevated the activity and gene expression levels of enzymes related to the phenylpropanoid metabolic pathway, including phenylalanine ammonia-lyase, cinnamic acid 4-hydroxylase, 4-coumarate coenzyme A ligase, and chalcone isomerase. Ultraviolet-B treatment caused oxidative damage to buckwheat sprouts and inhibited their growth, but ultraviolet-B treatment also enhanced the activity of key enzymes in the antioxidant system, such as catalase, peroxidase, superoxide dismutase, and ascorbate peroxidase. This research provided a technical reference and theoretical support for enhancing the isoflavone content in buckwheat sprouts through ultraviolet-B treatment.

Plant hormones play a critical role in the physiological and biochemical mechanisms of plants, with functions such as regulating the metabolic pathways of secondary metabolite production and alleviating external stresses. In this study, the synthesis of flavonoids in black soybean sprouts was induced by slight acid combined with the plant hormones abscisic acid (ABA) and melatonin (MT). The results indicated that the contents of daidzin, genistin, daidzein, and genistein in black soybean sprouts treated with slight acid were increased by 10 μM ABA and 75 μM MT, and the total flavonoid content was significantly enhanced. Compared with the slight acid treatment, the H₂O₂ and malondialdehyde (MDA) contents in black soybean sprouts were increased after ABA treatment, and the black soybean sprouts were further stressed. However, the H₂O₂ and MDA contents in black soybean sprouts were significantly decreased after MT treatment, indicating that the stress of black soybean sprouts can be alleviated by MT. Under slight acid stress, the genes related to flavonoid synthesis in black soybean sprouts were induced by exogenous ABA, promoting the accumulation of flavonoids; under exogenous MT treatment, the activity of phenylpropanoid metabolism enzymes was significantly increased, the genes related to flavonoid synthesis were upregulated, and flavonoid synthesis was induced. These results suggest that the combination of slight acid and plant hormone treatments promotes the accumulation of flavonoid substances during the germination of black soybeans. This research lays the foundation for improving the growth conditions of black soybeans and promoting the enrichment of flavonoid substances in black soybeans.

Chickpeas (Cicer arietinum L.) were popular for their high nutritional profile and abundance of bioactive constituents, making them highly sought after in the consumer market. This investigation evaluated the impact of germination on the levels of total phenolics, total flavonoids, and other bioactive compounds, as well as free amino acids, soluble proteins, dietary fiber, and starch, in two chickpea sprout cultivars. The results demonstrated that germination significantly enhanced the concentrations of total flavonoids and phenolics in chickpeas. Compared to ungerminated seeds, the total flavonoid content in Xinying No. 1 and Xinying No. 2 sprouts increased by 3.95-fold and 3.25-fold, respectively, while total phenolic content increased by 2.47-fold and 2.38-fold. Germination also significantly augmented free amino acid, soluble protein, and total dietary fiber content while reducing resistant starch and insoluble dietary fiber. Concurrently, the bioaccessibility of essential nutrients was substantially improved, as indicated by enhanced solubility. This research provided valuable insights for optimizing the nutritional quality and bioactive compound content of chickpeas through sprouting technology. These results provided critical insights for optimizing the nutritional and functional properties of chickpeas via sprouting and established a scientific basis for the development of functional foods from germinated chickpeas, underscoring their potential to support dietary health and wellness.

Chickpea is an important legume crop, characterized by its high nutritional value and abundant physiologically active compounds. Pulsed electric field (PEF), as an emerging non-thermal physical processing technology, has demonstrated unique advantages in regulating seed germination and the accumulation of secondary metabolites. In this study, chickpeas were subjected to germination combined with PEF treatment to optimize germination conditions, and the physiological and metabolic changes, as well as flavonoid biosynthetic patterns in chickpea sprouts under conventional germination and PEF-assisted germination were systematically investigated. The results showed that under the optimal conditions (12 h soaking, PEF treatment at 30 kV applied voltage, 6 µs pulse width, and 500 Hz frequency for 27 min, followed by 72 h germination), the total flavonoid content in chickpea sprouts reached a peak of 3025.27 ± 21.11 µg/g DW. Optimized PEF conditions markedly activated the enzyme activities of the phenylpropanoid pathway and induced the upregulated expression of their corresponding genes. Meanwhile, the activities of antioxidant enzymes and the expression levels of related genes in PEF-treated chickpea sprouts were also markedly enhanced. PEF can promote flavonoid accumulation and improve antioxidant capacity in chickpea sprouts by activating the phenylpropanoid metabolic pathway and the antioxidant system. This study contributes to the development of nutritious foods based on chickpea.