Effect of gamma irradiation on antioxidant potential, isoflavone aglycone and phytochemical content of soybean (Glycine max L. Merrill) cultivar Williams

Crotalaria madurensis flavonol glycosides' antibacterial activity against Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) infections are prevalent in hospitals and often lead to significant health complications. This study aimed to explore the chemical composition of the aerial part of Crotalaria madurensis and evaluate its antioxidant and antibacterial properties. The impact of gamma irradiation on the antibacterial properties of the plant extract and metabolite 1 against MRSA was also examined. Fourier-transform infrared (FTIR) analysis was conducted on the filtrates of untreated MRSA and MRSA treated with the plant extract and metabolite 1. Four flavonol glycosides were identified as gossypetin 8-methoxy, 3-O-β-D-xylopyranoside (metabolite 1), gossypetin 8-O-β-D-glucopyranoside (metabolite 2), kaempferol 3-O-β-D-glucpyranoside (Astragalin, metabolite 3), and herbacetin 7-methoxy-3-O-β-D-glucopyranoside (metabolite 4). All metabolites exhibited significant antioxidant properties using different assays. The antibacterial efficacy of the extract and metabolite 1, which showed substantial antioxidant properties compared to the other isolated metabolites, was evaluated. Both the plant extract and metabolite 1 significantly reduced the viability and cell count of MRSA at concentrations of 1.0 and 0.5 mg/ml. The antibacterial activity of the plant extract and metabolite 1 was assessed after gamma irradiation at 50 and 100 Gy, which did not significantly affect the antibacterial efficiency. FTIR analysis indicated that the plant extract and metabolite 1 significantly altered the band frequency values, bandwidth, and peak intensity % of the treated MRSA filtrate. Molecular docking studies suggested that metabolite 1 exhibited the highest antioxidant and anti-MRSA activity, with strong binding scores like the ligand, indicating an effective interaction and high affinity between metabolite 1 and the target molecule.

Response of Satureja hortensis L. to gamma radiation and its impact on secondary metabolite content and biochemical characteristics

PURPOSE

The current study investigated the effects of gamma irradiation on biochemical parameters and secondary metabolite accumulation in Summer Savory under field conditions.

MATERIALS AND METHODS

The dry seeds of Summer Savory (with a moisture content of 12%) were exposed to gamma radiation at the doses of 20, 40, 60, 80, and 100 Gy. Non-irradiated seeds (0 Gy) were used as control.

RESULTS

Our findings showed that gamma radiation at low doses (20-40 Gy) had no effect on biochemical parameters and secondary metabolites accumulation in S. hortensis. These parameters are steadily and significantly increased by raising gamma irradiation doses from 40 to 100 Gy. The highest amount of chlorophyll a and b, carotenoids, anthocyanin, and total phenolic and flavonoid content were observed in 80 and 100 Gy treatments. Plants exposed to 80 and 100 Gy treatments accumulated the maximum amounts of rosmarinic acid and caffeic acid, respectively. Furthermore, the analysis of S. hortensis essential oil revealed that gamma radiation significantly alters its components. Carvacrol, α-Pinene, and α-Thujene levels raised dramatically compared to control with an increase in gamma irradiation dose from 20 to 100 Gy, while Thymol and α-Terpinene levels lowered.

CONCLUSIONS

Our results showed that treatment of Summer Savory seeds with gamma radiation at 80 and 100 Gy doses could significantly be raised biochemical parameters and secondary metabolites accumulation under field conditions. The current study showed that gamma irradiation could be used as a pre-sowing elicitor to improve the quantity and quality of phytochemicals in Summer Savory.

Effect of radiation processing on phenolic antioxidants in cereal and legume seeds: A review

Phenolic compounds in cereal and legume seeds show numerous benefits to human health mainly because of their good antioxidant capacity. However, long-term storage and some improper preservation may reduce their antioxidant potential. It is necessary to retain or modify the phenolic antioxidants with improved technology before consumption. Radiation processing is usually applied as a physical method to extend the shelf life and retain the quality of plant produce. However, the effect of radiation processing on phenolic antioxidants in cereal and legume seeds is still not well understood. This review summarizes recent research on the effect of radiation, including ionizing and nonionizing radiation on the content and profile of phenolic compounds, and antioxidant activities in cereal and legume seeds, the influencing factors and possible mechanisms are also discussed. The article will improve the understanding of radiation effect on phenolic antioxidants, and promote the radiation modification of natural phenolic compounds in cereal and legume seeds and other sources.

Effects of okara and vitamin B2 bioenrichment on the functional properties and in vitro digestion of fermented soy milk

Due to highly nutritious and well-known prebiotic nature, okara (soy by-product) can improve the physiological benefits of probiotic consumption by enhancing the physicochemical stability and bioavailability of bacteria and metabolites, partially in food matrices and then in gastrointestinal tract. Initially, vitamin B₂ producing probiotic Lactobacillus plantarum UFG10 was immobilized with 4% okara for soy milk fermentation. SEM micrographs showed firm adherence of UFG10 to okara surface depicting efficient immobilization. Soy milk fermented with okara immobilized UFG10 showed enhanced β-glucosidase activity, stimulating the biotransformation of isoflavones from glucosides (daidzin, from 27.78 to 9.84 μg/mL; genistin, from 32.58 to 8.33 μg/mL) to aglycones (daidzein, from 0.19 to 30.84 μg/mL; genistein, from 1.42 to 33.10 μg/mL) and higher B₂ production (1.53 μg/mL, 12 h) confirmed by HPLC. Okara addition and B₂ enrichment could yield relatively higher antioxidant strength than control soy milk. PLSR correlation revealed the effects of okara and B₂ on the functional properties of soy milk. After okara immobilization, soy milk showed higher soy protein digestibility after in vitro digestion for 225 min, higher aggregation, and lower protein molecular chains, qualitatively confirmed with Atomic force microscope. Okara immobilized bacterial cells exhibited relatively greater resistance up to 55.1% (p < 0.05) in simulated GIT, indicating okara as an ideal substrate for an efficient immobilization which ultimately improved the fate of soy B₂ and protein bioaccessibility and functional products such as isoflavones for micro structural design of soy milk with improved nutrition and digestibility.

Antioxidant Contributors in Seed, Seed Coat, and Cotyledon of γ-ray-Induced Soybean Mutant Lines with Different Seed Coat Colors

The development of soybean with high antioxidant activities for use in the food and cosmetics industries is a target of breeding programs. In soybean, antioxidants are associated with seed color, although the metabolic basis for seed coloration remains incompletely understood. We selected six γ-ray-induced mutant lines that exhibited black, partially black, brown, partially brown, or yellowish-white pigmentation in the seed coat. Antioxidant activity and contents of anthocyanins, flavan-3-ols, and isoflavones were evaluated in the seed coat and cotyledons. The lines with black or brown seeds showed the highest antioxidant activities. The cotyledons showed no significant differences in seed coat components or antioxidant activities among lines. Black and brown seed coat components showed the highest antioxidant activities. The black seed coat contained five anthocyanins, whereas seed coats of brown- and yellow-seeded lines entirely lacked anthocyanins. Both black and brown seeds were rich in flavan-3-ols, including catechin and epicatechin, which were the predominant antioxidant contributors in brown seeds. Isoflavone contents showed weaker correlations with antioxidant activity than anthocyanins and flavan-3-ols. These results demonstrated that antioxidant activities were determined by anthocyanins in black seeds and flavan-3-ols in brown and black seeds, whereas relatively low antioxidant activities in yellow seeds reflected their high isoflavone contents.