Differential responses of B vitamins in black soybean seeds

Validation of the Vitamin B6 Profile (Pyridoxine, Pyridoxal, and Pyridoxamine) Analysis in Rice Consumed in Korea: Effects of Cooking and Variety

Rice, a widely consumed grain, contains various forms of vitamin B6, including pyridoxine (PN), pyridoxal (PL), and pyridoxamine (PM). However, limited information exists on their content and distribution in rice. This study analyzed the vitamin B6 profile and retention of different rice varieties consumed in Korea, using sonication-assisted acid extraction and HPLC-FLD. Retention rates were calculated based on B6 content before and after cooking. Five rice varieties were selected: Baromi2 (brown rice), Annammi, Chucheong (white rice), New breed white Baromi2, and New breed brown Baromi2. Vitamin B6 content ranged from 142.92 μg/100 g (Baromi2) to 35.89 μg/100 g (Chucheong). After cooking, Annammi showed the highest retention (109.4%), with pyridoxamine retaining 116.4%. Baromi2 had the lowest retention (34.5%), with pyridoxal at 22.1%. The analytical method demonstrated excellent accuracy (recovery rate 100.0-103.4%), precision (RSDr < 3.0%, RSDR < 6.7%), and linearity (R2 > 0.9998). The detection limits and quantification limits for the vitamin B6 vitamers ranged from 0.040 to 0.070 μg/100 g and 0.103 to 0.187 μg/100 g, respectively. The results showed significant variations in vitamin B6 profiles and individual retention rates across rice varieties, highlighting the need for more comprehensive data on B6 levels. Analyzing the pyridoxal, pyridoxamine, and pyridoxine provides a more complete understanding of the B6 profile of rice, enhancing nutritional evaluations and precision nutrition.

Transcriptome and targeted metabolomic integrated analysis reveals mechanisms of B vitamin accumulation in Areca catechu nut development

Areca catechu is well known as a medicinal plant that has high nutritional and medicinal benefits. However, the metabolism and regulatory mechanism of B vitamins during areca nut development remain largely unclear. In this study, we obtained the metabolite profiles of six B vitamins during different areca nut developmental stages by targeted metabolomics. Furthermore, we obtained a panoramic expression profile of genes related to the biosynthetic pathway of B vitamins in areca nuts at different developmental stages using RNA-seq. In total, 88 structural genes related to B vitamin biosynthesis were identified. Furthermore, the integrated analysis of B vitamin metabolism data and RNA-seq data showed the key transcription factors regulating thiamine and riboflavin accumulation in areca nuts, including AcbZIP21, AcMYB84, and AcARF32. These results lay the foundation for understanding metabolite accumulation and the molecular regulatory mechanisms of B vitamins in A. catechu nut.

Enhancement of Antioxidant Activities in Black Soy Milk through Isoflavone Aglycone Production during Indigenous Lactic Acid Bacteria Fermentation

Black soybeans contain high antioxidant compounds such as isoflavone but mainly in glucoside form, with low antioxidant activities. Fermentation by lactic acid bacteria (LAB) can enhance the antioxidant properties, but its ability is strain-dependent. This study aims to study the ability of Indonesian indigenous LAB, Lactiplantibacillus plantarum WGK 4, Streptococcus thermophilus Dad 11, and Lactiplantibacillus plantarum Dad 13, to enhance the antioxidant properties during black soy milk fermentation. Fermentation was carried out at 37 °C for 24 h. Viable cell, acid production, Folin–Ciocalteu assay, antioxidant activity (DPPH), isoflavone aglycone daidzein and genistein, and β-glucosidase activity were measured every six hours. All LAB strains could grow well during the fermentation of black soy milk. Lactiplantibacillus plantarum WGK 4 produced the highest acid (1.50%). All three LAB strains could enhance antioxidant activity (DPPH) from 24.90% to 31.22–38.20%, followed by increased isoflavone aglycone. All strains could increase daidzein and genistein content, ranging from 61% to 107% and 81% to 132%, respectively. All three Indonesian indigenous LAB enhanced antioxidant properties of black soy milk relatively at the same level and potentially could be used as a starter culture of black soy milk fermentation.

New insights into the accumulation of vitamin B3 in Torreya grandis nuts via ethylene induced key gene expression

Vitamin B₃, derived primarily from plant sources, is an essential nutrient for humans. Torreya grandis is rich in vitamin B₃, however, the mechanism underlying the biosynthesis and regulation of vitamin B₃ in T. grandis remains unclear. A systematic transcriptomic investigation was thus conducted to identify the gene expression pattern of vitamin B₃ biosynthesis in 10 T. grandis cultivars. The findings suggest that biosynthesis occurs mainly via the aspartate pathway. Expression and correlation analyses indicate that aspartate oxidase (AOX) and quinolinate synthase (QS) may play important roles in vitamin B₃ accumulation. Furthermore, co-expression network and ethephon treatments indicate that the ethylene response factor (ERF) may be involved in the regulation of vitamin B₃ biosynthesis in T. grandis nuts. Our findings not only help to elucidate the biosynthesis of vitamin B₃, but also provide valuable resource material for future genomic research and molecular-assisted breeding to develop genotypes with higher vitamin B₃ levels.