Influence of Agricultural Management on Phytochemicals of Colored Corn Genotypes ( Zea mays L.). Part 2: Sowing Time

Geographic differences and variation of functional components of brown rice in 690 mini-core collections from global germplasms

Objective

To understand the geographic differences and variations in the functional components of brown rice cores collected from global rice germplasms.

Methods

Four functional components, γ-aminobutyric acid (GABA), resistant starch (RS), total flavonoids, and alkaloids, in brown rice from 690 mini-core collections from 31 countries from five continents and the International Rice Research Institute, were analyzed using a spectrophotometry colorimetric method, and the results were statistically validated.

Conclusion

The highest average amounts of functional components were obtained in Asian germplasms, except for GABA, and total flavonoids were highest in brown rice from Europe and Oceania, followed by Asia. The highest coefficient of variation for GABA was observed in Asia; that for RS and total flavonoids was observed in Africa, followed by Asia; and that for alkaloids was observed in America, followed by Asia. Overall, Asian countries were the most prominent and representative zones with the highest genotypic potential for functional components of brown rice. Forty-one rice accessions with enriched functional components originated mostly from biodiversity-rich areas in China, followed by those in the Philippines. Late sowing favored the enrichment of these components in brown rice. The current study provides a reference for rice breeding with enriched functional constituents, and guidelines for screening functional rice that could be used for human chronic disease research.

Characterization and selection of functional yeast strains during sourdough fermentation of different cereal wholegrain flours

The increasing demand for healthy baked goods boosted studies on sourdough microbiota with beneficial metabolic traits, to be used as potential functional starters. Here, 139 yeasts isolated from cereal-based fermented foods were in vitro characterized for their phytase and antioxidant activities. The molecular characterization at strain level of the best 39 performing isolates showed that they did not derive from cross contamination by baker’s yeast. Afterwards, the 39 isolates were in vivo analyzed for their leavening ability, phytase activity and polyphenols content using five different wholegrain flours, obtained from conventional and pigmented common wheat, emmer and hull-less barley. Combining these findings, through multivariate permutation analysis, we identified the 2 best performing strains, which resulted diverse for each flour. Doughs singly inoculated with the selected strains were further analyzed for their antioxidant capacity, phenolic acids, xanthophylls and anthocyanins content. All the selected yeasts significantly increased the total antioxidant activity, the soluble, free and conjugated, forms of phenolic acids and anthocyanins of fermented doughs. This study revealed the importance of a specific selection of yeast strains for wholegrain flours obtained from different cereals or cultivars, in order to enhance the pro-technological, nutritional and nutraceutical traits of fermented doughs.

(Poly)phenols, Carotenoids, and Tocochromanols in Corn (Zea mays L.) Kernels As Affected by Phosphate Fertilization and Sowing Time

Corn (Zea mays L.) growth and development is often limited by the availability of phosphate. We thus hypothesized that phosphate fertilization may increase the contents of (poly)phenols, carotenoids, and tocochromanols (vitamin E) in corn grains. Corn plants cultivated on a soil fertilized with 44 kg phosphorus/ha were compared to plants grown on soil with low plant-available phosphate (1.6 mg CAL-P/100 g of soil), each sown early (April) and late (May) in a randomized field experiment. HPLC-DAD-(HR)-ESI-MSⁿ revealed 19 soluble and 10 insoluble (poly)phenols, comprising phenolic acids, phenolic amines, diferulic, and triferulic acids in corn grains. Contents of individual (poly)phenols, carotenoids, and tocochromanols in whole grains were significantly (p < 0.05) increased by sowing time, but not by phosphate fertilization. In conclusion, low phosphate availability did not impair the biosynthesis of (poly)phenols, carotenoids, and tocochromanols in corn grains.