Comprehensive multi-layered analyses of genotype-dependent proteo-metabolic networks reveal organellar crosstalk and biochemical pathways regulating aroma formation in rice

Molecular basis of rice aroma formation is sparsely known and developmental programs driving biochemical pathways towards aroma is in infancy. Here, discovery and targeted proteo-metabolome of non-aromatic and aromatic rice seeds across developmental stages identified a total of 442 aroma-responsive proteins (ARPs) and 824 aroma-responsive metabolites (ARMs) involved in metabolism, calcium and G-protein signaling. Biochemical examination revealed ARM/Ps were linked to 2-acetylpyrrolidine, γ-aminobutyrate, anthocyanin, tannins, flavonoids and related enzymes. Pairwise correlation and clustering showed positive correlation among ARM/Ps. Consistent with aroma-related QTLs, ARPs were mapped on chromosomes 3,4,5,8 and were mainly compartmentalized in cytoplasm and mitochondria. ARM/P-correlation network identified associations related to metabolism and signaling. Multiple reaction monitoring (MRM) confirmed role of catechins, quinic acid and quercetin in aroma formation. Pathway enrichment, multivariate analysis and qRT-PCR validated that calcium and G-protein signaling, aromatic/branched-chain aminoacid, 2-acetylpyrrolidine, oxylipin, melvonate and prenylpyrophosphate pathways, indole, phenylacetate, flavonoid, cinnamoic ester govern aroma formation in rice.

Antioxidant Properties of Gluten-Free Pasta Enriched with Vegetable By-Products

The only therapy for coeliac disease patients is to completely avoid foods containing gluten, a protein complex common in several small-grain cereals. However, many alternative gluten-free foods available on the market present nutritional deficiencies. Therefore, the aim of this research was to evaluate the composition and the antioxidant properties of gluten-free pasta enriched with 10% or 15% of tomato waste or linseed meal, two food industry by-products. The traits analysed were protein, lipid, ash and fibre content, heat damage, tocols, carotenoids and phenolics composition (by HPLC), antioxidant capacity, and pasta fracturability. The enriched pastas contained more fibre and lipids than the control, while the protein and ash values were similar. The addition of tomato and linseed waste improved tocols concentration but had no effect on carotenoids content. The free soluble polyphenols increase was similar for both by-products and proportional to the enrichment percentage, while the bound insoluble polyphenols were higher in linseed-enriched pastas. The samples with linseed meal showed the greatest antioxidant capacity and, at 10% addition, the highest fracturability value. In conclusion, the addition of tomato and linseed by-products significantly increases the presence of bioactive compounds (particularly polyphenols), improving the nutritional value of gluten-free pasta.

Investigation on Nutritional, Phytochemical, and Antioxidant Abilities of Various Traditional Rice Varieties

Rice (Oryza sativa L.) is a popular grain that is consumed by almost half of the world's population. Rice has several distinct breeds classified as traditional and ancient grains. The consumption of rice by 60% of the world's population is a staple food. Entire grain rice, often known as brown rice, is the unpolished counterpart of white rice, containing bran, germ, and endosperm. Eating whole-grain rice is linked to many health benefits; thus, scientists have focused on identifying and quantifying bioactive chemicals in this meal. The present study assessed the physio-chemical, cooking attributes, mineral contents, phytochemicals, and free radical scavenging capabilities of conventional rice cultivars using known approaches according to particle size analysis. Rice grain lengths varied between 4.10 ± 16 and 6.20 ± 007. The length and thickness ratios of rice were not substantially different (p > 0.05). Kattuyanam has the maximum protein content (9.99 ± 06%) of all the rice varieties that were physio-chemical investigated. It also has highest phenolic content and antioxidant properties compared to gallic acid equivalent (334.900 ± 61 g) (GAE)/100 g, followed by anthocyanins and flavonoids. Total phenolic content and phenolic fractions of the HPLC profile in tested landraces indicate the presence of bioactive substances derived from traditional rice cultivars and a range of phytonutrients, including phenol, revealing their healthy potentials in the present study.

Polyphenol Composition and Antioxidant Activity of Japonica Rice Cultivars and Intake Status

Japonica rice is produced mainly in northeast China, Japan, and the Korean Peninsula. Polyphenols and flavonoids are the main antioxidants in japonica rice. This study reported the polyphenol content and antioxidant activity of nine brown and white japonica rice cultivars. The total phenolic and flavonoid contents of brown rice were in the ranges of 241.98-296.76 GAE mg/100 g, and 225.30-276.80 RE mg/100 g, respectively. These values were significantly higher than that of white rice by 118.98-206.06% and 135.0-217%, respectively. The bound fraction from phenolics and flavonoids contributed 41.1-63.6% and 62.22-78.19% of the total phenolic and flavonoid content in brown rice, respectively, while these ranges were 55.5-73.5% and 46.07-66.83% in white rice, respectively. p-Hydroxybenzonic acid was the predominant phenolic acid in japonica rice. All four antioxidant capacities of brown rice (DPPH, ABTS, OH, FRAP) were higher by up to 1.68-2.85 times than those of white rice. The PZ21 (Yanfeng 47) japonica rice variety has outstanding antioxidant capacity based on the weights of each antioxidant index. According to the differences of functional substances among varieties, it can provide guidance for consumers and theoretical basis for the production of healthy food.

Phytochemical profiling and cellular antioxidant efficacy of different rice varieties in colorectal adenocarcinoma cells exposed to oxidative stress

In the present study, white (Baegilmi), brown (hyunmi) and black (chalheugmi) Korean local rice varieties ethanol extracts were analyzed for in-vitro antioxidant assays (ABTS, FRAP and DPPH), cellular antioxidant activities (CAAs) and phenolic phytochemicals content. The highest antioxidant assays, phenolic, flavonoid and anthocyanins content were identified among the free fractions of black rice. Phenolic phytochemicals were detected and quantified using the ultra-high-performance liquid tandem chromatography quadrupole flight mass spectrometry (UHPLC-Q-TOF-MS²). Which indicated the richness of several phytochemicals like ascorbic acid, vanillic acid, p-coumaric acid, catechin, epigallocatechin and quercetin in black rice than in other rice samples. The cellular antioxidant activities (CAA) of black rice were found equivalent to that of ascorbic acid, the standard employed in the assay. The CAAs of free fractions were as follows: white rice < brown rice < black rice. These findings are significant for enhancing human health through increased consumption of black and brown rice in the development of functional food products.

Quantification of Amino Acids, Phenolic Compounds Profiling from Nine Rice Varieties and Their Antioxidant Potential

In recent years, the health benefits of the pigmented rice varieties have been reported due to the richness of their bioactive compounds. Therefore, this study evaluated the antioxidant, total flavonoid, total phenolic, anthocyanin content, amino acid and individual phenolic compound quantification of nine Korean-grown rice varieties using spectrophotometric, HPLC-FLD-MS/MS and UHPLC Q-TOF-MS/MS methods. Our research found that the free fractions of DM29 (red rice) had the highest free radical scavenging ability of ABTS and DPPH. In contrast, the highest ferric reducing antioxidant power was observed in the 01708 brown rice variety. The majority of phenolic compounds such as quercetin, ferulic acid, p-coumaric acid, ascorbic acid, caffeic acid and genistein were found in the DM29 sample. The phenolic content of rice varies depending on its color, with DM29 red rice having the highest TPC, TFC and TAC levels. At the same time, the presence of the majority of amino acids was quantified in the 01708 and GR (Gangwon) brown rice varieties. According to this study, colored rice varieties are high in amino acids, phenolic compounds and antioxidants. This research would be beneficial in furthering our understanding of the nutritional value of different colors of rice and their high potential as a natural antioxidant.