Red onion skin extract rich in flavonoids encapsulated in ultrafine fibers of sweet potato starch by electrospinning.

Electrospinning encapsulation is a highly viable method to protect bioactive compounds and prevent their degradation. Hence, this study produced ultrafine fibers based on yellow and white sweet potato starches and a red onion skin extract (ROSE; 0, 3, 6, and 9 %, w/w) using electrospinning. The fibers were evaluated for morphology, thermogravimetric properties, antioxidant, in vitro release simulation, thermal resistance (100 and 180 °C), and wettability. The fibers with ROSE presented 251-611 nm diameters, 67-78 % loading capacity, and 51.6-95.4 and 13.4-99.4 % thermal resistance (100 and 180 °C, respectively); apigenin presented the highest thermal protection. The phenolic compounds showed low release using 10 % ethanol and greater release with 50 % ethanol. The fibers with 9 % ROSE showed 2,2'-azino-bis(3-ethylbenzothiazoline) 6-sulfonic acid radical inhibition above 92 %. The ultrafine fibers and the unencapsulated ROSE showed inhibitory action against Escherichia coli and Staphylococcus aureus; only unencapsulated ROSE showed bactericidal activity.

Extraction and characterization of phytochemical compounds from araçazeiro (Psidium cattleianum) leaf: Putative antioxidant and antimicrobial properties.

Underexplored species have phytochemical potential for pharmacological and nutraceutical applications. The fruits of such species, including aracá (Psidium cattleianum Sabine), are rich in specialized metabolites with putative antioxidant and antimicrobial activity; therefore, the leaves of these species are also a potential source of bioactive compounds. In this study, araçazeiro leaves were extracted using an aqueous infusion (Al) and a pressurized liquid extraction system with water (PLE-W), ethanol (PLE-E), and 1:1 water:ethanol ratio combination (PLE-W:E). PLE-W:E yielded a greater diversity of extracted compounds. Nonetheless, all extracts showed inhibitory activity against pathogenic Gram-positive and Gram-negative bacteria and antioxidant activity in the in vitro thiobarbituric acid reactive substances (TBARS) and reactive oxygen species (ROS) assays with rat brain and yeast model systems. Thus, araçazeiro leaves can be exploited as a promising source of bioactive compounds.

Apple Phenolic Extracts Strongly Inhibit α-Glucosidase Activity.

The beneficial health effects of apple consumption are well known, however, little is known about the potential of its phenolic fractions to inhibit α-glucosidases and thereafter to treat diseases related to the carbohydrate metabolism, such as postprandial hyperglycemia and diabetes. In the present study, the α-glucosidase inhibition and antioxidant activity of different phenolic fractions of apple were evaluated using the 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radical scavenging activity. Moreover, the phenolic fractions were chemically characterized by LC-MS in order to identify the compounds responsible for the biological properties. The purified extract (not fractionated) had the highest α-glucosidase and hydroxyl radical inhibitions. The purified extract and fractions III and IV were more active against the enzyme activity than the positive control acarbose, the drug used by diabetic patients to treat postprandial hyperglycaemia. Our results show that apple phenolic extracts strongly inhibit α-glucosidase acitivity, validating their potential to be used in the management of type 2 diabetes.

Discrimination of genotype and geographical origin of black rice grown in Brazil by LC-MS analysis of phenolics.

Physicochemical properties, cooking time, and phenolics profile of two black rice genotypes grown at six different locations in Brazil were determined. The cultivar IAC 600 and the elite-line AE 153045 were used. The main growing locations for black rice were considered, as follows: Alegrete (ALG), Capão do Leão (CPL), Guaratinguetá (GUA), Roseira (ROS), Santa Vitória do Palmar (SVP), and Taubaté (TBT). Principal component analysis (PCA) and supervised partial least squares-discriminant analysis (PLS-DA) from liquid chromatography-mass spectrometry (LC-MS) data sets showed distinction among genotypes and locations. Quercetin-3-O-glucoside and vanillic acid were the most relevant compounds for discriminating genotypes. SVP location provided the most distinctive black rice, with greater total phenolics content. Characteristics of black rice from SVP location were associated to effects of latitude and wind conditions. Hesperetin, vanillic acid, quercetion-3-O-glucoside, and p-coumaric acid were the most relevant compounds for discriminating locations.

Phosphate Fertilizer and Growing Environment Change the Phytochemicals, Oil Quality, and Nutritional Composition of Roundup Ready Genetically Modified and Conventional Soybean.

Phosphorus (P) intake, genotype, and growth environment in soybean cultivation can affect the composition of the soybean. This experiment was conducted in two locations (microregions I and II) using a randomized complete block design, including conventional soybean (BRS Sambaíba) and genetically modified (GM) [Msoy 9144 Roundup Ready (RR)] cultivars and varying doses of phosphorus fertilizer (0, 60, 120, and 240 kg/ha P2O5). Soybeans were evaluated for chemical composition, total phenols, phytic acid content, individual isoflavone content, antioxidant activity, oil quality, fatty acid profile, total carotenoid content, and individual tocopherol contents. Multivariate analysis facilitated reduction in the number of variables with respect to soybean genotype (conventional BRS Sambaíba and GM Msoy 9144 RR), dose of P2O5 fertilizer, and place of cultivation (microregion I and II). BRS Sambaíba had higher concentrations of ß-glucosides, malonylglucosides, glycitein, and genistein than Msoy 9144 RR, which showed a higher concentration of daidzein. The highest concentrations of isoflavones and fatty acids were observed in soybeans treated with 120 and 240 kg/ha P2O5, regardless of the location and cultivar.

Ethylene-dependent regulation of an α-L-arabinofuranosidase is associated to firmness loss in 'Gala' apples under long term cold storage.

Fruit texture changes impair the quality of apples submitted to long term storage, especially under cold. The changes are due to cell wall modifications during ripening and senescence and are associated to ethylene. We have investigated the activity of α-l-arabinofuranosidase, a glycosyl hydrolase acting on the side chains of pectin in the cell wall and middle lamella. The transcription of arabinofuranosidase coding sequences 1 and 3 was investigated in plant organs and in response to ethylene, employing hormone application and 1-methylcyclopropene. The transcription of arabinofuranosidase genes is not restricted to fruits, although upregulated by ripening and ethylene. Transcripts of the genes were detected under cold storage up to 180 days. Similarly, arabinofuranosidase activity increased with rising levels of ethylene and under cold storage. Levels of arabinofuranosidase3 transcripts were higher than those of arabinofuranosidase1, suggesting that the first is an important contributor to enzyme activity and texture changes during cold storage.