Profiling modifications in physicochemical, chemical and antioxidant properties of wild blackberry (Rubus sp.) during fermentation with EC 1118 yeast.

Mexico is an extensively diverse country with a wide variety of wild species of blackberries (Rubus spp.), which are rich in bioactive compounds, however, these fruits are underutilized. Fermentation is a process that transforms the chemical compounds of fruits and increases nutraceutical properties. This study aimed to determine the physicochemical changes and the bioactive compounds profile that take place during the fermentation of wild blackberries using yeast EC 1118 and to evaluate its relationship with antioxidant activity (AOx). The results indicated that after 96 h of fermentation the content of carbohydrates (56%), total phenolic compounds (37%), and anthocyanins (22%), decreased, respectively. The physicochemical parameters showed statistic differences (p ≤ 0.05) at the endpoint of fermentation. The diversity of fatty acids was increased (55%), compared with unfermented blackberries. The modification of carbohydrates, anthocyanins, catechin, gallic and ellagic acid profiles were also monitored performing chromatographic techniques. The AOx, determined by ORAC and DPPH assays, showed the highest results for ORAC at 96 h increased a 140.2%, while DPPH values enhanced a 36.6% at 48 h of bioprocessing. Strong positive correlations were found between fermentation time and DPPH values (r = 0.8131), between ORAC and gallic acid content (r = 0.8688), and between anthocyanin content and pH (r = 0.9126). The fermentation of wild blackberries with EC 1118 yeast represents an alternative for development and formulation of potential ingredients for functional foods. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at (10.1007/s13197-020-04953-x).

Improving Polyphenolic Compounds: Antioxidant Activity in Chickpea Sprouts through Elicitation with Hydrogen Peroxide.

Elicitation appears to be a promising alternative to enhance the bioactive compound content and biological activities of legume sprouts. Multi-response optimization by response surface methodology (RSM) with desirability function (DF) was used to optimize the elicitor concentration (hydrogen peroxide (H2O2)) and germination time in order to maximize total phenolic content (TPC), total flavonoids content (TFC), and antioxidant activity (AOX) of chickpea sprouts. Chemical, antinutritional, and nutraceutical properties of optimized chickpea sprouts (OCS) were also determined. The predicted regression models developed were efficiently fitted to the experimental data. The results of the desirability function revealed that optimum attributes in chickpea sprouts can be achieved by the application of 30 mM H2O2 and 72 h of germination time, with global desirability value D = 0.893. These OCS had higher (p < 0.05) TPC (7.4%), total iso-flavonoids (16.5%), AOX (14.8%), and lower phytic acid (16.1%) and saponins (21.8%) compared to H2O2 non-treated chickpea sprouts. Optimized germination conditions slightly modified the flavonoid profile in chickpea; eight iso-flavonoids were identified in OCS, including formononetin and biochanin A, which were identified as the major compounds. Results from this study support elicitation with H2O2 as an effective approach to improve phytochemical content and antioxidant activity in chickpea sprouts.

Phenolic Acids Profiles and Cellular Antioxidant Activity in Tortillas Produced from Mexican Maize Landrace Processed by Nixtamalization and Lime Extrusion Cooking.

Phenolic acids profiles, chemical antioxidant activities (ABTS and ORAC), as well as cellular antioxidant activity (CAA) of tortilla of Mexican native maize landraces elaborated from nixtamalization and lime cooking extrusion processes were studied. Both cooking procedures decreased total phenolics, chemicals antioxidant activity when compared to raw grains. Extruded tortillas retained 79.6-83.5%, 74.1-77.6% and 79.8-80.5% of total phenolics, ABTS and ORAC values, respectively, compared to 47.8-49.8%, 41.3-42.3% and 43.7-44.4% assayed in traditional tortillas, respectively. Approximately 72.5-88.2% of ferulic acid in raw grains and their tortillas were in the bound form. Regarding of the CAA initially found in raw grains, the retained percentage for traditional and extruded tortillas ranged from 47.4 to 48.7% and 72.8 to 77.5%, respectively. These results suggest that Mexican maize landrace used in this study could be considered for the elaboration of nixtamalized and extruded food products with nutraceutical potential.

Jatropha curcas Protein Concentrate Stimulates Insulin Signaling, Lipogenesis, Protein Synthesis and the PKCα Pathway in Rat Liver.

Jatropha curcas is an oil seed plant that belongs to the Euphorbiaceae family. Nontoxic genotypes have been reported in Mexico. The purpose of the present work was to evaluate the effect of a Mexican variety of J. curcas protein concentrate (JCP) on weight gain, biochemical parameters, and the expression of genes and proteins involved in insulin signaling, lipogenesis, cholesterol and protein synthesis in rats. The results demonstrated that short-term consumption of JCP increased serum glucose, insulin, triglycerides and cholesterol levels as well as the expression of transcription factors involved in lipogenesis and cholesterol synthesis (SREBP-1 and LXRα). Moreover, there was an increase in insulin signaling mediated by Akt phosphorylation and mTOR. JCP also increased PKCα protein abundance and the activation of downstream signaling pathway targets such as the AP1 and NF-κB transcription factors typically activated by phorbol esters. These results suggested that phorbol esters are present in JCP, and that they could be involved in the activation of PKC which may be responsible for the high insulin secretion and consequently the activation of insulin-dependent pathways. Our data suggest that this Mexican Jatropha variety contains toxic compounds that produce negative metabolic effects which require caution when using in the applications of Jatropha-based products in medicine and nutrition.

Sequentially Integrated Optimization of the Conditions to Obtain a High-Protein and Low-Antinutritional Factors Protein Isolate from Edible Jatropha curcas Seed Cake.

Jatropha curcas seed cake is a protein-rich byproduct of oil extraction which could be used to produce protein isolates. The purpose of this study was the optimization of the protein isolation process from the seed cake of an edible provenance of J. curcas by an alkaline extraction followed by isoelectric precipitation method via a sequentially integrated optimization approach. The influence of four different factors (solubilization pH, extraction temperature, NaCl addition, and precipitation pH) on the protein and antinutritional compounds content of the isolate was evaluated. The estimated optimal conditions were an extraction temperature of 20°C, a precipitation pH of 4, and an amount of NaCl in the extraction solution of 0.6 M for a predicted protein content of 93.3%. Under these conditions, it was possible to obtain experimentally a protein isolate with 93.21% of proteins, 316.5 mg 100 g(-1) of total phenolics, 2891.84 mg 100 g(-1) of phytates and 168 mg 100 g(-1) of saponins. The protein content of the this isolate was higher than the content reported by other authors.