Sorghum and pearl millet are grain crops that can grow in semi-arid climates, with nutritional and bioactive properties superior to those of major cereals such as rice, wheat, and maize. However, these properties vary a lot, depending on the genetic factors, growing conditions, and place of cultivation. Four sorghum and two pearl millet grains cultivars grown in the Far-North region of Cameroon were screened for their chemical composition and antioxidant profile. The proximate and mineral analyses were performed using AOAC standard methods. The antioxidant profile was assayed spectrophotometrically and details on the phenolic compounds were investigated using HPLC. The pearl millet cultivars, especially mouri, showed higher contents of proteins, lipids, ash, calcium, copper, iron, and zinc. The red sorghum specifically exhibited the greatest amounts of total polyphenols (82.22 mg GAE/g DE), total flavonoids (23.82 mg CE/g DE), and total 3-deoxyanthocyanidin (9.06 mg/g DE). The most abundant phenolic compound was gallic acid, while the most frequent were chlorogenic and ferulic acids. The maximum antioxidant activity against DPPH was observed in yellow-pale sorghum (87.71%), followed by red sorghum (81.15%). Among the studied varieties of cereals, mouri pearl millet and red sorghum were the best sources of nutrients and bioactive compounds, respectively. Their consumption should be encouraged to tackle nutrient deficiencies and non-communicable diseases within local populations.

This study aimed to use eggplant peels as a potential source of anthocyanins with biological activities. Two different extraction methods were tested in order to obtain extracts with a high anthocyanin content. The selected methods were the solid–liquid extraction (SLE) and ultrasound-assisted extraction (UAE) methods. For each method, two concentrations of ethanol (EtOH) were used, while varying the extraction time and temperature. Based on the results, the extracts obtained by SLE using EtOH 96% after 30 min of extraction at 50 °C showed the highest anthocyanin concentration. The UAE allowed the best results with EtOH 96% after 30 min at 25 °C. Both selected extracts showed similar chromatographic profiles, with delphinidin 3-O-rutinoside as the major anthocyanin, but in a higher concentration in UAE. The extracts also presented inhibitory activity against lipoxygenase (LOX), lipase, and α-amylase, thus suggesting a possible involvement in reducing the risk of various disorders. The first order kinetic model was used to predict the changes that can occur in the anthocyanin content and antioxidant activity from the eggplant peel extract. The calculated kinetic and thermodynamic parameters confirm the irreversible degradation of phytochemicals.

(1) Background: This study is designed to extract the bioactive compounds from beetroot peel for future use in the food industry. (2) Methods: Spectrophotometry techniques analyzed the effect of conventional solvent extraction on betalains and polyphenolic compounds from beetroot peels. Several treatments by varying for factors (ethanol and citric acid concentration, temperature, and time) were applied to the beetroot peel samples. A Central Composite Design (CCD) has been used to investigate the effect of the extraction parameters on the extraction steps and optimize the betalains and total polyphenols extraction from beetroot. A quadratic model was suggested for all the parameters analyzed and used. (3) Results: The maximum and minimum variables investigated in the experimental plan in the coded form are citric acid concentration (0.10–1.5%), ethanol concentration (10–50%), operating temperature (20–60 °C), and extraction time (15–50 min). The experimental design revealed variation in betalain content ranging from 0.29 to 1.44 mg/g DW, and the yield of polyphenolic varied from 1.64 to 2.74 mg/g DW. The optimized conditions for the maximum recovery of betalains and phenols were citric acid concentration 1.5%, ethanol concentration 50%, temperature 52.52 °C, and extraction time 49.9 min. (4) Conclusions: Overall, it can be noted that the extraction process can be improved by adjusting operating variables in order to maximize the model responses.

Effects of partial (50%) and total replacement of wheat flour with black rice flour on the phytochemical, physico-chemical, sensorial, and textural properties of muffins were studied. Partial or total replacement of wheat flour with black rice flour in muffins improved their nutritional and antioxidative properties with a positive effect on microbiological and color stability during the storage period in accelerated conditions. The low gluten muffins had an anthocyanin content of 27.54 ± 2.22 mg cyanidin-3-glucoside (C3G)/100 g dry weight (DW), whereas the gluten free muffins had 46.11 ± 3.91 mg C3G/100 g DW, with significant antioxidant values. Retention of 60% and 64% for anthocyanins and 72% and 80% for antioxidant activity after baking was found. The fracturability and hardness scores increased with the addition of black rice flour, whereas firmness and chewiness increased for gluten free muffins. The confocal analysis revealed a tendency of glucidic components to aggregate, with gathers of small bunches of black rice starch granules comprising anthocyanin. The results allowed designing two new value added bakery products, low and free gluten muffins, with significant high amounts of bioactive compounds, suggesting the functional potential of black rice flour.

The objective of this study was to encapsulate anthocyanins from red onion skins into different biopolymeric matrices as a way to develop powders with multifunctional activities. Two different variants of powders were obtained using a combination of gelation and freeze-drying techniques and characterized by encapsulation efficiency, antioxidant activity, phytochemical content, and color. Stability during storage and the bioavailability of anthocyanins in the in vitro simulated digestion were also examined. Powder V2, with a higher concentration of polysaccharides than V1, allowed a better encapsulation efficiency (90.53 ± 0.29%) and good stability during storage. Both variants had a high content of phytochemicals and antioxidant activity. In vitro investigations proved that an increased polysaccharides concentration offers the best protection for anthocyanins. Thus, a controlled release of the anthocyanins in the intestinal medium was achieved. The powder with the highest encapsulation efficiency was added to crackers, followed by phytochemical characterization to assess its potential added value. The addition of the micro-particles improved the functional characteristics such as antioxidant activity, showing its suitability for the development of bakery products. The attained results may bring implicit benefits to consumers, who can benefit from improved bioactive concentrations in foodstuffs, with significant health benefits.

Peroxidase (POD) was extracted from Prunus domestica and partially purified by three methods: ammonium sulfate precipitation, hydrophobic interaction chromatography, and ion exchange chromatography, respectively. The selected procedure allowed a 26.33-fold purification, and the molecular mass estimated by SDS-PAGE was 58 kDa. The purified enzyme presented enzymatic activity toward guaiacol, pyrogallol, catechol, and showed no activity toward ferulic, caffeic, and p-coumaric acids. In terms of optimum parameters for activity, the pH was 6.5, whereas the temperature was 25°C. The enzyme exhibited high stability in the pH range of 5.0–7.0 and in the temperature range of 25–70°C. The most potent inhibitors of POD were L-cysteine and sodium metabisulfite. The thermal inactivation displayed a first-order kinetic model, with an activation energy of E_a 84.79 ± 2.2 kJ/mol. POD extracted from plums exhibited high stability at high-pressure treatment, maintaining over 50% of the initial activity even at 700 MPa.