Production and Characterization of Cellulosic Pulp from Mango Agro-Industrial Waste and Potential Applications.

The growing demand for cellulosic pulp presents an opportunity to explore alternatives to this material, focusing on utilizing agro-industrial residues. Mango's tegument is a rich source of cellulose, making it a valuable raw material for manufacturing single-use articles or blends with biopolymers. In this sense, employing conventional alkaline and acid chemical treatments, the mango's tegument was treated to obtain cellulosic pulp. The teguments were subjected to treatment with alkaline solutions (2% and 4% NaOH w/v) at 80 °C for 1 or 2 h or with an acetic acid solution (1:1 or 1:2 CH3COOH:H2O2) at 60-70 °C for 1 or 2 h. After treatment, an evaluation was conducted to assess the yield, color, chemical analysis, and structural, thermal, and morphological properties. The alkali treatments produced cellulosic pulps with a light color with 37-42% yield and reduced hemicellulose content. The acid treatments produced orange-brown cellulosic pulp with 47-48% yield and higher hemicellulose content. The acid pulps were thermally more stable (maximum decomposition at 348-357 °C) than the alkali pulps (maximum decomposition at 316-321 °C). The crystallinity index demonstrated that both treatments increased the crystallinity of the cellulose pulps compared with the untreated tegument. The thermal stability of cellulosic pulp at the processing temperatures of disposable tableware (50-120 °C) revealed that plates, bowls, trays, and cups could be produced. Another potential application is as a component of blends with biopolymers to make straws or rigid food packaging (trays) with reinforced structures.

Bioactive Compounds in Extracts from the Agro-Industrial Waste of Mango.

Mango by-products are important sources of bioactive compounds generated by agro-industrial process. During mango processing, 35-60% of the fruit is discarded, in many cases without treatment, generating environmental problems and economic losses. These wastes are constituted by peels and seeds (tegument and kernel). The aim of this review was to describe the extraction, identification, and quantification of bioactive compounds, as well as their potential applications, published in the last ten years. The main bioactive compounds in mango by-products are polyphenols and carotenoids, among others. Polyphenols are known for their high antioxidant and antimicrobial activities. Carotenoids show provitamin A and antioxidant activity. Among the mango by-products, the kernel has been studied more than tegument and peels because of the proportion and composition. The kernel represents 45-85% of the seed. The main bioactive components reported for the kernel are gallic, caffeic, cinnamic, tannic, and chlorogenic acids; methyl and ethyl gallates; mangiferin, rutin, hesperidin, and gallotannins; and penta-O-galloyl-glucoside and rhamnetin-3-[6-2-butenoil-hexoside]. Meanwhile, gallic acid, ferulic acid, and catechin are reported for mango peel. Although most of the reports are at the laboratory level, they include potential applications in the fields of food, active packaging, oil and fat, and pharmaceutics. At the market level, two trends will stimulate the industrial production of bioactive compounds from mango by-products: the increasing demand for industrialized fruit products (that will increase the by-products) and the increase in the consumption of bioactive ingredients.

Comparison of nutritional properties and bioactive compounds between industrial and artisan fresh tortillas from maize landraces.

Consumers are seeking for native-traditional foods to improve their intake of both nutrients and health-promoting phytochemicals. This study was designed to evaluate the difference in content of nutrients and bioactive compounds from handmade tortillas elaborated by a small-scale artisan producer and tortillas sold by a large food retailer available to consumers. All tortillas were analyzed for chemical composition, dietary fiber, calcium and phytochemical content, antioxidant capacity, and phenolic acids profile. Chemical and nutritional variation in the tortillas was estimated using principal component analysis. Data showed that artisan tortillas made from blue and white maize landraces had significantly (p < 0.05) higher content of nutritional and bioactive compounds compared to those of the supermarket. Handmade blue maize tortillas (HBMT) had a high content of free phenolics content and the highest antioxidant capacity (DPPH and ABTS methods), which was around 1.7-2.1 fold higher than that of commercially produced white maize tortillas (CWMT). Total dietary fiber was higher in HBMT (15.7 ± 1.06 g/100 g) than in CWMT (11.6 ± 0.96 g/100 g). CWMT had the lowest calcium content (42.1 ± 0.9 mg/100 g) compared to handmade tortillas (155.5 ± 4.5 mg/100 g). HPLC results indicated the presence of ferulic, p-coumaric, caffeic, syringic and 4-hydroxybenzoic acids. Interestingly, handmade tortillas from blue maize had 4.5-fold ferulic acid content compared with commercially produced white maize tortillas, consequently it can be a good source of phenolic antioxidants, particularly ferulic acid. This study showed that artisan fresh tortillas had superior nutritional-nutraceutical properties compared to CWMT.

Postharvest application of pectic-oligosaccharides on quality attributes, activities of defense-related enzymes, and anthocyanin accumulation in strawberry.

BACKGROUND: The postharvest application of pectic-oligosaccharides (POS) as an elicitor to improve the postharvest shelf-life and nutritional quality by stimulating natural defense mechanisms in strawberries was studied. Strawberries (cv. Festival) were treated with POS (at 0, 2, 5, and 9 g L-1 ) and evaluated for firmness, weight loss, color, soluble solids, titratable acidity (TA), total phenolic and anthocyanin content, antioxidant capacity, decay, and some defense-related enzyme activity during storage at 2 ± 0.5 °C for 14 days. RESULTS: Treatment with POS significantly delayed (P < 0.05) strawberry decay, and reduced the water loss and softening of fruit during storage. Strawberries treated with POS showed a significant increase in total phenolic and anthocyanin content, and antioxidant capacity when compared with controls. Interestingly, POS induced higher activity of phenylalanine ammonia-lyase (PAL), chitinase, and ß-1,3-glucanase in strawberries. Compared to the control, the activity of enzymes was markedly increased in fruit treated with all tested POS concentrations, particularly chitinase, and ß-1,3-glucanase activities, but 5 and 9 g L-1 POS were the most effective treatments for maintaining the quality attributes and improving anthocyanin accumulation and antioxidant capacity of strawberries. CONCLUSION: These findings suggest that POS treatment could potentially be applied to maintain quality attributes, reduce decay, and further enrich the anthocyanin content and antioxidant capacity of strawberries during postharvest storage. The results also suggest that the positive effects of POS on strawberries could be associated with the rapid accumulation of chitinase and ß-1,3-glucanase activities, and the increase of PAL enzyme activity leading to the synthesis and accumulation of anthocyanins. © 2019 Society of Chemical Industry.