Evaluation of Sample Size Influence on Chemical Characterization and In Vitro Antioxidant Properties of Flours Obtained from Mushroom Stems Coproducts.

The mushroom industry generates large amounts of stem co-product. This is generated after mushroom harvest; stems are attached to the growth substratum, and their only use has traditionally been as compost. In this study, we investigated extensively for the first time this co-product and the influence of sample size (L->0.510 mm; LI-0.510-0.315 mm; SI-0.315-0.180 mm; S-<0.180 mm) on the characterization and antioxidant activity of flours obtained from stem co-products of Agaricus bisporus (ABSF) and Pleurotus ostreatus (POSF). ABSF was rich in protein (14 g/100 g), calcium (428.23-700.77 mg/100 g), and sorbitol (22.57-26.60 g/100 g), while POSF was rich in ß-glucans (36.62-40.34 g/100 g) and linoleic acid (20.57-39.86 g/100 g of lipid). Both species were flush in amino acids and had an umami flavour. ABSF showed more elevated values for emulsifying activity than POSF. The S sizes were highlighted for their yield, hydration properties, and oil holding capacity. Furthermore, ABSF-S exhibited heightened antioxidant capacity in vitro, in consonance with the total phenolic compounds observed (0.91 mg/g). However, the antioxidant assays in POSF presented a positive correlation with ß-glucan content. Our study suggests that these co-products could have several food-related applications, such as potential for use as an emulsifier, sweetener, or fortifier in the development of functional food, owing to their rich concentrations of fibre, protein, sorbitol, and ß-glucans. Nevertheless, it is necessary to understand the interactions of the flours with the potential food matrix prior to proceeding further with food-related applications.

Radical Scavenging and Cellular Antioxidant Activity of the Cocoa Shell Phenolic Compounds after Simulated Digestion.

The cocoa industry generates a considerable quantity of cocoa shell, a by-product with high levels of methylxanthines and phenolic compounds. Nevertheless, the digestion process can extensively modify these compounds' bioaccessibility, bioavailability, and bioactivity as a consequence of their transformation. Hence, this work's objective was to assess the influence of simulated gastrointestinal digestion on the concentration of phenolic compounds found in the cocoa shell flour (CSF) and the cocoa shell extract (CSE), as well as to investigate their radical scavenging capacity and antioxidant activity in both intestinal epithelial (IEC-6) and hepatic (HepG2) cells. The CSF and the CSE exhibited a high amount of methylxanthines (theobromine and caffeine) and phenolic compounds, mainly gallic acid and (+)-catechin, which persisted through the course of the simulated digestion. Gastrointestinal digestion increased the antioxidant capacity of the CSF and the CSE, which also displayed free radical scavenging capacity during the simulated digestion. Neither the CSF nor the CSE exhibited cytotoxicity in intestinal epithelial (IEC-6) or hepatic (HepG2) cells. Moreover, they effectively counteracted oxidative stress triggered by tert-butyl hydroperoxide (t-BHP) while preventing the decline of glutathione, thiol groups, superoxide dismutase, and catalase activities in both cell lines. Our study suggests that the cocoa shell may serve as a functional food ingredient for promoting health, owing to its rich concentration of antioxidant compounds that could support combating the cellular oxidative stress associated with chronic disease development.