Phytochemical analysis and in vitro and in vivo evaluation of biological activities of artichoke (Cynara scolymus L.) floral stems: Towards the valorization of food by-products.

Artichoke floral stems (AFS) food waste by-products were examined for their phytochemical constituents and their in vitro and in vivo biological activities. Although that the highest total phenol content and total flavonoid content were found in ethyl acetate extract, methanol extract possessed the strongest DPPH and ABTS radical scavenging activity, and showed the highest reducing ferric antioxidant power (FRAP). The anti-acetylcholinesterase activity was higher in butanol extract, whereas the ethyl acetate extract had the highest inhibitory effect on heat-induced protein denaturation. In alloxan-induced diabetic mice, the AFS methanol extract (AFSE) rich in caffeoylquinic acids and flavones reduced blood glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, creatinine, and improved liver, and renal antioxidative status. Administration of AFSE to diabetic mice reduced total cholesterol, triglycerides, LDL-cholesterol, and the atherogenic index of plasma (AIP) suggesting its hypolipidemic action. Overall, AFS could be considered as attractive source of health-promoting ingredients.

Purification and Partial Characterization of Peroxidases from Three Food Waste By-Products: Broad Bean Pods, Pea Pods, and Artichoke Stems.

In this study, peroxidases (PODs) from three waste by-products: broad bean pods (BBP), pea pods (PP), and artichoke stems (ARS) were purified and their optimal conditions were determined for the first time. The purification process resulted in 4.32, 7.21, and 8.9% of POD recoveries for PP, ARS, and BBP, respectively. They were purified 2.12-, 32.97-, and 10-fold with specific activities of 27.26, 266.43, and 27 U/mg of protein, respectively. Analysis of their optimal conditions showed that POD purified from BBP and PP exhibited the highest activity at 60 °C temperature and pH 6 and 8 with strong affinity with catechol substrate (Km of 0.356 and 0.189 mM; Vmax of 0.08 and 0.041 µM/min for BBP and PP, respectively). The highest activity of ARS POD was obtained under the following conditions: temperature at 50 °C, pH from 6 to 8, and guaiacol as substrate (Km 0.375 mM; Vmax 0.012 µM/min). Apart from giving the opportunity for recycling the food industry wastes, the studied waste by-products could represent an alternative source of PODs that could find several applications in the biotechnological, chemical, and food industries.

Broad bean (Vicia faba L.) pods: a rich source of bioactive ingredients with antimicrobial, antioxidant, enzyme inhibitory, anti-diabetic and health-promoting properties.

This study was aimed at investigating the chemical composition (proximate, minerals, fatty acids and phenolic compounds) and the in vitro (antimicrobial, radical scavenging, anti-acetylcholinesterase and protein denaturing activities) and in vivo (anti-diabetic and histo-protective effects in alloxan-induced diabetic mice) biological activities of broad bean pods (BBPs), a food waste by-product material. The results showed that BBPs have high dietary fiber (57.46%), carbohydrate (18.93%) and protein (13.81%) content versus low fat content (<1%) contributing to a low energy value of 139.24 kcal per 100 g. Profiling of fatty acids showed an abundance of the essential polyunsaturated α-linolenic and linoleic acids, exhibiting an excellent nutritional quality as revealed by their low atherogenic and thrombogenic indices and their hypocholesterolemic properties. The methanol extract which exhibited the highest total phenolic, flavonoid and tannin contents was found to be the most active extract in terms of antimicrobial and anti-radical activities. In alloxan-induced diabetic mice, the oral administration of a methanol extract (500 mg per kg bw) attenuated the elevated levels of serum alanine aminotransferase (ALA), aspartate aminotransferase (AST), and alkaline phosphatase activities, and urea, uric acid, and creatinine. It effectively normalized the status of lipid profiles, mitigated oxidative stress through the activation of antioxidant enzymes (CAT, GPx and SOD), and alleviated oxidative stress-mediated histopathological changes in the pancreas, liver, kidney and testis. Compositional analysis by HPLC-PDA-ESI-MS/MS revealed the presence of flavan-3-ols (catechin, epicatechin and their derivatives), flavones (apigenin derivatives) and flavonols (glycosides of quercetin and kaempferol), among others. These findings suggest that BBPs may be an effective functional food for the management of diabetes and its complications.