No abstract

Whole wheat is an exceptional source of phenolic compounds representing a promising phytochemical class to prevent diet-related chronic diseases thanks to its antioxidant activities. The present work reports the phenolic profile, the antioxidant capacity, the antimicrobial activity and the effect on Lactobacillus brevis growth of eight whole flours obtained from four ancient and modern wheat genotypes of Italian Triticum genus. Total phenolic content (TPC) and total flavonoid content (TFC) were quantified, and antioxidant activities were assessed using oxygen radical absorbance capacity (ORAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) in vitro tests. HPLC-DAD/FLD was used to detect the presence of phenolic compounds. Moreover, antimicrobial activity of whole flour extracts against some potentially pathogenic Gram negative and Gram positive bacteria and the effect of extracts on Lactobacillus brevis growth were assessed. Results showed quantitative differences (p < 0.05) in antioxidant activities, total phenolic content and concentrations of five phenolic acids (resorcinol, tyrosol, caffeic acid, syringic acid and ferulic acid) among the wheat genotypes. Pathogenic bacteria were significantly negatively affected by wheat extracts while the growth of L. brevis was stimulated. The principal component analysis (PCA) confirmed that the phenolic profile and the antioxidant activities were influenced by the genotypic characteristics of studied varieties, suggesting that the ancient Saragolla stand out for the most interesting phenolic profile. Overall, this research emphasizes how ancient and modern Italian Triticum spp. grains must be investigated to select the grains richer in bioactive compounds. Graphical abstract

Seeds of Vitis vinifera L. with a high content of bioactive compounds are valuable by-products from grape processing. However, little is known about the bioactivity of seeds from other Vitis species. The aim of this study has been to compare the phenolic composition, antimicrobial activity, and antioxidant activity of extracts from seeds of four Vitis species (V. riparia Michx., V. californica Benth., V. amurensis Rupr., and V. vinifera L.). Antioxidant activities were assessed as ferric-reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) scavenging activity, and oxygen radical absorbance capacity (ORAC). The antimicrobial activity was determined using the microdilution method against some Gram-negative (Escherichia coli, Salmonella enterica ser. Typhimurium, and Enterobacter aerogenes) and Gram-positive (Enterococcus faecalis and Staphylococcus aureus) bacteria. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to evaluate the phenolic profile of extracts. Flavan-3-ols, procyanidins, phenolic acids, flavonols, anthocyanins, and stilbenoids were detected. (+)-Catechin and (−)-epicatechin turned out to be the most abundant in the phenolic profile of V. amurensis seed extract. Phenolic acids prevailed in the extract from V. vinifera seeds. The V. riparia and V. californica seed extracts had higher contents of most individual phenolics compared to the other Vitis species. They also showed a higher total phenolic content, DPPH• scavenging activity, ORAC, and overall antibacterial activity. Total phenolic content significantly correlated with antioxidant activity and antimicrobial activity against E. coli. The principal component analysis (PCA) showed discrimination between V. vinifera, V. amurensis, and clustered V. riparia and V. californica with respect to variables. To recapitulate, this research demonstrates that seeds of different Vitis species, especially V. riparia and V. californica, are sources of molecules with antioxidant and antimicrobial activities that can be used in different sectors, such as in the food, cosmetic, and pharmaceutical industries.