Composition and Biological Properties of Blanched Skin and Blanch Water Belonging to Three Sicilian Almond Cultivars

The almond industry produces, by bleaching and stripping, two by-products: blanched skin (BS) and blanch water (BW). The aim of this study was to investigate the nutritional and polyphenolic profile, as well as the antioxidant, antimicrobial, antiviral, and potential prebiotic effects of BS and BW from three different Sicilian cultivars. The total phenols and flavonoids contents were >= 1.72 and >= 0.56 g gallic acid equivalents and >= 0.52 and >= 0.18 g rutin equivalents/100 g dry extract (DE) in BS and BW, respectively. The antioxidant activity, evaluated by 2,2-diphenyl-1-picrylhydrazyl scavenging ability, trolox equivalent antioxidant capacity, ferric-reducing antioxidant power, and oxygen radical absorbance capacity, was >= 3.07 and >= 0.83 g trolox equivalent/100 g DE in BS and BW, respectively. Isorhamnetin-3-O-glucoside was the most abundant flavonoid detected in both by-products. No antimicrobial effect was recorded, whereas BS samples exerted antiviral activity against herpes simplex virus 1 (EC50 160.96 mu g/mL). BS also showed high fibre (>= 52.67%) and protein (>= 10.99) contents and low fat (<= 15.35%) and sugars (<= 5.55%), making it nutritionally interesting. The present study proved that the cultivar is not a discriminating factor in determining the chemical and biological properties of BS and BW.

Automated summary

This study investigated the nutritional and polyphenolic profile, as well as the antioxidant, antimicrobial, antiviral, and potential prebiotic effects of blanched almond skin (BS) and blanch water (BW) from three different Sicilian cultivars. The results showed that the total phenols and flavonoids contents were high in BS and BW. BS exhibited antiviral activity against herpes simplex virus 1. It also had high fiber and protein contents and low fat and sugar contents, making it nutritionally valuable. The study indicated that cultivar does not significantly affect the chemical and biological properties of BS and BW.