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

Abstract

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 μg/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.

Pharmacognostic Evaluation of Monarda didyma L. Growing in Trentino (Northern Italy) for Cosmeceutical Applications

“…Total phenols were quantified according to Ingegneri et al [ 65 ]. Briefly, 10 µL of EE and HGE (12.5–100 mg/mL and 5.0–40 mg/mL for EE and HGE, respectively) was added to 90 µL of deionized water and Folin–Ciocalteu reagent (100 µL).…”

“…The FRAP assay was carried out according to Ingegneri et al [ 65 ]. Briefly, 10 µL of EE and HGE (1.0–8.0 mg/mL and 50–400 µg/mL, respectively) was added to 200 µL of fresh, pre-warmed (37 °C) working reagent consisting of 300 mM buffer acetate (pH 3.6), 10 mM 2,4,6-Tris(2-pyridyl)-s-triazine dissolved in 40 mM hydrochloric acid, and 20 mM ferric chloride, and incubated for 4 min at RT in the dark.…”

“…The DPPH assay was carried out according to Ingegneri et al [ 65 ]. Briefly, 3.75 µL of EE and HGE (1.0–8.0 mg/mL and 0.25–2.0 mg/mL, respectively) was added to 150 µL fresh 2.50 mg/mL DPPH methanol solution, mixed, and incubated in the dark for 20 min.…”

“…The TEAC assay was carried out according to Ingegneri et al [ 65 ]. The radical reagent was prepared by mixing 1.7 mM ABTS with 4.3 mM potassium persulfate, and incubated in the dark for 12 hrs.…”

Antioxidant Activity of a Sicilian Almond Skin Extract Using In Vitro and In Vivo Models

“…These effects encompass anti-inflammatory, antioxidant, antiangiogenic, antimicrobial, and antiproliferative actions. Recently, we assessed the composition and biological properties of blanched skin and blanch water, which are by-products originating from industrial blanching that were obtained from different Sicilian almond cultivars [21]. Almonds and almond skins are abundant in bioactive molecules, particularly polyphenols, flavonoids, tocopherols, tannins, fibers, minerals, amino acids, and fatty acids [22][23][24][25][26].…”