Exploring the Phytochemical Composition and the Bioactive Properties of Malbec and Torrontés Wine Pomaces from the Calchaquíes Valleys (Argentina) for Their Sustainable Exploitation

Hydroalcoholic extracts from Malbec and Torrontés wine pomaces (Vitis vinifera L.) originating from the high-altitude vineyards of Argentina's Calchaquí Valleys were characterized. Total phenolics, hydroxycinnamic acids, orthodiphenols, anthocyanins, non-flavonoid phenolics, total flavonoids, flavones/flavonols, flavanones/dihydroflavonols, and tannins were quantified through spectrophotometric methods, with the Malbec extract exhibiting higher concentrations in most of phytochemical groups when compared to Torrontés. HPLC-DAD identified more than 30 phenolic compounds in both extracts. Malbec displayed superior antiradical activity (ABTS cation, nitric oxide, and superoxide anion radicals), reduction power (iron, copper, and phosphomolybdenum), hypochlorite scavenging, and iron chelating ability compared to Torrontés. The cytotoxicity assessments revealed that Torrontés affected the viability of HT29-MTX and Caco-2 colon cancer cells by 70% and 50%, respectively, at the highest tested concentration (1 mg/mL). At the same time, both extracts did not demonstrate acute toxicity in Artemia salina or in red blood cell assays at 500 µg/mL. Both extracts inhibited the lipoxygenase enzyme (IC50: 154.7 and 784.7 µg/mL for Malbec and Torrontés), with Malbec also reducing the tyrosinase activity (IC50: 89.9 µg/mL), and neither inhibited the xanthine oxidase. The substantial phenolic content and diverse biological activities in the Calchaquí Valleys' pomaces underline their potentialities to be valorized for pharmaceutical, cosmetic, and food industries.

Study on the Effect of Climate Changes on the Composition and Quality Parameters of Virgin Olive Oil "Zalmati" Harvested at Three Consecutive Crop Seasons: Chemometric Discrimination

Trees of the olive (Olea europaea L.) cultivar Zalmati grown in Zarzis (Mednine) with different main climate traits (temperature, precipitation, humidity, and wind) were studied for 3 years to evaluate the impact of climate on the quality of olive oil. The effect on quality indices, free fatty acids, peroxide value, UV spectrophotometry, pigment content, and phenol and O-diphenol concentrations, of the three harvesting periods was considered. Linking to the purity parameters (fatty acid, triacylglycerol, total phenols, and tocopherols composition), our results showed a trivial reduction in fatty acid composition and polyphenols content caused by the high temperature. In fact, precipitation strongly affects the pigment content, which showed a significant decrease during rainy seasons. Nevertheless, principal component analysis allowed us to highlight the correlation between parameters and indicates that 57.8% of the variation of monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), MUFA/PUFA, α-tocopherol, C 18:1, and C 18:2 amounts was explained by the mean temperature.

Chemometric Analysis and Physicochemical Composition of Foreign and Tunisian Olive Oil: Consumer Preferences

This research was conducted to evaluate consumer preferences of seven extra virgin olive oils (EVOOs) from foreign and Tunisian cultivars. Two studies were carried out. The first is a comparative physicochemical characterization of the VOOs tasted by the consumers. The second is a consumer survey where each consumer tasted each VOO six times. Using simple linear regressions, we have performed a new method that gives a pairwise comparison between the oils. It revealed that Coratina and Chetoui cultivars were the most preferred revealing by the high concentration of polyphenols with 468 and 525 ppm, respectively, and Arbequina was the less preferred with 182 ppm. We have then performed a principal component analysis on the data composed by the physicochemical parameters that highly discriminate between cultivars. The latter showed important differences between the most and the less preferred oils and that oxidative stability, palmitic, palmitoleic, oleic, and linoleic fatty acids, triacylglycerol, β-carotene, and polyphenols seem to be the principal-choice drivers for consumers.

Production of biologically active hydroxytyrosol rich extract via catalytic conversion of tyrosol

An effective and economical process was established to produce hydroxytyrosol, a naturally occurring orthodiphenolic antioxidant molecule found in olive oil from its monophenolic precursor tyrosol. The approach proposed in the present work presents an environment-friendly method based on wet hydrogen peroxide catalytic oxidation with montmorillonite KSF as an inexpensive and environmentally benign solid acid at room temperature. The influence of the principal operating parameters including concentration of tyrosol, H₂O₂, and catalyst used were studied. The antioxidant activity was realized by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. High antioxidant activity was detected according to the high hydroxytyrosol production (IC₅₀ = 0.7 μg mL⁻¹). The bactericidal and fungicidal properties of hydroxytyrosol rich extract were investigated using the NCCLS broth dilution and EN 1276 standard methods. Positive bactericidal and fungicidal effects of concentrations ranging between 1–0.5 g L⁻¹ and 4–2 g L⁻¹ were obtained.

An effective and economical process was established to produce hydroxytyrosol, a natural antioxidant molecule.