Syrah Grape Skin Residues Has Potential as Source of Antioxidant and Anti-Microbial Bioactive Compounds

Abstract

In this study, we evaluated the effects of ultrasound-assisted extraction (UAE) under different time-temperature conditions on the content of bioactive compounds, antioxidant and antimicrobial activities of Syrah grape skin residue. The application of UAE showed a positive effect on the extraction of total flavonoids, and a negative effect on total polyphenols. The temperature of 40 °C and 60 °C without the UAE caused an increase of 260% and 287% of the total polyphenols, respectively. Nineteen individually bioactive compounds were quantified. The anthocyanin concentration (malvidin-3,5-di-O-glucoside 118.8–324.5 mg/100 g) showed high variation, to a lesser extent for phenolic acids, flavonoids, flavonols, procyanidins and stilbenes due to the UAE process. The Syrah grape skin residue has a high concentration of total phenolic compounds of 196–733.7 mg·GAE/100 g and a total flavonoid content of 9.8–40.0 mg·QE/100 g. The results of free radical scavenging activity (16.0–48.7 mg/100 mL, as EC50) and its inhibition of microbial growth (0.16 mg/mL, as EC50 for S. aureus, and 0.04 mg/mL, as EC50 for E. coli) by grape skin extract (UAE 40:20) indicate high antioxidant and antibacterial activity. It was concluded that the use of ultrasound needs further analysis for its application in this context, as it has shown deleterious effects on some compounds of interest. Syrah grape skin residue has potential as a source of bioactive antioxidants, antimicrobial activity and for use as a functional food ingredient.

Extraction of Antioxidant Compounds from Brazilian Green Propolis Using Ultrasound-Assisted Associated with Low- and High-Pressure Extraction Methods

“…The UESC sample presented flavonoid concentration 1.7 times higher than its control (ESC). The authors De Andrade et al [24] indicate that the pretreatment of grape skin samples with ultrasound improves the yield of FT. This can be justified because the ultrasound waves stimulate the formation of small bubbles subjected to rapid compression and expansion, causing rapid local increase in temperature and pressure, which facilitates the solubilization of compounds present in the matrix [26].…”

“…Efforts have been made to improve conventional methods, applying alternatives that improve the yield and reduce the time and costs of the extraction step [24,25]. One alternative is the increasingly common use of sonication as a pretreatment in extraction processes of bioactive compounds in plant matrices [26,27].…”

Unveiling the Bioactive Potential of Fresh Fruit and Vegetable Waste in Human Health from a Consumer Perspective

“…Studies have proved that these health-promoting compounds are highly accumulated in the skin, seeds, stems, and leaves of grapes [94,171]. Several studies have identified various phenolic compounds in grape skins, including phenolic acids, stilbenes, flavanols, flavonols, and anthocyanins [91,95,98], namely malvidin-3,5-di-O-glucoside and the flavonol quercetin-β-D-glucoside [172]. Regarding the nutritional value of grape pomace, it can be observed that red grape varieties are rich in dietary fibers, consisting mainly of lignin, cellulose, and hemicellulose [93].…”

Short Review on Bioactive Compounds Recovered From Vegetal Waste as a New Tool in Diabetes, Obesity and Dyslipidaemia Prevention and Treatment

“…An alternative to reduce the amount of unexploited waste with a negative impact on the environment is represented by their valorisation through green extraction, isolation and purification of bioactive compounds in order to obtain added value products, useful in the prevention and treatment of various maladies. Numerous studies have shown that vegetable waste is an important and low-cost source of primary and secondary metabolites with medicinal and nutritional value, such as phenolic compounds (phenolic acids [20,38,67,76], flavonoids [14,18,20,22,23,34,42,56,65,71,74], anthocyanins [20,21,35,57,71], vitamins (vitamin A [25], vitamin E [21], vitamin D [25], vitamin C [21,25,65,74], amino acids [25], alkaloids [11,18], glucosinolates [23], fatty acids [21], poly-saccharides [55], terpenes [14,38,57,74].…”