Valorization of grape (Vitis vinifera) leaves for bioactive compounds: novel green extraction technologies and food-pharma applications

Abstract

Grape leaves, scientifically known as Vitis vinifera, the primary by-product obtained after the processing of grapes, are gathered in enormous amounts and disposed of as agricultural waste. For more sustainable agriculture and better food systems, it is crucial to investigate these byproducts’ nutritional values. The primary bioactive compounds present in grape leaves are quercetin, resveratrol, caffeic acid, kaempferol, and gallic acid, which favour pharmacological effects on human health such as antioxidant, anti-inflammatory, anti-obesity, anti-diabetic, and hepatoprotective. Furthermore, grape leaves extract has been used as a functional ingredient for creating both food and non-food products. The aim of the current review is to review the nutritional and phytochemical composition of various varieties of grape leaves, their health-promoting characteristics and their applications. The study also highlights the various extraction techniques including conventional and non-conventional methods for extracting the various bioactive compounds present in grape leaves. Grape leaves bioactives can be extracted using environmentally safe and sustainable processes, which are in line with the rising demand for eco-friendly and healthful products worldwide. These methods are perfectly suited to the changing needs of both customers and industries since they lessen environmental effect, enhance product quality, and offer financial advantages.

Grapevine and Horseradish Leaves as Natural, Sustainable Additives for Improvement of the Microbial, Sensory, and Antioxidant Properties of Traditionally Fermented Low-Salt Cucumbers

“…It is also well known that lactic acid bacteria can decompose quinic acid and malic acid, which may finally give them a metabolic predominance over other groups of microorganisms during the fermentation of plant raw materials [28][29][30]. Grapevine leaves are a rich source of bioactive compounds, including quercetin and resveratrol [20]. Quercitin has strong antimicrobial activity against both Gram-negative and Gram-positive bacteria; however, research indicates a low inhibitory effect in the case of microorganisms belonging to the Lactobacillus genus, which may result in a metabolic predominance of lactic acid bacteria in the microbial population in the presence of these compounds [31,32].…”

“…The benefits result from the presence of probiotic lactic acid bacteria that have a positive effect on gut health, as well as the presence of biologically active compounds, including antimicrobials (organic acids, bacteriocins). Additionally, during the fermentation process, the elimination of compounds toxic to human health, such as phytates and tannins, and the formation of beneficial catabolites may occur; as a result, the fermented products are classified as super-foods [18][19][20].…”

Gut Microbiota Modulators Based on Polyphenols Extracted from Winery By-Products and Their Applications in the Nutraceutical Industry

“…Studies have shown that the number of polyphenols in red grapevine leaves is similar to that in red grape seeds. The leaf extracts reveal antioxidant, antimicrobial, and antitumor activities [ 88 ]. The chemical composition of grape leaves significantly fluctuates according to the development stage, but variety, harvesting period, environmental factors, and soil properties also change the phytochemical profile of the leaves [ 89 ].…”

“…The chemical composition of grape leaves significantly fluctuates according to the development stage, but variety, harvesting period, environmental factors, and soil properties also change the phytochemical profile of the leaves [ 89 ]. Although this viticulture waste is less valorized, studies have constantly shown the high antioxidant activity of leaf extracts, which could be due to the synergistic action of various bioactive compounds from different classes (polyphenols, tocopherols, carotenoids, and phytosterols) [ 88 , 89 ]. In recent work on grapevine leaves from 11 different types of vine varieties grown under the same agronomical conditions and in the same soil, Banjanin et al, 2021, revealed that flavonoids, total phenols, and carotenoids are the main bioactive compounds [ 90 ].…”

“…Similarly, grape leaf ethanolic extract inhibits pathogenic biofilm formation. This activity is related to polyphenolic compounds that suppress the activity of the quorum-sensing system used for cell-to-cell communication [ 88 ]. An in vivo study on obese mice fed daily with leaf extract (400 mg/kg) suggested that the bioactive compounds from the extracts prevent obesity by suppressing neuropeptide-Y, which reduces food intake through bile acid mediation.…”