1. giới thiệu Resveratrol has been studied intensively in recent decades as one of the major stilbene derivatives [1,2]. It is believed that this substance bears responsibility for the French paradox connected with wine consumption [3,4]. In addition to resveratrol, the stilbene derivative family encompasses such other biologically active compounds as viniferins [5], piceid [6], pinosylvin [7] and pterostilbene [8], to mention just the most important ones [9]. Wine production and viticulture technology produce four types of waste plant material: grape canes, leaves [10], grape marc and young lateral shoots. According to the literature, stilbenes contained in waste material from wine production are good sources of these substances for the pharmaceutical, cosmetic, and food industries [11]. In order to maximize yields of these compounds from viticulture and wine production byproducts, development of improved methods is required. It is known from the literature that some of the best solvents for stilbene extraction are alcohols (methanol or ethanol) from the protic group [11]. We studied extraction mainly using methanol as a protic solvent because of its physical properties, and we compared its extraction power with acetone as an aprotic solvent. In some cases we performed additional extraction steps to improve yields, because it has been observed, for example, that from the first extraction of stilbenes from grape cane only approximately 40% of total stilbenes were obtained, while the total yield of stilbenes from the first through fourth extractions was around 95% [12]. Our work focused on studying and comparing various methods of extracting stilbenes from grape canes, including maceration at laboratory temperature, higher temperature extraction, fluidized-bed extraction, Soxhlet extraction, microwave-assisted extraction, and accelerated solvent extraction.
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