Stability in time of the alcoholic extracts obtained from seeds and skins of Vitis vinifera

Abstract

nformation about the stability in time of the concentrations of total poly-phenols and anthocians in the vegetal alcoholic extracts obtained from the seeds and skins of Vitis vinifera or other vegetal sources rich in these compounds is not present in the specialized literature. This aspect is very important since the vegetal alcoholic extracts represent either the raw material from which, by complex methods, they isolated pure active principles, or they are used as such in different pharmaceutical, cosmetic and food products due to the benefic effects on the human health. [3,5] Starting from these we want to study the stability in time of the total poly-phenols and anthocians from the alcoholic extracts obtained from the seeds and skins of Vitis vinifera. The degree of stability of the concentrations of total poly-phenols, anthocians and the index of tanoid matters (ITM) was appreciated by calculation to % the values obtained at To as compared to the ones determined at given time intervals. We did not notice a specific manifestation of the stability in time depending on the grapes breed used as a raw material for the obtaining of alcoholic extracts. The experiment revealed that the total poly-phenols are stable in the first 3 months, but at 6 months the percentage values of the concentrations decrease so that at 9 months the degree of decrease of concentrations frequently surpasses 50%. All the alcoholic extracts, a significantly better stability of anthocians as compared to the stability of poly-phenols registering percentage values very high of concentrations even after 9 months from the moment of obtaining the extracts.