Some Chemical Characteristics and Oxidative Stability of Cold Pressed Grape Seed Oils Obtained from Different Winery Waste

Abstract

Various grape seed samples collected in wineries, as a by-product before and after the fermentation process of pomace and after fermentation and distillation process of pomace, are used for oil extraction by cold pressing. Fatty acid profile, content and composition of tocopherols, content and composition of phenols, as well as the oxidative stability of oils are investigated. Obtained results show that cold pressed grape seed oils are characterized by different nutritional quality and oxidative stability, due to peculiar effects of the fermentation and distillation processes. Cold pressed oil obtained from cleaned and dried seeds of grapes after fermentation and/or distillation process is richer in bioactive compounds compared to the oil obtained from grape seeds without fermentation. On the other hand, the high temperature in distillation process of pomace has a negative effect on the content of some bioactive compounds and oxidative stability of oil from this waste material. Practical Applications: In this paper, different cold pressed grape seed oils are analyzed for nutritionally important compounds and oxidative stability. The results show that, depending on the source of grape seeds as waste material, the nutritional quality of the obtained oils differs. In the production of high quality cold pressed grape seed oil, seeds from different sources of waste should not be mixed. It is not recommended to use the seeds from the waste material after distillation process in the production of high quality cold pressed grape seed oil. Some chemical characteristics of cold pressed grape seed oils obtained from different winery waste are analyzed. The different waste materials have a pronounced effect on the quali-quantitative profiles of bioactive compounds and induction period of oils. Obtained results show that cold pressed grape seed oils are characterized by different nutritional quality and oxidative stability, due to peculiar effect of fermentation and distillation processes. For production of high quality cold pressed oil, seeds from different winery waste material should not be mixed.