Antioxidant activity and storage regime of grape seeds fl akes a waste product in wine elaboration

RADKA ZAPRYANOVA VRANCHEVA, ATANAS IVANOV PAVLOV, ALBENA GEORGIEVA DURAKOVA, VELICHKA BORISOVA YANAKIEVA, KOLYO TENEV DINKOV, ADELINA LAZAROVA BOGOEVA

Abstract: The current scientifi c research is focused on the grape seeds – a waste product retrieved after alcoholic fermentation of wine, in the form of grape seeds fl akes. Recently, the grape residue has been considerated as a functional food product, a source of bioactive compounds (BAC) including antioxidants. The present study presents data about the antioxidant activity of grape seeds fl akes of different grape varieties of Bulgarian origin, analysed via four analytical methods differ in mechanism and reaction conditions, namely DPPH, ABTS, FRAP and CUPRAC. The obtained results were expressed as mM TE/g extract (842.50 ± 34.75; 959.63 ± 65.05; 94.73 ± 10.42 and 200.24 ± 48.60, respectively) and mM TE/g fl akes (as follows 141.40 ± 5.83; 161.06 ± 10.92; 94.89 ± 10.44 and 200.56 ± 48.68). The grape seeds fl akes were stored at room temperature – 25°С and relative air humidity of 75%. The storage regime was optimized to one month by means of packaging the product in a co-extruded barrier fi lm with copolymer covering for heat sealing. During the storage of grape seeds fl akes, analysis of their microbial load, granulometric composition and moisture content were performed.

Keywords: antioxidants; bioactive compounds; grape; grape seeds; grape seeds fl akes; winery by-products

Date published: 2019-04-09