Effect of dyes, produced from by-products of winemaking, on antioxidant and microbiological characteristics of boiled cream.

Boiled cream is a semi-finished pastry product. Adding different shades of colours to it ensures more aesthetically pleasing appearance of the product. A concentrate of natural anthocyanins, produced from by-products of grape processing, has antioxidant, anti-carcinogenic, antihistaminic and anti-inflammatory activity. The paper provides information about the effect of extracts produced from by-product of Georgian unexplored red grape varieties (Simonaseuli, Meskhuri Black, Gabasha, Sreluri, Saferavi) on semi-finished pastry products, more specifically on boiled cream. Dynamics of the antioxidant content change after adding the extract to the cream is observed and studied after 1 hour, as well as after 120 hours (5 days and nights). Ten samples of boiled cream (10g each) were taken in order to determine microbiological properties. Extracts of five grape varieties with 2 different concentrations were added to the samples and, additionally, a zero sample. The following microbiological characteristics were defined: mesophilic aerobic and facultative anaerobic microorganisms, bacteria of coli bacillus group, pathogenic microorganisms like Salmonella and Staphylococcus, number of B.cereus cells, yeast and mould. Each of the abovementioned characteristics were observed and determined for the duration of 5 days. This research is the proof that natural dyes are superior to synthetic ones. The reason for that is their ability to preserve phenols and flavonoids better than their synthetic analogue and to maintain antioxidant activity. Microbiological studies have shown that products, which are enriched with our natural extract, are prophylactics preventing free radical induced pathologies. According to the study, natural dyes with experimentally proven antioxidant properties can be recommended as mass consumption product. The facts make it possible to expand the range of competitive confectionery functionality, diversify colour shades of the cream, to improve its taste and aroma properties, enhance the nutritional value, and shelf life due to the large amount of antioxidants. Tab. 5, Fig. 5, Ref. 19.