The main objective of the research was to determine qualitative changes in strawberry nectars enriched with high methoxyl pectin preparations and stored for 4 months at 4 ºC and 20 ºC. In the nectars investigated, contents of total polyphenols, vitamin C (ascorbic acid), and anthocyanins were determined. Furthermore, half-life of anthocyanins and antioxidant activity were assayed, as were contents of total sugars, directly reducing sugars, and saccharose; also, the colour parameters using a CIE Lab system were measured. Directly after the production, the highest content of polyphenols and ascorbic acid were found in the control sample of nectar: 81.6 mg / 100 ml and 6.12 mg / 100 ml, respectively. As regards the content of anthocyanins and total antioxidant activity, their highest values were reported in the nectar with high methoxyl pectin preparations added: 13.9 mg /100 ml and 4.73 μ mol Trolox /ml, respectively. Additionally, the analyzed colour parameters: L *, a*, and b* were the highest in nectars with the addition of pectin preparation. After the 4-month storage, a statistically significant decrease in all the parameters investigated was found. It was proved that the values of the parameters analyzed remained at better levels in samples stored at 4ºC compared to samples stored at 20 °C. At the same time, no statistically significant and positive impact was found of the addition of pectin preparations on the qualitative parameters of the nectars studied.
strawberry, nectar, pectin, qualitative parameters, storage