ABSTRACT

The aim of the work was to determine the effect of sugar, pectin formulation, and L-ascorbic ad d on selected physico-chemical properties and organoleptic quality of frozen Węgierka Zwykła plums. Sugar at a dose of 10 g per 100 g of fruit in a loose form or as 60% syrup was used separately or with an addition of pectins or 0,5% L-ascorbic acid. A 1,5% solution of pectins at a dose of 10 g per 100 g of fruit was used separately or with an addition of 0,5% L-ascorbic acid. Plums were cut into halves, stoned, treated with an additives, placed in plastic containers, and frozen at -30°C. The temperature of -20°C at which frozen products were stored, was obtained after 90 min. The evaluation was carried out at the stage of row material and of frozen fruit directly after freezing and after 12-month storage. In the case of vitamin С and anthocyanins analyses were conducted at 3-month intervals. Fresh fruit contained 18,4% of dry weight, 11,3% of total sugars, 0,81% of acids as malic acid, 12,7 mg/100 g of vitamin C, and 17,9 mg/100 g o f anthocyanins. The addition of additives contributed to variability of frozen fruit with respect to the level of dry matter and sugars, and brought about a slight dilution of acids, vitamin C, and anthocyanins. Freezing did not significantly change the content of vitamin С and anthocyanins. On the other hand, one-year storage of the product frozen without the additives brought about a decrease in the content of vitamin С to 3,6 mg/100 g and of anthocyanins to 1,9 mg per 100 g of fruit. In the samples with the additives the respective values were 4,6-13,5 mg and 3,2-6,7 mg. After 12-month storage the organoleptic quality of frozen products without the antioxidants was 3,82 and of those with the antioxidants added 4,04-4,76 in a 5-score scale. From the analysed variants of additives used in freezing plums for dessert sugar syrup with an addition of L-ascorbic acid may be recommended on account of a good preservation of components, high organoleptic value, and also simple way of application. A solution of pectins with L-ascorbic acid can be used in preparing frozen fruit for people not tolerating sugar in their diet.