Хімічно-технологічна оцінка свіжих та заморожених плодів смородини червоної

Abstract

И.Д. Сазонова. Химико-технологическая оценка свежих и замороженных плодов смородины красной. Изучен ряд сортов смородины красной на пригодность ягод к замораживанию. В статье приведены результаты биохимических анализов свежих и замороженных плодов смородины красной, дана оценка качества замороженной разными способами продукции.

Irina Sazonova. Chemical-technological evaluation of fresh and frozen fruits red currant. The fruits of red currant, as well as many other berries are a natural source of vitamins. One of the methods allowing to conserve its fruits for a long time, is freezing. It is known that almost all the nutrients are conserved in the frozen berries. However when frozen the berries are subjected to crack, and when defrosted they may change the colour, consistency and taste. To exclude it you must comply with the technology of cold treatment of berries, as well as select cultivars with high chemical and technological parameters. For this purpose, several cultivars of red currant for suitability to freezing have been studied. The biochemical composition of fruits in fresh form, after freezing and storage has been evaluated. The experiment included 6 cultivars: President, Detvan, Leader, Yaroslavna, Konstantinovskaya, and White Fairy; and elite selection 43-45-1 of red currant bred by the Kokino base of the All-Russian Selection-Technology Institute of Horticulture and Plant Nursery. To study fresh berries they were selected in the optimum ripeness without pest and disease defects. After having examined the content of biochemical substances in fresh red currant berries, the fruits of these genotypes were frozen rapidly in a freezer at the temperature of -30ºC, followed by storage for 6 months at the temperature of -18 ºC. By studying the biochemical composition of fresh berries it was found that the highest content of soluble solids (SSs) – 10,6%, and reciprocally sugars in the fruit pulp (8,0%) were observed in the cultivar Konstantinovskaya. The cultivar Leader and the selection №43-45-1 proved to be close to this cultivar, where there was an accumulation of SSs at the level of 9,2% and 9,8% respectively. The cultivars Leader (1,63%) and Yaroslavna (1,70%) were isolated in accordance with the lowest accumulation of titratable acids in the fresh fruits. These parameters greatly influence the taste of the fruits. Thus, among the studied forms the cultivars Konstantinovskaya, Leader, Detvan and the selection №43-45-1 had the best tasting properties of the fresh berries. The cultivars Konstantinovskaya (77%), Yaroslavna (81%), and the selection №43-45-1 (88%) were isolated according to the accumulation of ascorbic acid. The cultivars Konstantinovskaya (5,5 N), Yaroslavna (7,2 N), and the selection №43-45-1 (7,3 N) had high strength of the fresh berries. After freezing and storage the biochemical composition of the berries changed slightly. In the fruits of the cultivars Leader and Yaroslavna there was an increase in the content of SSs to 9,5% and 9,0% respectively. On the presence of sugars in the frozen fruit pulps as well as in the fresh berries the cultivars Konstantinovskaya, Leader and the selection №43-45-1 were isolated. After defrosting the fruits the highest content of vitamin C was observed among those forms where the high accumulation of ascorbic acid in the fresh fruits (Konstantinovskaya, Yaroslavna, and the selection №43-45-1) had been noticed. While evaluating the quality of the frozen products according to the quantity of defective berries, including partly and fully discoloured ones as well as berries with cracked peels, there were isolated forms which had the least quantity of such berries. The cultivar Konstantinovskaya and the selection №43-45-1 turned out to be as such with the quantity of the defective berries of 81,5% and 96,3%. Their tasting score was 3,8 and 4,2 points respectively. In accordance with the standards of defects and valid standards for frozen products, the berries of the cultivar Konstantinovskaya were attributed to the higher grade, and the cultivar Yaroslavna and the selection №43-45-1 – to the second grade, and the rest – to the table grade. As a result of the researches, all the studied forms of red currant turned out to be suitable for conservation by rapid freezing. Wherein, a number of studied genotypes (Konstantinovskaya, Yaroslavna, and the selection №43-45-1) had slight changes in the composition of main quality parameters during prolonged storage, and the fruits remained virtually free of defects during defrosting.

Сазонова І.Д. Хімічно-технологічна оцінка свіжих та заморожених плодів смородини червоної. Вивчено ряд сортів смородини червоної на придатність ягід до заморожування. Наведено результати біохімічних аналізів свіжих і заморожених плодів смородини червоної, дано оцінку якості замороженої різними способами продукції.