Formation of Frozen Blackcurrant Fruits Quality

Abstract

Aims: Fruits of a multivitamin culture of blackcurrant have a pronounced seasonality of consumption. The essence of the problem is in the scientific substantiation of the rational way of fruits freezing in order to preserve their quality.
 Place and Duration of Study: The research was conducted during four years in the conditions of the laboratory of the Department of Technology of Storage and Processing of Plant Products at Uman National University of Horticulture and the workshop for rapid freezing of Uman canning plant.
 Methodology: Prepared berries of the consumer degree of ripeness of Pilot Oleksandr Mamkin, Mynai Shmyriov, Novyna Prykarpattia, Biloruska solodka varieties in the string bags were frozen by slow (-20 to -22°С) and rapid (-30 to -32°С) methods, packed in paraffined boxes, polyethylene bags of 400–500 g by weight. Losses in fruit weight, content of ascorbic acid, dry soluble substances, sugars, acids, sugar-and-acid index were determined during and for 10 months of storage (-18°C).
 Results: True chemical composition of the fruits took into account losses of their weight. It radically changed the level of indicators. Weight losses of the fruits was lower by a third during fast freezing, however, the overall indicators did not differ significantly until the end of storage: 11.9–12.1% by slow method against 10.1–11.2% by rapid way. The highest losses in the fruits were during the first 3 months, during 4–5 months – their level was stabilized and somewhat increased to the end of storage. Advantages by fruits packing in polyethylene bags were as follows: losses were 6–7 times lower than by string bags and 4–5 times – in paraffined boxes. Advantages of rapid freezing were in 1.2–1.6 times lower losses of the components of chemical composition. Usually, the frozen fruits of Biloruska solodka variety were better than other varieties under favourable weather conditions, they were not inferior.

Physical and mechanical properties and quality indicators of cereal grain

“…Obtained values of physical and mechanical indicators of corn grain (Table 4) were within the limits given in the literature sources [15,18]. However, corn grain (Table 4) of PR39B58 variety had the shape of an elongated ellipse.…”

“…Obtained values of physical and mechanical indicators of barley (Table 3) were within the limits given in the literature sources [13][14][15]18]. Savchuk, 2005) [13 -15, 18].…”

Influence of freezing on changes in the structure of black currant fruits

“…Crystals grow between the cells of the epidermis. As the authors of [10][11][12] point out, the process is accompanied by an increase in osmotic pressure due to an increase in the concentration of salts soluble in the liquid, which in turn causes the migration of moisture from the cells. Further growth of crystals occurs due to the moisture contained in the cells.…”

Development of temperature regime of storage of frozen black currants

“…It has been shown [2] that with an increase in the freezing rate, the deformation and division of cells decreases. Freezing whole fruits, with an average speed the reason for the hardening of the structure of frozen cherries and cherries [10].…”