The thesis is dedicated to scientific substantiation and improvement of the technology of quick-frozen fruit and berry half products due to the preliminary procession of the raw materials with cryoprotector solutions. This improved technology is alleged to be the one to obtain the quick-frozen half products practically identical to the natural raw.
It is the first time when the selection of raw materials, which are the best to freezing and obtaining the half products with enhanced biological and vitamin value, was scientifically substantiated. Besides, the set of methods of comparative organoleptic evaluation of fresh and frozen fruit-and-berry raw materials, which would allow forecasting objectively the quality of half products and to outline their storage terms, was proposed in this thesis for the first time. In particular, this work represents the firstly accomplished systematic research of the impact of 17 various cryoprotectors on 13 sorts of fruit and berries, which resulted in establishment of protectors’ positive action on cryogenous stability of plant objects during their freezing, long-term storage and defrosting. The most effective cryoprotectors were the mono- and combined ones, whose protection effect allowed retaining 85…90 % of ascorbic acid in various types of half products, meanwhile in the traditional freezing technologies this index does not exceed 30…35 %.
The scientific data about the main mechanisms of cryoprotectors’ impact, primarily obtained in the field of cryobiology, were proved in this work. Apart from the decrease of the amount of frozen water and lowering of its crystallization temperature, the moisture loss in defrosting was significantly minimized, which effects would provide as high qualitative and organoleptic indices of half products as those for fresh fruit and berries. The regression equation proposed in this work would allow predicting the vacillation of the amount of vitamin C in half products, whenever the researched factors are changed.
For practical realization of the results obtained, including satisfaction of the needs of population and the inquiries of restaurant business, the organizational, technological and economical measures to create the innovative enterprise to produce the quick-frozen fruit-and-berry half products were proposed.
There was defined the influence of the type of fruit and berry peels on the freezing process; in particular, the berries with dense peel (guelder and blackberries) showed the higher cryogenous resistance, which effect is accompanied by lower moisture loss in defrosting and therefore requires 30…35 percent less time to procession by cryoprotectors.
Theoretical researches on anthocyanins’ antioxidant activity with usage of the quant-and-chemical calculations gave the notion how their interactions with free radicals are going on and, from thence, how to avoid the free-radical processes. The technology proposed would result in the apparition of the product with increased biological value, with minimal losses of the essential biologically active components, like vitamins, and with the sensory indices retained. Due to the chill stress, the membranes of pathogenous microorganisms get destroyed, and this is beneficial for the half products’ microbiological purity.
The spheres of the usage of frozen half products in various branches of food technology are outlined; the recipes of an array of dishes and drinks are elaborated. There were also designed the projects of the technical conditions and technological instruction to produce the quick-frozen half products and calculated the economical effectiveness of the latter; their social effect, which is provision of Ukrainian population with high-vitamin foodstuffs, is elucidated.
