Belemets T.O. Development of technology of sour-milk products with polyfunctional fillers of natural origin. – Qualification scientific work with manuscript copyright.
The dissertation on competition of a scientific degree of the candidate of technical sciences on a specialty 05.18.04 – technology of meat, dairy and hydrobiont products. – National University of Food Technologies, Ministry of Education and Science of Ukraine, Kyiv, 2021.
The dissertation is devoted to the improvement of technologies of milk - containing products by development and application of scientifically substantiated blending of vegetable oils.
In accordance with a number of experimental studies, the possibility of 50% replacement of the mass fraction of milk fat in milk products by a blend of natural vegetable oils has been determined.
A special mathematical program has been developed in the “MatLab” environment to optimize the fatty acid composition of a blend of vegetable oils. According to the results of mathematical calculations, the percentage of selected vegetable blend oils according to the recommended by nutritionists ratios of the three main groups of fatty acids, as 1: 1: 1 and fatty acids of the family ɷ – 6: ɷ – 3, as 6: 1 – should consist of: 36,62 % walnut oil, 33,96 % rapeseed oil and 29,42 % corn oil.
It is established that under the condition of replacement of 50 % of milk fat in the composition of milk-containing curd paste and milk-sour cream sauce, the ratio of fatty acids of the families ɷ – 6: ɷ – 3 - are within the norms recommended by nutritionists, namely: 6,1: 1 and 6,2: 1, respectively.
The choice of emulsifier of natural origin - yolk powder, for the development of effective emulsions based on blends is substantiated and the appropriate amount of its introduction is determined – 3 % (by weight of the blend). The rational ratio of components in the composition of the plant emulsion - aqueous phase: fat phase: emulsifier, as 21: 76: 3, has been experimentally established.
A mathematical model of the process of emulsion formation in the form of a two-dimensional polynomial of the second degree is developed, which illustrates the dependence of the size of fat balls of emulsions on the speed of rotation of the working body of the emulsifier and processing time. Rational technological parameters of obtaining vegetable emulsions are: 2500 rpm, for the duration of processing – 3… 3,5 min, which ensures the achievement of the average size of fat globules 1,6 ± 0,2 micrometers.
It was determined that in order to obtain an extract from dry stevia leaves, it is expedient to grind it to a particle size of 3,9 ± 0,1 mm of leaves, and to use a hydraulic module – 1:15. It is proved that the use of whey as an extractant allows to increase the degree of extraction of the target component from the dried leaves of stevia by 12,1 % compared with the use as an extractant – water. Technological parameters of stevia extract production are scientifically substantiated: temperature – 80 ± 5 ºС, for processing duration – 25… 30 min, for extraction of 3,1… 3,4 % of extractive substances. It is substantiated that the use of a rotary-pulse apparatus for obtaining an extract from stevia leaves allows to increase the degree of extraction of extractives from 0,1 to 0,4 %; rational technological parameters of stevia extract production using a rotary-pulse apparatus: temperature – 85 ± 5 ºС, with exposure – 20… 25 min, which provides the maximum amount of extraction of extractives - 3,4… 3,5 %.
Based on the research, a rational percentage of flavoring agents in milk products was determined: stevia extract – 0,25 %, sublimated sea buckthorn powder – 4 %, garlic mixture 0,2 % and green onion – 1 %.
The safety indicators of dairy products by acid and peroxide numbers have been studied. It was found that at the time of reaching the shelf life of the sample of milk-containing curd paste with sea buckthorn (14th day), the value of acid number was – 0,32 mgKOH/h, peroxide – 2,3 PN, mmol 1/2O/ kg. The values of peroxide and acid numbers of the sample of milk sour cream sauce with a composite mixture of garlic and onion (on the 21st day) were respectively: 2,2 mmol 1/2O/ kg and 0,3 mgKOH/h.
Key words: milk products, blend of vegetable oils, fatty acid composition, vegetable emulsions, yolk powder, stevia extract, freeze-dried sea buckthorn powder.
