Vibrations in engineering and technology

Pavlo Luts – Candidate of Technical Sciences, Senior Lecturer of Department of machines and equipment of agricultural production of Vinnytsia National Agrarian University (3, Soniachna St., Vinnitsa, Ukraine, 21008, e-mail: luts@vsau.vin.ua, https://orcid.org/0000-0002-3776-8940).

The article presents the results of a study of the storage processes of dry beer grains, which are used as valuable feed raw materials in animal husbandry. The relevance of the study is due to the need to reduce the share of grain components in the composition of compound feeds, as well as to increase the efficiency of using secondary resources in the brewing industry in the context of the development of a circular economy and resource conservation. It was established that the high humidity of native beer grains (up to 70-86 %) determines the need for its preliminary dehydration and drying to a level of 6-10 %, which ensures the stability of quality indicators during storage. Fermentation is considered as an alternative approach, which allows increasing the microbiological stability of the product.

Experimental studies were conducted on samples of dry beer grains, which were stored for three months under different temperature and humidity conditions. During the research, changes in humidity, acidity, hydrogen index (pH), as well as the level of microbial contamination were monitored. The patterns of influence of environmental parameters on the intensity of biochemical and microbiological processes have been established.

It has been proven that increased relative humidity of air (over 60 %) leads to secondary moistening of feed, which is accompanied by activation of microflora and deterioration of its quality. An increase in temperature above 30 °C intensifies the processes of acid accumulation, which indicates the development of spoilage. It has been established that the key factor of stable storage is the control of water activity (aw < 0.85), which limits the development of mold fungi and bacteria. Based on the results obtained, rational storage parameters have been substantiated: temperature not higher than 20 °C and relative humidity of air 40-50 %. The practical significance of the work lies in the possibility of using the obtained results in the development of feed storage technologies, optimization of feed resource logistics and increasing the efficiency of use of brewing by-products in animal husbandry.

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