The objective of the research was to determine the impact of substituting 30-40 % of malt by nonmalted grain of naked fodder barley of Rastik cultivar, as well as the impact of the addition of Ceremix 2XL enzymatic preparation on the content of some selected protein compounds contained in brewing worts. The materials used in this study were barley malt of the Pilzen type and naked barley grain of Rastik cultivar. The non-malted raw material, its amount being 10 %, 20 %, 30 %, or 40 % of the charge, was gelatinized at a temperature of 90°C during a 10 minute period; the ratio between grain and water was 1:5. The process was conducted in three variants: gelatinizing of non-malted raw material without additives, with 5 %, or with 10 % of malt added. The mass gelatinized was mixed with malt at a temperature of 45°C. Next, it was mashed using a laboratory (congress) method. In the process variants when the gelatinization was performed with no malt added, the mashing process was performed using two methods: without the Ceremix 2XL enzymatic preparation or with this preparation added, its dose being 1.8 kg per one tonne of grain. A comparative sample was wort produced from malt only. Next, the barley grain, malt, and laboratory worts were assessed. The following parameters were determined by a Kjeldahl method: protein content in malt and in barley grain, and total nitrogen content in worts. The content of α amino acid nitrogen in worts was determined using a ninhydrin method. Furthermore, the Kolbach index was calculated. The entire determination procedure was three times repeated. It was found that when 10-40 % of malt was substituted by the non-malted naked barley grain of Rastik cultivar (regardless of the method used to gelatinize it), the product showed deficiency of the total soluble nitrogen and of free amino in worts. The application of Ceremix 2XL enzymatic preparation to the process of mashing the malt and non-malted barley grain mixture, gelatinized without the addition of malt, was the most effective way to ensure the sufficient quantity of protein hydrolysis products in worts.
naked barley grain, non-malted raw material, malt, wort, protein compounds, enzymatic preparation