بررسي اثر خصوصيات كيفي دو رقم گندم بومي ايران (كوه دشت و زاگرس) بر فرايند مالت سازي

Effect of malting on physico-chemical properties of two wheat varieties (Kohdasht, zaghros)

Malt is germinated cereal grain being rich in carbohydrates, proteins and B group vitamins and minerals. Malting is complex biotechnological process that includes steeping; germination and kilning of cereal grains under controlled conditions of temperature and humidity. In this study, two Wheat varieties (Kohdasht, Zagros) were obtained from Jahad-e-Agricultural organization of Golestan province. The preliminary assessment of samples such as viability and physico chemical properties were determined after two months storage. Malts were made from them in laboratory scale, mashed and then physicochemical properties of wort such as hot water extract, color, pH, Brix, reduced sugar, total solid nitrogen and free a-amino nitrogen were measured. Analysis of variance was performed with SAS and the differences among means were evaluated using the Duncanʹs multiple range tests. The results showed that during malting diastatic power and cold water extract improved and thousand kernel weight and protein content were decreased (P<0.05). The results also confirmed that there were linear relationship between nitrogen content (wheat), diastatic power, cold and hot water extract. Thousand kernel weight (40.78 gr) and cold water extract (20.77%) of malted wheat (Kohdast) was more than Zagros but ash (1.3%), diastatic power (179.91 °L) and total nitrogen (2.18%) of it was less (P<0.05). The results of physico-chemical properties of malted wheat showed that kohdasht variety had more hot water extract (67.154%), reduced sugars (64.192 g/L) and brix (8.25% w/w) but lower total soluble nitrogen (0.742%) and free amino nitrogen (98.585 mg/L) compared to Zagros (P<0.05).