Physicochemical characteristics of beer with rice nuruk

Abstract

Beer production with rice or other malt substitutes suffers from a lack of suitable enzymes for saccharification. For this reason, rice nuruk (fermentation starter) was tested as a starch replacement for malt in the saccharification process of beer production. The results of this study show that the enzyme activities of rice nuruk made with brewing fungi were higher than those of malt. Saccharification and glucoamylase activities were high in Aspergillus awamori KCCM 30790 and α-amylase activity was high in Aspergillus oryzae CF1003. Overall, malt beer had significantly higher alcohol, pH, total acid, volatile acids, amino acids, free amino nitrogen, bitterness unit and ΔE than rice nuruk beer. Where as Aspergillus awamori KCCM 30790 beer had significantly higher soluble solids, reducing sugar than malt beer. According to a sensory evaluation, malt beer was better color, flavor and Aspergillus oryzae CF1003 beer was better taste, texture, overall acceptability than other beer. Therefore Aspergillus awamori KCCM 30790 beer was suitable considering enzyme activities (saccharification, glucoalmylase) and physicochemical characteristics (soluble solids, reducing sugar). And then Aspergillus oryzae CF1003 beer was suitable considering sensory evaluation (taste, texture, overall acceptability). Therefore rice nuruk like Aspergillus awamori KCCM 30790 and Aspergillus oryzae CF1003 were suitable as a substitute material that can replace for malt in beer proceccing.

Identifying sensory attributes of Korean rice wine (makgeolli) using sensory evaluation and chemical analysis

“…From the scientific literature, researchers have observed rice (Chen et al, 2020) and fermentation culture (nuruk) significantly impact the flavor and volatile compounds produced in rice wine Kang et al, 2020;Shin et al, 2017). Esters tend to be the most abundant volatile compound found in different rice wines including Hong Qu glutinous rice wine (Chinese rice wine) (Liu et al, 2022), sake (Japanese rice wine) (Kang et al, 2016), and makgeolli (Jung et al, 2014;Park et al, 2014).…”