Multi-Analysis Characterization of Makgeolli Made from the Novel Glutinous Rice Cultivar ‘Gureumchal’: Free Amino Acids, GC–MS Volatiles, and Electronic Tongue-Derived Flavor Profile

This study evaluated the suitability of a new glutinous rice cultivar of <i>Gureumchal</i> as a raw material for <i>Makgeolli</i>, a traditional Korean rice wine, by comparing <i>Makgeolli</i> produced from <i>Gureumchal</i> with those made from a non-glutinous rice and another glutinous rice cultivar. <i>Makgeolli</i> was prepared using single and blended rice combinations, and their physicochemical characteristics, amino acids, volatile aromatic compounds, and E-tongue were analyzed. The <i>Gureumchal</i> produced generally higher levels of total amino acids and ester compounds, particularly fruity esters, when compared with the other rice formulations. A volatile aromatic compound analysis indicated that non-glutinous rice favored the formation of acetate esters typically associated with the acetyl-CoA pathway, whereas <i>Gureumchal</i> produced higher levels of fruity acyl-CoA-derived esters, such as ethyl hexanoate and ethyl octanoate. An E-tongue analysis further demonstrated that rice type strongly shaped the <i>Makgeolli</i>'s taste profile: glutinous rice samples, including <i>Gureumchal</i>, exhibited higher sweetness but low umami, whereas non-glutinous rice produced higher acidity and umami. Blended samples confirmed that manipulating the proportion of glutinous and non-glutinous rice allows the systematic adjustment of taste balance. Overall, <i>Gureumchal</i> formed a distinct flavor profile characterized by fruity esters and pronounced sweetness, indicating its potential to diversify <i>Makgeolli</i> quality and support targeted flavor design.