# 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

## TL;DR

This study evaluates a new glutinous rice cultivar, Gureumchal, for making Makgeolli, finding it produces a sweeter, fruitier flavor profile compared to other rice types.

## Contribution

The study introduces Gureumchal as a novel rice cultivar for Makgeolli and identifies its unique flavor profile through multi-analysis techniques.

## Key findings

- Gureumchal rice produced higher levels of total amino acids and fruity esters in Makgeolli.
- Blending glutinous and non-glutinous rice allows systematic adjustment of Makgeolli's taste balance.
- Gureumchal-based Makgeolli showed higher sweetness and fruity esters compared to non-glutinous rice samples.

## Abstract

This study evaluated the suitability of a new glutinous rice cultivar of Gureumchal as a raw material for Makgeolli, a traditional Korean rice wine, by comparing Makgeolli produced from Gureumchal with those made from a non-glutinous rice and another glutinous rice cultivar. Makgeolli was prepared using single and blended rice combinations, and their physicochemical characteristics, amino acids, volatile aromatic compounds, and E-tongue were analyzed. The Gureumchal 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 Gureumchal 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 Makgeolli’s taste profile: glutinous rice samples, including Gureumchal, 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, Gureumchal formed a distinct flavor profile characterized by fruity esters and pronounced sweetness, indicating its potential to diversify Makgeolli quality and support targeted flavor design.