Sensory Properties of Baijiu

Baijiu is a famous spirit worldwide and is particularly popular in China. Baijiu can be classified into 12 categories based on their aroma characteristics: strong-, light-, sauce-, rice-, mixed-, sesame-, herb-like-, feng-, laobaigan-, chi-, te-, and fuyu-aroma baijiu. The strong-aroma baijiu is the most produced, with many different brands. Gas chromatography-olfactometry (GC-O) technology was first used to study the aroma and flavour of baijiu in 2005 by Qian and Fan at Oregon State University. Since then, the aromas of many different types of baijiu have been characterized by using the GC-O approach. The key aromas of 5 aroma types of baijiu were confirmed by GC-O analysis, odour activity value (OAV), recombination, and omission tests. There are many industry standards for evaluating baijiu, with detailed measurement methods and terminology, and different aroma types of baijiu have different evaluation standards. Some progress has also been made in understanding the synergistic effect of aroma compounds in baijiu. In general, esters with similar structures show a synergistic effect, alcohols show a masking effect, and aldehydes and ketones have a synergistic effect. Some aroma compounds also affect the mouthfeel of baijiu, such as bitterness, sour, and astringent. Further research on the sensory evaluation of baijiu is needed to develop more specific and objective protocols. Knowledge of the aroma and flavour of baijiu has provided a theoretical basis for the consistent production of consumer-preferred high-quality baijiu and helped the sustainable growth of the baijiu industry.