Why is quinoa bitter? Researchers have found five key substances that cause bitterness

Recently, the reporter learned from the Institute of Hemp of the Chinese Academy of Agricultural Sciences that the functional factor utilization and biosynthesis team of the Institute, together with the Shanghai Academy of Agricultural Sciences, Inner Mongolia University, Shanxi University and other units, excavated and identified five key substances that determine the bitterness of quinoa. This study enriches the theoretical system of food bitterness substances and provides an important reference for the debittering of quinoa and the processing of low-bitter quinoa.

Yang Xiushi in a quinoa field. Photo courtesy of the interviewee

The research results were published online in Food Chemistry on April 11.

According to reports, quinoa is a kind of food crop native to the Andes region of South America, with comprehensive nutritional value, balanced proportion of essential amino acids, rich in polyphenols, flavonoids, polypeptides and other functional components, with the prevention and treatment of "three highs", obesity and other health effects, in the field of nutrition and health has a deep promotion and application value.

Quinoa ears. Photo courtesy of the interviewee

However, quinoa contains bitter substances that make it unacceptable in taste, limiting its use in the food industry. The saponins in quinoa are often thought to be the main cause of their bitter taste, but the key to determining bitterness is saponins. In addition to saponins, it is not clear whether there are other important bitter substances in quinoa.

Under the guidance of sensory evaluation, the researchers used solvent extraction and serial column chromatography to separate and purify the bitter components in quinoa, combined with liquid chromatography-mass spectrometry and nuclear magnetic resonance analysis, and identified five compounds with high content and low bitterness recognition threshold as the main bitter substances in quinoa. This study confirmed that triterpenoid saponins are important components that cause the bitter taste of quinoa, among which the commercial luricic acid derivative is the most important bitter contributor, and it was found for the first time that kaempferol derivatives are also closely related to the bitter taste of quinoa. The results of this study can provide basic data for quinoa debittering and low-bitterness quinoa food processing, and provide an important reference for low-bitter quinoa breeding.

Quinoa is a food crop native to the Andes region of South America. Photo courtesy of the interviewee

The research was supported by the Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences, the Yuelu Young Talents Project of the Hemp Research Institute of the Chinese Academy of Agricultural Sciences, and the Natural Science Foundation of Hunan Province.