The potential of spent coffee grounds hydrolysates fermented with Torulaspora delbrueckii and Pichia kluyveri for developing an alcoholic beverage: The yeasts growth and chemical compounds modulation by yeast extracts

Yunjiao Liu; Yuyun Lu; Shao Quan Liu

doi:10.1016/j.crfs.2021.07.004

The potential of spent coffee grounds hydrolysates fermented with Torulaspora delbrueckii and Pichia kluyveri for developing an alcoholic beverage: The yeasts growth and chemical compounds modulation by yeast extracts

Curr Res Food Sci. 2021 Jul 21:4:489-498. doi: 10.1016/j.crfs.2021.07.004. eCollection 2021.

Authors

Yunjiao Liu¹, Yuyun Lu¹, Shao Quan Liu^{1

2}

Affiliations

¹ Department of Food Science and Technology, Science Drive 2, Faculty of Science, National University of Singapore, 117542, Singapore.
² National University of Singapore (Suzhou) Research Institute, 377 Lin Quan Street, Suzhou Industrial Park, Jiangsu, 215123, China.

Abstract

This study evaluated the effects of yeast extracts (YE) addition (0 % and 0.25 %, w/v) on the no-volatile and volatile compounds of spent coffee grounds (SCG) hydrolysates fermented with single-cultures of two non-Saccharomyces wine yeasts, Torulaspora delbrueckii and Pichia kluyveri. The added YE improved the growth of both T. delbrueckii and P. kluyveri, especially P. kluyveri, resulting in higher ethanol production (1.98 % vs 1.47 %, v/v) by the latter yeast. In addition, the added YE did not impact on most of the alkaloids production regardless of yeast type, while significantly decreasing the contents of chlorogenic, and caffeic acids in SCG hydrolysates fermented with P. kluyveri. Furthermore, more odor-active compounds such as acetate esters and 2-phenylethyl alcohol were produced when YE was added, and P. kluyveri generated significantly higher amounts of esters compared to that of T. delbrueckii. Moreover, YE addition showed a more noticeable effect on the fermentation performance of P. kluyveri relative to that of T. delbrueckii. These findings indicated the potential of SCG hydrolysates fermented with evaluated non-Saccharomyces yeasts and may expand the applications on utilizing SCG to develop new value-added alcoholic products.

Keywords: Alcoholic fermentation; Pichia kluyveri; Spent coffee grounds; Torulaspora delbrueckii; Yeast extracts.