Assessment of Tannin Tolerant Non- Saccharomyces Yeasts Isolated from Miang for Production of Health-Targeted Beverage Using Miang Processing Byproducts

Abstract

This research demonstrated an excellent potential approach for utilizing Miang fermentation broth (MF-broth), a liquid residual byproduct from the Miang fermentation process as a health-targeted beverage. One hundred and twenty yeast strains isolated from Miang samples were screened for their potential to ferment MF-broth and four isolates, P2, P3, P7 and P9 were selected, based on the characteristics of low alcoholic production, probiotic properties, and tannin tolerance. Based on a D1/D2 rDNA sequence analysis, P2 and P7 were identified to be Wikerhamomyces anomalus, while P3 and P9 were Cyberlindnera rhodanensis. Based on the production of unique volatile organic compounds (VOCs), W. anomalus P2 and C. rhodanensis P3 were selected for evaluation of MF-broth fermentation via the single culture fermentation (SF) and co-fermentation (CF) in combination with Saccharomyces cerevisiae TISTR 5088. All selected yeasts showed a capability for growth with 6 to 7 log CFU/mL and the average pH value range of 3.91-4.09. The ethanol content of the fermented MF-broth ranged between 11.56 ± 0.00 and 24.91 ± 0.01 g/L after 120 h fermentation, which is categorized as a low alcoholic beverage. Acetic, citric, glucuronic, lactic, succinic, oxalic and gallic acids slightly increased from initial levels in MF-broth, whereas the bioactive compounds and antioxidant activity were retained. The fermented MF-broth showed distinct VOCs profiles between the yeast groups. High titer of isoamyl alcohol was found in all treatments fermented with S. cerevisiae TISTR 5088 and W. anomalus P2. Meanwhile, C. rhodanensis P3 fermented products showed a higher quantity of ester groups, ethyl acetate and isoamyl acetate in both SF and CF. The results of this study confirmed the high possibilities of utilizing MF-broth residual byproduct in for development of health-targeted beverages using the selected non-Saccharomyces yeast.

Keywords: Miang; byproduct valorization; fermentation; healthy beverage; non-Saccharomyces yeast.

Figure 1

Screening for the ethanol producing yeast isolated from Miang. The graphical ratio of a total screened yeast number, in comparison to the gas-forming and ethanol-producing isolates (a). Glucose consumption (g/L) and ethanol yield (g/g sugar consumption) of 24 yeast isolates and S. cerevisiae TISTR 5088 (control) after 3 days of fermentation in YPD medium at 30 °C (b).

Figure 2

Hemolytic activity of yeast isolates P2, P3, P7 and P9 on blood agar at 30 °C for 7 days (a) and growth of the yeast isolate on YMA containing 50 g/L tannin at 37 °C for 3 days (b).

Figure 3

Phylogenetic tree analysis of the yeast Cyberlindera rhodanensis P3 and P7, Wikerhamomyces anomalus P2 and P9, based on particle 26S rDNA D1/D2 region sequence using the neighbor-joining method. Bootstrap values >50% (based on 1000 replication) are given at the branch points. The scale bar shows a patristic distance of 0.10.

Figure 4

Heatmap using the total peak area (%) of VOCs produced with S. cerevisiae TISTR 5088, W. anomalus (P2, P9) and C. rhodanensis (P3, P7) on YM agar at 30 °C for 2 days.

Figure 5

Cell growth, glucose, and ethanol concentration profiles during the fermentation of MF-broth fermented by S. cerevisiae TISTR 5088, W. anomalus P2 and C. rhodanensis P3, with single and co-fermentation at 30 °C for 120 h.

Figure 6

Organic acid profiles during fermentation of MF-broth fermented by S. cerevisiae TISTR 5088, W. anomalus P2 and C. rhodanensis P3, with single and co-fermentation at 30 °C for 120 h.

Figure 7

PCA biplot of the organic acids, glucose, ethanol, and pH variables in the original and fermented MF-broth by S. cerevisiae TISTR 5088, W. anomalus P2 and C. rhodanensis P3, with single and co-fermentation at 30 °C for 120 h.

Figure 8

Bioactive compound and antioxidant profiles during the fermentation of MF-broth fermented by S. cerevisiae TISTR 5088, W. anomalus P2 and C. rhodanensis P3, with single and co-fermentation.

Figure 9

β-glucosidase activity of non-inoculated (control), S. cerevisiae TISTR 5088, W. anomalus P2 and C. rhodanensis P3 during MF- broth fermentation.

Figure 10

Heatmap and hierarchical cluster analysis representation corresponding to the 36 volatile compounds of original and fermented MF-broth inoculated with S. cerevisiae TISTR 5088, W. anomalus P2 and C. rhodanensis P3 at 30 °C for 120 h.

Figure 11

PCA biplot of the volatile compounds in the original and fermented MF-broth by S. cerevisiae TISTR 5088, W. anomalus P2 and C. rhodanensis P3, with single and co-fermentation at 120 h.