Development of a Functional Loog‐Pang Starter Using Selected Yeast and Fungal Strains for Black Glutinous Rice Sato Fermentation

The production of Sato using black glutinous rice offers a valuable opportunity to enhance its overall quality by leveraging the unique nutritional profile, bioactive compounds, and distinct sensory attributes of pigmented rice varieties. This study aims to develop an effective Loog-pang starter to produce black glutinous rice Sato. Yeast and fungal strains were isolated from Loog-pang Sato and Loog-pang Khao Mak samples collected from Roi Et and Yasothon provinces in Thailand. Fungal strains were selected based on their amylase production on soluble starch agar, while yeast strains were screened for their fermentation performance based on TDS reduction, ethanol production, and alcohol tolerance. The study successfully isolated eight fungal strains and 14 yeast strains. Fungal isolates FSA1 and FSA2 exhibited the highest amylase activity on starch agar after iodine treatment. Yeast isolate YKB1 demonstrated the highest alcohol tolerance when cultured in liquid media containing 10% and 15% alcohol. For Sato fermentation, this study utilized a ratio of fungal strain (FSA1 or FSA2) to yeast strain (YKB1). The highest alcohol production, at 16%, was achieved using Loog-pang made with the combination of FSA1 and YKB1. The yeast DNA sequencing analysis of YKB1 revealed a 95.57% similarity to Issatchenkia orientalis. The findings from this study present significant potential for enhancing Sato production by isolating yeast and fungi, enabling local producers to scale up production, improve production, and expand markets both locally and internationally.