Cultural, nutritional and microbial perspectives of tuak , a traditional Balinese beverage

Palm wine ( tuak ) is a traditional drink recognized worldwide as the traditional drink of Africa, Southeast Asia, and Central America. The history of alcoholic beverages in Indonesia is from the prehistoric era and is recorded in Borobudur, the largest Buddha temple in Indonesia, built in the eighth century. Although Indonesian society has experienced many social and cultural changes, the tradition of tuak production for daily drinks and ceremonies is strong and widespread and has been introduced as a tourism commodity in regions of Indonesia, especially in Bali. However, there are significant challenges in improving this traditional drink's quality and economic value. In this review, we conducted a desktop study and field survey to learn how tuak is part of Indonesian fermented beverage history, especially in Bali, linked to daily life in most traditional communities and supported by local regulators for the existence of this traditional heritage in society and economy. The nutritional composition of tuak comprises monosaccharides such as glucose and fructose, disaccharides including sucrose and maltose, organic acids, and bioactive compounds encompassing saponins, phenols, terpenoids, alkaloids, and flavonoids. Additionally, tuak contains minerals, alcohols, and essential aromatic compounds. The microorganisms engaged in the fermentation process predominantly comprise ambient air microbes and plant-associated microbes, with a significant prevalence of Saccharomyces cerevisiae , Saccharomyces chevalieri , and Zymomonas mobilis . Additionally, Candida tropicalis yeast is present in the microbial consortium involved in the fermentation. This understanding will provide comprehensive information from a socio-economic perspective to preserve production, celebrate culture and to further develop the value of traditional beverages.