Phenolic-rich lees from Philippine rice wine (tapuy) increases Caenorhabditis elegans lifespan in spite of having low antioxidant activity

Abstract

Tapuy is an indigenous wine produced in the Philippines. Rice wine fermentation produces a by-product of rice leftover and microbial biomass, collectively called lees, which usually is discarded as a waste product. However, studies have shown the potential value of lees as a healthy food source. We wanted to determine the nutritional profile of tapuy wine and its lees and their abilities to extend lifespan in Caenorhabditis elegans. Tapuy lees (7.65 g/100 g dry weight) was 18.5-fold greater in protein content compared to tapuy wine. Its sugar content (27.66 g/100 g dry weight) is similar to the tapuy wine’s sugar content (23.465 g/100 g dry weight). Through LC–MS/MS, 18.75% and 12.39% of spectral peaks in tapuy wine and lees were matched, respectively, to specific compounds, and several of them are associated with beneficial health effects. Furthermore, the phenolic content in tapuy lees (19,475.526 Gallic Acid Equivalent) is 6.5-fold greater compared to tapuy wine. Surprisingly, the DPPH and FRAP antioxidant assays show that tapuy lees had a lesser antioxidant ability compared to tapuy wine. However, C. elegans fed with supplementation of tapuy lees extract showed a 16.24% increase in mean lifespan, which is higher compared to the 6.10% increase in mean lifespan when supplemented with tapuy wine. Taking all these findings together, our study revealed that tapuy lees has a greater nutritional value than tapuy wine, and this underutilized and wastefully discarded product can be repurposed as a potential functional food. Graphical Abstract