Assessing the physicochemical and bioactivity properties of vinegar derived from ‘Phulae’ pineapple fruitlets during inoculated fermentation: a comparative study

Abstract

This study investigated the changes in physicochemical properties and bioactive compounds of vinegar made from ‘Phulae’ pineapple waste, a byproduct of fresh-cut pineapple processing in Thailand. The two-stage fermentation process included both alcoholic and acetic acid fermentation. The results showed that acetic acid concentration peaked at 7.84 ± 0.09 g/100 ml after 16 days of fermentation. Phenolic acid levels, measured by mass spectrometry, were highest after 40 days, correlating with maximum antioxidant activity. Fermentation time also affected flavonoids, fructose, and glucose concentrations, while phenolic acids remained high throughout. The bioactivity of pineapple vinegar (PAV) was comparable to commercial apple cider vinegar (AV), demonstrating superior enzyme inhibition, particularly against α-amylase, α-glucosidase, cholesterol esterase, and pancreatic lipase, as well as higher antibacterial activity. Besides, PAV had lower cytotoxicity than AV. This suggests that acetic acid fermentation of pineapple waste could offer a functional beverage with potential health benefits, such as diabetes and cholesterol regulation.