Dynamic changes in biochemical and physicochemical properties of cassava vinegar with and without agarwood leaf infusion

Lam, Wei Shan (2025) Dynamic changes in biochemical and physicochemical properties of cassava vinegar with and without agarwood leaf infusion. Final Year Project, UTAR.

PDF Download (3366Kb)

Abstract

Vinegar is a condiment made from raw agricultural ingredients containing starch and sugar through a double fermentation process: alcoholic and acetic. Although vinegar’s functional properties are well known, its physicochemical and biochemical changes during fermentation with the incorporation of plant-derived materials such as agarwood leaves remain underexplored. The objectives of this study are to assess the saccharification rate through reducing sugar and free amino acid analysis, and to determine ethanol production during the alcoholic fermentation stage of cassava., to study the dynamic changes in biochemical and physicochemical properties throughout the acetic acid fermentation process, and to determine the effect of agarwood leaf infusion on the biochemical and physicochemical properties of cassava-based vinegar. Cassava was first saccharified using ragi for two days, followed by 14-day alcoholic fermentation with wine yeast. Two sets were prepared: one with agarwood leaf infusion and one with water. Mother vinegar was added to initiate acetic acid fermentation. During fermentation, sugar (DNS test), free amino acids (ninhydrin test), alcohol (potassium dichromate test), pH, total titratable acidity, acetic acid (HPLC), and total phenolic content (TPC) (Folin-Ciocalteu method) were monitored and compared between both sets. The sugar content of cassava increased from 3.58% to 16.28% (db) after saccharification. The agarwood leaf-based sample had a lower pH (4.89), higher TPC (0.1402 mg GAE/mL), and lower alcohol content (5.56%) compared to the water-based sample (pH 5.15, TPC 0.1215 mg GAE/mL, alcohol 6.48%). The acetic acid concentration for both sets varied between 0.68 and 4.39 mg/mL. Phytochemical tests showed that alkaloids, flavonoids, and coumarins were present in both samples. Tannins were only detected in the agarwood leaf-based vinegar, and quinones only in the water-based vinegar. The overall physicochemical and biochemical profile of the vinegar was significantly improved by the addition of agarwood leaves infusion, as indicated by higher TPC and increased fermentation efficiency.

Actions (login required)