Effect of Food Grade Preservatives on the Physicochemical and Microbiological Properties of Coconut Toddy during Fermentation

Abstract

Toddy is a sugary sap obtained from young inflorescence of a coconut tree. It turns alcoholic and sour due to the uncontrolled rapid fermentation caused by the natural microbiota present in it. This ultimately leads to poor quality toddy of lesser shelf life. To control the rapid fermentation, “E-class” preservatives viz., sodium metabisulfite, sodium benzoate and calcium hydroxide were added at various levels to the toddy collection pots fastened to the spadix of the coconut trees prior to its collection. The effects of the preservatives on major physical, chemical and microbiological changes during natural fermentation were studied upon storage for 48 h. The reductions in the pH of the samples to which sodium metabisulfite (9%) or calcium hydroxide (4%) were added appeared to be lesser than the sodium benzoate (13%) and control samples (14%). The titrable acidity (TA) of the sodium metabisulfite and sodium benzoate treated samples increased by 10, 45% respectively while the TA of the calcium hydroxide reduced by 37%. There was a maximum reduction of oBrix in the control samples (54%) followed by sodium metabisulfite (28%), calcium hydroxide (19%) and sodium benzoate (13%) treated samples. There was an increase in ethanol content up to 9% in the sample to which sodium metabisulfite had been added. After 48 h of storage, spoilage bacteria such Acetobacter, Enterobacter, Bacillus and Staphylococcus species were developed.