Production of Bio-Extract from Wastewater Originated from Virgin Coconut Oil Manufacturing Process: Influence of Sugar Types

Abstract

The objective of this study was to investigate the influences of the types of sugars on physical, chemical and microbiological changes taking place during the preparation of bio-extract using wastes derived from the virgin coconut oil manufacturing process. Sugars adopted included palm sugar, brown soft sugar, white sugar, crystalline sugar and molasses. Raw materials, sugars, fish waste and wastewater were combined at the 1:3:1 ratio. Results showed that physical, chemical and microbiological evolutions took place rapidly during the first 2 weeks of the bio-extract fermentation. Furthermore, for all carbon sources employed except for molasses, changes in terms of electrical conductivity, pH, organic acid content and total viable count as well as germination index (GI) were insignificantly different (p>0.01), whilst statistically different from those obtained from bio-extract prepared using molasses as the carbon source. Bio-extract prepared using molasses as carbon source yielded the highest organic matter degradation efficacy, in terms of the total organic carbon (TOC) reduction, of 86% in comparison with 72% for palm soft sugar and 63-66% for brown sugar, crystalline sugar and white sugar. Bio-extract prepared with molasses also contained several beneficial organic acids, e.g., acetic acid (459 mM) butyric acid (27 mM) and propionic acid (29 mM), as well as potassium (3.7%) at significantly higher concentrations than those obtained with bio-extract prepared with other sugars (p<0.01).