Delipidation and Deproteination of Coconut Dregs Fermented with Aspergillus niger to Produce Prebiotic compounds

Abstract

Coconut dregs are the waste product of oil extraction, either to produce conventional cooking oil or virgin coconut oil (VCO). These coconut dregs contain mannan compound in the form of galactomannan. Fermentation of this compound could generate mannan-oligosaccharides, having prebiotic properties, due to the presence of mannanase enzyme during fermentation. A study on fermentation of coconut dregs was carried out with a delipidation process using n-hexane and deproteination using NaOH 1M. The fermentation process was done using Aspergillus niger with different duration of fermentation (48, 72, 96, 120 and 144 hours). The fermentation product was placed in the free-air container to kill the fungi and keep the biodegradation process through enzymatic process for 0, 24, 48 and 72 hours. The products were tested for prebiotic properties through spread plate method using Lactobacillus casei and Escherichia coli. The results of the delipidation process could decreased lipid content to 0.77% and the deproteination process could bring down crude protein of coconut dregs to 1.45%. The highest mannanase activity was found when coconut dregs were fermented for 120 hours with a value of 1.0331U/ml. Hydrolyzate produced during incubation had a prebiotic activity by increasing the population Lactobacillus casei and decreasing population of Escherichia coli. Lactobacillus casei bacteria increased from 2x10⁷ CFU/ml to between 30.6x10⁷ CFU/ml and 35.0x10⁷ CFU/ ml, whereas Escherichia coli bacteria decreased from 2x10⁷ CFU / ml to between 5.3x10⁶ CFU/ml and 8.3x10⁶ CFU/ml.

Keywords: Coconut dregs, Aspergillus niger, Prebiotics

DOI: 10.7176/JBAH/10-6-03

Publication date:March 31^st 2020