Preparation of Kombucha scoby cellulose by using fruit peel wastes as fermentation substrates

This research aimed to produce bacterial cellulose through fermentation of kombucha symbiotic cellulose of bacteria and yeast (SCOBY) by using fruit peel wastes as fermentation substrates. This research is divided into three main studies, namely proximate analysis of fruit peel wastes, correlation studies of fermentation process and characterisation studies of kombucha SCOBY cellulose (KSC). The fruit peel wastes used in this study were dragon fruit, jackfruit banana, saba banana and pumpkin. Several proximate analyses were conducted to determine the composition of carbohydrate, protein, fibre and ash in fruit peel wastes. The characterisation studies of KSC were carried out using Fourier transform infrared (FTIR) spectrometer, X-ray diffraction (XRD) spectrometer, thermogravimetric analyser (TGA), differential scanning calorimeter (DSC), field emission scanning electron microscope (FESEM) and energy dispersive X-ray (EDX) spectrometer. Based on proximate analyses, dragon fruit peel waste produced the highest KSC (7.67%) due to hogh composition of carbohydrate and protein. Dragon fruit peel waste exhibited the highest correlation in the fermentation process at 12% (w/v) of sugar concentrations with R2 value of 0.935. FTIR spectra of KSC produced from fruit peel wastes substrates confirmed the presence of methyl, hydroxyl and carbonyl functional groups which are identical to commercial cellulose. Meanwhile, results from XRD analysis revealed that the crystalline structures of KSC have prominent peaks at 2_ range of 14_-15_, 16_-17_ and 22_-23_ which represent cellulose I_. The TGA and DSC analyses showed that KSC from fruit peel wastes is thermally stable. Morphology of KSC exhibited microfibrils network and composition consist of carbon (C), oxygen (O) and sodium (Na). In conclusion, fruit peel wastes are suitable as alternatives to commercial fermentation substrates to produce bacterial cellulose. In implication, using fruit peel wastes as fermentation substrates in bacterial cellulose preparation will underpin environmental sustainability by converting agricultural wastes into beneficial products.