Improving bioavailability of fruit wastes using organic acid: An exploratory study of biomass pretreatment for fermentation

• Published in: Energy conversion and management Vol. 127; pp. 256 - 264
• Main Authors: Saha, Shouvik, Kurade, Mayur B., El-Dalatony, Marwa M., Chatterjee, Pradip K., Lee, Dae Sung, Jeon, Byong-Hun
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2016
• Subjects: Acetic acid; Bioavailability; Bioenergy; Biomass; Fruit wastes; Pretreatment; Bioenergy; Biomass; Pretreatment; Bioavailability; Acetic acid; Fruit wastes
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2016.09.016

[Display omitted] •Maximum sugar recovery was achieved with 100°C/1h treatment in 0.2M acetic acid.•C/N ratios (41–47) were retained in all FPWs after the acetic acid treatment.•Combined severity (−0.83) of acetic acid enhanced the bioavailability of the FPWs.•Acetic acid pretreatment is advantageous over mineral acid to curtail sugar loss.•Estimated methane yields are promising for the industrial feasibility. Maximizing the bioavailability of fermentable biomass components is a key challenge in biomass pretreatment due to the loss of sugars during conventional pretreatment approaches. Pretreatment of fruit peels and wastes (FPWs) with dilute acetic acid assisted in maximizing sugar recovery. Optimized conditions (0.2M acetic acid, 100°C, 1h) at 10% substrate loading resulted in enhanced sugar recovery from banana peels (99.9%), pineapple wastes (99.1%), grape pomace (98.8%), and orange peels (97.9%). These high sugar recoveries retained the high C/N ratios (41–47) suitable for effective bioenergy production through the fermentation of these pretreated biomasses. Scanning electron microscopy (SEM) indicated considerable disruption of biomass structural integrity during acetic acid treatment, enhancing the surface area available for better microbial attachment. Fourier transform infrared spectroscopy (FTIR) showed that the acetic acid pretreatment yielded only minor changes to the functional groups in the biomasses, strongly suggesting minimal loss of fermentable sugars. Thus, acetic acid pretreatment aids in enhancing the bioavailability of fermentable sugars from these FPWs biomass, enabling improvements in bioenergy production.