Author ORCID Identifier

0000-0002-8930-1808

Biosketch

My name is K. Rohil Kumar. I completed my Bachelor of Science (B.Sc.) in Biotechnology from Sri Venkateswara University, Tirupati, from 2013 to 2016. I then pursued a Master of Science (M.Sc.) in Biotechnology at Sri Venkateswara Institute of Medical Sciences (SVIMS), Tirupati, from 2016 to 2018. Following my postgraduate studies, I worked as a Junior Research Fellow (JRF) at Sri Venkateswara Veterinary University for six months during 2018–2019. In September 2021, I joined the Ph.D. program at SASTRA Deemed University, Thanjavur, under the supervision of Dr. Kiran BabuUppuluri, Associate Professor, School of Chemical and Biotechnology (SCBT). I successfully completed my Ph.D. defense on March 2, 2026. My doctoral research focused on the comprehensive utilization of jackfruit peel (JFP) through an integrated biorefinery approach. The primary objective of this research was to transform jackfruit peel, an abundant agricultural waste, into a range of value-added products, including renewable energy, biochemicals, biopolymers, biofuels, adsorbents, and biomedical nanomaterials. This work contributes to sustainable waste management and supports the development of a circular bioeconomy.

Date of Award

2-3-2026

Document Type

Thesis

School

School of Chemical & Biotechnology

Programme

Ph.D.-Doctoral of Philosophy

First Advisor

Dr. Kiran Babu Uppuluri

Second Advisor

Dr. PR Naren

Keywords

Jackfruit Peel Valorization, Renewable Energy, Biofuels, Biopolymers, Biomedical Nanomaterials

Abstract

Jackfruit (Artocarpus heterophyllus) peel (JFP), an abundantly available lignocellulosic biomass, remains largely underutilized despite being rich in cellulose, hemicellulose, lignin, and pectin. In India, approximately 13,460 hectares are under jackfruit cultivation, with Panruti in Tamil Nadu as a major production zone. The discarded peel often contributes to environmental pollution and greenhouse gas emissions. The present study emphasizes sustainable valorization of JFP through an integrated biorefinery framework for generating value-added bioproducts.

Major biopolymers, cellulose, hemicellulose, lignin, and pectin were extracted and fractionated, followed by detailed physicochemical characterization using FTIR, NMR, XRD, SEM, TGA, DSC, GPC, and BET analyses. Pectin extraction with 0.05 N oxalic acid yielded 15.80 ± 0.02% and exhibited a molecular weight of 209.27 kDa. Lignin isolated through optimized alkali-sulfidation displayed a molecular weight of ~7300 Da and high thermal stability.

Electrospun nanofibers prepared from a 7:3 blend of pectin (JFPP) and polyvinyl alcohol (PVA) exhibited a uniform morphology (average diameter = 187.32 ± 53.77 nm), a tensile strength of 2.21 MPa, and excellent hydrophilicity (contact angle = 25.8°). These nanofibers showed strong antibacterial performance (>16 mm inhibition zones against E. coli and S. aureus) and high cytocompatibility with human dermal fibroblasts, confirming potential for wound-healing applications.

Lignin utilization extended to two valorization routes: (i) polyhydroxybutyrate (PHB) biosynthesis using Oceanimonas doudoroffii MTCC 7730, with response surface methodology (RSM) optimization enhancing yield from 0.23 ± 0.052 g/L to 2.18 ± 0.086 g/L; and (ii) methylene blue (MB) adsorption, attaining a maximum capacity of 370.37 mg/g under Langmuir and pseudo-second-order kinetics. Depectinated and delignified JFP underwent steam-assisted oxalic acid pretreatment followed by enzymatic hydrolysis using crude cellulases from Trichoderma harzianum BPGF1.

The resultant hydrolysate was co-fermented by Saccharomyces cerevisiae and Kluyveromyces marxianus, enabling the efficient conversion of hexose and pentose sugars to ethanol, with a yield of 17.04 ± 0.41 g/L achieved under ANN–GA optimization. The overall study demonstrates a circular, eco-efficient biorefinery model for jackfruit peel valorization, integrating pectin-based nanofibers, lignin-derived PHB and adsorbents, and bioethanol generation. This comprehensive approach offers a sustainable and scalable pathway for converting agro-industrial residues into high-value biopolymers, functional materials, and renewable energy source.

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Graphical Abstract