AbstractsBiology & Animal Science

Contribution on cellulose nano - biotechnology for food bioprocessing

by Mrinal Nishant Kumar




Institution: University of Patras; Πανεπιστήμιο Πατρών
Department:
Year: 2015
Keywords: Ανάπτυξη βιοδιεργασιών τροφίμων; Χρήση βιοκαταλυτών; Ψυχρή παστερίωση; Νάνο/μίκρο πορώδης κυτταρίνη; Ακινητοποιημένα κύτταρα; Γαλακτική ζύμωση; Αλκοολική ζύμωση; Food bioprocess development; Biomass utilization; Cold pasteurization; Nano/micro porous cellulose; Immobilized cells; Lactic acid fermentation; Alcoholic fermentation
Record ID: 1153608
Full text PDF: http://hdl.handle.net/10442/hedi/35683


Abstract

The need for innovative and sustainable technologies in the area of food bioprocessing and fermentation technology has brought upon a great interest in the use of cheap renewable resources in the form of raw materials available in their natural existence. Wood sawdust and rice husk are such ubiquitous lignocellulosic biomasses that can be used as novel biodegradable micro/nano-tubular cellulosic materials (TCs) after a delignification process, alone or as composites with natural microbial biopolymers such as polylactic acid (PLA) and polyhydroxybutyrate (PHB), to design natural microbial biocatalysts for food bioprocessing. Specifically, TC from wood sawdust of Mangifera indica (mango tree) and Shorea robusta (sal tree), and husks of Oryza sativa (rice) of Indian origin were delignified and characterized in this study, and were used in various fermentation processes. Lignin was removed from the cellulose matrix by alkaline treatment to leave behind a porous, tubular structure. Surface characteristics, lignin content and other chemical components were analyzed to determine the chemical and structural differences among the cellulosic materials before and after the delignification treatment. The proximate analysis from the leaves, sawdust and husk extracts of the plant materials included the estimation of total carbohydrates, reducing sugars, nitrogen, crude protein, ash, relative water content (RWC). The results showed higher percentage of nitrogen, crude protein, ash and RWC in the leaves of sal than its sawdust. On the other hand, lower percentage of only RWC was found in the leaves of mango and rice compared to their sawdust and husk, respectively. This study will further help to set-up certain protocols for purification of the extracts as porous biopolymer materials for various applications.In the next part, carbonization of the TCs under nitrogen flow was done using various temperature/time combinations in order to increase their specific surface area. The materials were studied by TGA/DTA, SEM and BET analysis. Atomic Force¬¬ Microscopy, X-Ray Diffractometry (XRD) and FTIR analyses where also carried out in order to study the qualitative differences between the TCs and carbonized TCs. The presence of tubular structure in the delignified materials at the scale of 60-100 µm was observed distinctively through SEM analyses, whereas for the carbonized TCs a bristle and more crystalline form of structures where observed at the scale of 20-100 µm. The TGA/DTA analyses showed the mass change behavior of Indian origin TCs with progressive weight loss at a temperature of 350oC. The surface area and pore diameters were found to be of 3-4 fold increase in the carbonized TCs compared to the delignified TCs. The results from XRD showed the variation in the degree of crystallinity (CI) for delignified and carbonized TCs. The FT-IR analyses were done to monitor the chemical structure by identifying the functional groups present in each sample after delignification and carbonization, confirming loss of the most amount of lignin…