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http://hdl.handle.net/10603/495475
Title: | Ultrasound assisted nanocellulose extraction from microwave pre treated rice straw to develop bio nanocomposite for active packaging of horticultural produce |
Researcher: | Bhat, Mohd Ishfaq |
Guide(s): | Shahi, N.C. |
Keywords: | Engineering Engineering and Technology Engineering Multidisciplinary |
University: | G.B.Pant University of Agriculture and Technology |
Completed Date: | 2022 |
Abstract: | Lignocellulosic biomass (especially agricultural residue) is a sustainable feedstock for production of valueadded newlinematerials through specific processing techniques and sequences as per the desired end-product. The newlinepresent study aimed to utilize one such agro-residue viz. rice straw by converting it into high crystalline newlinenanocellulose to develop a bifunctional bio-nanocomposite for active packaging of horticultural produce. The newlinefirst objective involved the application of a modified microwave assisted sodium chlorite pretreatment for newlineintensive and quick delignification of rice straw. The effect of four critical process parameters on the newlinedelignification percentage of the rice straw was studied. The delignification was manifested by characterization newlineusing Fourier transform infrared spectroscopy, x-ray diffraction and scanning electron microscopy. Using a newlineBox-Behnken experimental design (BBD), the effect of four critical process parameters, viz. microwave power newline(480-800 W), microwave treatment time (4-12 min), bleaching solution concentration (0.4-3.0 %), and newlinebleaching time (1-5 h) on the delignification (%) was investigated, and the process was optimised using newlineresponse surface methodology (RSM). The experimental data best fitted a quadratic model with an R2 of newline0.9964. The optimized value of process parameters in aforementioned sequence was found to be 671 W, 8.66 newlinemin, 2.67 %, and 1h respectively, for the best delignification of 93.51 percent. The absence of lignin peaks newline(1516 and 1739 cm-1) was corroborated by deconstructed morphological structure and higher crystallinity newlineindex in the optimised delignified sample (53.7 %). The optimized delignified rice straw powder was then newlinesubjected to ultrasound assisted acid hydrolysis for nanocellulose extraction, preceded by the removal of newlinehemicellulose and silica. The effect of sulfuric acid concentration (40-70%), ultrasonic treatment time (30-120 newlinemin) and ultrasound power (150-250 W) on the crystallinity index (%) and the mean particle size (nm) of the newlinenanocellulose crystals, was studied through BBD and optimized through RSM. The optimum process newlineparameters were obtained as 51.62 % sulfuric acid concentration, 48.55 min ultrasonic treatment time and 238. newline80 W ultrasound power. The mean particle size and the crystallinity index at these optimum parameters were newline69.01nm and 89.72 %, respectively. The spectral characterization revealed the increased intensity of peaks newlinecorresponding to the cellulose. The transmission micrograph of the nanocellulose revealed a rod like structure newlinewith average length and width of 190 ± 6 nm and 35 ± 3 nm, respectively. The nanocellulose crystals at 1, 5 newlineand 10% concentration levels were used for reinforcement of chitosan biopolymer along with the addition of newlinethe titanium dioxide (TiO2) nanoparticles at its 1, 3 and 5% concentration levels. The overall performance of newlinethe developed bio-nanocomposite was measured in terms of thermal, mechanical, water vapor permeability newline(WVP) and water sensitive properties. Thickness of the developed films varied from 0.12 to 0.17 mm. The newlineWVP and the tensile strength were reduced and increased by 27 % and 78 %, respectively for bionanocomposite newlinewith 10 % cellulose nanocrystals and 3% TiO2 concentration. The thermal stability of the newlinedeveloped bio-nanocomposite was better as compared to neat chitosan film in terms of higher glass transition newlineand melting temperature. The best bio-nanocomposite was used for storage study of fresh-cut apple slices. The newlinedeveloped bio-nanocomposite showed promising results in terms of preserving the firmness, color and the newlineradical scavenging activity of fresh-cut apple slices for a storage study period of 11 days. newline |
Pagination: | 171 p.p. |
URI: | http://hdl.handle.net/10603/495475 |
Appears in Departments: | Department of Process and Food Engineering |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
01_title.pdf | Attached File | 113.49 kB | Adobe PDF | View/Open |
02_prelim pages.pdf | 248.5 kB | Adobe PDF | View/Open | |
03_table of content.pdf | 151.3 kB | Adobe PDF | View/Open | |
04_abstracts.pdf | 601.35 kB | Adobe PDF | View/Open | |
05_chapter 1.pdf | 114.89 kB | Adobe PDF | View/Open | |
06_chapter 2.pdf | 301.49 kB | Adobe PDF | View/Open | |
07_chapter 3.pdf | 1.33 MB | Adobe PDF | View/Open | |
08_chapter 4.pdf | 2.65 MB | Adobe PDF | View/Open | |
09_chapter 5.pdf | 134.99 kB | Adobe PDF | View/Open | |
10_annexure.pdf | 359.79 kB | Adobe PDF | View/Open | |
80_recommendation.pdf | 247.27 kB | Adobe PDF | View/Open |
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