Development, Characterization, and Application of Pearl Millet Starch-Based Nanocomposite Films Reinforced With Kudzu Cellulose Nanocrystals
Date of Award
Doctor of Philosophy (PhD)
William Scott Whiteside
The accumulation of plastic waste has created serious human, wildlife, and environmental problems. Because of increasing consumer consumption, post-consumer packaging has become a major source of plastic waste. Therefore, there is a great need to develop alternative packaging materials which are environment-friendly, economical, and effective. The current research focused on developing pearl millet starch (PMS)-based biopolymer films reinforced with kudzu cellulose nanocrystals (CNCs) as an alternative to plastic packaging. Nanocomposite films were formulated by blending PMS and glycerol (30%) with different kudzu CNCs concentrations (1–7wt%) using the solution casting process. The prepared PMS/kudzu CNCs nanocomposite films were tested for various parameters, including film properties, food packaging, and biodegradability. Results demonstrated that the incorporation of kudzu CNCs increased crystallinity, heat and water-barrier properties, tensile strength, and Young’s modulus of nanocomposite films, with optimum properties achieved at 5% kudzu CNCs. Further, clove bud oil (CBO) Pickering emulsions at 0.5, 1, 1.5, and 2 wt% were incorporated into nanocomposite films to develop active films. Overall, active nanocomposite films displayed improved thermal, mechanical, and water barrier properties, with an optimum CBO Pickering emulsion concentration determined to be1.5%. Active nanocomposite films were slightly rougher, opaque, and more yellowish than non-active films, but not to the extent that impacted film transparency and usefulness drastically. Moreover, nanocomposite films with CBO displayed antimicrobial properties against E. coli and S. aureus. To assess practical applicability, nanocomposite films were used as a packaging material to improve the shelf life of fresh grapes at 5°C storage. PMS film reinforced with kudzu CNCs and CBO was most effective in extending the shelf life of fresh grapes for up to 15 days by maintaining the weight, firmness, and soluble solids. The study suggested that PMS/kudzu CNCs/CBO films have the potential for commercial packaging of foods during short storage periods without adversely affecting their quality and sensory attributes. Finally, biodegradation analysis of nanocomposite films was conducted using the soil burial method. In general, all three biopolymer films showed good biodegradation behavior, and they all degraded between 15 to 21 days, suggesting that PMS/kudzu CNCs/CBO-based films provide a technique for the production of biodegradable packaging material. In conclusion, our research demonstrated that PMS/kudzu CNCs/CBO-based active nanocomposite films have a good potential to develop active and sustainable packaging materials for the short-term storage of food products.
Bangar, Sneh, "Development, Characterization, and Application of Pearl Millet Starch-Based Nanocomposite Films Reinforced With Kudzu Cellulose Nanocrystals" (2022). All Dissertations. 3227.