Department of Food Process Engineering, School of Bioengineering, The College of Engineering and Technology, SRM Institute of Science and Technology, SRM Nagar, Kattankulathur, 603203, Chengalpattu District, Chennai, Tamil Nadu, India.
Department of Food Process Engineering, School of Bioengineering, The College of Engineering and Technology, SRM Institute of Science and Technology, SRM Nagar, Kattankulathur, 603203, Chengalpattu District, Chennai, Tamil Nadu, India.
Chemosphere. 2022 Mar;291(Pt 1):132786. doi: 10.1016/j.chemosphere.2021.132786. Epub 2021 Nov 8.
Environmental pollution due to the usage of non-biodegradable synthetic plastic and agro-waste disposal/burning are major issues nowadays. Hence, in the present study, agro-waste (coconut shells) was selected as raw material to synthesize cellulose nanofibers, and it was incorporated into a biodegradable packaging film to enhance its properties. Coconut shell cellulose nanofibers (CNF) were synthesized by a combination of mechanical (ball milling), chemical (acid hydrolysis), and physical (ultra-sonication) methods with an excellent yield of 41.67 ± 1.07%. After each treatment, the crystallinity index was improved, it was 74.38% for the untreated coconut shell powder, and 98.62% for the CNF obtained after ultra-sonication. After chemical treatments, FTIR analysis was done to confirm the removal of non-cellulosic material. The structure and morphology of the nanofiber were concluded from SEM, AFM, TEM, and the size obtained was up to 29 nm. The cellulose nanofibers were then incorporated into polyvinyl alcohol (PVA) polymer matrix with the linseed oil and lemon oil. The essential oil improved the antioxidant properties of PVA-CNF film, and free radicle scavenging activity was 31.52 ± 0.08% upon the addition of oils. Moreover, PVA-CNF-oil-based composite film showed good antimicrobial activity against food-borne pathogens. Hence, it can be used in the preparation of active packaging in the food industry. Similarly, the mechanical and thermal properties of bio nanocomposite film inferred superior quality than neat PVA film. The optical properties of the developed film were on par with polyethylene film. The film also exhibited excellent biodegradability; 87.34 ± 0.91% degradation was obtained on the 45th day. Another major objective of the study was to provide a hydrophobic nature to PVA-based film. It was improved by incorporating essential oil and coconut shell nanofibers; the contact angle measured was 91.3° ± 0.79°. Hence, the prepared bio nanocomposite film is suggested as an alternative material for non-biodegradable food packaging, thereby reducing plastic pollution.
由于不可生物降解的合成塑料和农业废物处理/燃烧造成的环境污染是当今的主要问题。因此，在本研究中，选择农业废物（椰子壳）作为原料来合成纤维素纳米纤维，并将其掺入可生物降解包装膜中以提高其性能。椰子壳纤维素纳米纤维（CNF）通过机械（球磨）、化学（酸水解）和物理（超声）相结合的方法合成，得率为 41.67±1.07%。在每次处理后，结晶度指数都得到了提高，未处理的椰子壳粉末为 74.38%，超声处理后得到的 CNF 为 98.62%。化学处理后，进行 FTIR 分析以确认去除了非纤维素材料。通过 SEM、AFM、TEM 得出纳米纤维的结构和形态，得到的尺寸高达 29nm。然后将纤维素纳米纤维掺入聚乙烯醇（PVA）聚合物基质中，并加入亚麻籽油和柠檬油。精油提高了 PVA-CNF 膜的抗氧化性能，添加油后自由基清除活性为 31.52±0.08%。此外，PVA-CNF-油基复合膜对食源性病原体表现出良好的抗菌活性。因此，它可以用于食品工业中活性包装的制备。同样，生物纳米复合材料薄膜的机械和热性能推断出比纯 PVA 薄膜更好的质量。所开发薄膜的光学性能与聚乙烯薄膜相当。该薄膜还表现出优异的生物降解性；第 45 天获得 87.34±0.91%的降解。本研究的另一个主要目标是为基于 PVA 的薄膜提供疏水性。通过掺入精油和椰子壳纳米纤维来提高其疏水性；测量的接触角为 91.3°±0.79°。因此，建议制备的生物纳米复合材料薄膜作为不可生物降解食品包装的替代材料，从而减少塑料污染。
