Food Protectants & Infestation Control (FPIC) Department, CSIR-Central Food Technological Research Institute, Mysuru, India; Academy of Scientific and Innovative Research, Uttar Pradesh 226015, India.
Polymer Materials Lab, Food Packaging Technology Department, CSIR-Central Food Technological Research Institute, Mysuru, India; Academy of Scientific and Innovative Research, Uttar Pradesh 226015, India.
Int J Biol Macromol. 2024 Nov;281(Pt 1):136190. doi: 10.1016/j.ijbiomac.2024.136190. Epub 2024 Oct 2.
Current study provides insight on the feasibility of polylactic acid (PLA) integrated with (1:1 ratio) of essential oils belonging to Ocimum gratissimum (OG) and Mentha spicata (MS) for prevention of major stored insect pests (Sitophilus oryzae and Oryzophilus surinamensis) in Sorghum and Pearl millet. A combination of OG and MS essential oils (1:1) was incorporated into the PLA polymer matrix. Further, SPME analysis of synthesized PLA showed the presence of volatiles corresponding to carvone (6.44 %) and thymol (6.22 %). Synthesized PLA composites were tested against S. oryzae and O. surinamensis using Sorghum and Pearl millets, and insect mortality was equivalent to commercial super bags (CSB). The head space oxygen decreased significantly in CSB and slightly in PLA bags. Thickness of EO blended PLA composite was increased (99 μm), tensile strength (23.94 MPa), WVTR (1.42 g/m.hr) analysis, significant folding ability, and swelling capacity (0.24 %) showed slight reduction in composite film. TGA showed good thermal stability (334˚C) and XRD displayed the increased crystallinity (38.35 %) in PLAOM films, SEM and FTIR analysis of the synthesized composite films revealed complete homogenization of EO and PLA matrix. In addition, SEM analysis of insects (control & treated) revealed less topology changes in the elytra. Biodegradability study confirmed the weight loss in PLA films. Hence, current approach of using composite EO's with PLA offers sustainable solution for prevention of infestation during storage of millets.
本研究探讨了将聚乳酸（PLA）与奥罗莫氏菌（OG）和薄荷（MS）精油（1:1 比例）结合用于防治高粱和珍珠粟中主要仓储害虫（米象和苏门答腊稻象）的可行性。将 OG 和 MS 精油（1:1）混合物掺入 PLA 聚合物基质中。此外，对合成 PLA 的 SPME 分析显示，存在与香芹酮（6.44%）和百里酚（6.22%）相对应的挥发性物质。合成的 PLA 复合材料分别用于高粱和珍珠粟，对米象和苏门答腊稻象进行了测试，其杀虫效果与商业超级袋（CSB）相当。CSB 中的顶空氧气显著降低，而 PLA 袋中的氧气略有降低。EO 共混 PLA 复合材料的厚度增加（99μm），拉伸强度（23.94MPa）、WVTR（1.42g/m.h）分析、显著的折叠能力和膨胀能力（0.24%）显示复合膜略有降低。TGA 显示良好的热稳定性（334°C），XRD 显示 PLAOM 薄膜的结晶度增加（38.35%），合成复合薄膜的 SEM 和 FTIR 分析显示 EO 和 PLA 基质完全均匀化。此外，对昆虫（对照和处理）的 SEM 分析显示，鞘翅的拓扑变化较小。生物降解性研究证实 PLA 薄膜的重量损失。因此，当前使用复合 EO 与 PLA 的方法为防止小米储存期间的虫害提供了可持续的解决方案。
