Energy Research Center, Panjab University, Chandigarh 160014, India.
Dr. S. S. Bhatnagar University Institute of Chemical Engineering and Technology, Panjab University, Chandigarh 160014, India.
Int J Biol Macromol. 2024 Aug;274(Pt 2):133239. doi: 10.1016/j.ijbiomac.2024.133239. Epub 2024 Jun 17.
The research focused on the fabrication of composite coatings using buckwheat starch (BS) and xanthan gum (XG) with incorporation of lemongrass (Cymbopogon citratus) essential oil (LEO) with varying concentration (0.75 %, 1.0 % and 1.25 % (w/v). BS was extracted from buckwheat groats (Fagopyrum esculentum) and its physico-chemical characteristics were determined. BS showed spherical and polygonal morphology and its XRD pattern was similar to starch extracted from other cereal sources. The amount of reducing sugar, starch and amylose content in extracted BS were 0.99 ± 0.33 %, 86.32 ± 0.22 % and 21.02 ± 1.89 % respectively, which indicates that BS is a suitable base material for the formation of edible coatings. XG was mixed with BS in different ratios (1:1, 2:1, 3:1 and 4:1) to optimize the best ratio of combination for composite coatings. The coating with a ratio of 2:1 was very smooth and was chosen for incorporation of LEO and the coatings physical, functional, mechanical, thermal and micro-structural characteristics were examined. The coating S5 with 1.25 % (w/v) concentration of LEO showed the best results with least moisture content (MC), minimum water vapor permeability (WVP) and maximum contact angle value. Moreover, the S5 formulation had the highest antioxidant (73.3 %) ability and maximum antimicrobial efficiency with inhibition zones of 22.09 ± 0.06 mm and 28.65 ± 0.14 mm against S. aureus and E. coli respectively. The coatings were then coated on plum fruit, and various parameters like weight loss, pH, shrinkage and TSS were calculated every 4th day during the 20 days of refrigeration period. The coated plums' ripening pace was delayed by the S5 formulation which improved moisture retention, maintained the plums' TSS value and overall pH. Therefore, composite coatings made up of BS, XG and 1.25 % (w/v) can be used as a cost-effective bio-active coating material for plum preservation under refrigeration conditions.
研究集中在使用荞麦淀粉（BS）和黄原胶（XG）制备复合涂层，其中掺入不同浓度（0.75%、1.0%和 1.25%（w/v）的柠檬草（Cymbopogon citratus）精油（LEO）。BS 是从荞麦米（Fagopyrum esculentum）中提取的，其物理化学特性已确定。BS 呈球形和多边形形态，其 XRD 图谱与其他谷物来源提取的淀粉相似。提取的 BS 中还原糖、淀粉和直链淀粉的含量分别为 0.99±0.33%、86.32±0.22%和 21.02±1.89%，这表明 BS 是形成可食用涂层的合适基础材料。XG 与 BS 以不同比例（1:1、2:1、3:1 和 4:1）混合，以优化复合涂层的最佳组合比例。比例为 2:1 的涂层非常光滑，因此选择用于掺入 LEO，并对涂层的物理、功能、机械、热和微观结构特性进行了检查。含 1.25%（w/v）LEO 的涂层 S5 表现出最好的结果，具有最低的水分含量（MC）、最小的水蒸气透过率（WVP）和最大的接触角值。此外，S5 配方具有最高的抗氧化（73.3%）能力和最大的抗菌效率，对金黄色葡萄球菌和大肠杆菌的抑制区分别为 22.09±0.06mm 和 28.65±0.14mm。然后将这些涂层涂在李果上，在 20 天的冷藏期内，每 4 天计算一次各种参数，如失重、pH 值、收缩和 TSS。S5 配方使李果的成熟速度变慢，提高了保水能力，保持了李果的 TSS 值和总 pH 值。因此，由 BS、XG 和 1.25%（w/v）组成的复合涂层可以用作在冷藏条件下保存李果的具有成本效益的生物活性涂层材料。
