The present study aimed to optimize the conditions for the synthesis of gold nanoparticles (AuNP) using chitosan and to assess its effectiveness as temperature threshold indication for frozen storage conditions. Chitosan concentration of 0.25% and temperature of 90 °C for 15 min was optimum for synthesizing AuNP. The maximum absorbance (λ_max) was observed at 530 and 540 nm for 0.125% and 0.25% chitosan, respectively, indicating shifting of peak toward longer wavelengths (red shift) with increasing chitosan concentration indicating larger AuNPs. A prominent absorption peak at 1367 cm⁻¹ by Fourier transform-infrared (FTIR) spectrum corresponding to C−C stretching of the glucosamine group of chitosan indicates the chitosan capping on the AuNP. Higher peak intensity and a peak shift toward shorter wavelength were observed for AuNPs exposed to frozen temperature abused conditions. Distinctly clear visible color variation from cherry red to gray indicates its application as temperature abuse indicator in frozen products.

本研究旨在优化使用壳聚糖合成金纳米颗粒（AuNP）的条件，并评估其作为冷冻储存条件的温度阈值指示的有效性。壳聚糖的浓度为0.25％，温度为90°C，持续15分钟是合成AuNP的最佳选择。的最大吸光度（λ_最大）在530观察和用于分别0.125％和0.25％脱乙酰壳多糖，540纳米，表示峰的朝向较长波长（红移）随着脱乙酰壳多糖浓度指示较大的AuNP移。在1367 cm ^-1处有一个明显的吸收峰对应于壳聚糖葡糖胺基团的C-C拉伸的傅里叶变换红外光谱（FTIR）表明，壳聚糖在AuNP上封端。对于暴露于冷冻温度滥用条件下的AuNP，观察到较高的峰强度和向较短波长的峰位移。从樱桃红到灰色的明显清晰可见的颜色变化表明其在冷冻产品中用作温度滥用指示剂。