Thermal Properties of Ultrasound-Extracted Okra Mucilage

Abstract

Utilizing chemical and physicochemical techniques, the mucilage part of okra was extracted with the use of ultrasound, and the polysaccharide extract’s structural and thermal characteristics were assessed. Analysis of the extraction yield revealed that there was no discernible impact of time and that the yield increased with a decreasing okra to distilled water ratio (mean 8%). Differential scanning calorimetry was employed to determine the phase change enthalpy by examining the glass transition temperature and enthalpy. The glass transition temperatures of the samples were found to be about 50 °C and the melting temperatures were in the range of 166–170 °C for varied solid/solvent ratios (1:10, 1:25, 1:30, and 1:50) and extraction durations of 5 and 30 min. Using thermogravimetry (TG) and differential thermogravimetry (DTG) techniques, it was discovered that the okra polysaccharides were thermally stable with considerable weight loss above 240 °C. For the purpose of illuminating the bonds of the polysaccharides, FTIR analysis was used to characterize the polysaccharides obtained by the varying extraction times and rates of solid/solvent. This analysis provides detailed information about the composition of the extracts. It was found that the molecular structure of the mucilage from okra was unaffected by the varying ratios and times. The study’s findings indicated that the use of ultrasound could be a promising approach for extracting polysaccharides that possess strong thermal stability, making them suitable for use in various industrial applications. The study noted that variations in ultrasound application time and solid/solvent ratios did not appear to impact the thermal stability of the extracted polysaccharides. The important parameters for the extraction conditions such as the time and low amount of sample used are preferred for applications. The findings obtained indicate that ultrasonic extraction application at a 1/50 solid/solvent ratio for 5 min is statistically significant in terms of thermal properties and yield. These findings could have important implications for the energy costs associated with the industrial use of ultrasound extraction.