Okra varieties: Effect of different extraction techniques on the physicochemical, functional, and morphological attributes of okra polysaccharides

This experiment was designed to investigate the impact of different extraction techniques on the yield, and physicochemical, functional, and morphological properties of okra varieties. Specifically, combined ultrasound-microwave extraction UMAE exhibited a significantly higher extraction yield (23.99%) compared to microwave-assisted extraction MAE (15.29%), ultrasound-assisted extraction UAE (14.01%), and hot water extraction HWE (11.72%). Functional attributes such as water-holding capacity, solubility, and swelling index were significantly affected by these four extraction methods. The utilization of UMAE extraction led to a decrease in extraction time and displayed a significantly higher level of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging antioxidant activity (89%) and ferric-reducing antioxidant power (687 μmol TE/100 g), in comparison to other extraction techniques. All crude okra polysaccharides showed similar structural features via FTIR but exhibited diverse morphological features. The combined UMAE extraction method has the potential to effectively overcome the limitations of the three existing extraction procedures and enhance the extraction yield in an eco-friendly environment. The results showed that the Sabaz Pari variety and the UMAE extraction yielded the most favorable outcomes. Additionally, UMAE may serve as a potential source of food hydrocolloids with novel functional and biological properties adaptable to the food industry.