Effect of microwave-assisted extraction (MAE) method on the characteristics of protein extract from edamame (Glycine max (L.) Merrill)

Abstract

Edamame, a type of soybean, is a promising source of plant-based protein. Protein extraction from edamame was conducted using the microwave-assisted extraction (MAE) method, which utilizes thermal damage to the tissue to facilitate protein extraction with a solvent. Food-grade distilled water was chosen as the solvent, as the protein extract is intended to enhance the nutritional value of meatballs and sausages. The study employed a Completely Randomized Design (CRD) with variations in extraction time (0, 20, 40, and 60 minutes) and pH levels (7, 9, and 11), with each condition tested three times. In the conducted study, it was found that microwave-assisted extraction methods significantly enhanced the quality of protein content from edamame. The thermal effects of microwaves effectively disrupted tissue, facilitating the breakdown of cells and the extraction of valuable components. Our findings showed that protein yield improved with increasing extraction pH, making alkaline conditions—particularly at pH 9—beneficial for maximizing protein extraction. The optimum protein yield of 77.76 ± 0.20% was achieved at pH 9 with a 60-minute extraction time. However, higher alkaline pH levels were associated with decreased protein purity. Consequently, the highest protein content, at 94.12 ± 0.21%, was achieved at pH 7 with a 60-minute extraction time.