Valorization of Glycine max (Soybean) Seed Waste: Optimization of the Microwave-Assisted Extraction (MAE) and Characterization of Polyphenols from Soybean Meal Using Response Surface Methodology (RSM)

Abstract

The present study aimed at determining the optimal conditions for extraction of total phenolic compounds from soybean (Glycine max) meal, a by-product of the soybean seeds industry, using a green protocol with microwave-assisted extraction (MAE). A face-centered composite design (FCCD) was used for optimization. Based on a screening aimed to determine the factors that significantly influenced the responses, a 50% hydro-ethanolic solution was used with solvent/dry matter ratio (60/1–110/1), power (120–270 W), and time (0–10 min) as factors, while the responses studied were total phenolic and flavonoid contents. FTIR, TLC, DPPH, and FRAP anti-oxidants tests were used to characterize the extracts obtained with optimum conditions. The factors that significantly influenced both responses were the individual effect of all factors, the interaction between solvent/dry matter ratio and extraction time, the quadratic effect of solvent/dry matter ratio, and power for total phenolic content, while only the quadratic effect of power significantly influenced the flavonoid content. The highest contents of phenols (13.09 mg GAE/g) and flavonoid (7.39 mg CE/g) were obtained at 120 W for 0.16 min with a solvent/dry matter ratio of 60/1. ATR-FTIR spectra indicated the presence of polyphenolic compounds in the extract, namely flavonoids. TLC indicated the presence of at least nine compounds in the extract, among which catechin and quercetin were identified with respective Rf of 0.98 and 0.93. DPPH assay showed the anti-oxidant capacity for the extract with an IC50 of 194.98 µg/ml. RSM permitted us to develop a green protocol for maximum extraction of polyphenols from soybean seeds waste using less solvent, low power, and a reduced time in MAE.

Microwave‐assisted extraction of bioactive compounds from Sarawak Liberica sp. coffee pulp: Statistical optimization and comparison with conventional methods

“…It is reasonable to anticipate the observed outcomes, as flavonoids are a type of phenolic compound. Similar findings were reported by Woumbo et al ( 2021 ), who noted that the responses of TPC and TFC were both influenced by the same effects for the MAE of polyphenols from soybean meal using the parameters (solvent/dry matter ratio, power, and time).…”

Effect of feeding frequency on water quality and growth of Litopenaeus vannamei fed extruded and pelleted diets

“…Polyphenols are particularly abundant in common plant raw materials, such as soybean meal, which is reported as one of the richest avonoid legume sources. The polyphenols are not destroyed during the different treatments that seeds undergo and may wind up in soybean meals(Woumbo et al 2021). Extrusion cooking at barrel temperatures up to 120°C, as in this study, can decrease the content of antinutritional polyphenols.…”

Optimization of Temperature and Drying Time on Flavonoids Levels of Anjasmoro Variety Soybean (Glycine Max) Extract Using Response Surface Methodology

“…The disadvantages of using ethanol in high concentration from an economic perspective are the expensive and inefficient extraction costs (Alam et al, 2013;Shi et al, 2003). Flavonoids from soybeans also can be extracted using 70 % methanol as well as ethanol at a concentration of 60-99.5 % (Chen et al, 2021;Malenčić,et al, 2021;Le et al, 2019;Woumbo et al, 2021;Hsieh et 2022). However, methanol is rarely used due to its toxicity properties (Joshi & Adhikari, 2019).…”