Comparative Study of Microwave and Ultrasound-Assisted Extraction of Phosvitin From Egg Yolk

This study investigated the efficacy of microwave and ultrasound technologies in extracting phosvitin from egg yolk. Extractions were conducted for 4 and 8 min using ultrasound powers of 200, 300, and 400 W, and microwave powers of 180, 360, and 600 W. The %yield, %phosphorus, and %nitrogen of the extracted phosvitin were measured. FT-IR and SDS-PAGE analyses were performed to characterize the phosvitin. The superior samples from each extraction method were further evaluated for antioxidant properties, emulsifying activity index (EAI), and emulsion stability index (ESI). Samples treated with microwave power of 180 W for 4 min (MT4P180, 4.68%) and ultrasound power of 200 W for 4 min (UT4P200, 3.77%) had the highest %yield compared to other treatments with a significant difference (p < 0.05). The highest ratio of phosvitin to total protein with a significant difference (p < 0.05) was observed in microwave samples treated at 600 W for 8 min (MT8P600, 76.68%) and in ultrasound samples treated at 400 W for 8 min (UT8P400, 54.41%). The presence and purity of phosvitin were confirmed by FT-IR (Peaks at 976 and 1079 correspond to PO₄ ^3-) and SDS-PAGE (bands in the 31-47 kDa range), respectively. The antioxidant activity of MT8P600 (36.20%) was significantly higher than that of UT8P400 (23.58%) (p < 0.05). EAI and ESI in the UT8P400 (24.30-98.5) were significantly higher than those of MT8P600 (20.8-83.7) (p < 0.05). Therefore, microwave technology is considered a modern and efficient method for producing phosvitin, a natural and biodegradable antioxidant and emulsifier, for use in food products.