Optimization of germination and ultrasonic-assisted extraction for the enhancement of γ-aminobutyric acid in pumpkin seed

Germination arid ultrasonic-assisted extraction (UAE) are economical and effective methods to enhance bioactive compounds in plant seeds. We optimized the germination parameters and UAE parameters by using response surface methodology to maximize the recovery of gamma-aminobutyric acid (GABA) in pumpkin seeds. The optimal germination conditions were as follows: soaking the seeds at 28 degrees C for 6 h with 0.2% CaCl2, 3.8 mg/ml monosodium glutamate, and 4.0 mg/ml vitamin B-6, then germination at 30 degrees C for 61.6 h. The optimal conditions for UAE were as follows: 1:75 (w/v) material-to-solvent ratio, 220 W ultrasonic power, and ultrasonic treatment at 50 degrees C for 14.4 min, which afforded an extraction yield of 2679 +/- 10 mg/100 g. Moreover, the GABA-enhanced extract showed the potential of hypolipidemic effect in type 2 diabetes rats. These results confirmed that a combination of germination and UAE increased the GABA yield from pumpkin seeds and provided a basis for GABA-enhanced production to improve lifestyle-associated diseases.

Automated summary

The combination of germination and ultrasonic-assisted extraction (UAE) was found to increase the yield of gamma-aminobutyric acid (GABA) in pumpkin seeds. The GABA-enhanced extract showed potential hypolipidemic effects in type 2 diabetes rats.