Ultrasound‐microwave assisted extraction of proteins from Moringa oleifera leaves: Comparative optimization study and LC‐MS analysis of the protein concentrate

Abstract

Moringa oleifera leaves contain significant amount of high quality protein which can be utilized as nutrition supplements and food functional ingredients. In this study, the extraction process of M. oleifera leaves protein was optimized by response surface methodology. Traditional solvent extraction conditions for maximum protein recovery were 0.15-M Tris-HCl concentration, 38-min extraction time, and 128:1 (v/w) solvent/solid ratio at 34°C, and the protein yield was 68.99 mg/g. Furthermore, ultrasound-microwave assisted extraction (UMAE) was adopted to product the leaves protein, and the results showed that the optimum extraction conditions were solvent/solid ratio 91:1 (v/w), extraction time 148 s, extraction temperature 41°C, microwave power 81 W, the yield of protein was 82.07 mg/g. Compared with the conventional solvent extraction method, UMAE exhibited significantly high extraction efficiency. Through LC-MS technology identification and bioinformatics analysis, it is verified that the extracted proteins could provide energy and material basis for the functions of M. oleifera leaf. Practical applications Moringa oleifera leaves have a high protein content and reasonable composition of essential amino acids, which is a high-quality plant protein with great development potential. In the present study, the response surface method was used to optimize the process of ultrasonic and microwave synergistic extraction of M. oleifera leaves protein, which is effective and significantly increased the protein yield. According to the results of LC-MS identification and bioinformatics analysis, the proteins played a leading role in maintaining the normal tissue, structure, and function of M. oleifera leaves, participated in the growth and metabolism of M. oleifera leaves, and provided material and energy supply for the functional performance of M. oleifera leaves.