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.

Impact of ultrasound processing on alternative protein systems: Protein extraction, nutritional effects and associated challenges

“…Apart from using water and alkali as solvents for protein extraction, few studies have employed other solvents, such as Tris HCl buffer, ethanol, sodium phosphate buffer for UAE from moringa leaves [95] , walnut meal [59] and Arthrospira platensis [96] , respectively. Universally, the solvent should be judiciously selected so that, apart from being non-toxic, it has low vapour pressure, viscosity, and surface tension to facilitate high-intensity cavitation [46] .…”

“…Cheng, Shu [95] explored the use of US combined with MW for the extraction of protein from Moringa oleifera leaves. The authors used tris-HCl buffer (pH 9.0) as the solvent of extraction at 91:1 solvent: solid ratio in an ultrasonic-microwave system (US frequency of 25 kHz, US power of 300 W, MW power of 81 W) operated at 41 °C for 148 s. The protein yields of the extraction treatment using combination of the 2 technologies was 82.07 mg/g, higher than that achieved by traditional solvent based extraction using Tris-HCl buffer solution without US and MW application, which reached 68.99 mg/g.…”

“… LC-MS identified 19 proteins having molecular mass ranging from 10 to 90 kDa. Cheng, Shu [95] Sesame bran US power: 550 W Temperature: 43 °C Enzyme (alcalase): 0.12–2.40 AU/100 g Vacuum time: 1–30 min Restoration time after vacuum application: 1–90 min Vacuum pressure: 100–650 mmHg Protein yield increased by 41.6 % with US, vacuum and enzyme together applied at optimum conditions compared to standard alkaline extraction Optimum conditions of VUE were 1.82 AU/100 g enzyme concentration, 8 min vacuum time, 68 min restoration time and 238 mmHg vacuum pressure – Görgüç, Özer [101] …”

A Comprehensive Review of Moringa oleifera Bioactive Compounds—Cytotoxicity Evaluation and Their Encapsulation

“…Over the years, several extraction techniques have been developed ( Figure 2 ), including traditional extraction (solvent, hot water, solid state fermentation) and nontraditional techniques (ultrasound, microwave, enzymatic) [ 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ]. Whereas conventional extraction methods include longer extraction durations, toxicity, volatility, flammability, and lower extraction efficiency [ 58 , 59 , 60 ], nontraditional are considered to be better for the environment since they use fewer synthetic chemicals and produce a better yield and quality of extract [ 14 , 61 , 62 , 63 , 64 ].…”

“…The extraction yields on 26 ± 2%, 15 ± 2 g/mL DPPH, Trolox equivalent antioxidant capacity 16 ± 1 Trolox/100 g dry leaf [ 55 ]. Moreover, for the protein extraction, ME conditions (solvent–solid ratio 91:1 mL/g, extraction time 148 s, extraction temperature 41°C, microwave power 81 W) showed significantly high extraction efficacy (82.07 mg/g) compared to conventional solvent extraction method (68.99 mg/g) [ 61 ].…”