Development of an Aqueous Polyethylene Glycol-Based Extraction and Recovery Method for Almond (Prunus armeniaca L.) Protein

Abstract

A novel method for protein extraction from sweet almonds with aqueous polyethylene glycol (PEG) as solvent and recovery from the extraction solution was developed. The extraction yields of different solvents, such as sodium hydroxide, sodium chloride, PEG 200, PEG 400, and PEG 600 aqueous solutions, were investigated and PEG 200 showed the highest extraction efficiency. The PEG-based microwave-assisted extraction (MAE) parameters were then optimized using response surface methodology. Under optimum condition, PEG 200 concentration of 25 % (w/w), liquid to solid ratio of 22 mL g −1 , microwave power of 120 W, extraction temperature of 45°C, and extraction time of 4 min, the average extraction yield was 93.75 ± 3.15 %. Subsequently, the almond protein was recovered from the extraction solution containing PEG with an isoelectric point-ethanol synergy precipitation protocol. The combined technique integrated the speed of isoelectric point precipitation with the completeness of alcohol precipitation. The recovery of almond protein was 98.81 % with a time of 3-5 min. The proposed PEG-based MAE and synergy precipitation protocol provide a rapid and effective method for almond protein extraction and recovery and have the potential to be used for other plant proteins.

Ultrasonic-assisted extraction and functional properties of wampee seed protein

“…Extraction is the key step for the isolation and recovery of proteins. Many methods like traditional alkaline, salt, reverse micelle, organic solvent, and enzyme extraction have been used to extract plant proteins (Ge et al, 2016). However, there are several latent disadvantages in these methods.…”

An automated food protein isolation approach on preparative scale by two‐dimensional liquid chromatography with active modulation interface

“…Proteins from a lyophilized egg, purchased from local supermarkets, were extracted as already reported , with slight modifications. Briefly, 60 mL of n ‐hexane (15 mL/g) was added to 4 g of lyophilized sample.…”

Revalorization of Almond By-Products for the Design of Novel Functional Foods: An Updated Review

“…Despite its scarce applicability to almond and by-products thereof, MAE has been successfully applied to the extraction of phenolic compounds from other tree nuts and corresponding by-products such as Pistacia vera and Anacardium occidentale. In general, the power used in compounds extraction from nuts by-products could reach values ranging from 100 to 1000 W, generally associated with short extraction times (between 1 to 12.5 min), despite it can reach up to 1 h [45,62,63]. Additionally, MAE has been used in other species from the same genus, such as Prunus armeniaca L., for protein extraction purposes [62].…”

“…In general, the power used in compounds extraction from nuts by-products could reach values ranging from 100 to 1000 W, generally associated with short extraction times (between 1 to 12.5 min), despite it can reach up to 1 h [45,62,63]. Additionally, MAE has been used in other species from the same genus, such as Prunus armeniaca L., for protein extraction purposes [62].…”