Protein isolation methods from edible insects: A systematic review

The development of edible insects, especially Orthoptera orders such as crickets and grasshoppers/locusts, as alternative protein sources continue to grow through various preparations such as flour, concentrates, and isolates to support future food security. The objective of this research was to explore the protein extraction techniques and optimal conditions for producing insect protein concentrates and isolates. A systematic literature review was conducted following the PRISMA guidelines. The formulation of questions using the PICO strategy is population (edible insect, Orthoptera), intervention (edible insect protein extraction method), comparison (extraction pH, extraction time, extraction temperature, precipitation pH), and outcome (protein content and yield). A total of 721 articles were gathered from various reputable sources, and 31 articles that met the study criteria were selected. Based on this literature review, it was determined that the most efficient condition for protein isolation and extraction involved processing at pH 10.5 and 40°C for 60 minutes, followed by precipitation at pH 4–4.5, yielding the highest protein content and recovery. Additionally, modifications such as salting-in to enhance protein solubility, salting-out to increase protein concentration, ultrafiltration for protein purification, and ultrasound treatment to improve protein yield could be applied when necessary.