Protein extraction yield, lipid composition, and emulsifying properties of aqueous extracts of Rhynchophorus phoenicis larvae extracted at pH 3.0 to 10.0

• Published in: Future foods : a dedicated journal for sustainability in food science 2021-12, Vol.4, p.100037, Article 100037
• Main Authors: Fogang Mba, Aymar Rodrigue, David-Briand, Elisabeth, Viau, Michèle, Riaublanc, Alain, Kansci, Germain, Genot, Claude
• Format: Article
• Language: English
• Subjects: Chemical engineering; Chemical Sciences; droplet size; Edible insects; Emulsifying properties; ingredients; insects; Palm weevil; protein concentrates; Protein extraction yield; Rhynchophorus phoenicis; triacylglycerols
• ISSN: 2666-8335; 2666-8335
• DOI: 10.1016/j.fufo.2021.100037

•Proteins were extracted from Rhynchophorus phoenicis (Rp) larvae by buffers (pH 3–10).•The Rp protein extraction yield and lipids were the highest at alkaline pHs (9–10).•The co-extracted lipids contained at alkaline pHs high levels of free fatty acids;.•The pHs 9.0 and 10.0 aqueous extracts of Rp larvae stabilize oil-in-water emulsions.•Alkaline pHs are suitable to extract and prepared protein concentrate/isolate of Rp. Aqueous extracts of Rhynchophorus phoenicis larvae were prepared at pHs 3.0 to 10.0 to screen their macronutrient composition, emulsifying properties and identify the best conditions to extract a functional protein ingredient. The results showed that the aqueous extracts contained both proteins (0.85 – 4.62 mg/mL), characterized by a large range of molecular weights, and lipids (0.28 to 1.54 mg/mL). The lipids were composed mainly of triacylglycerols (0.21 to 0.95 mg/mL) and free fatty acids (FFA, 0.06 to 0.62 mg/mL) with the highest FFA levels at alkaline pHs; they contained 4.1 to 8.8 g polyunsaturated fatty acids per 100 g total fatty acids. The highest protein extraction yield (54%) of the insect proteins occurred at pH 9.0–10.0. Whatever the extracting pH, the aqueous extracts were able to stabilize oil-in-water emulsions. The emulsions prepared with the pH 9.0 and 10.0 aqueous extracts had however the lowest mean droplet size (d4.3 < 2 µm), and showed no creaming after storage at 4 °C for one weak, indicating that stable emulsions can be prepared at these pHs. Alkaline conditions of extraction will thus be suitable to prepare protein concentrate/isolate of R. phoenicis larvae and test their aptitude to be used to formulate new food products. [Display omitted]