Optimization of sunflower albumin extraction from oleaginous meal and characterization of their structure and properties. (February 2020)

• Record Type: Journal Article
• Authors: Sara, Albe Slabi; Mathé, Christelle; Basselin, Mélody; Fournier, Frantz; Aymes, Arnaud; Bianeis, Marine; Galet, Olivier; Kapel, Romain
• Is Part Of: Food hydrocolloids. Volume 99(2020)
• Publication Date: 2020-02
• Subjects: Sunflower albumin -- Solid/liquid extraction -- Response surface methodology -- Multi-objective optimization -- Structure -- Functional; Hydrocolloids -- Periodicals; Food additives -- Periodicals; Colloïdes -- Périodiques; Aliments -- Additifs -- Périodiques; Colloids; Food additives; Periodicals; Electronic journals; 664.06
• DOI: 10.1016/j.foodhyd.2019.105335
• Languages: English
• ISSNs: 0268-005X

Abstract

Abstract: This article proposes an alternative extraction strategy for the valorization of the sunflower meal leading to the production of an albumin isolate for human nutrition and a valuable residual meal for feed application. For this purpose, a response surface methodology was employed to study the effect of pH (3–6) and NaCl (0–0.5 mol.L −1 ) on albumin extraction (yield, content, and phenolic contamination). Total phytate and nitrogen content in residual meal were also considered. As a result, the significant influence (p-value<0.05) of both pH and NaCl concentration on investigated responses was demonstrated. The analysis of regression and variance confirmed a high accuracy of developed models for process prediction. Based on generated equations, a multi-objective optimization was applied for simultaneous maximization of albumin extraction performances and the residual meal value. The best trade-off for sunflower albumin extraction was found at pH 4.1 and 0.25 mol.L −1 of NaCl concentration. Under this condition, good albumin recovery was achieved (>70%), whereas extract was enriched in sunflower albumin fraction (>90% of total proteins) and phenolic contamination of albumins was considerably reduced (<1.6 mg of covalently bound chlorogenic acid per gram of proteins). The selected condition produced value-added residual meal with low phytate level (<4% on dry matter basis) and high protein content (>40% on dry matter basis). Further purification of sunflower albumins yielded a white color product characterized by excellent solubility (approximately 100% at pH 2–11), stable conformation of structure against pH and temperature, and beneficial functional properties (foaming and emulsifying). Graphical abstract: Image 1 Highlights: Selective extraction of sunflower albumins occurred at pH range from 3 to 6. Optimal extraction condition was pH 4.1 and 0.25 mol.L −1 NaCl. Albumins extracted were white, highly soluble and thermoresistant. Functional properties of sunflower albumins were comparable to soy proteins. Low-phytate and high-nitrogen residual meal for feed was obtained.