Protein isolate of coffee seed meal obtained by a response surface methodology: a new antioxidant's source

• Published in: Journal of food measurement & characterization 2023-08, Vol.17 (4), p.4100-4113
• Main Authors: Jmoui, Ines, Mechmeche, Manel, Khalfallah, Roua, Setti, Khaoula, Hamdi, Moktar, Kachouri, Faten
• Format: Article
• Language: English
• Subjects: Amino acids; Animal protein; Antioxidants; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Coffee; Electrophoresis; Engineering; Food Science; Food sources; Freeze drying; Functional foods & nutraceuticals; High performance liquid chromatography; Hydrophobicity; In vitro methods and tests; Liquid chromatography; Low molecular weights; Lysine; Meals; Methionine; Molecular weight; Original Paper; Proteins; Response surface methodology; Seed meal; Seeds; Tyrosine; Valine
• ISSN: 2193-4126; 2193-4134
• DOI: 10.1007/s11694-023-01926-4

Faced with the problems of animal protein price increases, the development of new, inexpensive and sustainable sources of protein will be a prerequisite. Seeds meals may be one of such source, also upgrading them is a solution to a major environmental problem. Coffee seed meal is one of these by-products. In this work, we thought to value it by preparing a protein isolate by response surface methodology (RSM) and central composite rotatable design (CCRD) methods. Results showed that the protein yield of the optimized defatted and roasted coffee protein isolate (DRCPI) under these conditions was 85.70% which was in good agreement with the value predicted by the model (82.52%). Three protein components with low molecular weight were identified by gel electrophoresis. DRCPI also showed higher antioxidant capacity determined by four in vitro methods (DPPH, ABTS, AAT, FRAP). Amino acids content was also determined by HPLC (High Performance Liquid Chromatography) and showed that DRCPI contains the most essential amino acids with predominance of methionine–valine (212.76 mg/100 g), also the presence of tyrosine and lysine in addition to the hydrophobic amino acids (591.82 mg/100 g) that improve the antioxidant activity. The obtained results indicate that DRCPI with good functional properties can be used in various applications. Freeze-drying has improved the nutritional and biological quality of the protein isolate, which makes it important to think about their valorization in functional food.