Green solvent processing: Effect of type of solvent on extraction and quality of protein from dairy and non-dairy expired milk products

Abstract

The present study was designed to study the effect of green solvent processing in two folds, (i) to extract valuable protein from dairy and non-dairy expired milk products and (ii) to compare extraction efficiency and quality of extracted protein using conventional (CS) and green solvents (GS). Ethyl acetate, ethanol, isopropanol, n-heptane and cyclopentyl methyl ether (CPME) were selected as the GS for the possible substitution of hexane and ethyl ether. For each respective solvent, protein recovery, structural and functional modifications were studied. Protein yield was extracted most effectively by GS n-heptane in dairy milk (5.33 ± 0.01%) with a protein purity of 39.73 ± 0.90%. Non-dairy milk and product had similar protein yield when treated with CS and GS. Total mean of extraction efficiency, structural and functional modifications across all samples showed GS solvents were statistically more effective than CS.

Keywords: Ammonium Sulfate (PubChem CID: 6097028); Bicinchoninic Acid (PubChem CID: 71068); Copper (II) sulfate pentahydrate (PubChem CID: 24463); Cyclopentyl methyl ether (PubChem CID: 138539); Ethanol (PubChem CID: 702); Ethyl acetate (PubChem CID: 8857); Ethyl ether (PubChem CID: 3283); Extraction efficiency; Green solvent; Hexane (PubChem CID: 8058); Isopropanol (PubChem CID: 3776); N-heptane; Protein recovery; Renewable protein; n-Heptane (PubChem CID: 8900).