Se in Se-enriched peanut, and losses during peanut protein preparation

This study determined the Se species in Se-enriched peanut, and Se losses during peanut protein processing by enzymatic extraction, high-performance liquid chromatography (HPLC) separation and inductively coupled plasma-mass spectrometry determination. The study revealed that mixed enzymes (protease and lipase, 2:1 w/w) in Na2S2O3, assisted by 1h ultrasonic processing, could effectively extract Se speciation from defatted peanut powder. Separation of organic Se by HPLC was optimised using pentafluoropropionic anhydride at a concentration of 0.1% in 2% methanol as mobile phase. Selenomethionine is the dominant Se species in peanut, accounting for 65% of the total Se. During the peanut protein preparation, nearly 37% of Se losses were due to the complexity of the multistage process. The loss can be ascribed to volatilisation, dissolution, degradation or other physical modes of transfer or loss.