To better understand the role of peach proteins in juice precipitation induced by high pressure CO2 (HPCD), proteins extracted from peach juice were subjected to HPCD and heat, and changes in particle size distribution (PSD) and structure were investigated. PSD analysis showed aggregations of proteins were both induced by HPCD and heat, but HPCD induced a stronger aggregation. The endotherm of HPCD- and heat-treated proteins moved to lower temperature, indicating that higher-order structures were altered after treatments. Furthermore, proteins related to HPCD- and heat-induced precipitation were analyzed by proteomics and bioinformatics. It was found that proteins with low content of α-helix and hydrogen bonds were more inclined to precipitate under HPCD, and HPCD precipitated proteins with more compact structures than heat, which might cause the stronger aggregation of proteins by HPCD. In conclusion, HPCD could induce the aggregation of peach proteins by destroying higher-order structures, which contributes to juice precipitation.
Keywords: Ammonium sulfate (PubChem CID: 6097028); Bromophenol blue (PubChem CID: 8272); CHAPS (PubChem CID: 107670); DTT (PubChem CID: 19001); High pressure CO(2); Peach protein; Precipitation formation; Structural analysis; Thiourea (PubChem CID: 2723790); Tris–HCl (PubChem CID: 93573); Urea (PubChem CID: 1176).
Copyright © 2016 Elsevier Ltd. All rights reserved.