Effect of heat pretreatment before isoelectric solubilisation/precipitation on the characteristics of Pacific oyster ( Crassostrea hongkongensis) and Antarctic krill ( Euphausia superba) protein isolates
Summary Heat treatment is a convenient way to eliminate the effects of endogenous enzymes on the industrial production of stable products. This study describes the preparation of protein isolates from oysters (OPI and HOPI) and krill (KPI and HKPI) by isoelectric solubilisation/precipitation (ISP) w...
Published in: | International Journal of Food Science & Technology |
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Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2020
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Subjects: | |
Online Access: | http://dx.doi.org/10.1111/ijfs.14702 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fijfs.14702 https://onlinelibrary.wiley.com/doi/pdf/10.1111/ijfs.14702 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/ijfs.14702 |
Summary: | Summary Heat treatment is a convenient way to eliminate the effects of endogenous enzymes on the industrial production of stable products. This study describes the preparation of protein isolates from oysters (OPI and HOPI) and krill (KPI and HKPI) by isoelectric solubilisation/precipitation (ISP) with or without heat pretreatment and comparatively presents their characteristics. The results showed that the solubilities of HOPI (24.08 ± 1.94%) and HKPI (42.29 ± 0.78%) were higher than those of OPI (13.46 ± 0.78%) and KPI (21.71.46 ± 1.51%), and the free and total sulphhydryl (‐SH) content and surface hydrophobicity of HOPI and HKPI were higher than those of OPI and KPI, which are related to higher fat content of HOPI (10.37 ± 0.55%) and HKPI (34.89 ± 1.19%). SDS–PAGE and gel chromatography pattern results showed that macromolecular proteins were degraded by endogenous enzymes in OPI and KPI, while they remained unaffected in HOPI and HKPI. The FT‐IR spectra showed similar patterns between OPI and HOPI and between KPI and HKPI. While the essential amino acid content was similar for OPI and HOPI (47.06 ± 1.33% and 47.93 ± 1.02%), that of KPI and HKPI (50.89 ± 0.89% and 51.19 ± 1.11%, respectively) was not significantly different. |
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