Abstract
Aqueous dispersion properties of a protein concentrate
obtained from turnip rapeseed (Brassica rapa) press cake
were investigated. Protein content of the press cake was
enriched from 35.9% to 45.8% by sequential
supercritical-CO2 extraction, milling and air
classification. The protein denaturation degree and the
solubility in the prepared protein concentrate were
compared with a commercial canola protein isolate.
Partial loss of the protein native structure was observed
in the protein concentrate. The ?-potential in the
soluble fraction of the protein concentrate dispersion
was ca. 20 mV lower (more negative) compared with the
commercial isolate at pHs 4-10, which was attributed to
the presence of charged carbohydrates such as pectin in
the protein concentrate. To improve the dispersion
stability of the protein concentrate, enzymatic
crosslinking with transglutaminase and microfluidization
at 1850 bars were applied. Microfluidization resulted in
the formation of rod-like aggregates formed mainly of the
insoluble cell wall polysaccharides glued together with
proteins as imaged by confocal laser scanning microscopy.
Improvement in colloidal stability was observed in all
samples upon microfluidization. Pre-treatment with
transglutaminase resulted in different distributions of
the components in the rods and further improved
dispersion stability against sedimentation. Heat
treatment caused compaction of the structures.
Original language | English |
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Pages (from-to) | 29-37 |
Journal | Food and Bioproducts Processing |
Volume | 99 |
DOIs | |
Publication status | Published - 2016 |
MoE publication type | A1 Journal article-refereed |
Keywords
- microfluidization
- protein concentrate
- rapeseed
- solubility
- transglutaminase
- turnip rape