Effect of alkaline pH-shift processing on in vitro gastrointestinal digestion of herring (Clupea harengus) fillets
Artikel i vetenskaplig tidskrift, 2013

The effect of alkaline pH-shift processing on herring (Clupea harengus) protein oxidation, salt solubility and digestibility, has been evaluated. For the latter, herring mince and pH-shift produced herring protein isolate, both raw and heat-treated, were digested using a static gastrointestinal in vitro model. The pH-shift process resulted in drastically lowered protein salt solubility and increased lipid oxidation while protein carbonyl formation was unaffected. Yet, no significant differences in the degree of hydrolysis (DH) were observed between mince and isolates after completed gastrointestinal digestion, something which was confirmed by a similar release of proteinaceous material <3 kDa and similar free amino acid profiles. The polypeptide profiles of digested samples however revealed that two peptides (33 and 36 kDa) were present in larger amounts in the digested protein isolate compared to the digested herring mince. The results indicate that alkaline pH-shift processing had limited quantitative influence on the gastrointestinal digestibility of herring proteins despite its negative effects on protein salt solubility and lipid oxidation.

functional proteins

digestibility

acid solubilization

gelation characteristics

Solubilisation

myofibrillar proteins

solubilization process

lipid oxidation

pH-Shift

proteins

cod muscle

muscle

by-products

Precipitation

Salt

Alkaline

Gastrointestinal

Oxidation

In vitro digestion

Författare

Sofia Marmon

Chalmers, Kemi- och bioteknik, Livsvetenskaper, Livsmedelsvetenskap

Ingrid Undeland

Chalmers, Kemi- och bioteknik, Livsvetenskaper, Livsmedelsvetenskap

Food Chemistry

0308-8146 (ISSN)

Vol. 138 1 214-219

Ämneskategorier

Klinisk medicin

Hälsovetenskaper

DOI

10.1016/j.foodchem.2012.10.035