Recovery and Functionality of Wash Water Protein from Krill Processing

Microfiltration followed by ultrafiltration was used to concentrate soluble proteins in the wash water of cephalothorax and krill muscle and to remove organic substances and microorganisms. Wash water, concentrate, and ultrafiltrate were characterized. Most of the proteins from muscle thus extracted were less than 67 kDa, while from cephalothorax there was a large amount of 100−150 kDa proteins. Filtrate exhibited low levels of chemical oxygen demand (COD) and total viable count (TVC). Emulsion properties were assayed for different protein concentrations in freeze-dried cephalothorax and muscle concentrates. The first one presented poor emulsion stability in contrast to the second one. Measurements of emulsion activity index (EAI) and stability in the muscle concentrate emulsion were virtually unaffected by ionic strength (0−3% NaCl) and slightly affected by pH. Keywords: Ultrafiltrate; microfiltrate; wastewater; protein emulsion; krill