Effect of pork meat proteins on the binding of volatile compounds

The binding ability of pork meat proteins (sarcoplasmic, myofibrillar and isolated actin and actomyosin) was determined by measuring the relative headspace concentration of the volatile compounds in the presence of each protein (expressed as percentages of the free volatiles relative to a standard solution without protein) using solid-phase microextraction (SPME) and gas chromatography analysis. The sarcoplasmic homogenates bound higher quantities of the volatile compounds assayed (3-methylbutanal, 2-methylbutanal, 2-pentanone, hexanal, methional and octanal) than myofibrillar homogenates. The addition of salts also affected the binding ability of sarcoplasmic and myofibrillar proteins. Actomyosin was able to bind all the assayed volatile compounds although the binding depended on protein concentration and conformation, and it was highly affected by frozen storage. On the other hand, G-actin was unable to bind any of the assayed volatile compounds although the polymerized form (F-actin) bound higher quantities of the volatile compounds. (C) 2007 Elsevier Ltd. All rights reserved.