A study on sensory properties of sodium reduction and replacement in Asian food using difference-from - control test.

This study examined the effects of sodium reduction and flavor enhancers on the sensory profile of two types of hawker foods commonly consumed in Singapore, namely chicken rice and mee soto broth. The 'difference-from-control' test was the method adopted in this study involving 24-29 trained panelists. Combinations included blind control, two levels of sodium reduction, and two levels of flavor enhancers in sodium-reduced recipes. In the sodium-reduced recipes, two levels of NaCl, 0.48% and 0.55%, for chicken rice, and 0.76% and 0.86% for mee soto (equivalent to 31% and 22% reduction in NaCl), were used. Monosodium glutamate (MSG) or Ajiplus (®) (a blend of MSG and nucleotides) at 0.20% and 0.40% were added to the recipes comprising a reduction of 40% in NaCl (equivalent to 31% and 22% reduction in sodium, respectively) compared with the control. It was found that the inclusion of MSG or Ajiplus (®) in 40% NaCl-reduced recipe resulted in a significant increase in perception of umami taste (P < 0.05) when compared to the control. By adding flavor enhancers into the 40%-reduced salt chicken rice recipes, the perception of saltiness was significantly increased when compared to 22% and 31% sodium reduced recipes. Similarly for mee soto broth, there was a significant increase in perception of chicken flavor, umami taste, mouthfeel sensation, and sweet taste (P < 0.05) with a decrease in the perception of sour and bitter taste when compared to control. By adding 0.40% MSG into the 40%-reduced salt recipes, the perception of saltiness was maintained when compared with control.

Identification of high molecular weight proteins in squid muscle by Western blotting analysis and postmortem rheological changes.

The high molecular weight protein connectin (also called titin) in Japanese common squid (Todarodes pacificus) mantle muscle was identified by western blotting analysis with 3B9, the mouse anti-chicken skeletal muscle connectin monoclonal antibody. Similarly to vertebrate samples, there exists connectin in invertebrate squid mantle muscle, and the amino acid sequences are assumed to resemble those present in the A band of vertebrate connectin, judging by the specificity of 3B9. Moreover, the connectin in squid muscle migrated in this study as a closely spaced doublet of alpha and beta (titins 1 and 2). Between 5 and 7 h post-mortem, the SDS PAGE patterns of the squid sample indicated a change of the doublet bands into a single beta-connectin band. Simultaneously, the rheological properties of the squid muscle changed substantially. This degradation of alpha-connectin into beta-connectin in the muscle can explain the critical change that occurs during the post-mortem tenderization of squid muscle.