Properties of Salted Shrimp Paste (Kapi) fromAcetes vulgarisas Affected by Postmortem Storage Prior to Salting

The impact of postmortem storage time of shrimp (Acetes vulgaris) on the quality of shrimp and the resulting Kapi, or salted shrimp paste, was investigated. When shrimp were stored at room temperature (28–30C) for up to 15 h, total volatile base, trimethylamine contents, thiobarbituric acid reactive substances, Trichloroacetic acid-soluble peptide content and total viable count increased with increasing storage time. Myosin heavy chain and actin underwent degradation throughout the storage. Kapi with purplish red color became darker and had higher antioxidative activity when shrimp used as raw material were stored for a longer time prior to salting. Kapi showed varying volatile compounds, dependent on the storage time of shrimp and more likely contributed to different flavors. However, Kapi showed the lower odor-likeness score when the unfresh shrimp were used. Therefore, storage and handling time of shrimp before salting had the marked influence on the quality of Kapi. Practical Applications Kapi, or salted shrimp paste, is one of the popular condiments in Thai foods. In general, small shrimp (Acetes spp.) which is used as a raw material for making kapi was susceptible to degradation and oxidation. In addition, the delays in the salting of shrimp always occur due to the transportation before off-loading or processing. During postmortem storage of shrimp, significant deterioration and loss of nutritional value take place, leading to the distorted quality of the final product. Different freshness of raw materials could bring about products with different appearance, flavor, taste as well as other sensorial properties.