Development of thermal process for Gaeng Phed Gai in Retort Pouches

Abstract: Gaeng Phed Gai - a traditional Thai dish containing chicken in coconut milk with red chili and striped bamboo shoot - packed in retort pouches was processed to commercial sterility in a still retort. Process lethality was determined by temperature measurements and use of bioindicators. The quality of the product was evaluated by microbiological tests, analysis of nutritional contents and sensory assessment. The product was commercially sterile after the heat treatment, but the sensory quality was insufficient. For taste, juiciness and overall acceptability, heat-treated product received significantly lower scores than the untreated product. Calculations of cook value and further reinforced the impression that the product was overheated due to the slowness of the retort used. Searches in scientific databases revealed reports from several Asian studies of similar products and processes. These show that it is possible to produce food consisting of large pieces in liquid medium, retaining an acceptable quality for extended periods of storage at ambient temperatures. The conclusion is that it should be possible to produce shelf-stable Gaeng Phed Gai with a good quality, if further tests are carried out with a faster retort. It is recommended that pouches with Gaeng Phed Gai are heat-treated to a process lethality (F0) of 10 minutes, as this would guarantee consumer safety and low levels of economical spoilage. An F0 as low as 6 minutes can be used if the initial levels of heat resistant spores in the raw materials are proven to be low by practical tests.