กระบวนการผลิตน้ำพริกแกงเผ็ดกระป๋องโดยเทคโนโลยีเฮอร์เดิล / อรอง จันทร์ประสาทสุข = Hurdle technology for canned red curry-paste process / On-ong Chanprasartsuk
The objective of this research was to apply the hurdle technology to the canned red curry- paste process in order to reduce the heat required to destroy microorganisms. Spices used included dried big chilli, dried chilli, garlic, red onion, kaffir, lemongrass and galanga. The optimum number of washing the spices was investigated. The washed spices were then ground into red curry-paste. The chemical, physical and microbiological properties of the red curry-paste were analysed. The paste was then adjusted to pH 4.0-5.0 using citric acid and a[subscript w] 0.83-0.93 using salt. The samples were incubated at 55 ํC up to 20 days for microbiological investigation. The results showed that washing dried big chilli, dried chilli, garlic, red onion, kaffir and galanga 2 times and lemongrass 3 times were optimum to reduce the Total Plate Count (TPC) and C. botulinum. The prepared red curry-paste had pH, a[subscript w] and moisture content of 5.3, 0.96 and 64%, respectively. The TPC was 4.93 log CFU/g and viable C. botulinum was not detectable. For the adjusted pH and a[subscript w] red curry-paste, the red curry-paste having pH of 4.0 and a[subscript w] of 0.83-0.93 had the lowest TPC. There was no viable C. botulinum in all red curry-paste samples. And the microorganism survived in the red curry-paste having pH of 4.0 and a[subscript w] of 0.93 was found to be B. stearothermophilus. The process time of the red curry-paste at 110 ํC with 3D- and 5D-process was 61 and 87 minutes, respectively. After incubation at ambient temperature, 35 ํC and 55 ํC up to 1 month, there was no B. stearothermophilus detected.
