Development of ready-to-cook Cambodian Korko soup base

Abstract

This study develops a prototype of a ready-to-cook Cambodian Korko soup base by surveying the perception of 400 Cambodian consumers and found that 44.5% of replies prefer ready-to-cook Cambodian Korko soup base in powder form. After that, the effect of different drying temperatures on the properties of Cambodian Korko soup base ingredients (herb, spice, and fermented fish) was investigated on physicochemical, antioxidants, and microbiological properties. At higher temperature 80 oC, water activity, moisture content was decreased faster and DPPH and FRAP were decreased compared to lower temperatures 70 oC and 60 oC. On the other hand, histamine in fermented fish was increased at higher temperatures and Brix. After drying, there were four product prototypes developed including (1) dried form and (2) paste form in the oBrix of 60, 45, and 30. Water activity, moisture content, histamine content, total plate count, yeast, and mold were found over the safety limitation on paste product prototypes such as oBrix of 60, 45, and 30. Therefore, the powder form at 0.38±0.56 water activity was selected for further study. Moisture sorption isotherm of the ready-to-cook Korko soup powder at 30 oC and water activity in the range of 0.113-0.970 were determined by a static gravimetric method. The isotherm exhibited Type III behavior. The moisture sorption data were fitted to the GAB model. The monolayer, taken as the safe minimum moisture level in the product prototype found at 0.068-gram water per gram dry matter. In addition, the ready-to-cook Korko soup powder was monitored during 6 weeks of storage at different temperatures 30 oC, 40 oC, and 50 oC in terms of moisture content, water activity, color, solubility, caking, rancidity, and microbiological properties. The results showed that the changes in physical and chemical properties of the product prototype during storage slightly increased in water activity, moisture content, TPA, and decrease in solubility and color coordinates. In addition, at 30-40 °C and 40-50 °C, the Q10 values were 1.11 and 1.10, respectively. As a result, the instant Korko powder had predicted expiry dates of 3.96, 3.56, and 3.24 years when kept at 30, 40, and 50 °C, respectively. The microorganisms during the storage were within the safety limit under the regulation. Then, the ready-to-cook Korko soup base was evaluated by 32 panelists to score the product prototype preference for further development. The prototype got an overall liking score of 4.1±1.32. From the JAR rating, the prototype had a lower aroma and flavor. The second sensory evaluation (n=30) of the improved prototype showed that the overall liking was 4.67±1.01. Moisture Content, water activity, ash, protein, crude fiber, fat, carbohydrate, solubility, histamine, L*, a*, b* and microorganisms were analyzed on the final product prototype and found at 2.79, 0.375, 22.39, 10.22, 4.27, 2.63, 62.97, 60.82, 32.56, 62.07, 2.37, 20.55, respectively. The number of microorganisms was at the safe level to consume. Hence, the consumer survey (n=400) on the product preferred form was found 44.5% of the powder form.