DRYING KINETICS, PACKAGING AND SENSORY ANALYSIS OF HIGH QUALITY DRIED SHRIMP

摘要

The aims of the project were to investigate drying of shrimp with 3 heat sources and to evaluate qualities and reliability of dried samples with 4 different package bags.Inlet drying temperature for all experiments was varied between 69 and 92 °C with constant air flow rate of 1.1±0.1 m/s. The percentage of recycled hot air was fixed at 95%.Initial moisture content of fresh shrimp and anchovy fish was in ranges of 300-400% drybasis. The infrared (IR) drying, hot air (HA) drying, solar drying and combined HA-IR sources were carried out and the desired final moisture content was about of 16±2% drybasis. The results showed that the drying rate relatively depended on drying temperature whilst the drying rate using combined HA-IR sources was faster than drying with other heat sources. The drying kinetic equation using Page’s model was the best fitting to all experimental data.Due to evaluate energy consumption, drying with IR had relative low energy consumption compared to drying with other heat sources.For quality analysis of four different material packaging (Polypropylene, Nylon-LLDPE, Nylon/Al/LLDPE and Vacuum Nylon/Al/LLDRE) during shelf life period, it showed that among ambient air surrounding the water activity, yeast and fungi significantly increased with duration period of storage (p≤0.05) especially for dried shrimp packaging with polypropylene bag. The determination of colorness showed that the redness value of dried shrimp significantly decreased with shelf life period (p<0.05).Finally the sensory evaluation showed that texture and total acceptability slightly decreased when the storage time increased. The suggested storage time of high quality dried shrimp using Polypropylene bag was 3 month, Nylon/LLDPE bag and Nylon/Al/LLDPE bag without vacuum seal was 4 month and finally, dried shrimp packaging with vacuum Nylon/LLDPE bag and Nylon/Al/LLDPE bag can be stored for 5 months.