Author : Suwan Viratchakul

Summary : Determination of drying rate of herring in the dryer at various drying temperatures and different air velocities showed that the drying rate was dependent on both the drying temperature and the air velocity. The higher the drying temperature and the air velocity, the more rapid the rate of drying. Drying temperature as high as 76.7 deg C (170 deg F) coupled with 5,600 cmps. air velocity could be used satisfactorily for herring. The study on equilibrium moisture content (EMC) of dried herring indicated that at 43.3 deg C (110 deg F) and 70 percent relative humidity the EMC was 36.7 per cent. This indicates that herring must be dried to a moisture content below 36.7 per cent to have a longer shelflife. The effect of potassium sorbate as a fungistatic agent in the storage of dried herring was only to delay the development of mold growth. The use of polyethylene bag as packaging material delayed browning and off-odor development, but did not prevent the fungal growth. Dried herring stored at 21.1 deg C (70 deg F) has longer shelflife and better quality than those stored at room temperature.