fifteen shrimps per treatment were soaked in the solution of amino acid at 1.0 g/100 ml in combination with 3.0 g/100 ml NaCl at a ratio of shrimp: solution at 1: 1.5 (by weight) for 3 h at 4 ± 1 C.Each amino acid: nonpolar amino acid (phenylalanine, methionine,proline, isoleucine, and glycine), polar uncharged amino acid (threonine), negatively charged amino acid (glutamic acid), and
basic positively charged amino acid (lysine and arginine) were usedin the preliminary study in order to select appropriate amino acids for the shrimp treatment before freezing. The sample soaked in the water without any salt or amino acid was set as a control. After soaking, the shrimps were drained for 5 min, packed in polyethylene bags and then frozen in an air-blast freezer (Thermoscience®) at 30 C with air-velocity of 5 m/s until the core temperature reached 18 C. The core temperatures were recorded by using thermocouples with a data logger. The frozen samples were stored in a freezer (18 C) for a week before the analysis. Soaking and thawing yield were determined after a freeze-thaw cycle before the shrimps were cooked and sensory tested. All experiments were carried out in three replications and the results
were averaged.