Effect of temperature-time pretreatments on the texture and microstructure of abalone (Haliotis discus hanai)

The effects of temperature/time pretreatments on the texture and microstructure of abalone (Haliotis discus hanai) meat with the same myofibril extraction rate (60-66.7%) were investigated. The abalone samples were categorized into control and four treatment groups of different heating temperature/heating time combinations as 50 degrees C/120 min, 60 degrees C/10 min, 70 degrees C/5 min, and 80 degrees C/2 min, respectively. Compared to the control samples, the abalone samples heated at 60 degrees C/10 min were the most tender (minimum shear force). It is clear that a sharp reduction in hardness was observed in heat treated abalone meat samples, compared to the raw samples. Nuclear magnetic resonance (NMR) showed that the water distribution pattern in abalone samples changed as they were experiencing different heat treatments. Particularly, the immobilized water components in samples heated at 60 degrees C/10 min increased significantly. The textural properties of these samples evaluated after an 80s-reheating by microwave were of superior quality. It is concluded that the optimal condition for pretreatment abalone was 60 degrees C/10 min, which could significantly improve the textural properties of preprocessed abalones.