KEEPING FRESHINESS DF TILAPIA BY PARTIAL FREEZING

Effect of partial freesing on keeping freshness of tila,pia was investigated. Changes in K value, an index for estimating freshness, bacteria number and. pH value were fallawed during storage at一3±0.55℃. The results were compared with that ire storaged. The out sections of muscle tzssus were observed. under microseope and conpared with fresh and the fish frozen at一18℃. The results obtained were summarised as follows: 1.Though. the temperature of ps.rtial fxeezing was only three degrees lower than ice storage, the preservation effect was shown much better. In the case storage period could be prolonged to one month. 2. There was no definite intercorrelation between pH and freshness. 3.The fce crystal farmed in fish muscle storaged at 3±0.55℃ was the type of slow freezing，frozen water percentage was lower than that of storaged at 一18℃ and muscle tissue of non-frozen part seemed no differencfl from fresh muscle.