The traditional method to measure the freezing point of fruit is freezing the juice in NaCl saturated water ()6
C) while reading the temperature every 30 s. If we use this method we can only get the freezing point of juice
and cannot get the freezing point of the fruit. We confirmed that the freezing point of fruit is different to that
of juice. When the fruit is frozen, ice crystals are formed in the gap between the cells first. With the increase in icecrystal water comes out of the cells and makes the cells smaller. The cell membrane prevents water transferring out of the cells, which makes it difficult to form the ice crystals. Meanwhile, the respiration of fruit gives out heat. All the above factors bring down the freezing point of fruit. In the juice the freezing point is only affected by
the concentration.