Effect of atmospheric concentration and vacuum concentration on the quality of concentrated coconut milk

Firstly,the effects of vacuum degree,temperature and time on the concentration percentage,p H and sensory of concentrated coconut milk(CCM) prepared by atmospheric concentration and vacuum concentration were studied. Then the texture characteristics,sensory quality and storability of the concentrated coconut milk obtained by atmospheric concentration were compared with that of concentrated coconut milk produced by vacuum concentration. Results showed that the concentration percentage of CCM prepared by atmospheric concentration was 49.6% when the concentrated temperature was 90 ℃ and time was 120 min. Compared with atmospheric concentration,the concentration efficiency of CCM could reach to 51.7% when the vacuum degree was 0.75,temperature was 45 ℃ and time was 60 min,and the CCM looked white and without brown and separation of oil-water. Moreover,test of texture characteristics and sensory quality showed that the CCM produced by vacuum concentration exhibited better texture characteristics. After stored at 37 ℃ for 30 days,the acidity,colony unit forming and peroxide value of the CCM with vacuum concentration were not obviously changed. Whereas,the acidity,colony unit forming and peroxide value of the CCM gained with atmospheric concentration increased(p<0.05),and its p H obviously decreased to 4.5.