Thermal processing conditions affect in vitro immunostimulatory activity of Aloe vera juice

Aloe vera is known for its immunomodulatory effects. Aloe juice is regarded as health drink. Aloe juice is subjected to thermal processing to preserve its quality. In the present study, effect of heat treatment and concentration on immunostimulatory activity of Aloe vera juice was assessed through in vitro lymphocyte proliferation activity and phagocytic activity. Aloe vera juice was subjected to different heat treatments viz. 70 degrees C/10 min, 80 degrees C/10 min, and 121 degrees C/15 min. Applied heat treatment had no significant (p > 0.05) effect on lymphocyte proliferation activity of Aloe juice. However, with an increase in the concentration (> 1 mu L), sterilized (121 degrees C/15 min) Aloe vera juice showed reduction in lymphocyte proliferation activity. Control Aloe juice samples obtained highest phagocytosis (%) values compared to the heat treated samples. At higher temperature processing (80 degrees C/30 min and 121 degrees C/15 min) and concentrations (300 mu l) a significant (p < 0.001) decrease in phagocytosis (%) of Aloe juice was observed.