Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2000.100.103BalochWaqar A. Kaleem BalochMusa A. SaleemShahzada BalochAhmad K. 1200031Water sorption properties of tomato powder at intermediate moisture range (0.11 to 0.88 Aw) was characterized and its storage stability evaluated at 40°C by following changes in carotenoid contents, browning and pH. The sorption isotherm produced was of the sigmoid shape with safe moisture level of 12 percent which confirmed to 0.67Aw. The rate of carotenoid breakdown decreased from 7.6 x1 02 to 0.48 x102 mg/g per hr with the increase in water activity from 0.51 to 0.67 Aw and then it intensified sharply on further rise in water activity. Whereas, the rate for browning and pH increased continuously with gain in water activity. Since appearance of dense brown colour is more deterrent to quality of the product, the stock required for prolonged storage at 40°C may be maintained at a compromised lower water activity levels close to 0.67 Aw so as to retain the desired quality characteristics of the product at an acceptable levels.]]>Anonymous,19891989AOAC.,198414th Edn.,Baloch, A.K., K.A. Buckle and R.A. Edwards,197712309316Baloch, W.A., S. Khan and A.K. Baloch,199732117120Caurie, M.,19705301307Hodge, J.E.,19531928943Jayaprakasha, H.M., K.J. Rao and W.A.L. Kumar,1997w) on the stability of foods: A critical appraisal.]]>34273285Karel, M.,19751975pp: 177-202pp: 177-202Labuza, T.P. and M. Saltmarch,19811981pp: 605-650pp: 605-650Rockland, L.B.,19603213751376Silva, S.D., M.F.F. Leitos, I. Chirose, I. Belazari and R.B. de Campae,19758910918Tripathi, R.N. and N. Nirankar,198926137141Von Elbe, J.H.,19871987pp: 55-74pp: 55-74