Physical and structural characteristics of dates

This chapter presents the geometric characteristics, sorption isotherm, state diagram and instrumental texture profile analysis (TPA) of dates. The surface area and volume of date fruit can be estimated considering its shape as oblate spheroid. The GAB model parameters for date-fruits are compiled and can be used to predict the moisture sorption isotherm within the water activity 0.1 and 0.9. The BET monolayer values of date flesh vary from 8.88 to 12.43 g/100 g dry solids. Parameters of the Chen model for predicting freezing point are compiled for different dates. Similarly, parameters of Gordon-Taylor model are also compiled. The ultimate maximal-freeze-concentration condition of Deglet Nour dates was determined T_m' equal to -38.2 �C and T_g' as -48.0 �C with unfreezable water as 22 g/100 g. Thermal and mechanical analysis can be used to explore different structural characteristics of date flesh; these are matrix mobility, reaction and softening characteristics, melting and instrumental TPA.