Physico-chemical characterization of date varieties using multivariate analysis

BACKGROUND: The fruit of date palm is consumed as an ideal high-energy food. It is also used for the treatment of colds, fever, liver and abdominal troubles. Its nutritional composition strongly depends upon variety and ripening stage. A number of varieties are available in Pakistan but little is known about their composition and nutritional characteristics. Inherent moisture, volatile matter, ash, fixed carbon, sugar and mineral metals of seven commercial date varieties (Aseel, Basra, Begun, Janshoor, Mazoee, Rabee and Zaidi) were investigated. The physical and chemical compositions with respect to maturation were also monitored for the Aseel variety. RESULTS: The results showed significant varietal differences in moisture, ash and mineral metal composition when analysis of means was conducted at an alpha level of 0.05. The difference between means was insignificant (P > 0.05) for volatile matter, glucose, fructose and total reducing sugars. All varieties were found to be an excellent source of total reducing sugar (78%), potassium (403 - 632 mg per 100 g) and calcium (27.41 - 81.47 mg per 100 g). A gradual increase in total reducing sugar and minerals, especially potassium and copper, was observed with maturation. Variety Aseel was grouped on the basis of maturation using principal component analysis. Local date varieties were separated with 48.63% level of similarity from Iranian variety (29.17%) using Cluster analysis. CONCLUSION: This study provides an overview of the physico-chemical properties of date varieties. The sample varieties showed significant differences except for sugar and volatile matter. Multivariate analysis was found to be an important statistical tool for the separation of samples on the basis of geographical origin and maturations. (c) 2008 Society of Chemical Industry.