Instrumental Texture Profile Analysis of Date-Tamarind Fruit Leather with Different Types of Hydrocolloids

Date-tamarind fruit leathers with varied textural characteristics were prepared by drying a paste containing hydrocolloid (starch, pectin, dextrin or guar gum) and water at 70 degrees C for 28, 42, 56, 70 and 84 h. Hardness, cohesiveness, adhesiveness, springiness, brittleness, resilience, gumminess and chewiness of the blank date-tamarind fruit leather (i.e., without any hydrocolloid) did not show any correlation with the moisture content ranges (29 - 41 g/100 g sample) used in the present study. Hardness and gumminess increased when hydrocolloids were added, while cohesiveness, resilience and springiness decreased. With the exception of dextrin all other hydrocolloids increased chewiness. Principal Component Analysis (PCA) identified 5 principal components (i.e., 5 factors: plasticity, elasticity, hydrocolloids' concentration, resilience, cohesiveness) affecting the characteristics of each date-tamarind fruit leather. The cluster analysis identified 4 classes of the fruit leathers and bi-plot (i.e., including all products and their characteristics), generated through PCA, recognized these classes as hard-chewy, soft-springy, hard-fragile and soft-resilient leathers.