Physicochemical properties and sensory evaluation of green and red spinach crackers

Abstract

Green and red spinach are leafy vegetables prepared in varieties of Malaysian dishes. Utilisation of vegetables or fruits in baked foods such as crackers could increase nutritional values besides creating new flavor of the food. The objectives of this study were to determine the physicochemical properties and sensory acceptability of crackers incorporated with green spinach (Spinacia oleracea) and red spinach (Amaranthus dubius). The crackers were prepared by substituting 5%, 10% and 15% of green or red spinach with flour in the formulations. The formulated crackers were analysed for proximate compositions according to AOAC Methods, hardness and colour properties were determined using Texture Analyzer and chromameter respectively. Descriptive sensory evaluation was performed using 7-scale hedonic method to determine products preferences. The results showed that flour substitution with green or red spinach powder had decreased the moisture (3.35 to 10.48%) but increased the ash (2.34 to 3.23%), fat (11.2 to 13.93%) and protein (8.61 to 9.79%) content of crackers. Hardness values of both crackers were increased (4500 N to 5461 N) with increasing percentage of spinach powder used. The hardness decreased as longer time of storage applied. Lightness, redness and yellowness of crackers decreased with increased percentage of spinach used. Similarly, the colour intensities were decreased during four weeks of storage. In sensory evaluation, the lowest percentage of spinach in crakers (5%) received higher sensory acceptabilities than control and other formulations. In conclusion, the incorporation of green or red spinach in crakers at all percentages had increased nutritional values. The incorporation of 5% of green or red spinach received higher consumers' acceptability among all formulations. It is recommended that green or red spinach powder could be incorporated in crackers up to 5% level for commercialization.