Physico-chemical and nutritional evaluation of cookies with different levels of eggplant flour substitution

Abstract

Four types of eggplant – Chinese eggplant (CE), Green Goddess eggplant (GGE), Indian eggplant (IE), and Thai eggplant (TE) – were used to develop cookies (10% and 15% of substitution). Substitution of eggplant flour has significantly increased the nutritional values of cookies (protein, crude fiber, and fat). Eggplant cookies also showed higher total phenolic content (TPC) and free radical-scavenging effect on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical compared to control. IE cookies showed the highest TPC and DPPH values, followed by TE, GGE, and CE. Cookies with 15% substitution level of all eggplant flour had significantly lower peroxide values showing greater stability against rancidity and oxidation compare to control cookies (IE > TE > GGE > CE > control). Incorporation of eggplant flour had significantly increased the hardness and a* values (color parameter) of cookies. Overall, the nutritional value of cookies was improved by the substitution with eggplant flour and IE cookies showed the greatest in terms of overall properties.