Physical characteristics, nutritional composition and acceptability of gluten-free crackers produced from germinated pearl millet (Pennisetum glaucum), defatted-sesame seed (Sesamum indicum) and defatted-tigernut (Cyperus esculentus) composite flours

AbstractCrackers are flat, crispy, baked snacks typically prepared from wheat flour. Recently, increasing efforts are being made towards the use of novel ingredients with health, economic and nutritional benefits in the production of crackers. In this study, physical, chemical and sensory characteristics of gluten-free crackers (GFCs) developed from germinated pearl millet, defatted-sesame seed and defatted-tigernut composite flours (90:0:10, 80:10:10, 70:20:10, 60:30:10) against those of 100% wheat cracker (WHFC) were investigated. Compared to wheat flour, formulated composite flours demonstrated higher water and oil absorption capacities but swelling indices were comparable. While WHFC showed higher (P < 0.05) colour characteristics (L*, a* and b*) as well as higher weight, thickness and diameter, the GFCs exhibited improved spread ratio. The developed GFCs were also higher in ash (2.41–2.71%), fibre (3.63–4.18%), protein (9.14–12.21%), and energy (376.82–381.58 kCal/100 g) but lower in carbohydrates (67.60–69.76%). Phytates were generally low in all the crackers, whereas WHFC showed highest trypsin inhibitors (8.8 mg/100 g). GFCs containing defatted-sesame seeds had the highest calcium (2.81 mg/100 g) and lowest iron (0.17 mg/100 g) contents, respectively. In vitro protein digestibility was generally higher (P < 0.05) in the developed GFCs than wheat cracker. Mean sensory scores of > 6 on a 9-point Hedonic scale indicated that the GFCs were generally accepted by the panellists. The study revealed the potentials of composite flours prepared from germinated pearl millet, defatted-sesame seed, and defatted-tigernut flours in the production of acceptable, nutritious and healthy crackers.