The Hibiscus sabdariffa calyxes’ residue (HSR) remained after the extraction of beverage is discarded which contributes to environmental pollution. The objective of this study was to explore the suitability of incorporating different amount of HSR (0%, 1.25%, 2.5%, 3.75%, and 5.0%) in crackers to enhance dietary fiber and antioxidant content. Physicochemical properties, antioxidants activity, nutritional quality, sensory profile and microstructure properties of samples containing HSR were examined and compared with control crackers. Cracker protein and fat levels decreased as HSR increased from 0.0% to 5% while ash increased. The total dietary fiber DF increased from 3.36% to 8.17% where the highest DF was reached at 5% HSR. The content of phenols increased from 5.99 to 17.57 mg/g and total flavonoid content increased from 49.36 to 104.63 mg/g of crackers incorporated with 5% HSR. DPPH radical scavenging activity increased two fold by increasing HSR up to 5%. HSR containing crackers exhibited darker L values than none/less HSR containing ones. In sensory ranking tests, acceptable crackers with pleasant flavor were obtained by incorporating up to 3.75% HSR into the cracker’s formula. Crackers prepared with 5% HSR received the poorest sensory rating compared to non/less HSR enriched cracker. Scanning electron microscopy (EM) images of the prepared crackers revealed marked changes caused by incorporating HSR as upon HSR addition the surface was observed to be scratched, cracker and rougher. Overall results suggest that HSR is a potential functional food ingredient high in fiber content and antioxidants activity that may be processed into flour and used in food applications, such as baked goods.

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late gluten-free bakery products. The gluten-free bakery products available on the market present poor organoleptic quality, not comparable to wheat ones. Research and development is needed to improve the structure, mouth feel, texture, acceptability and shelf-life of these products. Results from a number of recent studies have highlighted the need for an improvement in the quality of cereal based gluten-free products. Reduced volume, tough and/or dense texture, and reduced flavor development are among the problems that gluten-free bakery products are suffering from [Sumnu et al., 2010].Although the tiger nut cultivation dates back to ancient Egypt, where tubers were found in sarcophagi and tombs of the earliest dynasties, it is largely unexploited [Tigernuts Traders, 2013]. Tiger nut (Cyperus esculentus) belongs to the family Cyperaceae and the order, Cyperales. Tiger nut is a tuber that is grown in the soil and is found worldwide in warm and temperate zones, occurring in Southern Europe and Africa. It has a dimension ranging from 6-10 mm and occurs in different varieties. The color is brown and has a sweet flavor when eaten. Tiger nut has been used extensively mainly for human consumption in Spain [Ukwuru et al., 2011; Tigernuts Traders, 2013] and eaten cold as drink. Tiger nut can be extracted into milk like liquid that is treated and bottled. The flour is used to make cakes and biscuits while oil is used for cooking [Wise, 2013].During the last decade, considerable efforts have been directed towards improving the gluten-free product qual- The effect of using tiger nut flour to improve the functional properties of gluten-free biscuit was explored. Corn flour in the biscuit formulation was replaced at three levels, 10, 20, and 30% with tiger nut flour (TNF). Biscuit containing only corn flour was used as control. Prepared biscuits were analyzed for their proximate composition, physical properties, diameter, thickness, color, texture, and were subjected to measurements using differential scanning calorimetery (DSC) and scanning electron microscopy (SEM).Incorporation of tiger nut flour resulted in a significant increase in fibre and ash contents and in a decrease in protein content. The spread ratio of the biscuits increased significantly by increasing TNF content, which is considered a desirable quality attribute. Tiger nut-containing biscuits exhibited lower total color difference ∆E value compared to the control sample.Thermal characteristics of TNF-containing biscuits differed significantly (P≤0.05) from the control where TNF resulted in decreased onset gelatinization temperature (To) and peak temperature (Tp). Furthermore, enthalpies of control biscuits were significantly higher than of those containing TNF; that might be due to partial gelatinization since their enthalpies were smaller than in control biscuits.Measurement of baked biscuits texture showed that hardness and resilience values decreased when TNF content in the biscuit formulation increased. Microscopic observation revealed that TNF-containi...

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