Consumer acceptability of acha and malted Bambara groundnut (BGN) biscuits sweetened with date palm

Abstract

Biscuits are ready to eat and convenient food product consumed among all age groups in most countries. The objective is to evaluate utilisation of acha, malted BGN and date palm flour in gluten-free, sugar-free biscuits. Mixture design was used to establish the appropriate proportion of acha, malted BGN and date palm flours for consumer acceptable biscuit. The sensory, physical, proximate and microbial properties of the biscuits were determined. The linear mixture model for taste, flavor and overall acceptability significantly (p < 0.05) explained the effect of the components on the sensory quality of the biscuits with strong correlation coefficient ranging from 0.574 for flavor to 0.944 for taste. The adequate precision was greater than 4 and the lack of fit was not significant. Hence, the linear mixture model could be used to navigate the space. Significant differences (p ≤ 0.05) existed in color, taste, flavor, texture, crispiness and overall acceptability of the biscuits. The biscuit produced with 60:10:30 acha, malted BGN and date palm, respectively was most preferred with a mean of 7.3. There was no significant difference between the preferred biscuit and the control 60:10:30 acha, malted BGN and sugar, respectively in colour, taste, flavour, texture except in crispiness. The physical properties for the most preferred biscuit are weight 23.0 g, height 3.0 g, spread ratio 7.7 and break strength 750 g with fat 20.1%, protein 11.9%, ash 2.6%, moisture 1.2%, crude fibre 4.3% and carbohydrate 60.0%. The microbial count for the most acceptable sample ranged from $1.0x{10}^3$ to $4.0x{10}^3$ cfu/g for bacteria and $1.0x{10}^4$ to $5.0x{10}^4$ cfu/g for mold/yeast. Hence, acha, malted BGN and date palm flours could produce consumer acceptable gluten-free, sugar-free biscuits.

Keywords: Acha; Biscuit; Consumer acceptability; Date palm; Food analysis; Food science; Malted Bambara groundnut; Microbial analysis; Mixture design; Nutrition; Physical properties; Proximate composition; Sensory evaluation.

Figure 1

Trace (Piepel) plot (a) and response surface (b) for the effect of acha (A), malted BGN (B) and date palm (C) flours on the taste of the biscuits.

Figure 2

Trace (Piepel) plot (a) and response surface (b) for the effect of acha (A), malted BGN (B) and date palm (C) flours on the flavor of the biscuits.

Figure 3

Trace (Piepel) plot (a) and response surface (b) for the effect of acha (A), malted BGN (B) and date palm (C) flours on the overall acceptability of the biscuits.

Figure 4

Packaged most acceptable acha-malted Bambara groundnut composite. biscuits (XKL- 60:10:30 acha, malted BGN, date palm flour).