Effect of Baking Temperature on the Quality of Baked Sweet Potato Crisps

Aim: To investigate the effect of baking temperature on the quality characteristics of baked sweet potato crisp samples.
Place and Duration of Study: Department of Food Technology, Federal Institute of Industrial Research, Oshodi, Lagos Nigeria, from February to October, 2013.
Methodology: Yellow fleshed sweet potato were mashed upon cooking to form dough; and mixed with other baking ingredients. The developed dough was shaped and baked using five baking temperature levels (110ºC, 120ºC, 130ºC, 140ºC and 150ºC). The following analysis were carried out on the baked sweet potato crisp namely –proximate, textural and sensory analysis. The results obtained were statistically analyzed using Analysis of Variance and the means separated using Duncan Multiple Range Test (DMRT).
Results: The result of the proximate analysis shows that moisture content ranged between 3.31 to 5.76 %, crude protein 2.61 to 3.22 %, fat 8.93 to 14.01%, crude fibre 2.59 to 4.79 %, ash 2.56 to 3.59 % and carbohydrate 71.56 to 78.15%. The result of the textural properties of the circular baked sweet potato crisps (dough thickness of 3.3mm and 30mm diameter) showed that the force at peak of the baked crisp samples ranged between 5.83 to 20.30 N, deformation at peak ranged between 1.33 and 2.22mm, while deformation at break ranged between 1.88 and 3.69mm. Sensory evaluation of the baked sweet potato crisps showed that crisp sample baked at 120ºC had the highest sensory rating of all the samples in terms of overall acceptability.
Conclusion: The study revealed the possibility of producing crunchy baked sweet potato crisps using a baking temperature range not exceeding 140ºC. There is however need to strike a balance between the desirable sensory qualities and the textural properties to ensure product that would be acceptable to consumers.