Comparative Quality Evaluation of Roasted Cashew Nut Kernel: Effect of Roasting Methods

Abstract

This study was conducted to determine the effect of two roasting methods on the chemical, microbial as well as the sensory qualities of cashew nut kernels. Raw cashew nut was processed to obtain the plain cashew kernels and was divided into two portions which were subjected to different roasting treatments using conventional-air oven and halogen oven at a temperature of 200°C for 40 min, respectively. Proximate analysis showed that the conventional-oven roasted cashew kernel had higher moisture content, protein and crude fiber values of 4.68%±0.18, 18.34±0.94 and 2.11±0.08, respectively than the roasted sample using halogen-oven. In halogen-oven roasted kernel, the fat, carbohydrate, fatty acid and metabolizeable energy contents were higher (45.62±0.98, 2.53±0.08, 30.04±0.95, 39.23±0.85 and 2480.04±21.00, respectively). The mineral analysis indicated that the halogen-oven roasted kernels had higher values except in the case of Magnesium (Mg), which was higher in the conventional-oven roasted cashew nuts. The microbial assessment of the cashew kernels showed that halogen-oven cashew roasted kernel had a reduced value in all the microbiological analysis carried out with the exception of staphylococcus count. However, <em>E. coli</em> was not present in any of the cashew kernel samples. Based on the sensory rating, halogen-oven roasted cashew kernel had the highest overall acceptability sensory rating. It was observed that chemical parameters of fat, fatty acid and metabolizable energy show positive correlation at both (p<0.01) and (p<0.05) for the sensory attributes of color, taste, crispiness, flavor and overall acceptability while the chemical parameters of moisture content protein and crude fibre showed a negative correlation for all the sensory attributes. The results of this study indicated that halogen-oven will be better option for producing nutritious and wholesome roasted cashew nut kernels with acceptable sensory qualities.