Air-impingement De-shelling of Chestnuts (C. mollisima): Process Parameter Optimization

Abstract

Presently in China de-shelling of chestnuts is done manually, which is tedious, time consuming and labor intensive. The de-shelling operation has become the greatest problem and poses a bottleneck to the chestnut processing industry in China. To overcome this problem, the objective of this study is to derive optimum conditions for chestnut de-shelling using air-impingement de-shelling technology. Response surface methodology was employed to analyze the effects of air temperature (163-197oC), processing time (109-311s) and air velocity (6.68-9.73m/s) on the rate of water loss, de-shelling rate and lightness. Prediction models were also established. Optimum conditions obtained were 179oC of air temperature, 278s of processing time and 7.83m/s of air velocity. Values predicted by the models for the water loss, de-shelling rate and lightness under optimized conditions are 4.14%, 86.95% and 58.65, respectively. The experimental data fit well with the predicted values.