Optimization of the technology for peeling hickory kernel by lye

The technology of peeling hickory kernel by lye was studied. Based on the single factor experiments, rotation regression orthogonal combination design with three factors and five levels in which concentration of NaOH, soaking temperature and soaking time were chosen as examining factors and peeling effect was chosen as assessment index which was quantitated in order to decrease assessing error in this design was used. Then a regression equation was founded using the data in the design. After the statistical test and analysis of the equation, the optimum condition was found as follows: concentration of NaOH , soaking temperature and soaking time 0.9%, 78℃ and 3min separately. Under this condition, the theoretic extremum of the peeling effect(mark) was 96.6. The results of scale-up experiments showed that hickory kernels were very easy to peel and the quality of kernels was good.