不同焙烤温度和时间对澳洲坚果果仁颜色的影响

Effects of Different Roasting Temperatures and Times on the Color of Macadamia Nut Kernels

坚果果仁的颜色在焙烤过程中能发生显著变化。针对澳洲坚果果仁在不同焙烤条件下的颜色指标（亮度值、红绿值、黄蓝值、饱和度和色调角）的变化规律进行研究,并找出焙烤条件与果仁颜色的关系。根据颜色指标的变化规律将焙烤条件大致划分为4个焙烤程度：（1）浅度焙烤。焙烤条件为130℃焙烤10-15 min、150℃焙烤5 min和170℃焙烤4 min,果仁颜色奶白色;（2）中度焙烤。焙烤条件为130℃焙烤25-40 min、150℃焙烤10min和170℃焙烤6 min,果仁颜色淡黄色;（3）中深度焙烤。130℃焙烤50-60 min、150℃焙烤15 min和170℃焙烤8 min,果仁颜色金黄色;（4）深度焙烤。150℃焙烤20-30 min和170℃焙烤10-14 min,果仁颜色深黄色。通过建立焙烤坚果颜色与焙烤程度的关系,更好地指导澳洲坚果的焙烤工艺和拓展坚果产品的应用范围。

The color of nut kernels changes significantly during roasting. Change law of color indexes including lightness value, red-green value, yellow-blue value, chromic value and hue value of macadamia nut kernels roasted in different roasting conditions were analyzed in order to find out the relationship between roasting conditions and the color of nut kernels. All the roasting conditions are divided into four roasting degrees： light, medium, medium-dark and dark, which corresponding to the color changes of kernels. （1）Nut kernels roasted at 130℃ for 10-15 min, 150℃ for 5min and 170℃ for 4 min are divided into light roasting degree, of which kernel colors are similar to creamy white of raw nuts; （2）Nut kernels roasted at 130℃ for 25-40 min, 150℃ for 10 min and 170℃ for 6 min are divided into medium roasting degree, of which kernel colors became light yellow;（3）Nut kernels roasted at 130℃ for 50-60 min, 150℃for 15 min and 170℃ for 8 min are divided into medium-dark roasting degree, of which kernel colors rapidly changed to be golden yellow;（4）Nut kernels roasted at 150℃ for 20-30 min and 170℃ for 10-14 min are divided into dark roasting degree, of which kernel colors become deep yellow. Establishment of the relationship between roasted nut colors and roasting degree could better guide the roasting technology of macadamia nuts and expand application of nut products.