Comparison of peanut butter color determination by CIELAB L,a,B and Hunter color-difference methods and the relationship of roasted peanut color to roasted peanut flavor response

Information concerning an optimum roasted peanut color to which peanut samples should be roasted for optimum roasted peanut attribute response is incomplete. Comparison of the Minolta Chroma Meter II CR-100 and Model 96 Spectrogard color systems indicates that the CR-100 system can be used for the measurements needed. However, it only gives CIELAB color values directly. A simple equation, Hunter L = CIELAB L - 7, can be used to convert L values to L values in the L range 52-65. By use of four data sets from a 3-year period, an optimum L value was found to which peanuts should be roasted to obtain optimum roasted peanut attribute response. Across these data sets optimum L varied from 58.2 to 59.5, suggesting that samples should be roasted to L values of 58-59 or L values of 51-52 when optimum roasted peanut attribute is of primary interest. Analysis of the data has shown that adjusting for overroast and/or underroast attributes when present reduces the correlation to zero between the roasted peanut attribute and roast color