Descriptive sensory analysis of light, medium, and dark colored kernels of black walnut cultivars

Abstract

Abstract BACKGROUND: Kernels of black walnut trees ( Juglans nigra L.) are characterized by their unique fruity, woody, musty and sweet flavors. While most of the crop is produced from native trees, an increasing volume of kernels is harvested from grafted trees of improved cultivars. Cultivars produce nuts with desirable cracking qualities and have larger kernel size than those of native trees. However, kernel color of black walnuts can be variable due to time of harvest and hulling. The objective of this study was to evaluate flavor attributes of light, medium and dark colored kernels of Emma K, Kwik Krop, Sparks 127 and wild black walnut trees. RESULTS: Eighteen flavor terms were used for descriptive analysis of walnut kernels. Floral/fruity and sweet flavors varied among wild and Sparks 127 kernels. Various flavor characteristics were affected by kernel color. Dark colored kernels had more intense burnt, musty/dusty, oily, woody, astringent, and sour flavors than light colored kernels. CONCLUSION: This study demonstrated that eliminating dark colored Emma K and Sparks 127 kernels by color sorting will likely limit acrid, rancid and bitter flavors in the marketplace, which may be perceived as unappealing by consumers. Light colored kernels are produced by shaking trees early in the harvest season and hulling fruits immediately after harvest. Copyright © 2009 Society of Chemical Industry