DESCRIPTIVE ANALYSIS OF KERNELS OF BLACK WALNUT (JUGLANS NIGRA L.) AND PERSIAN WALNUT (J. REGIA L.)

Abstract

Two types of walnuts are valued for their nuts, the Persian walnut (Juglans regia L.) and eastern black walnut (Juglans nigra L.). While there is a well-established market for Persian walnuts, there is a relatively small, but increasing demand for black walnuts in the United States. In spite of their availability in the marketplace, their similarities in sensory characteristics of kernels, as well as their unique attributes have not been explored. The objective of this study was to characterize selected Persian and black walnut cultivars using aroma, flavor, and texture sensory attributes. Twenty-two terms were used for descriptive analysis of walnut kernels. All but two attributes (fruity and painty/rancid) were common to black and Persian walnut kernels. Black walnuts were distinguished from Persian walnuts by their overall aroma and fruity and musty flavors. Overall aroma, fruity, woody, musty, and sweet flavors also varied among the kernels of some black walnut cultivars. Kernels of Persian walnuts generally had higher ratings of nutty, woody and astringent flavors than those of most black walnut cultivars. This study demonstrated that Persian and black walnut kernels share common sensory attributes, but also have unique characteristics. The aroma and fruity flavor of black walnuts can be promoted in the marketplace, which will distinguish them from Persian walnuts.