title: Volatile compounds in light, medium, and dark black walnut and their influence on the sensory aromatic profile.
abstract: Light, medium, and dark colored kernels from 3 different cultivars (Emma K, Kwik Krop, and Sparks 127) and one wild species of black walnut were studied for their aroma volatiles. Solid-phase microextraction-gas chromatography-mass spectrometry was used to determine the aromatic compounds present in the headspace of these samples. Partial least square regression was used to correlate the instrumental aromatic data with the sensory responses, obtained in a previous study, for the same samples. Thirty-four aromatic compounds were found in the black walnut cultivars, highlighting among them the presence of 14 esters. Although more than 50% of the total concentration of volatile compounds, esters were not important compounds in determining the differences in the sensory aromatic profiles of the 3 colors of the nuts. As a general trend, the concentration of total volatile compounds was always significantly higher in light black walnuts than in the medium colored samples; medium colored samples had higher volatile content than the dark black walnuts. The presence of hexanal was related to rancid and acrid aromas and was determined to differentiate the dark black walnuts from the medium and light colored samples.
  
  
  CONCLUSIONS
  The data presented in this article will help understand the aromatic differences between light, medium, and dark colored kernels of domestic and wild black walnut. The aromatic profile of these nuts, not studied until this moment, can be used as a model to develop flavorings and new products by the food industries.
authors.affiliation: Hospitality Management, Culinary Arts and Food Science, Drexel Univ, Philadelphia, PA 19104, USA. jeehyun.lee@drexel.edu
authors.forename: Jeehyun
authors.initials: J
authors.lastname: Lee
authors.forename: Laura
authors.initials: L
authors.lastname: Vázquez-Araújo
authors.forename: Koushik
authors.initials: K
authors.lastname: Adhikari
authors.forename: Michele
authors.initials: M
authors.lastname: Warmund
authors.forename: Janelle
authors.initials: J
authors.lastname: Elmore
mesh_terms: D000447:Aldehydes / Q000032:analysis; D004952:Esters / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D031324:Juglans / Q000737:chemistry*; D009754:Nuts / Q000737:chemistry*; D009812:Odorants / Q000032:analysis*; D010936:Plant Extracts / Q000032:analysis*; D052617:Solid Phase Microextraction; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D000447:Aldehydes; D004952:Esters; D010936:Plant Extracts; D055549:Volatile Organic Compounds; C010463:n-hexanal