Investigation of smoke flavoring development, flavor profile, and polyphenols in pecan shells

Currently pecan shells are a by-product from pecan processing. To eliminate waste from processing several applications have been explored. However, there are no studies for smoke flavoring. The objective of this study was to develop a pyrolysis method, volatile analysis via gas chromatography-mass spectrometry, and nonvolatile analysis using pH, titratable acidity, ˚Brix, and total polyphenols. Twelve pyrolysis samples were created with variance in temperature, time, and moisture. Around 60-180 volatiles were identified in smoked pecan samples, with phenols being the most dominated. The smoked pecan shells were determined to have a pH range of 4.5-5.7, a ˚Brix range of 0.1-0.4, a titratable acidity range of 0.1-0.22%, and total polyphenol concentration from 1.51-12.04 mg/ml. The results suggested that smoked pecan shells had the potential to be used as smoke flavorings, since the smoke pecan shells and benchmarks contained similar volatile compounds. This study provides an approach for food industry to reduce waste and upcycling agricultural biomass.