Identification of Key Off-Flavor Compounds During Storage of Fried Pepper (Zanthoxylum Bungeanum Maxim.) Oils by Sensory-Directed Flavor Analysis and Partial Least Squares Regression (Plsr)

Abstract

Fried pepper oil (FPO) is one of widely used flavoring oil in China, but it suffers from complex chemical reactions to give unpleasant odor. The aim of this paper is to study the main causes of off-flavor in FPO, as well as identify key off-flavor compounds in FPO. Fifty-eight volatiles were identified using HS-SPME-GC-MS (headspace-solid phase microextraction-gas chromatography-mass spectrometry) during storage. Fifteen off-flavor compounds were initially targeted by odor activity values (OAVs) calculations and partial least squares regression (PLSR) analysis. Eventually, five key off-flavor compounds were identified by recombination experiments and omission text, which were hexanal, (E)-2-octenal, terpinyl acetate, α-terpineol, and hexanoic acid. The off-flavors are mainly speculated to derive from the oxidative degradation of long-chain fatty acids and the acid-catalyzed rearrangement of terpenes. The results of the study provide a theoretical basis for the regulation of off-flavor in FPO and a practical guide for the industrial production of FPO.

Keywords: Fried pepper (Zanthoxylum bungeanum Maxim.) oil, STORAGE, Off-flavor, Recombination Experiments, Omission Text, Oxidative degradation