Evolution Analysis of Free Fatty Acids and Aroma-Active Compounds during Tallow Oxidation.

Shiqing Song,Xiaoyan Tian,Feiting Zheng,Lei Shi,Min Sun,Tao Feng,Lingyun Yao

doi:10.3390/molecules27020352

Abstract

To explore the role of fatty acids as flavor precursors in the flavor of oxidized tallow, the volatile flavor compounds and free fatty acid (FFAs) in the four oxidization stages of tallow were analyzed via gas chromatography (GC)–mass spectrometry (MS), the aroma characteristics of them were analyzed by GC–olfactory (GC-O) method combined with sensory analysis and partial least-squares regression (PLSR) analysis. 12 common FFAs and 35 key aroma-active compounds were obtained. Combined with the results of odor activity value (OAV) and FD factor, benzaldehyde was found to be an important component in unoxidized tallow. (E,E)-2,4-Heptadienal, (E,E)-2,4-decadienal, (E)-2-nonenal, octanal, hexanoic acid, hexanal and (E)-2-heptenal were the key compounds involved in the tallow flavor oxidation. The changes in FFAs and volatile flavor compounds during oxidation and the metabolic evolution of key aroma-active compounds are systematically summarized in this study. The paper also provides considerable guidance in oxidation control and meat flavor product development.

Highlights

Lipid oxidation or decomposition can lead to an undesirable flavor
Leanness is responsible for the basic meaty flavor common to all meat types, whereas volatile compounds sourced from different types of lipids can provide meat its characteristic flavor [4]
Varlet found that in fish, fatty acid and triglyceride oxidization led to the production of hydroperoxides, which degraded to produce many saturated or unsaturated aliphatic aldehydes the most important hydroperoxide decomposition products [11]

Summary

Introduction

Lipid oxidation or decomposition can lead to an undesirable flavor. the oxidative degradation of lipid is essential for the development of the characteristic meat flavor [1,2]. Many of the compounds in meat are lipid oxidation and free radical reaction products all of which play an important role in the formation of the distinctive flavor characteristics of meats such as beef, pork, and lamb [3]. Many researchers have explored the importance of lipid oxidation and degradation in characteristic flavor formation in meat products under different processing conditions. These meat products have included Beijing duck, marinated pork meat, and Chinese bacon [5,6,7]. Oxidative lipid degradation produces many volatile compounds, and hundreds of volatile compounds have been identified in heated beef fat. Nonanal is the most significant aldehyde produced via oleic acid oxidation [13]. 1-Octen-3-ol, which has a strong mushroom flavor, can be derived from the oxidative breakdown of linoleic acid [14]

Methods

Results

Conclusion