Determination of Origin of Commercial Flavored Rapeseed Oil by the Pattern of Volatile Compounds Obtained via GC–MS and Flash GC Electronic Nose

Abstract

Flavored rapeseed oil (FRO) is a typical hot‐pressed oil and is widely consumed in China due to its strong characteristic flavor and intensive color. In this study, volatile profiles of 33 representative commercial rapeseed oils in China are characterized by gas chromatography‐mass spectrometry (GC‐MS) and flash gas chromatography (GC) electronic nose system. 51 volatile compounds are identified and the nitriles (methallyl cyanide and 5‐cyano‐1‐pentene), aldehydes (nonanal, 3‐furaldehyde, and 5‐methyl‐2‐furancarboxaldehyde), alcohols (1,5‐hexadien‐3‐ol, 2‐furanmethanol, and phenylethyl alcohol), and pyrazines (2,5‐dimethyl‐pyrazine and 2,6‐dimethyl‐pyrazine) are the major volatile compounds in FROs. Glucosinolate degradation products account for the highest proportion of these volatiles, which are found to have a positive correlation with the erucic acid content (R2 = 0.796, p < 0.01). FRO from Sichuan province in the southwest of China can be characterized by the obvious distinctions in flash GC electronic nose combined with principal component analysis, which indicates that the flash GC electronic nose can be used as a promising method to identify the origins of FRO. Practical Applications: This work is helpful for expanding the knowledge of volatiles of commercial flavored rapeseed oil. The data can also serve as a basis for the quality assessment of hot‐pressed rapeseed oil. Meanwhile, the flash GC electronic nose combined with principal component analysis can be used as a promising method for the classification of flavor rapeseed oil production areas.

Identification of the Olfactory Profile of Rapeseed Oil as a Function of Heating Time and Ratio of Volume and Surface Area of Contact with Oxygen Using an Electronic Nose

“…The oil chromatographic analysis identified a few or several dozen characteristic volatile compounds [ 35 ] present in the samples differing in the volume and constant surface of contact with oxygen and subjected to the 6-, 12-, and 18-h frying process determining the oil odour [ 36 ]. Table 2 presents the main volatile chemicals in the heat-treated oils and in the control sample as a function of retention time.…”

Flavor of rapeseed oil: An overview of odorants, analytical techniques, and impact of treatment

“…In the study of Zhang, Wu, et al. (2020), dimethyl sulfoxide was detected in 17 out of 33 commercial fragrant rapeseed oil samples, dimethyl trisulfide only in four oils, but neither dimethyl disulfide nor dimethyl sulfide was found in these oils. The distinction might be caused by various genetic types of rapeseed and the treatment conditions.…”

“…In a very recent study, Zhang, Wu, et al. (2020) found that glucosinolate degradation products were responsible for the pungent aroma and had a positive correlation with the erucic acid content. This finding might be related to the fact that rapeseed samples with a high erucic acid content (>3.0%) accounted for 92.5% of the whole samples in Sichuan, based on the “2018 National Rapeseed Harvest Quality Survey Report” in China.…”

“…In North America, Europe, Australia, and Japan, significant amounts of rapeseed oil with low erucic acid content are used as cooking oil. In North America and Australia, the rapeseed ( Brassica napus and Brassica rapa ) with low amounts of glucosinolates and erucic acid is known as “canola.” However, rapeseed oil with a high amount of erucic acid still predominates in some rapeseed producing areas such as China and India that did not take part in the development and conversion to canola‐type rapeseed (Przybylski et al., 2005; Zhang, Wu, et al., 2020). Widespread attention has also been paid to a type of high‐oleic rapeseed oil that contains a higher percentage of oleic acid and shows therefore more oxidative stability.…”

Study on discrimination of different grades of rapeseed oil based on flavor fingerprint

“…At present, many researchers have studied the flavor composition of rapeseed oil. Based on the flavor fingerprint, Gas chromatograph-Mass Spectrometry (GC-MS) technology has been proved suitable for vegetable oil category classification [6], origin identification [7], adulteration detection [8][9][10], processing flow control [11,12], as well as storage management [13]. These current studies mainly focused on the change of oxidation stability [14], quality indicators such as trace elements and aflatoxins of vegetable oil in the production process [15], and the optimization of process conditions [16,17].…”