JEOL : Analysis of aroma components in honey by HS-SPME-GC-TOFMS

Honey is produced by bees collecting flower nectar, mixing it with their internal enzymes, and ripening it within their hive. The flavor of honey depends on the flower type of nectar source. Honey with multiple nectar sources is called "Mixed flower honey", and honey with one nectar source is called "Single flower honey". In Japan, Astragalus honey and Acacia honey which have mild flavor among single flower honey have been preferred. But Manuka honey and Jarrah honey which have rich flavor have also been attracted attention in recent years due to health consciousness.

In this MSTips, we introduce the results of headspace-solid-phase microextraction-gas chromatography-time-of-flight mass spectrometry (HS-SPME-GC-TOFMS) analysis of aroma components that affect the flavor of honey. In HS-SPME, a sample is sealed in a headspace vial, and the SPME fiber is exposed to its gas phase to adsorb volatile components. Highly sensitive analysis is possible by easily extracting and concentrating volatile components. In addition to this HS-SPME, the GC pretreatment autosampler HT2850T (HTA S.R.L.) can also handle liquid injection and HS-gastight syringe injection by replacing the syringe attachment. Since honey, which is a natural product, is expected to contain components not registered in the NIST database, we used JMS-T2000GC and msFineAnalysis AI, which are capable of AI structural analysis.

Three types of commercially available honey (Mixed flower / Acacia / Jarrah) were used as samples. 5 g of each was sealed in a 20 mL headspace vial (Figure 1). HS-SPME extraction was performed at 70℃ for 30 minutes using HT2850T, and EI/FI measurement was performed using JMS-T2000GC (Figure 2). For data analysis, msFineAnalysis AI was used to perform qualitative analysis and difference analysis between samples.

Table 1 Measurement conditions

Figure 3 shows the TIC chromatograms of three types of honey (Mixed flower / Acacia / Jarrah). Linalool oxide was strongly detected in Mixed flower honey. Linalool oxide was also detected in Acacia honey, but its intensity was about 1/10 of that in Mixed flower honey. Acetoin was strongly detected in Jarrah honey, but linalool oxide was not detected in this honey. Although they were both honeys, they had significant differences in the type and intensity of their aroma components.

Figure 3 TIC chromatograms of three types of honey

Figure 4 shows the results of a difference analysis between Mixed flower honey and Acacia honey using msFineAnalysis AI. In 18 peaks with an intensity ratio of up to 1% to the maximum peak, 12 peaks were strongly detected from Mixed flower honey, 1 peak was strongly detected from Acacia honey.

Figure 4 Difference analysis result between Mixed flower honey an Acacia honey

Figure 5 shows the results of a difference analysis between Mixed flower honey and Jarrah honey using msFineAnalysis AI. In 37 peaks with an intensity ratio of up to 1% to the maximum peak, 12 peaks were strongly detected from Mixed flower honey, 19 peak were strongly detected from Jarrah honey.

Figure 5 Difference analysis result between Mixed flower honey and Jarrah honey

Table 2 shows a combined peak list of two difference analysis results (Mixed flower and Acacia honey, Mixed flower and Jarrah honey). The difference analysis function of msFineAnalysis AI can compare only two samples, but it is possible to compare three or more samples by combining peak lists. This peak list includes area values and can be easily graphed by exporting to spreadsheet software.

In addition, 4 of 38 peaks were not registered in the NIST database, but the compound name and structural formula could be obtained by AI structure analysis. Some of these peaks were relatively strong, and obtained information were important to understand the characteristics of the sample.

Table 2 Combined peak list of two difference analysis

mainlib : The structure formula was obtained from NIST database/ AI=from AI structure analysis

Figure 6 shows a graph of the area values of each peak created from Table 2. For the major peaks, aroma type were added as annotations. Mixed flower honey had multiple strong floral aromas, Acacia honey had mild floral aromas and Jarrah honey had rich aromas such as butter and herb-like. These results were reflected the characteristics of each type of honey.

Figure 6 Peak area of each compounds

It was able to detect aroma components in honey with high sensitivity by HS-SPME-GC-TOFMS using HT2850T and JMS-T20000GC. Although some of the detected peaks were not registered in the NIST database, it was able to obtained the compound name and structural formula by AI structural analysis using msFineAnalysis AI. So, it was confirmed that these devices and software are effective for analyzing aroma components in foods.

Medicine

Food / Plant

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Jeol Ltd. published this content on 06 March 2024 and is solely responsible for the information contained therein. Distributed by Public, unedited and unaltered, on 06 March 2024 07:06:03 UTC.