Sample

Red chili powder

(fresh, medium-infected and high-infected)

Commercial chili powder (12 products)

Solvent-free solid injector

Instrument Agilent Technologies 6890Aequipped with a 5973 MSD

Column HP-5MS (30 m x 0.25 mm i.d, 0.5μm film thickness, Agilent, (USA)

Column flow 1 mL/min (He)

Oven temp. 50℃ (4 min) – 4℃/min – 250℃ (1 min)

Injector temp. 250℃

Ion source temp. 230℃

Quadruple temp. 150℃

In this study, the volatiles organic compounds generated fromfresh and infected red pepper powder were characterized usingsolvent-free solid injection (SFSI) coupled with GasChromatogram-mass spectrometry(GC-MS), in order toinvestigate adulteration in commercial red pepper powder.

Jae-Han Shima*, Ah-Young Koa, Md. Musfiqur Rahman, Aa. M. Abd El-Atyb, Jin Janga, Jeong-Heui Choia, M. I. R Mamuna

aNatural Products Chemistry Laboratory, Biotechnology Research Institute, Chonnam National University, Gwangju, Republic of KoreabDepartment of Pharmacology, Faculty of Veterinary Medicine, Cairo University, 12211-Giza, Egypt

Table 1. Volatile organic compounds generated from healthy andinfected chili powder using solvent-free solid injection andgas chromatography/mass spectrometry.

• Chili peppers in the genus Capsicum are native plants ofAmerica, and very popular in several parts of the world. Dueto their unique spicy, pungent taste, color, and naturalflavoring, they have become an emblematic ingredient inmany regional cuisines. Chili contains large amounts ofvitamins A, B, C, and small amounts of carotene, whichmake it a good source of vitamins.

•• Volatile organic compounds (VOCs) are generally correlated

with flavor and fragrance in foodstuffs and are importantfactors to evaluate consumer acceptance or rejection of foodproducts. In addition, volatile compounds possess aromatic,anti-fungal, insecticidal, biological signaling, and therapeuticproperties. Therefore, investigating VOCs is important toassess food quality, authenticity, purity, and origin.

Homepage : http://altair.chonnam.ac.kr/~jhshim E-mail : jhshim@jnu.ac.kr

Identification of volatile organic compounds generated from healthy and infected powdered chili using solvent-free solid injection coupled with GC/MS: Application to adulteration

Abstract

Introduction

Sample Preparation and vaporization

Solvent-free solid injector vaporization procedures

GC/MS analytical conditions

Volatile compounds emitted from pepper powder

Fig. 2. Schematic diagram of the solvent-free solid injector (SFSI).

In order to distinguish between VOCs generated inhealthy and infected chili powder, SFSI technique wasused.A total of 43 compounds were confirmed in healthy,medium-infected and severely infected chili powder.Trimethylamine and isosorbide were useful asbiomarkers for identifying infected chili and could beused to investigate adulteration in chili powder.The coupling of SFSI-GC/MS was an effectivetechnique for the rapid analysis and characterization ofVOCs in chili power.

Conclusions

To investigate adulteration in commercial chili powder, the volatile organic compounds of healthy and infected powdered chili pepper were characterized using a solvent-free solidinjector (SFSI) coupled with gas chromatography/mass spectrometry (GC/MS). Except for one compound (capillary compound for blank), 43 compounds were identified in healthy andinfected chili powder. Specifically, 31, 36, and 41 compounds were identified in healthy, medium-infected, and severely infected chili powder. Among these compounds, acetic acid(13.77%), propanal (2.477%), N-methylpyrrole (1.986%), and 2-methyl-propanal (1.768%) were leading volatiles in the healthy chili powder. In contrast, infected chili powder contained9,12-octadecadienoic acid, ethyl ester (15.984%), acetic acid (11.249%), hexadecanoic acid, methyl ester (3.3%), N-methylpyrrole (3.221%), and 2-furanmethanol (2.629%) as majorcompounds. Trimethylamine and isosorbide were detected in both medium and severely infected chilli, but not in healthy chili. This means that these compounds could be used asbiomarkers to distinguish between healthy and infected chili. The proposed technique was applied to 12 commercial chili powders, and trimethylamine and isosorbide were detected in sixsamples. These results suggest that a contaminated chili that was added to a healthy one could be successfully identified by a combination of the SFSI and GC/MS.

Keywords: Healthy; Infected; Red pepper powder; Chili; Adulteration; Solid injector; Sample preparation, gas chromatography-mass spectrometry

Objectives

Materials and Methods

Glass crusherSilicone seals

Glass capillary

Outlet of vaporized sample

Supporting bar

(1) (2) (3)

(4) (5) (6)

Fig. 1. Infected red pepper and adulterated red pepper powder.

Fig. 3. Solvent-free solid injector (SFSI) vaporization procedures.

Red pepper powder sample (1 mg)

Put in a soft glass capillary tube

Seal both ends of the tube

Place the tube in a SFSI

Coupled with a GC/MS

Pre-heating time 7 min

GC/MS analysis

Preparation

Vaporization

Results

Fig. 4. Representative gas chromatography/mass spectrometrychromatograms (full scan mode) of the volatile organiccompounds (A) blank sample, (B) healthy, (C) medium-infected, and (D) severely infected (E) commercial chilipowders.

No. RT Compound

Blank Fresh Infected (M)

Infected (H)

Relative area (%)

1 1.721 Propanal - 2.477 2.167 1.160

2 1.773 Trimethylamine - - 0.332 0.473

3 1.861 Acetic acid, methyl ester - 1.345 1.261 0.709

4 2.015 Propanal, 2-methyl- - 1.768 1.412 0.658

5 2.197 2,3-Butanedione - 0.855 1.147 0.359

6 2.270 2-Butanone - 0.641 0.568 0.296

7 2.342 Furan, 2-methyl- - 1.324 0.969 0.443

8 2.827 Acetic acid - 13.777 11.249 7.419

9 2.897 Butanal, 3-methyl- - 1.318 1.154 0.565

10 3.031 Butanal, 2-methyl- - 1.215 0.979 0.493

11 3.182 2-Propanone, 1-hydroxy- - 0.624 0.553 0.402

12 3.506 2,3-Pentanedione - 0.276 0.181 0.115

13 4.489 N,N-Dimethyl-2-aminoethanol - 0.310 0.686 0.606

14 4.629 N-Methylpyrrole - 1.986 3.221 1.631

15 4.894 Pyridine - - 0.125 0.080

16 4.998 Pyrrole - 0.116 0.245 0.238

17 7.200 Pyrazine, methyl- - 0.190 0.324 0.559

18 7.613 Unknown compound 1 - 0.615 0.374 -

19 8.619 2-Furanmethanol - 1.429 2.629 1.221

20 9.083 Unknown compound 2 - 0.576 0.978 0.390

21 10.780 Pyrazine, 2,6-dimethyl- - 0.413 0.392 0.414

22 10.947 Butyrolactone - 1.011 1.297 0.822

23 13.014 2-Furancarboxaldehyde, 5-methyl- - 1.039 0.396 0.085

24 15.813 2-Cyclopenten-1-one, 2-hydroxy-3-methyl- - 0.294 0.303 0.200

25 16.367 2-Pyrrolidinone, 1-methyl- - 0.179 0.496 0.261

26 16.490 Benzeneacetaldehyde - 0.151 - 0.228

27 17.273 Ethanone, 1-(1H-pyrrol-2-yl)- - 0.490 0.568 1.155

28 17.910 2-Pyrrolidinone - - - 0.914

29 18.440 Phenol, 2-methoxy-/Phenol, o-methoxy- - 0.342 0.289 0.866

30 18.734 Acetoglyceride - - - 1.339

31 19.427 Maltol - 1.174 - 0.887

32 20.438 Unknown compound 3 - - 2.122 0.959

33 23.272 1,2-Benzenediol - - 0.352 -

34 26.843 Isosorbide - - 0.539 1.051

35 34.721 2-Propanone, 1-(4-hydroxy-3-methoxyphenyl)- - 0.461 0.379 0.175

36 40.338 Tetradecanoic acid, methyl ester, - - - - 0.302

37 45.874 Hexadecanoic acid, methyl ester - - 0.629 1.340 3.300

38 46.312 Pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl)- - - 0.525 0.430 0.598

39 46.986 Unkown compound 4 - 12.566 1.167 1.116 1.595

40 50.260 9,12-Octadecadienoic acid (Z,Z)-, methyl ester 12.566 - 1.062 3.539 15.984

41 50.323 Unkown compound 5 - - - 1.602 3.994

42 50.866 Octadecanoic acid, methyl ester - - - 0.398 1.108

43 51.757 9,12-Octadecadienoic acid, ethyl ester - - - - 0.751

44 52.242 Hexadecanamide - - - - 0.463