Study On The Flavor Components Of Fermented Capsicum Annuum

Fermented Capsicum was a traditional fermented food in China. It was popular in Hunan, Hubei, Sichuan, Chongqing and Jiangxi province et al. Traditional fermented Capsicum was fermented with the Lactic acid bacteria that existing on the surface of Capsicum, but through inoculating Lactic acid bacteria could make the flavor better and shorten the fermented time. The studies about fermented Capsicum were focused on Lactic acid bacteria, et al. The aspect of its flavor compounds was studied very little. Analysis of flavor components of fermented Capsicum could not only explore the formation mechanism of flavor, but also take a consult of improving flavor and fermenting technics.This study has analyzed the flavor components of fermented Capsicum with HPLC (High Performance Liquid Chromatography) and GC/MS. The HPLC method and GC/MS method were developed to study the flavor compounds of fresh Capsicum, fermented Capsicum and fermented Capsicum sauce. The main conclusions were as follow.1. A method for simultaneous determination of 8 organic acids in fermented capsicum by reverse phase high performance liquid chromatography was developed. Hypersil-ODS2 column(4.6mm×200mm,5μm)was used at 17℃and mobile phase was 2% CH₃OH-0.05 mol/L KH₂PO₄(pH 2.8)with flow rate of 0.8 mL/min. Detection wavelength was at 214 nm. The relative standard deviations were lower than 3%, and the recoveries were 92.87% to 106.15%.2. In this study, two methods (extracted with heating or ultrasonic) were used to extract organic acids, it is proved that extraction with heating is better than ultrasonic.3. Following fermentation, the content of oxalic acids, citric acids and succinic acids was decreased; the content of malic acids, lactic acids and acetic acids was increased; the content of formic acids was increased in samples fermented at 20℃, but decreased in samples fermented at 28℃; the change of tartaric acids was not clear.4. Lactic acids was the highest content acid during fermentation, its content was about 13.5 percent to 46.8 percent; at the end of fermentation, its content reach to 1300 mg/100g. Compared with lactic acid, other acids were relatively low content, at the end of fermentation, the average contents of other seven acids were 300 mg/100g to 600 mg/100g.5. In the same fermented days, the content of organic acids in the sample that fermented at 28℃was higher than fermented at 20℃. This means high fermented temperature could induce the formation of organic acids and shorten the time.6. The GC/MS method was: Shimadzu GCMS-QP2010 (Shimadzu, Japan.) was equipped with a capillary column: Rtx-5MS (30 m×0.25 mm×0.25 um, Restek, corp, USA.) and a quadrapole mass filter. 1μL volume of sample was injected into column and the split ratio was 50:1. The oven temperature was held at 35℃for 10 min and increase from 35℃to 250℃at the rate of 4℃/min, and the final temperature was maintained for 10min. The flow rate of helium, the carrier gas, was 0.84mL min^-1. The temperature of injector was 250℃; the ion source temperature and interface temperature were 230℃and 250℃, respectively. Other conditions were as follows: ionization energy, 70 eV; mass range 35～500 amu; and scanning rate 0.5 scans s^-17. The aroma components were increased following fermentation either at 20℃or 28℃.8. More aroma compounds were detected in the samples fermented at 20℃, Acetic acid; Ether, sec-butyl ethyl; Butanal, 3-methyll; Ethyl caproate; Benzeneacetaldehyde; Nonanal; Estragole; Piperitone; 3-Undecene, 2-methyl; Pentadecane, 2-methyl; Pentadecane; Tridecanal; Myristic acid, ethyl ester; Pentadecanoic acid, ethyl ester; 1-Heptadecanol, acetate and Ethyl 9-hexadecenoate were formed at low fermented temperature, but not detected in the samples fermented at 28℃. Low temperature may be the better condition to form aroma compounds.9. Through analyzed three different fermented Capsicum samples, we concluded that the main aroma compounds of fermented Capsicum were Ethyl Acetate; Ethyl amyl ether; Ethylbenzene; Benzene, 1,3-dimethy; beta.-cis-Ocimene; Linalool; alpha.-Terpineol; Tetradecane, 2-methyl; Hexadecanoic acid, ethyl ester; Linoleic acid ethyl ester; Linolenic acid, ethyl ester.10. The main aroma compounds of fermented C. frutescens L. were Ether, ethyl isopropyl; Propane, 1-ethoxy-; Ethyl Acetate; Acetal; Linalool; Benzoic acid, 2-hydroxy-, methyl ester(Salicylic acid, methyl ester); Butanoic acid, 2-methyl-, hexylester; Hexyl n-valerate; Butanoic acid, 3-methyl-, hexyl ester; Hexanoic acid, hexyl ester; n-Decanoic acid; 3-Undecene, 2-methyl; Longifolene-(V4); Hexadecane.11. The main aroma compounds of fresh Capsicums were Ethyl Acetate; Caproic aldehyde; Acetal; 2-Hexenol; Anisole, p-propenyl; Hexanoic acid, hexyl ester; Tridecane, 2-methyl; 3-Undecene, 2-methyl; Tetradecane, 2-methyl; Linalool; trans-Nerolidol; Tridecanal; 3,7-Dimethyl-6-nonen-l-ol acetate; Decanoic acid, hexyl ester; 1-Heptadecanol, acetate; Myristylaldehyde.12. The main aroma compounds of fermented Capsicums sauces were Ether, ethyl isopropyl; Propane, 1-ethoxy; Ethyl Acetate; Ether, sec-butyl ethyl; Butanal, 3-methyl; Acetal; Ethyl amyl ether; Ethylbenzene; Pinene; beta.-Myrcene; alpha.-Phellandrene; Eucalyptol; beta.-cis-Ocimene; Terpinolene; Linalool; alpha.-Terpineol; 2-Decenal, (E); 2,4-Decadienal, (E,E); Copaene; Tridecane; 3-Undecene, 2-methyl; Pentadecane.