【作者】 贾洪锋；

【导师】 贺稚非；

【作者基本信息】 西南大学 ， 食品科学， 2007， 硕士

【摘要】 发酵辣椒是我国的一种传统发酵食品，由于其独特的风味而深受人们的喜爱，特别是在湖南、湖北、四川、重庆和江西等地家庭广泛制作。传统的发酵辣椒主要是利用天然附着在辣椒表面的微生物（主要是乳酸菌）进行发酵，发酵时间较长；而人工接种发酵可以明显的缩短发酵时间。关于发酵辣椒的研究主要集中在菌种的分离选育、发酵工艺的优化和风味的调配等方面，关于发酵辣椒中风味物质的研究较少。对于其风味物质的研究不但可以推测发酵辣椒风味的形成机制，防止不良风味产生，同时还可以对发酵工艺的优化和风味的调配提供理论依据。本文以新鲜辣椒及其发酵产品为研究对象，采用高效液相色谱和气相色谱／质谱联用对新鲜辣椒及其发酵产品中的风味物质进行了分析。在实验中建立了有机酸的高效液相色谱分析方法，同时建立了香气成分分析的气相色谱／质谱联用分析方法，对不同的新鲜辣椒及其发酵产品中的风味物质进行了比较，还分析了辣椒在发酵过程中风味物质的变化。主要实验结论如下：1．在实验中建立了同时测定8种有机酸的色谱分析条件：Hypersil-ODS2色谱柱（4.6mm×200mm，5μm），2％甲醇-0.05mol／LKH₂PO₄（pH2.8）作为流动相，流速0.8mL／min，柱温17℃，进样量5μL，检测波长214nm。在此条件下，8种有机酸能够得到较好的分离，回收率92.87％～106.15％，RSD＜3％。2．比较了加热提取和超声波提取对发酵辣椒中有机酸的提取效果，表明加热提取效果好于超声波提取，但是两种方法对于不同有机酸的提取效果有所不同，除草酸和琥珀酸含量是以超声波提取较高外，其余的几种酸以加热提取效果更好。3．对不同温度条件下发酵辣椒中的8种有机酸进行了定性和定量分析。两种温度条件下，在发酵前后，草酸、柠檬酸和琥珀酸的含量减少；苹果酸、乳酸和乙酸含量增加；甲酸的含量在发酵温度为20℃时有所增加，但在发酵温度为28℃时有所下降；由于在发酵过程中的某些阶段未检测到酒石酸，所以酒石酸的变化情况尚需进一步的研究。某些阶段未检测到酒石酸可能是由于样品中酒石酸含量太少或者是由于草酸影响了酒石酸的检测，这些还需进一步的研究。4．在发酵过程中，乳酸是有机酸中含量最大的酸，其含量占总酸的，发酵结束时其含量达到1300mg／100g左右，含量占总酸的30％左右，乳酸可能在发酵辣椒的成酸作用中起主导地位；其他的酸含量相对较少，发酵结束时其含量均在300～600 mg／100g之间，但是在发酵辣椒的风味形成中同样具有重要的作用。5．在相同的发酵时间，即发酵的第一天和第七天，28℃下发酵辣椒的总酸值均高于20℃下发酵辣椒的总酸值，其差值在100mg／100g～160mg／100g左右，说明在相同的时间内，较高的发酵温度有利于乳酸菌产酸，能够缩短发酵的时间。6．实验中建立了提取和分离分析发酵辣椒中主要风味物质的方法。采用同时蒸馏萃取法以无水乙醚提取发酵辣椒中的风味物质，同时蒸馏萃取2h，其提取效果最好。GC／MS分析条件为：岛津气相色谱质谱联用仪（GCMS-QP2010），Rtx-5MS毛细管柱。GC：程序升温，初温35℃，保留10min，以4℃／min的升温速率升温至250℃，保留10min。进样口温度250℃。进样量1uL，分流比50：1，He气流速33 cm／sec。载气压力35.3 kPa。MS：接口温度250℃，离子源温度230℃。质量范围35～500，电离方式：EI，70 eV，扫描速率0.5 s／scan。四极杆质量分析器。谱库：NIST05和NIST05s。在此分析条件下能够较好的完成对发酵辣椒中风味物质的分离和分析。7．发酵辣椒在发酵的过程中，由于微生物的发酵及辅料等的作用，其中的风味物质呈增加的趋势，不论是在20℃还是在28℃下发酵，其中的风味物质都是逐渐增加的。8．对比20℃和28℃下发酵辣椒中的风味物质可以看出，28℃下发酵其物质的种类较20℃下发酵少，乙酸、仲丁基乙醚、3-甲基丁醛、己酸乙酯、苯乙醛、壬醛、对烯丙基茴香醚、薄荷酮、2-甲基-3-十一烯、2-甲基十五烷、十五烷、十三醛、肉豆蔻酸乙酯、十五烷酸乙酯、十七烷基乙酸酯、9-十六碳烯酸乙酯等物质在低温发酵时出现，而在28℃时没有检测到，较低温度虽然发酵比较慢，但是更有利于风味物质的形成，尤其是酯类的形成。较高温度发酵则可以缩短发酵时间。9．实验中比较了3种不同的发酵辣椒中的风味物质。乙酸乙酯，乙基戊基醚，乙苯，间二甲苯，β-顺式罗勒烯，β-里哪醇，α-萜品醇，2-甲基-十四烷，棕榈酸乙酯，亚油酸乙酯，亚麻酸乙酯等物质在以上3种发酵辣椒中都能检测出，它们可能是发酵辣椒中的共有物质。同时可以看出，购买的发酵辣椒样品中挥发性物质的相对含量较少，远远低于实验室接种标准菌种发酵的样品，发酵的风味不够突出。10．发酵小米椒中物质种类和相对含量都较丰富，异丙基乙基醚，丙基乙基醚，乙酸乙酯，乙缩醛，β-里哪醇，2-羟基-安息香酸甲酯（水杨酸甲酯），2-甲基-丁酸己酯，戊酸己酯，3-甲基-丁酸己酯，己酸己酯，癸酸，2-甲基-3-十一烯，长叶烯，十六烷等相对含量较高，可能是主体物质。11．鲜椒中含有大量的物质，共检测出烷烃17种，烯烃10种，醚5种，醇类14种，醛类15种，酮5种，酸2种，酯17种。其中乙酸乙酯，正己醛，乙缩醛，2-乙烯醇，对丙烯基茴香醚，己酸己酯，2-甲基十三烷-，2-甲基-3-十一烯，2-甲基-十四烷，β-里哪醇，反式橙花叔醇，十三醛，3，7-二甲基-6-壬烯-1-醇乙酸酯，癸酸己酯，十七烷基乙酸酯，肉豆蔻醛的相对含量较高，同时鲜椒中含有大量的烷烃。12．辣椒酱中的物质成分明显的比鲜椒和发酵辣椒中多，在4种辣椒酱中共检测出176种物质，其中异丙基乙基醚，丙基乙基醚，乙酸乙酯，仲丁基乙醚，3-甲基-丁醛，乙缩醛，乙基戊基醚，乙苯，松萜，β—月桂烯，α-水芹烯，桉树脑，β-顺式罗勒烯，萜品油烯，β-里哪醇，α-萜品醇，（E）-2-癸烯醛，（E，E）-2，4-癸二烯醛，可巴烯，十三烷，2-甲基-3-十一烯，十五烷等物质为4种辣椒酱共有，可能是辣椒酱中的主要风味物质。更多还原

【Abstract】 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.更多还原