首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Phenolic compounds contribute to the quality of raw cocoa, the basis of all chocolate products. Detailed research is needed about the variability of these substances in unprocessed cocoa seed and during seed processing. For the present study, seed samples of Upper Amazon Forastero, Lower Amazon Forastero, Nacional, Criollo and Trinitario from different origins were compared in order to estimate the influence of genetic and site-specific features on the phenolics. Besides ripe, fresh cocoa seed, different fermentation stages of Criollo samples were analysed. Total polyphenols were examined using Folin–Ciocalteu reagent. RP-HPLC–PDA was adapted to analyse the monomeric cocoa polyphenols. Criollo seed contains no anthocyanins, but greater amounts of caffeic acid aspartate than samples of other cocoa types. No genetically determined differences in the amounts of total polyphenols and (−)-epicatechin were found. In contrast, soil fertilisation may lead to cocoa seed with significantly smaller amounts of total polyphenols, flavan-3-ols and anthocyanins, but larger quantities of caffeic acid aspartate than those from unfertilised locations. The diminution of catechins found during fermentation and drying is stronger in the Criollo seed samples than described for other genotype groups. This may be responsible for the mild flavour of Criollo chocolates. Caffeic acid aspartate turned out to be highly resistant to degradation, with an average of 33% of the original content remaining in fully fermented cocoa seed. The results could be used in trials to produce raw cocoa with specific contents of phenolics.  相似文献   

2.
The volatile compounds of 10 Piper species cultivated in Hainan Island, China, have been investigated. Eighty compounds were profiled after headspace–solid phase microextraction (HS–SPME) with gas chromatography–mass spectrometry (GC–MS). Mean Bray–Curtis similarity value was only 22.78 ± 1.98% among the different Piper species. The volatile compounds were largely grouped as hydrocarbons, aldehydes, alcohols, acids, ketones, esters, and phenols. The main compounds comprised benzaldehyde, cinnamaldehyde, β-caryophyllene, ocimene, lavandulol, myrcene, cubebene, terpinene, linalool, α-caryophyllene, β-elemene, and germacrene. Principal component analysis revealed that Piper laetispicum, Piper longum, Piper hainanense, Piper betle, and Piper flaviflorum were characterized by high contents of β-caryophyllene, α-caryophyllene, germacrene, and β-pinene. Piper puberulum and Piper cathayanum were associated with high contents of linalool, myrcene, and germacrene D. On the other hand, Piper pseudofuligineum and Piper retrofractum were related with high contents of ocimene. Finally, Piper auritum was associated with high content of cinnamaldehyde. Volatile profiling of Piper species by HS–SPME–GC–MS and the interrelationship investigated among the volatiles can be used as a roadmap for future resource utilization or biotechnological applications.  相似文献   

3.
Acetone dry powder (AcDP) was prepared for six cocoa genotypes, namely Forastero (Amelonado type), Criollo, Trinitario, SCA 12, UIT1 and PBC 140. Hydrophobic oligopeptides were produced when autolysis of AcDP was carried out at pH 3.5. Comparative HPLC analysis showed that autolysis of AcDP from various genotypes revealed a similar pattern of oligopeptides. Most of the hydrophobic oligopeptides were not generated during autolysis of AcDP in the presence of protease inhibitor (Pepstatin A), indicating that the generation of these oligopeptides was due to the action of cocoa cotyledon aspartic endoprotease. This finding implies that the splitting action of aspartic endoprotease on vicilin (7S)‐class globulin (VCG) from various genotypes was the same. The information from the study provides additional evidence that there are no obvious differences in VCG composition between various genotypes. © 2002 Society of Chemical Industry  相似文献   

4.
Cocoa originates from beans of the cocoa tree (Theobroma cacao L.) and it is an important commodity in the world and the main ingredient in chocolate manufacture. Its value and quality are related to unique and complex flavors. Bulk cocoas (Forastero type) exhibit strong basic cocoa notes, whereas fine varieties (Criollo, Nacional) show aromatic, floral, or smoother flavor characteristics. About 600 various compounds (alcohols, carboxylic acids, aldehydes, ketones, esters, and pyrazines) have been identified as odor‐active components. The specific cocoa aroma arises from complex biochemical and chemical reactions during the postharvest processing of raw beans, and from many influences of the cocoa genotype, chemical make‐up of raw seeds, environmental conditions, farming practices, processing, and manufacturing stages. There has been much research on cocoa flavor components. However, the relationships between all chemical components that are likely to play a role in cocoa flavor, their sensory properties, and the sources and mechanisms of flavor formation are not fully understood. This paper provides an overview on cocoa flavor from a compositional and a sensory perspective. The nonvolatile and volatile chemical components of cocoa and chocolate flavor, and their sensory properties correlated to the main influences involved in flavor formation, are reviewed.  相似文献   

5.
Extracts obtained by supercritical carbon dioxide extraction of cones and leaves of hop (Humulus lupulus L) at different combinations of temperature and pressure were analysed for their α- and β-acids and volatiles, using HPLC and GC respectively. The yield and composition of the mixtures of bitter compounds from the cones were largely influenced by the temperature and pressure applied during the extraction. Bitter compounds could not be detected in the extracts from the leaves. The most important volatile components identified were β-myrcene, β-caryophyllene and α-humulene. The extraction parameters also influenced the composition of the mixture of volatiles from the cones and leaves, 40°C and 20.0 MPa being optimum for the extraction of both bitter compounds and volatiles, which are thought to be important for the aroma of beer.  相似文献   

6.
Cocoa cotyledons contain vicilin (7S)‐class globulin (VCG), a major storage protein. It is the native source of oligopeptides and free amino acids which have been identified as precursors of cocoa‐specific aroma and are formed through proteolysis during fermentation. High‐resolution electrophoresis of native proteins isolated from ripe, unfermented cocoa cotyledons harvested from different cultivars was used to determine genetic differences of the genotypes. Flavour differences have been reported to exist after standard fermentation in cocoa beans harvested from various genotypes. In this paper, SDS‐PAGE and 2D IEF/SDS‐PAGE polypeptide separation patterns are shown which were separately isolated from cotyledons of various genetic origins. Cotyledons from three cultivars belonging to genetically distant varieties and a hybrid, Criollo, Forastero and Trinitario, did not reveal any analytical identity differences of VCG subunit polypeptide bands. Additionally, proteins of cotyledons harvested from three of those clones which were reported to produce genotype‐specific flavour differences in raw cocoa after standard fermentation, SCA 12, UIT1 and PBC 140, when analysed in the same way, did not indicate differences. Thus the cotyledon storage proteins from various genetically different cocoa trees are, within methodological limits, the same. We conclude that aroma differences in raw cocoa harvested from various genotypes are the result of other genetic, physiological or curing‐related factors, but are not due to genetic differences of aroma precursors derived from storage proteins. © 2002 Society of Chemical Industry  相似文献   

7.
为了探讨鲻鱼肉中特征性挥发物,利用顶空固相微萃取-气-质联用(HS-SPME-GC-MS)法检测真空包装0℃下贮藏期间鲻鱼肉挥发性风味。实验结果显示,共鉴定出七大类76种化合物,并分析贮藏期间鲻鱼肉中主要的挥发物相对含量变化、气味特征及其来源。研究发现,鲻鱼挥发性风味以烃类、杂环类、醇类和醛类为主,冷藏期间一直能够被检测到的8种主要特征性挥发物分别为:十二烷、十六烷、二十八烷、甲苯、萘、2,4-二叔丁基苯酚、二丁基羟基甲苯和亚硫酸。通过主成分分析冷藏期间鲻鱼特征性挥发物变化规律,提炼出4个主成分因子,为进一步研究鲻鱼挥发性风味成分奠定了基础。   相似文献   

8.
巴氏灭菌前后沃尔卡姆柠檬汁挥发性成分的分析比较   总被引:1,自引:0,他引:1  
梅明鑫 《中国酿造》2020,39(10):176
为探究巴氏灭菌对新鲜沃尔卡姆柠檬汁香气的影响,采用顶空固相微萃取-气相色谱-质谱联用法(HS-SPME-GC-MS)分析巴氏灭菌前后新鲜柠檬汁的挥发性成分。结果表明,巴氏灭菌前后的柠檬汁中分别共鉴定出86种和94种挥发性成分,主要挥发性风味物质的种类及其相对含量均有不同。巴氏灭菌后,醇类、酯类化合物相对含量分别增加了9.15%和0.86%,而烷烯类、醛酮类物质相对含量分别下降了10.77%、0.40%。巴氏灭菌后原有的挥发性成分有所变化,同时也生成了新的物质,但是柠檬汁中柠檬烯、萜品油烯、β-蒎烯、α-松油醇、4-萜烯醇、月桂烯、香茅醇、1-β-红没药烯等主体挥发性成分没有发生明显变化。  相似文献   

9.
为研究生产因素(原料品种、原料产区、酵母、氮源)对工业规模哈密瓜蒸馏酒挥发性物质的影响,采用顶空固相微萃取-气相色谱质谱联用(HS-SPME-GC-MS)仪对哈密瓜蒸馏酒挥发物质进行分析。结果表明,不同的哈密瓜蒸馏酒样品中共检出76种挥发性物质,包括醇类12种,萜烯类8种,醛酮类5种,酸类3种,酯类23种,苯环类15种,含硫化合物3种,呋喃类4种,其他类化合物2种。其中共有化合物12种,包括1-壬醇、含硫化合物等,含量主要受到原料品种和产区的影响;主成分分析(PCA)结果表明,产区对哈密瓜蒸馏酒挥发性物质影响最大。相同产区下,氮源的添加、原料品种和酵母也对蒸馏酒的挥发性成分有显著影响(P<0.05)。  相似文献   

10.
腐乳发酵过程挥发性风味成分的变化   总被引:1,自引:0,他引:1  
卢靖  刘平  张丽珠  车振明 《食品科学》2014,35(16):175-179
采用固相微萃取法结合气相色谱-质谱法对腐乳发酵过程不同时期的挥发性风味成分进行分析,共鉴定出化合物110 种,包括酯类41 种、醛类19 种、酮类12 种、醇类12 种、酸类9 种、烃类9 种、其他类化合物8 种。不同发酵时期腐乳挥发性风味成分差异明显,随着发酵的进行,挥发性风味成分的种类逐渐增多。在前发酵过程中,豆腐白坯经毛霉发酵成毛坯,醛类相对含量显著降低,酯类、醇类相对含量以及种类逐渐增大;在后发酵过程中,随着后发酵时间的延长,醛类、酸类、酯类相对含量逐渐升高,烃类、醇类相对含量逐渐降低。其中正己醛、苯乙醛、壬醛、双戊烯、异戊醇、己酸乙酯、苯乙酸乙酯、戊酸乙酯、辛酸乙酯、2-正戊基呋喃、烯丙基甲基二硫醚对腐乳风味的形成贡献较大。  相似文献   

11.
Selected volatile compounds of chocolate ice creams containing 0.6, 4.0, 6.0, or 9.0% milk fat or containing 2.5% milk fat, cocoa butter, or one of three fat replacers (Simplesse, Dairy Lo, or Oatrim) were analyzed by gas chromatography and gas chromatography-mass spectrometry using headspace solid-phase microextraction. The headspace concentration of most of the selected volatile compounds increased with decreasing milk fat concentration. Fat replacers generally increased the concentration of volatiles found in the headspace compared with milk fat or cocoa butter. Few differences in flavor volatiles were found between the ice cream containing milk fat and the ice cream containing cocoa butter. Among the selected volatiles, the concentration of 2,5-dimethyl-3(2-methyl propyl) pyrazine was the most highly correlated (negatively) with the concentration of milk fat, and it best discriminated among ice creams containing milk fat, cocoa butter, or one of the fat replacers.  相似文献   

12.
The volatile constituents of blood orange wine were determined. Moro variety (Citrus sinensis[L.] Osbeck) was used for the production of wine. The fermentation was performed spontaneously at 20C. Volatile components were extracted with dichloromethane, and analyzed by gas chromatography‐flame ionization detection (GC/FID) and gas chromatography‐mass spectrometry (GC/MS). A total of 64 volatiles, including higher alcohols (20), esters (13), terpenes (11), acids (7), volatile phenols (6), lactones (2), acetal compounds (2), ketone (1), aldehyde (1) and acetoin (1) were identified in wine. The total amount of volatile compounds was 125.0 mg/L. Higher alcohols and esters were the largest groups and made up more than 86% of the volatiles.  相似文献   

13.
Aroma volatiles of mango (Mangifera indica L.) determine consumer acceptability and influence selection, whilst breeding. To assess their variety, composition and possible impact on cultivar relationships, volatile blends of 22 Indian and five non-Indian cultivars were investigated using solvent extraction and gas chromatography. Totally 84 volatiles belonging to various chemical classes were detected. Based on the cumulative occurrence of members of these classes, cultivars were grouped as monoterpene or sesquiterpene dominant. α-Pinene, β-myrcene and β-caryophyllene were found in all 27 cultivars. For ordination, common compounds with high (relative) concentration provided quantitative characters, whereas the rare and lesser ones provided qualitative (binary) characters; non-Indian cultivars separated from Indian ones but displayed close relations within their groups. In conclusion, mango flavour is dominated qualitatively as well as quantitatively by terpene hydrocarbons; ancient selection of mango cultivars is hinted to be driven by different aroma characters in different parts of the world.  相似文献   

14.
为研究不同加工工艺紫娟白茶的关键香气化合物,采用顶空固相微萃取-气相色谱-质谱联用技术(Headspace solid-phase micro extraction and gas chromatography mass spectrometry,HS-SPME-GC-MS),结合感官审评、PCA验证、OPLS-DA分析以及相对香气活度值(Relative odor activity value,rOAV),分析筛选紫娟白茶的关键香气化合物。结果表明:共检测出82种主要香气组分,以醇类、酯类、杂环及芳香族化合物为主,芳樟醇、水杨酸甲酯、苯甲醇、β-紫罗兰酮等相对含量较高,rOAV法分析结果显示:1-辛烯-3-醇、α-紫罗兰酮、苯乙醛、水杨酸甲酯等9种挥发性有机化合物对自然萎凋的紫娟白茶(TZW)花果香馥郁且带毫香、辛香、药香的香气形成具有较大贡献,1-辛烯-3-醇、α-紫罗兰酮、β-紫罗兰酮、苯甲醛等9种挥发性有机化合物对复式萎凋紫娟白茶(CZW)果香浓郁且带花香、辛香的香气形成具有较大贡献。OPLS-DA分析结合rOAV发现1-辛烯-3-醇和水杨酸甲酯是TZW与CZW香气差异的关键化...  相似文献   

15.
采用5.0 g/L茶多酚溶液浸泡草鱼片,通过顶空固相微萃取-气相色谱-质谱(headspace solid phase microextraction-gas chromatography-mass spectrometry,HS-SPME-GC-MS)联用结合电子鼻技术检测冷藏草鱼片贮藏期内挥发性成分的变化。结果表明:HS-SPME-GC-MS法共检出挥发性成分161 种,主要为醛类及醇类物质;空白组检出的醛类及醇类物质相对含量随贮藏时间的延长呈持续增长趋势,烃类物相对含量先降低后升高,酯类物质相对含量先升高后降低,其他物质含量呈现上下波动趋势。茶多酚组检出的醛类物质显著低于空白组,醇类物质在贮藏后期少量存在,己醛、1-辛烯-3-醇等使鱼体呈腥味的物质大幅度降低,酸类物质相对含量增加。经电子鼻检测结果发现,茶多酚组在贮藏后期各传感器的响应值显著低于空白组。微生物检测结果表明,茶多酚处理能够有效抑制草鱼片在冷藏期内微生物包括产气细菌的生长。综上结果表明茶多酚可以显著降低冷藏草鱼片腥味物质的生成。  相似文献   

16.
Volatile compounds with a major contribution to aroma have been quantitatively determined in four traditional tomato cultivars and one commercial F1 hybrid. One of the traditional cultivars was the most appreciated for flavour and overall acceptability in tests performed using a panel of 30 untrained tasters. The same cultivar showed significantly higher contents of hexanal and cis‐3‐hexenal volatile compounds, which have been previously reported to be two of the most important contributors to tomato flavour. On the basis of a small number of fruits per cultivar, significant differences among very closely related tomato cultivars can be detected for volatile aromas, thus allowing the use of the determination of volatiles as a possible tool in tomato breeding programs, making even the selection of single plants possible. Copyright © 2004 Society of Chemical Industry  相似文献   

17.
Effects of various roasting conditions on antioxidant properties of five Theobroma cacao L. varieties were investigated. The cocoa beans were roasted at four different temperatures (110–150°C) and three different air humidities (0.3–5.0%). The raw cocoa beans were characterized by high antioxidant activities. The antioxidant properties of the roasted cocoa beans varied markedly among the analyzed cultivars and geographical regions and were affected by roasting conditions. Generally, cocoa beans of the cv. Forastero from Brazil exhibited higher total phenolic content, free radical scavenging activity, and metal chelating ability than samples of the other analyzed cocoa varieties. Roasting at 110°C caused negligible changes in total phenolics content and antioxidant activity of cocoa beans, while almost all samples tended to have lower antioxidant potential when roasting temperature increased. The air humidity used in roasting did not affect the total phenolics content and antioxidant activity for lowest roasting temperature (110°C). Moreover, the obtained results revealed that thermal processing at the higher temperatures and elevated air humidity resulted in the higher antioxidant capacities. It was also found that the ferrous ion chelating activity of cocoa beans increased with the roasting temperature (in the range from 110 to 150°C), with the exception of cv. Trinitario from Papua New Guinea. The data showed that roasting at lower temperatures with humid air are more favorable in terms of preserving the bioactivity of roasted cocoa beans.  相似文献   

18.
通过顶空固相微萃取-气相色谱-质谱联用技术(HS-SPME-GC-MS)测定熏马肠中的挥发性风味物质。从5个不同样品中共鉴定出106种风味物质,包括烃类、醇类、酯类、酸类、醛类、酮类、酚类、呋喃类、含氮类等化合物。其中烃类、醇类、酸类、酮类、酚类化合物含量较高,空白组和发酵剂组熏马肠中挥发性风味化合物的种类和含量都存在着一定的差别。  相似文献   

19.
Cocoa in the world market is the ripened bean of the cocoa tree (Theobroma cacao L) that has been properly fermented and dried. A number of varieties are found such as Amelonado and F3Amazon which are considered ‘bulk’ cocoas by the FAO. Chocolate produced by these cocoas does not, possess the additional flavours associated with the ‘finey’ types such as Trinitario and Criollo. Literature exists on the composition of cocoa bean meal but the work reported has been on bulk samples received by chocolate manufacturers or found in warehouses. These are beans harvested from several trees and of varied and unknown species growing in different localities. Therefore differences due to environmental and varietal factors will be masked. This work, which was carried out on cocoas from south-eastern Nigeria, is aimed at highlighting the variation in composition (if any)of the cocoa bean between (a)individual species, (b) individual trees of each species planted at the same time and in the same geographical area, (c) individual trees of the same species, planted in the same area but having an age difference of some ten years.  相似文献   

20.
The cocoa (Theobroma cacao) fermentation was carried out using starter consortia of Saccharomyces cerevisiae, Lactobacillus plantarum, and Acetobacter aceti with 10% inoculum. The fermented beans were soaked with sterile water (1:3 wt/v) for the duration of 1, 3, and 5 h. The treated beans were dried to the moisture content of 7 ± 1%. The samples were then roasted, ground and subjected to steam distillation. The volatiles were extracted and identified using GC-MS. The samples soaked for 1 h scored 100% cut score along with 0.85% fermentation index. The volatile and non-volatiles were associated with beans treated in water after fermentation. Volatile compounds were classified as esters, alcohols, acids, aldehydes, ketones, pyrazines, hydroperoxides, and hydrocarbons. Most of the oxygenated aliphatic compounds and aromatics were potentially derived via an acetic acid and shikimic acid pathways, respectively. Untreated cocoa beans contained 12 sesquiterpene hydrocarbons potentially derived through the mevalonic acid pathway and contributed to harsh notes. Also, these metabolites were completely absent in the treated samples indicating depletion while soaking. Thus, the treated samples (1 h) had enhanced quality with high flavor notes with 8.5 rating on sensory evaluation. Thus, these soaking treatments with fermentation lead to improvement of flavor profiles which confers improved cocoa quality.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号