Identification of aroma‐active compounds in fresh and stored ‘Mor’ mandarins

In this study, gas chromatography–olfactometry (GC‐O) (sniffing) combined with gas chromatography–mass spectrometry (GC‐MS) analysis was applied to identify volatile aroma‐active compounds in homogenised segments of fresh and stored ‘Mor’ mandarins. The GC‐O nasal impact frequency method was used to identify Twenty‐three aroma‐active compounds, of which seventeen odorants were identified by GC‐MS. The aroma of fresh ‘Mor’ mandarins derived from a mixture of eleven odorants that contribute ‘green’ [(E)‐3‐hexenol and hexanal], ‘fresh’ [(E)‐carveol], ‘fruity’ (ethyl 2‐methylbutanoate), ‘citrus’ (limonene), ‘floral’ (linalool), ‘musty’ (β‐myrecene and γ‐terpinene), ‘potato’ (α‐terpinene), ‘mushroom’ (unknown 2) and ‘cabbage’ (α‐cubebene) odours. During postharvest, storage losses were observed in ‘green’ [(E)‐3‐hexenol] and ‘fresh’ [(E)‐carveol] odours, accompanied by increases in ‘fruity’ (ethyl propanoate) and several unpleasant aromas, such as ‘alcohol’ (ethanol), ‘musty’ [α‐pinene, (E)‐2‐nonenal and 1‐terpinen‐4‐ol] and ‘fatty’ (octyl acetate and δ‐cadinene) odours, all of which possibly account for the observed decrease in sensory acceptability after harvest.     

Reducing the Influence of the Thermally Induced Reactions on the Determination of Aroma-Active Compounds in Soy Sauce Using SDE and GC-MS/O

A method based on simultaneous distillation extraction (SDE) coupled with gas chromatography–mass spectrometry/olfactometry (GC-MS/O) was developed for the analysis of volatile profiles in soy sauce. Its optimum operating conditions were as follows: 100 mL soy sauce plus 100 mL saturated brine; 2 h extraction using 50 mL dichloromethane. Eighty-eight volatile compounds were identified. Of these, 26 aroma-active compounds were detected by GC-O including 3-(methylthio)propanal, 2-methoxy-4-vinylphenol, 2-methoxyphenol, 2-methylbutanoic acid, 2,3-butanedione, phenylacetaldehyde, 2-ethyl-6-methylpyrazine, 3-methylbutanal, 2-methylbutanal, 3-methyl-1-butanol, and 2-methyl-1-butanol (which occurred at a high odor intensity in both high-salt liquid-state fermentation soy sauce (HLFSS) and low-salt solid-state fermentation soy sauce (LSFSS). SDE analysis of the odorless soy sauce indicated 12 volatiles (mainly Strecker aldehydes and α-dicarbonyl compounds). Thus, the proportions of these compounds (1.94–54.07 %) shown in previous GC-MS results could result from thermal degradation of non-volatile compounds in soy sauce. Especially, the contribution of 3-methylbutanal, 2-methylbutanal, phenylacetaldehyde, 3-(methylthio)propanal, and 2,3-butanedione to the aroma of soy sauce could be overestimated by conventional SDE-GC-O. With a full consideration of such limitations, this study will improve the application of SDE on aroma analysis of complex food matrix.     

不同淀粉质原料对高盐稀态酱油香气品质的影响

为了研究不同淀粉质原料(面粉、麸皮)对高盐稀态酱油香气品质的影响,本文利用定量描述分析(QDA)对面粉类酱油(FSS)、麸皮类酱油(WSS)的感官特征进行分析,通过顶空-固相微萃取(HS-SPME)和液液萃取(LLE)结合气相色谱-质谱联用(GC-MS)定量对比分析了两种酱油挥发性化合物组成。FSS中酸香、土豆香、麦芽香显著性高于WSS,焦糖香、烟熏香显著性低于WSS(p0.05)。GC-MS共分离鉴定出94种挥发性化合物,其中以酸类、酮类、醛类占主要比例,HS-SPME法能萃取出较多的醛类、含硫化合物,LLE法对呋喃(酮)类、酸类化合物萃取效果较好。通过对酱油中17种关键香气活性物质定量分析以及香气活性值(OAV)的计算,有9种化合物OAV值大于20。其中3-甲基丁醛OAV值最高,HDMF、愈创木酚均有较高的OAV值,且在WSS中高于FSS,与感官分析中的焦糖香、烟熏香结果一致;FSS中2-甲基丁醛、3-甲硫基丙醛的OAV值高于WSS,与麦芽香、土豆香感官分析结果相符。     

Olfactometric characterization of aroma active compounds in fermented fish paste in comparison with fish sauce,fermented soy paste and sauce products

Aroma active compounds in commercial fermented fish meat paste product (fish miso), fermented soy paste (soy miso), fish sauce and soy sauces were characterized by using a dynamic headspace method for volatile isolation and GC olfactometry for odor perception. A total of 123 volatile compounds consisting mainly of aldehydes, alcohols, esters, ketones, furans, sulfur and nitrogen-containing compounds, aromatics and acids were consistently identified. A major 16 odor-active compounds were distinguished to contribute as key aroma compounds for the miso and sauce products. Olfactometric and sensory findings clearly differentiated miso products with caramelic, fruity aroma notes, whereas fish sauce products were characterized by ammoniacal, fishy, nutty and cheesy odor note. Soy sauce products, however, were dominated by nutty and cheese aroma. Use of koji for fish miso production was found effective to enhance sweet aroma to the product with a reduction of nutty, meaty and rancid nuance. Principal component analysis employed for statistical interpretations clearly elucidated the relationship among different types of fermented products.     

Fermentation of Soy Sauce with Immobilized Whole Cells

Soy sauce was produced continuously for 80 days in 280 liter column-type reactors containing immobilized whole cells of Pediococcus halophilus, Saccharomyces rouxii, and Torulopsis versatilis entrapped in calcium alginate gels. The divided lactic acid and alcohol fermentation by viable cells of three kinds with feed solution obtained from enzymatic hydrolyzate of koji and defatted soybean meal proceeded in shorter time than a complex fermentation of moromi (soy sauce mash) in the slurry state. The refined products fermented by this process had good taste and flavor, and were close to the conventional soy sauce with respect to organic acid and aroma components.     

Characteristic odour compounds in shochu derived from rice koji

Shochu, a traditional Japanese distilled liquor, makes use of rice koji, which is koji mould grown on rice grain. Rice koji is an essential ingredient of Japanese liquors such as shochu, and it plays a role as a source of the enzyme to degrade starch. However, there has been no research on the effect of rice koji on the flavour of shochu. Therefore, in this study, the volatile compounds in shochu derived from rice koji were investigated. Two shochu samples were prepared to assess the contribution of rice koji to the flavour. One shochu sample was prepared from rice koji, yeast and water (rice koji‐shochu). The other shochu sample was obtained from steamed rice and various enzymes instead of rice koji (enzyme‐shochu), along with yeast and water. The volatile compounds were analysed by gas chromatography–mass spectrometry (GC‐MS) and GC‐MS/olfactometry with aroma extract dilution analysis. The results showed that enzyme‐shochu had a higher flavour dilution value of dimethyl trisulphide and hexanal, whereas rice koji‐shochu had a higher flavour dilution value of some ester compounds that imparted aromatic odours such as fruity. Some unknown peaks representing compounds that impart characteristic odours such as soda, potato, lavender, and tea‐like were specifically detected in rice koji‐shochu. The concentrations and calculated odour active values of 14 compounds were measured. These results showed that isovaleraldehyde, ethyl caprylate, ethyl caproate and ethyl 2‐methylbutyrate played an important role in imparting the specific odour of rice koji‐shochu. Copyright © 2016 The Institute of Brewing & Distilling     

Effect of different cooking methods on the flavour constituents of mushroom (Agaricus bisporus (Lange) Sing) soup

The effect of different cooking methods on the flavour of mushroom soup was assessed. The results indicated that the levels of free amino acids and 5’‐nucleotides in the microwaved mushroom soup were (P < 0.05) higher than those in boiled and autoclaved mushroom soup. The number of volatile compounds identified in the boiled mushroom soup was (P < 0.05) higher than those in autoclaved and microwaved mushroom soup. The main aroma‐active compounds found in mushroom soup were 1‐octen‐3‐one (mushroom‐like), 3‐octen‐2‐one (cooked mushroom‐like), 2,6‐dimethyl pyrazine (roast nut), benzeneacetaldehyde (floral), dihydro‐5‐methyl‐2(3H)‐furanone (sweet) and some unknown compounds with popcorn and sauce flavour. In addition, boiled, autoclaved and microwaved mushroom soup possessed thirteen, ten and nine aroma‐active compounds (with flavour dilution factors > 1), respectively. Thus the flavour of mushroom soup is dependent on the cooking methods as proved by gas chromatography and olfactometry analysis.     

Comparison of aroma characteristics of 16 fish species by sensory evaluation and gas chromatographic analysis

The aroma properties of fish broths prepared from 16 fish species (10 saltwater, three freshwater, two anadromous and one brackish water species) were described quantitatively by reference to 10 sensory attributes. Principal component analysis (PCA) and cluster analysis of sensory attributes classified the fish into four groups. Group 1, characterised by a strong ‘green’ odour, comprised all three freshwater species (loach, pond smelt and carp), two saltwater whitefish species (snapper and conger) and eel. Group 2 included migratory coastal species (sardine, banded blue‐sprat and mackerel) and was distinguished by strong ‘fish oil’ and ‘grilled fish’ notes. Group 3 consisted of swordfish, sablefish and salmon, which exhibited a strong ‘fried chicken’ note. Group 4 included flounder, cod, tuna and goby, which were scored high for ‘cooked fish’, ‘roasted soy sauce’, ‘canned tuna’ and ‘sweet’ aromas. Partial least squares regression (PLSR) models derived from selected influential peaks in the gas chromatograms of the volatile components in the broths for each attribute were highly predictive (R² ≥ 0.936). The selected peaks corresponded well to each sensory attribute. © 2003 Society of Chemical Industry     

光照对酱油发酵影响初步研究

研究了不同光质对发酵酱油的影响,结果显示不同光质发酵酱油在其色泽(A530)、氨氮含量、固形物含量、还原糖含量、总酸含量、红指、黄指等指标之间的变化率没有明显差异(p>0.05),经感官评价,其色泽、香气、滋味方面也均没有显著差异(p>0.05)。对无光控温发酵酱油与传统晒露发酵酱油进行比较,中性和酸性蛋白酶活力在无光控温发酵酱油中均下降得较快,但氨氮含量却增加较快。它们的总游离氨基酸含量分别为5.246g/100mL和4.480g/100mL;通过GC-MS对酱油的挥发性成分进行分析,无光控温发酵酱油中的挥发性成分较丰富,而且其大部分醇类、酸类、酯类、醛类、酚类和其他挥发性物质的含量均比传统晒露发酵酱油高。     

酶法制备大豆多肽及在酱油发酵中的应用

以脱脂大豆粕为原料,采用复合酶解技术制取大豆多肽酶解液,将制备的大豆多肽应用于酱油发酵前期,并从酱油理化指标、感官评价及香气分析三方面归纳其对酱油主要品质的影响。结果表明,先加中性蛋白酶（温度55 ℃,pH值为6.5,酶用量为4 500 U/g蛋白,酶解3 h）后,再加入碱性蛋白酶（温度55 ℃,pH值为9.0,酶用量为3 000 U/g蛋白,酶解1 h）。此时水解度达22%,多肽得率达10.84%。添加大豆多肽的酿造酱油色泽棕红亮,醇香、酱香浓郁,整体滋味均优于普通酿造酱油。气质联用（GC-MS）鉴定出酱油中含挥发性风味化合物40种,其中主要香气化合物为醇类69.41%、酸类23.06%、醛酮类4.45%、杂环酯类2.47%等,大豆多肽提高了酿造酱油的综合品质,滋味和香气明显优于传统发酵酱油,可用于开发功能营养型酱油。     

Variations in volatile compounds and flavour in Idiazabal cheese manufactured from ewe's milk in farmhouse and factory

Stage of lactation, use of bulk milk or milk from individual flocks, and cheese‐making in farmhouse or industrial factory are important factors affecting the production and quality of Idiazabal cheese. The volatile composition of cheese samples made from raw ewe's milk in farmhouses or industrial plants at two different times of the year and aged for 90 and 180 days was analysed by dynamic headspace coupled to GC‐MS. Short‐chain fatty acids, primary and secondary alcohols, methyl ketones and ethyl esters were the most abundant compounds in the aroma of Idiazabal cheese samples. Differences in the volatile composition were found between farmhouse and industrial cheeses made at different times of the year and ripened for 90 or 180 days. Likewise, the sensory profiles of the farmhouse and industrial cheeses were significantly different, regardless of the time of the year and ripening time. The results for the principal component analysis (PCA) performed on the sensory attributes of the cheese samples showed two PCs defined as ‘farmhouse flavour factor’ and ‘industrial flavour factor’. Farmhouse cheeses showed high scores for buttery, milky and toasty odours, and buttery and nutty flavours, whereas industrial cheeses showed high scores for sharp, rennet and brine odours, and rennet and rancid flavours. The percentages of methyl ketones such as 3‐hydroxy‐2‐butanone, 2‐butanone, 2‐pentanone and 2‐heptanone, and acids such as n‐propanoic, 2‐methylpropanoic and 3‐methylbutanoic acids were higher in farmhouse cheeses than in industrial cheeses. On the other hand, the percentages of esters such as ethyl butanoate and ethyl hexanoate, and alcohols such as 3‐methyl‐1‐butanol, and acids like n‐hexanoic acid were higher in industrial cheeses than in farmhouse cheeses. Relationships between sensory attributes and volatile compounds were studied on the basis of the differences found in sensory profile and volatile composition between farmhouse and industrial cheeses. Copyright © 2005 Society of Chemical Industry     

QUALITY OF FISH SAUCE PRODUCTS FROM RECYCLED BY‐PRODUCTS FROM FISH GEL AND KAMABOKO PROCESSING

ABSTRACT

In order to make effective reuse of kamaboko processing wastes and to minimize the amount of waste disposal, the production of two kinds of fish sauces was tried on a small industrial scale from the wastes with or without the addition of the meat of deepsea smelt (Glossanodon semifasciatus). They were fermented for 6 months at room temperature using salt and koji mold. As a control, a fish sauce was also produced only from the deepsea smelt meat. The recovery of fish sauce from the initial mashed mixture ranged between 75 and 79%, depending on the ingredients in the three fish sauce products. The total nitrogen content of the waste sauce and the mixed sauce was lower than that of the control. The levels of the original additives to kamaboko products, β‐carotene and sorbic acid, were very low in these fish sauces. The taste‐active components of the waste sauce and mixed sauces were lower than those of the control. Sensory evaluation revealed that the former two waste sauces were less bitter and higher in saltiness than the control. However, no difference was found in umami taste between these products. These findings suggest that the wastes from kamaboko processing factories could be reused as fish sauce for food condiments.

PRACTICAL APPLICATIONS

Recent development in the food industry in Japan has enabled the surimi‐based products to be mass produced and standardized even in the fish gel, kamaboko trade. However, a serious problem has arisen in the development of kamaboko processing through the discharge of the wastes, i.e., nonstandard products or fragments, from kamaboko processing factories. It is clear that the waste from kamaboko processing factories is transformed effectively into fish sauce by using soy sauce koji mold. As a result, the amount of the discharged wastes from kamaboko factories are able to be minimized because the liquefaction ratio of the fish sauce mushes (moromi) from the wastes after fermentation was high and the products have a high umami taste and agreeable soy sauce‐like flavor.     

Effect of fermentation by Aspergillus oryzae on the biochemical and sensory properties of anchovy (Engraulis japonicus) fish sauce

This study obtained an anchovy flavourful fish sauce by a bioprocess of aerobic fermentation with Aspergillus oryzae OAY1 in a period of time as short as 3 days. Amino nitrogen of the fish sauce increased to 7.35 mg mL^?1 by optimisation with response surface methodology (RSM). Results of chemical analysis showed that amino nitrogen, hydrolysis degree, reducing sugar and total amino acids all increased, along with the enhanced antioxidant activity. With regard to biogenic amines, most of the tested biogenic amines decreased after fermentation. Electronic nose test revealed that the odour of the fish sauce became more balanced and favourable after fermentation. In addition, volatile odorant analysis and sensory evaluation showed that no particularly unpleasant flavour ingredient was found in the anchovy fish sauce, and the taste was overall satisfactory. Meanwhile, consumer acceptance test showed that the anchovy fish sauce produced in this study using A. orzyae OAY1 had a high consumer acceptance similar to the commercial anchovy fish sauce. This aerobic fast‐fermentation process provided an efficient method for high‐quality fish sauce production.     

Monitoring of Yeast Communities and Volatile Flavor Changes During Traditional Korean Soy Sauce Fermentation

Flavor development in soy sauce is significantly related to the diversity of yeast species. Due to its unique fermentation with meju, the process of making Korean soy sauce gives rise to a specific yeast community and, therefore, flavor profile; however, no detailed analysis of the identifying these structure has been performed. Changes in yeast community structure during Korean soy sauce fermentation were examined using both culture‐dependent and culture‐independent methods with simultaneous analysis of the changes in volatile compounds by GC‐MS analysis. During fermentation, Candida, Pichia, and Rhodotorula sp. were the dominant species, whereas Debaryomyces, Torulaspora, and Zygosaccharomyces sp. were detected only at the early stage. In addition, Cryptococcus, Microbotryum, Tetrapisispora, and Wickerhamomyces were detected as minor strains. Among the 62 compounds identified in this study, alcohols, ketones, and pyrazines were present as the major groups during the initial stages, whereas the abundance of acids with aldehydes increased as the fermentation progressed. Finally, the impacts of 10 different yeast strains found to participate in fermentation on the formation of volatile compounds were evaluated under soy‐based conditions. It was revealed that specific species produced different profiles of volatile compounds, some of which were significant flavor contributors, especially volatile alcohols, aldehydes, esters, and ketones.     

Effect of a halophilic aromatic yeast together with Aspergillus oryzae in koji making on the volatile compounds and quality of soy sauce moromi

Koji making is an essential step in the production of high‐quality soy sauce. In this study, we inoculated koji with a halophilic aromatic yeast (Zygosaccharomyces rouxii) and Aspergillus oryzae and investigated the effects on the volatile compounds and quality of soy sauce moromi. Our results suggest that the optimal yeast inoculation was approximately 1.5 × 10⁶ yeast per gram of koji, and excessive yeast greatly decreased A. oryzae enzyme activity. In comparison with the control group, there were no significant changes in the concentrations of amino nitrogen, total titratable acids, total soluble nitrogen and reducing sugar by extending the fermentation time during the first fermentation month, whereas the concentration of glutamate in the yeast‐inoculated sample increased by 46.16% and the arginine concentration decreased by 61.07%. After the second fermentation month, 17, 38 and 38 volatile components were identified by GC–MS in C1, C2 and C5, respectively. Moreover, a large number of volatile components, such as 2‐Methoxy‐4‐vinylphenol, ethyl acetate and 1‐Octen‐3‐ol were found in C2 and C5. And the total contents of volatile compounds in C2 were obviously higher than C5. This work furthers our understanding of the traditional multistrain koji making and provides a new method for enhancing the quality and flavour of soy sauce.     

Evaluation of volatile flavour compounds from cashew apple (Anacardium occidentale L) juice by the Osme gas chromatography/olfactometry technique

The headspace volatile components of the juice of cashew apples from a commercial Brazilian dwarf genotype were separated by high‐resolution gas chromatography and identified by GC/MS. Five judges evaluated the GC effluents using the Osme technique in order to determine the importance of each compound to the characteristic cashew aroma. Esters methyl 3‐methyl butanoate, ethyl 3‐methyl butanoate, methyl butanoate, ethyl butanoate, ethyl trans‐2‐butenoate and methyl 3‐methyl pentanoate were important to the sweet, fruity and cashew‐like aroma. Cis‐3‐hexenol, hexanal and 2‐methyl‐2‐pentenal presented different green notes. In spite of the flame ionisation detector being unable to detect sulphur compounds, the olfactometric analysis revealed chromatographic regions where sulphur‐like odours were perceived by the Osme sensory panel. The most intense unpleasant odour was due to 2‐methyl butanoic acid, which was described as very stinky. The sensory panel showed good olfactory sensitivity and reproducibility. Sensory and instrumental data correlation allowed a greater understanding of the role of several volatile compounds in the sensory quality of the juice. Copyright © 2003 Society of Chemical Industry     

2种不同工艺酱油原油的挥发性成分的分析

通过用SPME萃取结合GC-MS分析了2种不同工艺酱油原油的挥发性成分,用面积归一化法测定其组分的相对含量,2种酱油中共鉴定出117种(7大类)挥发性风味化合物,天然晒露的酱油共有62种,低盐保温发酵原油有84种,所鉴定的风味化合物包括15种醇,10种酚,18种酸,19种酯,21种醛酮化合物,27种杂环化合物和7种含硫化合物。其中O-愈创木酚、乙酸、3-甲基丁酸、2-甲基丁酸、2-甲基丁醛、苯甲醛、苯乙醛和三甲基吡嗪为2种酱油中都存在的主体物质。尽管酱油中多数香气成分含量极微,但是多种香气成分的存在极大地丰富了酱油的风味。     

Quantification of volatile compounds in Chinese soy sauce aroma type liquor by stir bar sorptive extraction and gas chromatography-mass spectrometry

BACKGROUND: Considering the important of aroma compounds on the quality of baijiu, stir bar sorptive extraction (SBSE) coupled with gas chromatography–mass spectrometry was applied to the aromas analysis of baijiu (Chinese liquor). RESULTS: Based on the results of optimization, a total of 76 volatile compounds were identified from 14 Chinese liquors, including 25 esters, 10 alcohols, 9 aldehydes and ketones, 8 aromatic compounds, 5 furans, 3 nitrogen‐containing compounds, 6 acids, 4 phenols, 3 terpenes, 1 sulfide‐containing compound, 1 lactone, and 1 acetal. By principal component analysis based on quantification results, 14 Chinese liquor samples could be classified into three groups. CONCLUSION: SBSE is a fast, simple, effective, and reliable method for extracting volatile compounds from Chinese liquor. The chemometrics approach revealed that LJ liquor with soy sauce aroma could exhibit more prominent sauce flavor through extending the time of storage, and its peculiar manufacturing practice was responsible for the soy sauce flavor. Copyright © 2011 Society of Chemical Industry