肉制品中的风味物质及其分析方法

肉类在加工处理过程中形成特殊的风味,其风味特征由其所含化学成分的性质决定。风味物质包括味道活性化合物、风味增强剂及芳香成分等,由美拉德反应和脂质的热降解产生。通过提取,可对肉类风味物质进行量化的仪器分析,而气相色谱—质谱联用技术(GC-MS)是挥发性风味物质分析的首选。     

Key meat flavour compounds formation mechanism in a glutathione-xylose Maillard reaction

The formation mechanism of meat flavours formed from a glutathione-xylose Maillard reaction was studied using a group of model reactions with [¹³C₅] xylose/xylose (1:1), heated at 132 °C for 90 min. Volatiles, especially the aroma-active compounds, and non-volatiles were analysed respectively with GC-O-MS and LC-TOF-MS. Analysis of the mass spectra showed that furfural, 2-furfurylthiol and thiophene were ¹³C₅-labelled and hence stem from xylose, whereas 2-methyl-3-furanthiol, 2-methyl-thiophene and 2-pentyl-thiophene, which showed similar formation patterns with only unlabelled compounds, may be from thiamine and/or cysteine carbons. In the process of Maillard reactions, GSH can be capable of cleaving in the position of glutamyl and cysteinyl, and then form 5-oxoproline or pyroglutamic acid (PCA), cysteine, and Cys-Gly dipeptide, which can form cyclic (Cys-Gly).     

Motives for food choice: a comparison of consumers from Japan, Taiwan, Malaysia and New Zealand

With increasing emphasis on understanding consumer preferences in export markets, particularly in Asia, there is a need to determine those factors that influence food choice in other cultures. The Food Choice Questionnaire (FCQ), which assess the relative importance of nine factors thought to be important motives in food choice: Health, Mood, Convenience, Sensory Appeal, Natural Content, Price, Weight Control, Familiarity, andEthical Concern, was administered to groups of female consumers in Japan, Taiwan, Malaysia, and New Zealand. The Food Neophobia Scale was also administered in New Zealand, Taiwan and Japan. There was agreement between Taiwanese and (ethnically Chinese) Malaysian consumers in the most important food choice factors: Health, Natural Content, Weight Control andConvenience. In contrast, Price was most important for Japanese consumers and Sensory Appeal for New Zealand consumers. Familiarity was rated as least important by all countries, and Ethical Concern was also considered unimportant by all countries except Japan, where it was rated as relatively important. Older consumers generally gave higher ratings. Differences between consumer groups were also shown in the degree of neophobia. These data are important in demonstrating differing motives for food choice cross-culturally, and also provide indications of which food claims may be useful in promoting choice in the countries studied.     

Serum concentrations of polyfluoroalkyl compounds in Faroese whale meat consumers

To learn the extent of human exposure to polyfluoroalkyl compounds (PFCs) in a remote fishing population, we measured, in Faroese children and pregnant women, the serum concentrations of nine PFCs, including perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), and perfluorononanoate (PFNA), by using online solid-phase extraction coupled to isotope dilution high-performance liquid chromatography-tandem mass spectrometry. The serum samples analyzed had been collected between 1993 and 2005 from 103 children 7 years of age, 79 of these children at 14 years of age, and from 12 pregnant women and their children 5 years later. PFOS was detected in all samples analyzed, and both PFOA and PFNA were detected in all but one of the samples. The concentrations found are comparable tothose reported elsewhere. Correlations between paired concentrations were poor. However, PFOS and PFNA concentrations correlated well with the frequency of pilotwhale dinners and with concentrations of mercury and polychlorinated biphenyls. One whale meal every two weeks increased the PFOS concentration in 14-year-olds by about 25% and PFNA by 50%. The high frequency of detection of most PFCs suggests widespread exposure in the Faroe Islands already by the early 1990s, with whale meat being an important source.     

Relationship between odour-active compounds and flavour perception in meat from lambs fed different diets

To identify the most important aroma compounds in 20 d-aged meat from castrated heavy Corriedale lambs fed one of four diets, grilled loin samples were subjected to a dynamic headspace-solid phase extraction (DHS-SPE) and gas chromatography–olfactometry (GC–O). Most of the important odorants were aldehydes and ketones. To evaluate the effect of finishing diet on carbonyl compounds, a derivatization of the headspace carbonyls using o-[(2,3,4,5,6-pentafluorophenyl)methyl]hydroxylamine hydrochloride (PFBHA) and analysis by GC–MS was conducted. Diet did not affect aliphatic saturated aldehydes. The meat from lambs finished on pastures, without a concentrate supplement, had very low concentrations of lipid-derived unsaturated aldehydes and ketones and Strecker aldehydes, possibly because of the protective effect of antioxidants that occur in the diet naturally. Lamb flavour was related to the concentration of heptan-2-one and oct-1-en-3-one, but rancid or undesirable flavours were not related to the abundance of carbonyl compounds.     

A comparison of the flavour volatiles from cooked beef and pork meat systems

The headspace volatiles from beef and pork cooked with and without added adipose tissue were entrained on Tenax GC before analysis by gas chromatography (g.c.) and combined gas chromatography-mass spectrometry. Lipid-derived volatiles dominated the headspaces of all samples and the only qualitative difference between beef and pork was an alkene of lipid origin which was peculiar to beef samples. A comparison of the areas of 37 g.c. peaks from replicate analyses of the different meat preparations using canonical variates and stepwise discriminant statistical techniques unambiguously distinguished the lean meats and the lean meats cooked with adipose tissue of either species. Adding adipose tissue to lean meat did not result in proportional increases in lipid-derived volatiles.     

Effects of some technologies of curing uncomminuted meat products on their flavour Part 2. Contents of carbonyl compounds and their relation to flavour

Studies were made of carbonyl compounds and the flavour components of two types of uncomminuted pork products, loin and neck, manufactured by three technologies: I. brine curing; 11. dry curing, and 111. dry curing using 0.6 % honey. Meat flavour was evaluated by a trained panel by the method of sensory profiles, using a 5 point scale. A considerable increase was found in the contents of total carbonyl compounds in the meat products manufactured by technology II, and particularly by technology III. The difference in mono-carbonyl compounds and ketoglycerides was insignificant. The data from the sensory analysis indicated a more intensive flavour in the latter meat products, which was particularly marked in the those made of loin.     

现代食品工业高新技术在肉味香精中的应用

本文简要介绍了肉味香精的概念和发展状况，对现代食品工业高新技术在肉味香精中的应用作出了较为全面的阐述。     

Extrusion parameters and consumer acceptability of a peanut-based meat analogue

Despite its high protein content and low cost, defatted peanut flour (DPF) remains underutilised in human foods. The objectives of this study were to: (1) determine the best extrusion parameters for a peanut-based textured meat analogue (TMA); (2) develop new TMA products from DPF and (3) evaluate their consumer acceptability. Preliminary runs using a wide range of extrusion parameters were conducted. A central composite RSM design was used to determine the optimal extrusion conditions within the best ranges revealed by the preliminary runs. Three levels of moisture, screw-speed and barrel temperature were used in 31 runs. Expansion ratio, bulk density, texture profile, water absorption/solubility indexes of the extrudates were determined and used as indicators of product quality. Peanut-based TMAs produced at optimal extrusion conditions were flavoured with beef flavour and evaluated by a 60-member sensory panel for flavour, texture, and overall liking, using a 9-point hedonic scale. Optimisation studies revealed that the most important extrusion conditions are in descending order: protein content, temperature, moisture and screw-speed. Extrusion conditions that produced the best TMA were 60–65% protein, 50–55% moisture, 160–165 °C and 80–90 r.p.m. Sensory acceptability of snacks incorporating peanut-based TMAs was similar or better than those containing soya-based TMAs in terms of flavour, texture, off-flavour and overall liking. TMA produced from inexpensive DPF has the potential to compete with commercial meat analogues, thereby adding value to the peanut industry.     

Distinguishing meat reducers from unrestricted omnivores,vegetarians and vegans: A comprehensive comparison of Australian consumers

Meat reducers are a growing but largely unexplored population subgroup in Australia. A comprehensive understanding of individual characteristics associated with meat consumption preferences can help inform strategies aimed at encouraging healthier and more environmentally sustainable food choices. Using online survey data from a nationally representative sample of 2797 Australian food shoppers, this study 1) compares characteristics (dietary, psychosocial and socio-demographic) of consumers with distinct self-identified dietary preferences (unrestricted omnivores, meat reducers, vegetarians and vegans); 2) identifies the psychosocial and socio-demographic predictors of the meat-reducer diet group; and 3) determines whether predictors of the meat-reducer diet group differ based on diet group classification method (i.e. self-identified dietary preferences versus self-reported consumption frequency of animal-source foods). Results reveal that relative to unrestricted omnivores and meat avoiders, meat reducers are unique with respect to their meat consumption behaviours; beliefs regarding the nutritional adequacy and food choice adequacy of meat-free diets; and the relative importance they place on egoistic food choice factors. Considering self-identified dietary preferences, multivariate regressions found that stronger beliefs regarding meat-free diet adequacy and lower importance placed on egoistic food choice factors predict meat reducers relative to unrestricted omnivores; and weaker beliefs regarding meat-free diet adequacy and higher importance placed on egoistic food choice factors predict meat reducers relative to meat avoiders. Findings from this study can provide insight on how to more holistically address the concerns and motivations of consumers with distinct meat consumption preferences.     

Contributions of non-volatile and volatile compounds to the umami taste and overall flavour of shiitake mushroom extracts and their application as flavour enhancers in cooked minced meat

Aqueous extracts of dried shiitake mushrooms (Lentinus edodes) were prepared as taste and flavour enhancers for meat formulations. Effects of time and temperature on the chemical and sensory properties of the extracts were examined. Extracts prepared at 70 °C had significantly higher concentrations (p < 0.001) of the savoury tasting 5′-ribonucleotides than those prepared at 22 °C but increasing the extraction time from 30 to 360 min only increased their recovery slightly (p = 0.053). In contrast, higher temperature extracts had considerably smaller concentrations of the major volatile compounds, such as lenthionine, 1-octen-3-ol, 1,3-dithiethane and dimethyl disulfide, because of loss through volatilisation.     

Wine cluster formation in New Zealand: operation,evolution and impact

This paper analyses the Waipara wine cluster, located in the South Island of New Zealand, in relation to formation, operation, evolution and impact. The unique methodological approach of this research is that it analyses the current and desired future state of the cluster and secondly examines the cluster in relation to both the domestic and international markets. Key findings from the research include a greater understanding of the relationships between cluster members, the operation of cluster, problems within the cluster and how the cluster operates for both domestic and international markets. The research lends itself to a new definition of internationalisation –‘direct and indirect methods of increasing the likelihood of international sales’– and also provides new insights for cluster theory, wine clusters and the wine industry in general. Some of the practices detailed have use in the wider wine community of the world, making the paper of interest to a wide audience.     

The flavour of muscat wine: The sensory contribution of some volatile compounds

Nine volatile constituents of a Muscat de Frontignan wine were selected as potentially important to the aroma of this wine by sniffing the chromatographic effluent following gas-chromatographic separation of an aroma extract. Their concentrations were determined by mass fragmentometry and their olfactory thresholds estimated in a white base wine by calculating odour impact values. Ethyl-cinnamate and β-ionone contributed significantly to the aroma of the wine investigated.     

Determination of some water-soluble aroma precursors in goat meat and their enrolment on flavour profile of goat meat

Selected water-soluble precursors, including sugars, free amino acids and nucleotides, were quantified in raw and cooked goat meat, as a part of a study which the main aim was to better understand the aroma formation in goat meat. When compared with the same precursors in beef, lamb and chicken, levels in goat meat were generally similar, except for fructose and glycine, which were present at higher concentrations in goat meat. Fructose, glucose, IMP, and cysteine suffered the greatest losses during the cooking process and seem to be most involved in aroma formation in goat meat. The effects of these precursor changes on the volatile compound composition and formation process of them on cooked goat meat are discussed.     

Pod storage time and spontaneous fermentation treatments and their impact on the generation of cocoa flavour precursor compounds

Most of volatile flavour compounds occurred during the cocoa postharvest operations including pod storage and fermentation whom effects on these metabolites were aimed by the present study. Three different spontaneous fermentation treatments were performed on the farm, and the main isolated yeasts were identified using PCR-DGGE technique. Fermented cocoa beans were solar-dried, and their flavour compounds were identified using solid phase microextraction technique–gas chromatography–mass spectrometry. The main results showed that Pichia kudriavzevii was common yeast involved in the cocoa fermentation. Thirty flavour precursor compounds grouped into six chemical families including alcohols and pyrazines were identified in raw cocoa samples. ACP showed that short durations of pod storage and fermentation promote the formation of flavour precursors of cocoa. No spontaneous cocoa fermentation treatment influenced the occurrence of aroma compounds. The generation of flavour compounds depends only on the pod storage and the fermentative microorganisms of cocoa.     

Dialysis of flavour compounds: Yields of extraction on model solution

The extraction of 58 flavour compounds by Nafion membrane dialysis was studied using a model solution. Reproducibility and yield of the method were investigated. The coefficient of variation of the extraction yield was less than 15% for 48 of the 58 compounds tested. When the number of carbon atoms increased, the extraction yield fell to zero for compounds with more than ten carbon atoms. Flavour compounds with a cyclic structure showed a better diffusion rate through the membrane than other compounds with the same number of carbon atoms. The extraction yield seems to be correlated mainly to the hydrophobicity of the molecule. The use of the method for quantitative analysis was studied. Extraction rate can be considered as constant regardless of the quantity of compounds. The separation of flavour compounds from lipids was studied by this method. A better extraction yield with lipids was observed for eight compounds, for all other molecules no significant difference could be observed. The oil does not diffuse through the dialysis membrane.

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Dialyse von Aromaverbindungen. Ausbeute an Extrakt einer Modellösung

Zusammenfassung Es wurde die Extraktion von 58 Aromasubstanzen durch Dialyse an einer Nafion-Membran unter Verwendung einer Modellösung untersucht. Die Reproduzierbarkeit und die Ausbeute der Methode wurden ermittelt. Der Variationskoeffizient der Extraktionsausbeute war kleiner als 15% für 48 der getesteten 58 Substanzen. Die Ausbeute verringert sich bei steigender Anzahl von Kohlenstoffatomen, und fällt auf 0 bei Substanzen mit mehr als 10 Kohlenstoffatomen. Aromasubstanzen mit ringförmiger Struktur zeigen eine bessere Diffusionsrate als andere Substanzen mit derselben Anzahl von Kohlenstoffatomen. Die Extraktionsausbeute scheint hauptsächlich mit der Hydrophobizität der Substanzen korreliert zu sein. Die Anwendbarkeit der Methode für die quantitative Analyse wurde untersucht. Die Extraktionsrate kann als unabhängig von der Substanzmenge betrachtet werden. Die Trennung von Aromasubstanzen und Lipiden mit dieser Methode wurde untersucht. Eine verbesserte Extraktionsausbeute wurde für 8 Substanzen beobachtet, für alle anderen Substanzen wurden keine signifikanten Unterschiede beobachtet. Das Öl diffundiert nicht durch die Dialysemembran.

     

Perception of mealiness in apples: a comparison of consumers and trained assessors

  The Repertory Grid method was used to aid consumers in developing a vocabulary to describe the sensory characteristics perceived from samples of three varieties of apples (Cox, Jonagold and Boskoop) from three different harvest dates each (early, middle, and late harvest). The aims of this work were to study whether consumers perceived different degrees of mealiness and to compare the perceptual spaces of samples obtained from consumer data and from conventional profiling with a trained panel, using Generalized Procrustes analysis. The relative positions of samples were similar for the consumers and the trained assessors' consensus spaces but the latter resulted in a better separation of samples. Boskoop samples were perceived as more acid, astringent, crispy and hard while the Cox variety was described as sweeter and more floury. Jonagold samples were perceived as juicier and occupied an intermediate position, with the mealy Jonagold sample closer to the Cox samples. The agreement between sample spaces showed that both panels perceived the major differences between samples in a similar way but the trained panel was able to differentiate further, mainly between the texture characteristics. Received: 8 January 1998 / Revised version: 18 March 1998