Sensory properties of Cheddar cheese: changes during maturation

The aroma, flavour and texture of 16 samples of commercial Cheddar cheese have been profiled after ripening at 10 °C for 3, 4, 6, 8, 10 and 12 months. Systematic changes in sensory character have been studied and the main changes during maturation identified. Although sensory character changed slowly during ripening, assessment early in the maturation period was an unreliable estimate of ultimate sensory character. Progressive changes in Cheddar aroma and flavour, creamy flavour, acid flavour and mouth-coating character were noted during ripening. Changes in minor components of aroma and flavour were also observed but, on average, were small. Two samples eventually developed marked rancid character and another became excessively bitter. The relation between gross composition of the cheese and sensory properties was investigated. In the early stages of ripening, the ratings for Cheddar flavour and mouth-coating character were associated with the salt content of the cheese and with the concentration of fat in dry matter. However, as the cheese matured these associations weakened.     

Thermal taster status associates with oral sensations elicited by wine

Backgrounds and Aims: Individual differences in the perception of wine flavour may contribute to variation in wine consumer behaviour. Two phenotypes shown to associate with the intensity of oral sensations elicited by simple solutions are thermal taster status (TTS) and responsiveness to the bitterant 6-n-propylthiouracil (PROP). Thermals tasters (TTs) perceive ‘phantom’ tastes when the tongue is thermally stimulated. Here, we investigate the effect of TTS and PROP responsiveness on the perceived intensity of oral sensations elicited by wine. Methods and Results: Two white (2008 Pinot Grigio, Italy and 2007 Gewürztraminer, Canada) and two red (2007 Valpolicella, Italy and 2007 Cabernet Sauvignon, Chile) wines were assessed by 20 TTs and 20 thermal non-tasters (TnTs). TTs rated the intensities of sweet, sour, bitter, astringent and overall flavour higher than TnTs, and males (17) tended to rate these sensations higher than females (23). Unexpectedly, PROP responsiveness was not associated with intensity ratings of oral sensations for any wine (P(r) > 0.05). Neither TTS, PROP responsiveness, nor gender was linked with liking scores of the wines. Conclusion: TTS may be an important determinant of individual differences in oral perception of wine. Significance of Study: Understanding how individuals differ in their perception of wine can assist with product development, formulation and marketing.     

论述利用美拉德反应制备牛肉香味料

本文对美拉德反应机理及如何产生肉香的原因进行了陈述，根据以上的原理，选用关键的氨基酸且它们的恰当配比与葡萄糖进行梅拉德反应，确定了能产生最逼真的浓郁牛肉香的组合配比。     

DISCRIMINANT ANALYSIS OF SENSORY AND INSTRUMENTAL DATA ON BEER

Stepwise discriminant analysis has been used to examine sensory and instrumental data on forty six different brands of ale from five brewing companies. The beers were classified also according to four evenly spaced bands of original gravity within the range 1·030 to 1·050. Two samples of each beer from brews several months apart were analysed. Eighty of the beers were correctly assigned to brewing companies from data on four sensory and five instrumental parameters. The most important of these parameters were iso-amyl alcohol content and caprylic flavour, both of which relate to products of fermentation. Eighty six of the beers were correctly classified into gravity bands using data on thirteen sensory parameters relating to the beer flavours. In this case the three most important parameters were body (palate-fullness), viscous (thick) mouthfeel and aldehydic/estery character.     

THE INFLUENCE OF HAFNIA PROTEA (OBESUMBACTERIUM PROTEUS) ON BEER FLAVOUR

Numerous strains of Hafnia protea (originally Obesumbacterium proteus) were grown in brewer's wort in the absence and presence of Saccharomyces cerevisiae. The presence of H. protea gave rise to increased levels of n-propanol, isobutanol, isopentanol, dimethyl sulphide, dimethyl disulphide and 2,3-butanediol in finished beer. Concentrations of dimethyl sulphide and dimethyl disulphide varied according to the bacterial strains, but the increased levels of fusel alcohols and 2,3-butanediol were strain-independent.     

Effects of lard on the formation of volatiles from the Maillard reaction of cysteine with xylose

BACKGROUND: The presence of lipid oxidation products in the Maillard reaction pathway is of particular interest today. The objective of this study was to investigate the effect of lard and its oxidation products on the formation of volatiles from cysteine and xylose model systems. RESULTS: Headspace volatiles generated in reaction mixtures were examined by solid‐phase microextraction in combination with gas chromatography‐mass spectrometry. The addition of lipid had a suppressing effect on most of the sulfur‐containing compounds derived from the reaction between cysteine and xylose, especially for 2‐methyl‐3‐furanthiol, 2‐furanmethanethiol, 2‐methylthiophene, and 3‐methylthiophene. One of the intermediates—furfural—was also formed in much lower concentration when lard was present. In addition, cysteine and xylose modified lipid oxidation pathways, so that lipid‐derived alcohols, alkylfurans and aliphatic acids were formed rather than aldehydes. Compared with the lard heated alone, most aldehydes were formed at lower levels in the lard‐containing reaction mixtures, and several aldehydes including hexanal, heptanal, (2E)‐heptenal and (2E,4E)‐heptadienal were absent. CONCLUSION: The addition of lipid was inhibitory to the formation of most sulfur‐containing compounds in the Maillard reaction. Furthermore, Maillard reaction products influenced the formation of products from lipid oxidation. Copyright © 2011 Society of Chemical Industry     

Volatile oil composition of greek mountain tea (Sideritis spp.)

The composition of the essential oils of two species of the genus Sideritis (Labiatae) was investigated by gas chromatography-mass spectroscopy (g.c.-m.s.). Ca50 components were identified. The smell of the diluted oils closely resembled that of a beverage prepared from it in the Balkans, the so-called ‘mountain tea'’.