Principal component analysis of TI-curves: Three methods compared

Dijksterhuis, Garmt; Flipsen, Margo; Punter, Pieter

doi:10.1016/0950-3293(94)90017-5

Cited by 40 publications

(20 citation statements)

References 7 publications

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“…According to Dijksterhuis (1993) and Dijksterhuis et al (1994), a non-centered, non-scaled principal component analysis (PCA) was performed on the raw T-I data, considering time points as observations and individual curves as variables. PCAs were run separately for each stimulus and sensory attribute for a total of nine PCAs (three for sweet taste, three for anise/licorice flavor, and three for cooling).…”

Section: Discussionmentioning

confidence: 99%

Isovanillic Sweeteners: Sensory Evaluation and In Vitro Assays with Human Sweet Taste Receptor

et al. 2008

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The natural compound phyllodulcin and its derivatives, the so-called isovanillic sweeteners, are a large and homogeneous group of sweet compounds. This paper describes the results on the systematic analysis of the taste profile of some representative compounds of this family. They show a marked sweet taste but also some afternotes as a licorice/anise flavor and a cooling effect that have been studied by means of time-intensity techniques. A comparison of data on sweet taste intensity assessed by sensory evaluation and by affinity tests with cloned human sweet taste receptor hT1R2/hT1R3 shows that for this homogeneous class of compounds-in vivo and in vitro estimates of sweet taste intensity are consistent.

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Section: Discussionmentioning

confidence: 99%

Isovanillic Sweeteners: Sensory Evaluation and In Vitro Assays with Human Sweet Taste Receptor

et al. 2008

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“…Originally applied to single attribute timeintensity flavour analysis, 8 PCA of time-intensity GCO data provides a principal aromagram that represents the weighted average of each assessor's time-intensity data. Therefore, PCA accounts for most of the variation within and between individual assessor time-intensity GCO measurements.…”

Section: Contribution Of Odour-active Volatile Compounds To Cheddar Cmentioning

confidence: 99%

“…7 This technique measures the intensity and duration of odours as they elute, and each odours peak area corresponds to the odour-activity of the volatile compound responsible. To overcome interpretation discrepancies associated with time-intensity GCO data, 10 non-centred principal components analysis (PCA) 8 was used to analyse time-intensity data.…”

Section: Introductionmentioning

confidence: 99%

Comparison of volatile compounds released during the consumption of Cheddar cheese with compounds extracted by vacuum distillation using gas chromatography–olfactometry

O'Riordan

Delahunty

2001

Flavour & Fragrance J

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Buccal headspace analysis is an in vivo extraction technique capable of extracting volatile compounds released during consumption in concentration ratios that stimulate the olfactory receptors. Vacuum distillation is designed to measure the total volatile profile of a food and as a result pays little attention to conditions in the mouth that determine volatile release and aroma stimulation. Volatile extracts of mature Cheddar cheese were obtained using buccal headspace analysis and vacuum distillation. Cheddar cheese volatile extracts were compared using gas chromatography-olfactometry and gas chromatography-mass spectrometry. Estimation of odour intensity was carried out using a time-intensity gas chromatography-olfactometry technique similar to OSME. Odour-active volatile compounds identified in Cheddar cheese buccal headspace analysis extracts included dimethyl sulphide, 2,3-butanedione, 3-methylbutanal, toluene, ethyl butyrate, hexanal, 2-heptanone, heptanal,˛-pinene, methional, ethyl hexanoate and dimethyl trisulphide. All of these volatile compounds have previously been associated with the volatile profile of Cheddar cheese. Vacuum distillation obtained a near-complete volatile extract of Cheddar cheese, which was distinguished from buccal headspace analysis extracts by the presence of low vapour pressure odour-active volatile compounds. Significant differences (p < 0.05) between extractions were determined for the quantities of ethyl butyrate, 2-heptanone and ethyl hexanoate, the odours of which were also identified in both extractions. Buccal headspace analysis and vacuum distillate principal aromagrams of mature Cheddar cheese were obtained using non-centred principal components analysis. Qualitative odour differences were observed between both extractions, in particular for odour intensity measurements of one odour, 'raw mushroom'. Tentative relationships between gas chromatography-olfactometry odour intensity measurements and corresponding gas chromatography-mass spectrometry quantitative measurements were established.

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“…Several studies have focused on the research of appropriate methods to combine individual time-intensity data in a summarised curve, or consensus curve, in order to visualise sample differences, thus simplifying interpretation of results. Curve averaging techniques include: normalisation (Liu & MacFie, 1990;MacFie & Liu, 1992;Overbosch, van Der Enden, & Keur, 1986), modelling the shape of time-intensity curves (Dijksterhuis & Eilers, 1997), modelling by PCA (Dijksterhuis, 1993;Dijksterhuis, Flipsen, & Punter, 1994;Van Buuren, 1992) or by STA-TIS (Chaya, Perez-Hugalde, Judez, Wee, & Guinard, 2004).…”

Section: Introductionmentioning

confidence: 99%