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Justin G. Bendall

Bio: Justin G. Bendall is an academic researcher. The author has contributed to research in topics: Chromatography detector & Aroma. The author has an hindex of 2, co-authored 2 publications receiving 189 citations.

Papers
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Journal ArticleDOI
TL;DR: Differences in milk flavor are primarily caused by concentration differences of a common set of flavor compounds, rather than by the occurrence of compounds uniquely associated with a particular feed.
Abstract: Volatile compounds were extracted from fresh milk produced by New Zealand cows using the newly developed solvent-assisted flavor evaporation (SAFE) technique. The two samples that were used came from cows that had been fed on different diets and represented the considerably different flavors of Northern hemisphere and New Zealand milk. Using gas chromatography−olfactometry (GC−O), 71 aroma compounds were found from the milk extracts, 66 of which were identified. Nearly all of the aroma compounds were common to both extracts, despite the two milk samples having quite different flavors. Only one compound, γ-12:2 lactone, was significantly odor-active for the extract of milk from cows fed a supplement diet, but was not found for the extract of milk from cows fed a pasture diet. Thus, differences in milk flavor are primarily caused by concentration differences of a common set of flavor compounds, rather than by the occurrence of compounds uniquely associated with a particular feed. Keywords: Milk; gas chromat...

204 citations


Cited by
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Journal ArticleDOI
TL;DR: The appearance of terpenes in sheep and goat milk is enhanced by grazing on some novel pasture species, such as Galium verum, Cichorium intybus and Chrisantemum coronarium, which modify milk and cheese sensorial profile, compared to grazing on conventional forages.

247 citations

Book ChapterDOI
01 Jan 2006
TL;DR: The triacylglycerols are relatively simple molecules consisting of a glycerol backbone to which are esterified three fatty acid molecules as discussed by the authors, and the resultant milk fat is a complex mixture of triacylsglycerol molecules due to the large variety of constituent fatty acids.
Abstract: The lipid (fat) fraction of milk is composed mainly of triacylglycerols, with minor contributions from diacylglycerols, free (unesterified) fatty acids, phospholipids and sterols. Trace amounts of fat-soluble vitamins, β-carotene and fat-soluble flavouring compounds are also present. These lipids exist in milk in the form of small globules surrounded by a membrane, which maintains the integrity of the globule. Although the vast bulk of the lipids are in the core of the globule, some fat is found in the milk fat globule membrane (MFGM), for example the majority of the phospholipids and small amounts of triacylglycerols and sterols. The triacylglycerols are relatively simple molecules consisting of a glycerol backbone to which are esterified three fatty acid molecules. However, the resultant milk fat is a complex mixture of triacylglycerol molecules due to the large variety of constituent fatty acids. The physical properties of the milk fat, for instance, the wide melting range of −40 °C to 40 °C, are in part a consequence of the composition of the triacylglycerol. This can markedly affect the functional properties of dairy products. For this reason, much research has gone into determining the constituent fatty acids and the way they are arranged on the glycerol backbone, and the rationale of variations in the composition. The minor components are also important in the overall attributes of milk fat, for instance the desirable flavour; hence, it is important to understand not only what is in milk lipids, but how they interact.

220 citations

Journal ArticleDOI
TL;DR: It was concluded that 3-methylindole was the major cause of pastoral flavour in sheepmeat, and that fat oxidation products represented a background flavour that varied quantitatively but not qualitatively with fatty acid profile.
Abstract: Variations in diet, age and castration were employed to generate a range of flavours that were chemically analysed to find the cause of ‘pastoral’ flavour in sheepmeat and its relationship to species flavour. Lambs were raised on pasture (ram or castrate) or on a maize-based or lucerne-based concentrate diet (ram only). They were slaughtered at 132 and 232 days. Fat from animals raised on concentrates had lower proportions of fat-hardening stearic acid and higher proportions of oxidation-prone fat-softening oleic and linoleic acids. Concentrations of species-characterising short branched-chain fatty acids (BCFAs), typified by 4-methyloctanoic acid, were lower for pasture-fed lambs, particularly at 232 days, although between-animal variation was high. Castration did not statistically affect BCFA concentration at this age. Correlations between BCFAs and testes weight were not significant, suggesting that they were not acting as sex pheromones. Concentrations of 3-methylindole (skatole) in perirenal fat were higher for the pasture diet at both slaughter dates. Concentrations of 4-methylphenol in the fat were not affected by diet. However, 3-methylphenol was more abundant in pasture treatments. A sensory panel found that the intensity of ‘sheepmeat’ flavour was higher for pasture-raised animals, but that associations of ‘barnyard’ flavour (which has been linked to pastoral flavour) with diet were more complex. The issue was resolved by fat sniffing. Panel responses to heated subcutaneous fat were recorded as frequency of descriptive terms drawn from a limited lexicon. Volatiles from fats pooled by treatment were resolved on a gas chromatographic column whose effluent was monitored by odourport sniffing. Compounds were identified by parallel chromatographic/mass spectrometric runs. The headspace concentrations of these compounds were then measured for individual animals. These data were related to frequency data by the principal component method. ‘Mutton’ and ‘sheepmeat’ odour notes were clearly linked to indoles (skatole particularly) and, to a lesser extent, methylphenol, setting these notes apart from ‘lamb’, an odour note more associated with lucerne and maize diets through higher concentrations of BCFAs. It was concluded that 3-methylindole was the major cause of pastoral flavour in sheepmeat, and that fat oxidation products represented a background flavour that varied quantitatively but not qualitatively with fatty acid profile. © 2002 Society of Chemical Industry

166 citations

Journal ArticleDOI
TL;DR: This review provides an update on the understanding of the chemical reactions (lipid oxidation, Strecker and Maillard reactions, thiamine degradation) and a discussion of the principal aroma compounds derived from those reaction or other sources in cooked meat, mainly focused on ruminant species.
Abstract: This review provides an update on our understanding of the chemical reactions (lipid oxidation, Strecker and Maillard reactions, thiamine degradation) and a discussion of the principal aroma compounds derived from those reaction or other sources in cooked meat, mainly focused on ruminant species. This knowledge is essential in order to understand, control, and improve the quality of food products. More studies are necessary to fully understand the role of each compound in the overall cooked meat flavour and their possible effect in consumer acceptability.

163 citations

Journal ArticleDOI
TL;DR: The HS-SPME technique developed in this study is accurate and relatively simple, and can be used for the quantification of thermally derived off-flavor compounds in milk.

160 citations