Meat Odour Research Articles

The effect of supplementation of a white clover or perennial ryegrass diet with grape seed extract on indole and skatole metabolism and the sensory characteristics of lamb

AbstractCondensed tannin in the form of a grape seed extract (GSE) was dosed to weaned wether lambs fed white clover (WC) or perennial ryegrass (PRG) over a 9‐week period to determine whether the ‘pastoral’ flavour and odour of meat could be altered. The concentrations of the pastoral flavour compounds indole and skatole were determined in the rumen fluid, blood plasma and intermuscular fat. The odour and flavour of fat and meat from the slaughtered lambs was assessed by a trained panel. The rumen fluid and blood plasma concentrations of indole and skatole were higher in those lambs fed WC compared to PRG (P < 0.05) and the overall meat flavour intensity was greater when feeding WC (P < 0.01). The observed concentration of indole and skatole in the fat between WC and PRG feeding treatments was not statistically different. Power analysis indicated that increasing the number of lambs per treatment group from 20 to 65 would result in a higher fat skatole concentration (P < 0.05) being detected in lambs fed WC compared to PRG. Dosing with GSE gave a small reduction in skatole concentration in the rumen fluid and reduced plasma concentration of indole and skatole (P < 0.001). Odour and flavour scores of the fat and meat samples were not particularly high however, dosing with GSE lowered the overall and sweet odour and the sheepy, camphor, faecal and barnyard flavour (P < 0.05). Although the plasma concentration of indole and skatole suggests that GSE reduced indole and skatole formation, the intermittent supply of the GSE to the rumen environment was not sufficient to reduce their concentration in the fat. Hence, the small difference in the scores for pastoral odour and flavour attributes associated with GSE treatment may arise from other unknown factors. From a primary investigation, there was no difference in the concentration of indole and skatole in fat samples collected from carcasses before and after chilling. Further investigations into meat pastoral flavour are warranted through feeding condensed tannin‐containing forages. Copyright © 2007 Society of Chemical Industry

Effects of Prima gland clover (Trifolium glanduliferum Boiss cv. Prima) consumption on sheep production and meat quality

Gland clover (Trifolium glanduliferum Boiss) is a recently introduced and released clover species for use in Mediterranean agricultural systems in southern Australia. There is little information on the expected animal production from this pasture plant although it is known to contain coumarins. Coumarins may have a direct effect on the production of grazing ruminants through a reduction in feed intake and may also have the ability to influence the flavour and odour of meat. In this study, Merino hogget ewes were grazed on eight 0.5 ha replicate plots sown to monocultures of either Prima gland clover or Dalkeith subterranean clover (Trifolium subterraneum ssp. subterraneum L.). The Prima gland clover was estimated to contain between 80 and 300 mg coumarin/kg dry matter. Three sheep were allocated to the plots on 7 September and 1 sheep from each plot was slaughtered on 29 September. Two additional sheep were allocated to the plots on 28 September and another 2 on 19 October. At the end of the experiment on 8 November, each plot contained 2 sheep that had grazed for 3, 6 or 9 weeks. All sheep were slaughtered at this time. The 2 sheep that remained on the plots from 7 September to 8 November were used for the comparison of animal production between the 2 clover species. Following slaughter, measurements were made of carcass characteristics and meat eating quality. The liveweight gain and wool growth of the 2 treatments were similar over the 9 weeks, however, the sheep on the Prima gland clover plots grew faster over the first 3 weeks. The faster growth rate is consistent with a higher in vitro digestibility of the Prima gland clover at this time. The similarity in feeding value of the 2 clover species indicates that there was no depression in feed intake associated with the Prima gland clover. There were some small significant differences in meat eating quality between the groups. Meat from sheep grazing the Prima gland clover was drier and had a more pleasant taste. These differences are unlikely to be large enough to have any commercial significance. The results indicate that the Prima gland clover has a feeding value at least equivalent to the Dalkeith subterranean clover and that, under the conditions of this experiment, the coumarin concentrations in the Prima gland clover are not high enough to affect either feed intake or the flavour and odour of meat.

Effects of goat milk or milk replacer diet on meat quality and fat composition of suckling goat kids

The effects of a diet with goat milk “GM” or milk replacer “MR” on the meat quality and fat composition of suckling Murciano-Granadina kids were studied. MR consisted of powdered skimmed milk, coconut oil and fat, and cereal products and by-products. Raw meat quality (moisture, protein, lipids, ash, collagen, cholesterol, haem pigments, CIELab colour, pH and water retention capacity), fatty acid “FA” composition and eating quality of cooked meat (odour, flavour and texture) were determined. Diet had only a slight effect on raw meat quality but had a pronounced effect on fatty acid composition and eating quality of cooked meat. MR diet increased the water/protein proportion in the muscle. The saturated/unsaturated FA ratio in GM and MR fat was 0.94 and 2.27, respectively. The major FA in GM and MR fat were C16:0 and C18:1, respectively. Short-chain C4–C12 hardly accumulated in the adipose tissue of suckling kid, increasing the relative percentages of C14–C20. This effect was more pronounced in MR fat, due to the fact that MR contained more short-chain fatty acids than GM. MR diet gave cooked meat a more intense characteristic goat meat odour and flavour, more tenderness and more juiciness than the natural suckling diet. This fact could be related to differences in meat and fat composition.

Analysis of Early Lipid Oxidation in Smoked, Comminuted Pork or Poultry Sausages with Spices

Dynamic headspace/gas chromatography-mass spectrometry (GC-MS), front-face fluorescence spectroscopy, and a gas-sensor array technique (electronic nose) have previously detected lipid oxidation in pork back fat or mechanically recovered poultry meat earlier than or at the same time as a sensory panel. The present study was focused on measurement of early lipid oxidation in a more complicated product (freeze-stored, smoked sausages with spices). During the storage time, formation of components contributing to rancid odor and flavor (e.g., hexanal and 1-penten-3-ol) could be monitored with dynamic headspace/GC-MS. The GC-MS data also showed a decrease in 2-furancarboxaldehyde, which could indicate loss of Maillard type components often associated with acidic or meat odor and flavor. The fluorescence spectra were difficult to interpret, probably due to the simultaneous influence from increasing levels of lipid oxidation products and loss of fluorescent Maillard or spice components. The gas-sensor array responses were dominated by signals from, e.g., spice and smoke compounds.

Relationship between linoleic and α-linolenic acids in cooked meat odour development

During cooking, chemical reactions within the muscle produce volatile and non-volatile compounds characteristic of meat aroma and taste. Polyunsaturated fatty acids (PUFA) are essential in these reactions (Mottram and Edwards, 1983). In ruminants, differences in intramuscular PUFA composition have been classically associated with high n-3 content in grass fed animals and high n-6 content in concentrate fed animals. We investigated the effect on odour perception of in vitro reactions between linoleic and α-linolenic acids in the presence of cysteine and ribose, when they were present in ratios similar to those found in meat from animals reared on forage- or concentrate-based diets.

Production of Volatiles from Amino Acid Homopolymers by Irradiation

ABSTRACT: Amino acid homopolymers were used to determine production of radiolytic volatiles by irradiation. Many new volatiles were generated, and the amounts of volatiles in amino acid homopolymers changed after irradiation. Each amino acid homopolymer group produced different odor characteristics, but the intensities of odor from all amino acid groups were weak, except for sulfur‐containing amino acids. Sulfur‐containing amino acids produced various sulfur compounds; the overall odor intensity of irradiated sulfur amino acids was very high and the odor characteristics of sulfur amino acids were similar to irradiation odor of meat. Our results indicated that the contribution of methionine to the irradiation odor would be far greater than that of cysteine.

Modelling the effect of fatty acids in odour development of cooked meat in vitro: part I—sensory perception

We have investigated the contribution of muscle components to the development of cooked meat odour in an aqueous model system using trained taste panels. Reaction mixtures were prepared with oleic, linoleic and linolenic acids with or without cysteine and ribose in a buffer with or without ferrous sulphate. Odour profiles were assessed and triangular tests were used to determine the ability of panellists to discriminate between mixtures. The presence of sugar and amino acid was highly detectable by panellists independently of the fatty acid considered ( P<0.001). However, the presence of C18:3 made differences more obvious between mixtures than the presence of C18:1 or C18:2. ‘Meaty’ notes were only associated with cysteine and ribose. ‘Fishy’ notes were only apparent in C18:3 mixtures with or without sugar and amino acid, although the presence of cysteine and ribose decreased the perception. The addition of Fe ++, a pro-oxidant present in the muscle, produced a reduction in the score of the attributes although the pattern was the same as when Fe was not used in the mixtures. Only ‘fishy’ notes that were exclusively perceived in C18:3 mixtures showed a higher score in the presence of iron. Iron also produced a better discrimination in C18:3 mixtures, which were closely related to ‘grassy’ notes in the presence of cysteine and ribose.

Effect of Brussels sprouts and inulin/rape seed cake on the sensory profile of pork M. longissimus dorsi

The objective of the present study was to evaluate the influence of two diets containing either Brussels sprouts or inulin/rape seed cake, compared with a standard diet (control) for slaughter pigs on flavour and odour attributes and sensory profile of cooked pork. Three weeks prior to slaughter 24 female pigs were allocated to three diets: (1) a standard grower-finishing diet (control) for slaughter pigs containing barley, wheat and soy-bean meal, (2) the control diet containing 11 energy percent Brussels sprouts and (3) a diet containing 25% inulin and 55% rape seed cake. The odour and flavour of the cooked meat from inulin/rape seed cake-fed pigs differed significantly from the other two diets, showing reduced meat odour, increased pig and acrid odour, increased pig flavour, reduced fresh flavour and total impression. Meat from the Brussels sprouts-fed pigs deviated only slightly from the control-fed pigs.

Beef shelf life in low O 2 and high CO 2 atmospheres containing different low CO concentrations

The use of atmospheres with low concentrations of CO (0.1 to 1%), in combination with O 2 (24%), high CO 2 (50%) and N 2 (25 to 25.9%), for preserving chilled beef steaks was investigated. The atmosphere used as reference contained 70% O 2+20% CO 2+10% N 2. Bacterial counts showed that all atmospheres containing CO greatly reduced total aerobic population numbers, including Brochothrix thermosphacta. Lactic acid bacteria, however, were not affected. CO concentrations of 0.5–0.75% were able to extend shelf life by 5–10 days at 1±1°C, as demonstrated by delayed metmyoglobin formation (less than 40% of total myoglobin after 29 days of storage), stabilisation of red colour (no change of CIE a* and hue angle after 23 days), maintenance of fresh meat odour (no variation of sensory score after 24 days) and significant ( P<0.01) slowing of oxidative reactions (TBARS).

Some Possibilities for Influence on the Stress Level and the Boar Taint in Pigs by Estrogens

ABSTRACTImmature female pigs from the Danube white breed at the age of 2.5 months, were treated only once intramuscularly with 17, β-estradiol or diethylstilbestrol dipropionate—100 μg kg−1 body weight. The corticosteroid concentration in the blood plasma has been determined fluorimetrically. At the third hour after the estrogen administration the level of the plasma corticosteroids increased by 33–35% and at the 24th hour it showed values equal to those obtained before the hormonal treatment. The possibility for the estrogens to participate in the raising of the adaptive potentialities of the pigs to different stress factors is assumed. Male non-castrated pigs from the same breed, fattened to 110 kg were treated for 5 days before the slaughter intramuscularly daily with diethylstilbestrol dipropionate—50 μg kg−1 body weight. The individual levels of indoles have been determined fluorimetrically in protein-free extracts of blood plasma. The values in the treated animals are lower than in the control. The possibility of the estrogens to lessen the specific unpleasant odour of boar meat due to indoles to a great extent is supposed.

Release of volatiles during the flowering period of Hydrosme rivieri (Araceae)

The release of volatile compounds from a flower of Hydrosme rivieri was recorded during the whole flowering period (7 days). The quantities of six odour components (dimethyl disulphide, dimethyl trisulphide, n-alkanes C 10, C 11, C 12 and C 13) forming the main part of emanating volatiles were plotted versus time. n-Alkanes started to emanate 3 days before the release of dimethyl disulphide and dimethyl trisulphide (the components with a rotting meat odour).

Characterisation of qualitative changes in frozen, unpeeled cold-water shrimp ( Pandalus borealis ) by static headspace gas chromatography and multivariate data analysis

Static headspace gas chromatography and descriptive sensory methods for the characterisation of quality changes in frozen, unpeeled cold-water shrimp were developed. Frozen shrimps in various stages of oxidation were investigated. In a multivariate statistical analysis the whole chromatogram, regarded as a fingerprint, correlated with the sensory scores of taste and odour. The areas of 8–11 chromatographic peaks were sufficient to predict the score of rancid taste and rancid odour of shrimp meat, with a prediction error of 0.7 cm on a 10-cm line scale. Peak areas did not correlate with crispiness of the shell or toughness of the meat. Individual peaks were not identified, but multivariate data analysis was able to pinpoint the peaks in the chromatogram that were important with respect to the development of certain sensory attributes. The possibility of developing a routine screening method is discussed.

Responses of two genotypes of chicken to the diets and stocking densities of conventional UK and Label Rouge production systems—II. Sensory attributes

French Label Rouge quality chickens are reputed to possess improved sensory characteristics compared with birds reared under intensive conditions. The effects of genotype, diet, stocking density and age on eating quality were evaluated in a 2 × 2 × 2 experiment. The results suggest that genotype, diet, age and, to a lesser extent, stocking density can influence eating quality. The most pronounced sensory differences between the two genotypes were in the appearance and texture of the cooked meat. In particular, scores for toughness were higher for breast meat from Ross than ISA birds, though the opposite effect was observed for the thigh meat. Diet and age also affected texture, with the breast meat from chickens on the Label Rouge diet, or from older birds, having lower scores for toughness. Effects on odour and flavour were generally small and subject to genotype × diet interactions. The odour and flavour intensity of breast meat increased with age, while the odour intensity of thigh meat was higher in birds reared at low stocking density.

Pasture species effects on carcass and meat quality

Increasing concerns about food quality and animal fat in the human diet have promoted research into the effects of different forage species on carcass quality and fat content. This trial investigated the effect on carcass composition and the intensity of sheep meat flavour and odour of five different pure pasture species: Grasslands Lancelot plantain (Plantago lanceolata), Grasslands Puna chicory (Cichorium intybus), Grasslands Huia white clover (Trifolium repens), Grasslands Nui high-endophyte perennial ryegrass (Lolium perenne) and Grasslands Goldie lotus (Lotus corniculatus). Although pasture species did affect meat quality and fat content, there appeared to be an inverse relationship with carcass weight: larger lambs had more fat, which was related to difference in body size and relative maturity rather that pasture species. Pasture species also influenced muscle ultimate pH, sheep meat odour, foreign odours, and flavours, but did not affect sheep meat flavour. Keywords: Cichorium intybus, meat flavour, Lolium perenne, Lotus corniculatus, meat odour, Plantago lanceolata, Trifolium repens

Detectable Odor Thresholds of Selected Lipid Oxidation Compounds in a Meat Model System

ABSTRACTOrganic compounds, pentanal, hexanal, t‐2‐hexenal, t‐2‐heptanal, t‐2‐octenal, and t,t‐2,4‐decadienal, were added individually to lean ground beef. Detectable odor threshold (DOT) was determined by a 10‐member sensory panel using triangle tests. Descriptive analysis using category scales measuring intensity was used to assess odor intensities contributed by specific compounds in an effort to relate quantitative differences in qualitative characteristics to oxidized beef. DOT for pentanal was 2.67 ppm; hexanal was 5.87 ppm; heptanal was 0.23 ppm; t‐2‐hexenal was 7.87 ppm; t‐2‐octenal was 4.20 ppm; and t,t‐2,4‐decadienal was 0.47 ppm. Common terms used to describe odor of meat containing added compounds were rancid, painty, and herbal.

INFLUENCE OF LACTIC ACID AND MODIFIED ATMOSPHERE ON THERMAL DESTRUCTION OF LISTERIA MONOCYTOGENES IN CRAWFISH TAIL MEAT HOMOGENATE1

ABSTRACT Precooked homogenized crawfish tail meat was inoculated with Listeria monocytogenes, treated with lactic acid, and packaged in various atmospheres for D value determinations at 60C. D60 values using 0.0, 0.5, 0.75, and 1.0% lactic acid (LA) treated meat were 4.68, 4.41, 3.46, and 2.49 min, respectively. LA increased sensitivity of L. monocytogenes to heat but this was not solely due to a reduction of pH. Sensory analyses of odor, color, taste, and texture of uninoculated whole crawfish tail meat demonstrated no significant differences (P &gt; 0.05) between LA treated samples and controls. D60 values for the bacterium in crawfish tail meat homogenate packed in air, O2, CO2, or N2 were 10.58, 9.22, 11.68, or 12.97 min, respectively, which were not significantly different (P &gt; 0.05). When 1% LA was added, significant decreases (P &lt; 0.05) in D60 values were observed in each packaging atmosphere. Similar (P &gt; 0.05) D60 values for crawfish tail meat treated with 1% LA and packed in air, O2, CO2, or N2 were 3.44, 3.88, 3.48, or 3.08, respectively. These results show that heat treatments of 60C were lethal to L. monocytogenes in packaged crawfish tail meat homogenate regardless of package atmosphere. Additionally, LA increased the lethality of heat to the bacterium in all tested package atmospheres.

Effect of breed and ultimate pH on the odour and flavour of sheep meat

Abstract Coopworth and Merino lambs were slaughtered at 8 months after being grazed together on ryegrass/clover pasture from weaning. The flavour and odour intensities of the cooked lean (longissimus lumborum muscle) and odour intensity of subcutaneous fat were assessed by an analytical panel. Sheepmeat flavour in the lean was stronger (P < 0.01) in Coopworth and foreign flavour was stronger in Merino (P < 0.001). However, the mean pH of the meats also differed significantly (P < 0.001) (Coopworth, 5.77; Merino, 6.16), thereby confounding the effects of pH and breed. Panellists' comments pointed to a breed effect in subcutaneous fat odour, but means for sheepmeat and foreign odours in the fat were statistically identical. Meat toughness, assessed by the same panel, peaked around pH 6.0, irrespective of breed. In a parallel study of the Merino lambs and five Merino cross breeds, an in-house panel assessed acceptability rather than intensity of meat attributes. All crosses and the pure Merino produced meat ...

Centralized bulk pre‐packaging of pork retail cuts

SummaryThe performance of a commercial bulk pre‐packaging system was compared to a laboratory system in terms of quality attributes such as microbiology, colour, odour, and acceptability of PVC‐overwrapped pork retail cuts. A similar retail shelf life of 3 days was achieved after either 0, 7, or 14 days bulk storage with both packaging systems. The colour of the samples from both systems was pale to normal during the trial. After 14 days storage the samples from both systems were still acceptable and had a fresh meat odour. The results show that the commercial system (Cryovac GFII, Darex Africa (Pty) Ltd, Kemptonpark RSA) may be applied successfully for 100% CO2 bulk packaging of PVC‐overwrapped pork retail cuts.

Preservative effect of combinations of acetic acid with lactic or propionic acid on buffalo meat stored at refrigeration temperature

A silverside of buffalo was cut in 15 equal-sized steaks and divided into five groups, each group containing three steaks. The steaks from groups 1,2,3 and 4 were treated with 1, 2, 3 and 4% acetic:lactic acid combinations, respectively, and the fifth group was kept as a control. Similar treatments were also given with acetic: propionic acid mixtures. The microbial analysis and changes in colour and odour were noted at 0, 24, 72 and 168 h. The bacteriostatic and bacteriocidal action of the acid mixtures increased with increasing concentration but the effect was reduced as the time advanced. Both acid mixtures had pronounced antibacterial effect on gram negative organisms than gram positive ones. The 3% acetic: lactic acid combination showed reduction in bacterial numbers without affecting the colour and odour of buffalo meat and is recommended for decontamination and preservation of meat for up to seven days at refrigeration temperature (7 ± 1°C).

Effect of dietary linoleic acid on the fatty acid composition of pig muscle

The fatty acid composition of meat has important effects on its succulence and flavour. The neutral lipids of muscle, are mainly energy stores resembling adipose tissue and affect the succulence of meat. However, the phospholipids, which are structural components of muscle, are important in the development of the species specific cooked meat flavour and odour. We have investigated the effects of feeding diets differing mainly in their linoleic acid content on the fatty acid composition of the lipids of M. Longissimus dorsi (LD) of pigs.