Nerys M. Griffiths

Undesirable sensory properties of the dried pea (Pisum sativum). The rôle of saponins

Abstract The role of saponins in the undesirable sensory properties of the dried pea P sativum is reported. The sensory properties of isolated soyasaponin I are defined and described as bitter, astringent and metallic. The distribution of saponin in various air-classified pea flour fractions shows that the protein-rich fraction may contain sufficient saponin to cause undesirable tastes.

Influence of packaging on microbiological, chemical and sensory changes in chill‐stored turkey portions

1. Microbiological, chemical and sensory changes were determined for turkey breast fillets and drumsticks in either oxygen‐permeable film or vacuum packs during storage at 1 °C. 2. The use of vacuum packs delayed “off” odour development from 16 to 25 d in the case of breast fillets and from 14 to 20 d for drumsticks but in each case the detection of definite “off” odours was often preceded by marked changes in flavour. 3. At spoilage, pseudomonads predominated on both breast fillets and drumsticks in oxygen‐permeable packs whilst in vacuum packs the predominant organisms comprised two groups of bacteria resembling “ a typical lactobacilli “, one being more common on breast fillets, the other on drumsticks. 4. Protein breakdown (measured in tyrosine equivalents) was observed in all samples during storage and occurred most rapidly in vacuum‐packed breast fillets. Hypoxanthine, which has been associated with flavour changes in meats, increased in concentration at least four‐fold over the storage period.

The microbiology and sensory evaluation of pheasants hung at 5, 10 and 15 °C

Synopsis Pheasants hung for 9 d at 10 °G were found to be more acceptable than those hung for 4 d at 15 °G or for 18 d at 5 °G. The birds stored at 15 °G were tough by comparison with those held for longer at the lower temperatures and the clostridia, including Clostridium welchii, increased considerably in the intestines during the storage period. Microbial growth in the muscle tissue was generally found to occur only in birds in which the gut had been perforated by shot. There is an indication that 9 d at 10 °C produced a more “ gamey “ bird than 18 d at 5 °G or 4 d at 15 °G, but the most “ gamey “ birds, independent of temperature, were those in which the muscle was damaged by shot.

The spoilage flora and shelf‐life of duck carcasses stored at 2 or ‐ 1°c in oxygen‐permeable or oxygen‐impermeable film

1. A comparison was made of” oven ready “ duck carcasses stored at 2 or — 1 °C and wrapped in either a low‐density oxygen‐permeable polyethylene film or a heat‐shrunk oxygen‐impermeable film. 2. At spoilage the main organisms at 2 and — 1 °C on the carcasses wrapped in the oxygen‐permeable film were pseudomonads, producing unacceptable “off odours” when their numbers were >108/cm2. This occurred in about 10 d at 2 °C but in about 19 d at ‐ 1° C. 3. The effect of wrapping in the heat‐shrunk oxygen‐impermeable film was to delay or inhibit the growth of pseudomonads and thus extend the shelf‐life by more than 50% at either temperature. The predominant organisms isolated from the spoiling carcasses were atypical lactobacilli and enterobacteria. 4. Sensory assessment of the carcasses stored at — 1 °C by a trained panel indicated that, although less obvious “ off odours “ were produced by the micro‐organisms growing on the carcasses wrapped in the impermeable film, differences were detected at 33 d when the num...

The identification of the goitrogen (-)5-vinyloxazolidine-2-thione (goitrin), as a bitter principle of cooked brussels sprouts (Brassica oleracea L. var. gemmifera).

Zusammenfassung(−)5-Vinyloxazolidine-2-thione (goitrin), ein weit bekannter kropferzeugender Stoff, läßt sich als das bittere Element des gekochten Rosenkohls (Br. oleracea L. var. gemmifera) beweisen. Die Identifizierung ist mit chemischer Analyse und sensorischer Beurteilung durchgeführt worden.Summary(−)5-Vinyloxazolidine-2-thione (goitrin), a well-known goitrogen, has been identified as a bitter principle in cooked Brussels sprouts (Br. oleracea var. L. gemmifera). The identification was carried out by chemical analysis and sensory assessment.

Chemical and organoleptic changes in poultry meat resulting from the growth of psychrophylic spoilage bacteria at 1°C

Synopsis The growth of pigmented Pseudomonas or of Pseudomonas putrefaciens to counts of 106‐107/g over a period of 3–5 d at 1° C had no influence on the flavour of the cooked meat when compared with meat that had been stored for similar times under aseptic conditions.

Influence of diet on the intestinal microflora and meat flavour of intensively‐reared broiler chickens

1. An attempt has been made to modify the composition of the gut flora of broiler chickens by dietary means in order to determine any concurrent changes in meat flavour. 2. Birds given a diet containing an increasing proportion of whole wheat supplemented with fresh green vegetable matter (special diet) were compared with conventionally‐fed controls. At 12 weeks of age those receiving the special diet had 10 to 100‐fold higher counts of Escherichia colt and faecal streptococci in the duodenum and lower small intestine and showed differences in the intestinal incidence of species and biotypes of lactobacilli. 3. Evaluation of cooked breast‐meat samples by a trained sensory panel showed a significant difference in flavour (P < 0.01) between conventional and special‐diet birds which varied from perceptually very slight to slight. The main terms used in distinguishing special‐diet birds from conventional controls included ‘richer’, ‘meatier’ and ‘sweeter’. 4. Storage of plucked, uneviscerated birds at 4 °C fo...

Fumigation of poultry food with methyl bromide: Effects on egg flavour, number and weight

1. Rhode Island Red females were fed, from hatching, on diets which had been fumigated with methyl bromide at the concentration recommended for the elimination of salmonellae or at 1 1/2 times this value. 2. Body weight, egg weight or egg number were not significantly affected by treatments, but sexual maturity may have been slightly delayed. 3. There was some evidence of an adverse effect on egg flavour, particularly by the trained sensory panel. 4. Principles of experimental design for this type of experiment are discussed.

Fumigation of poultry food with methyl bromide: Effects on flavour and acceptability of broiler meat

1. Broilers were fed on control and treated commercial diets to test the effects of fumigation with methyl bromide gas at 69% and 25% over the value recommended for the elimination of salmonellae. 2. A trained sensory panel found significant taint in roasted meat from birds fed on the fumigated food. More than half of the consumers in the home panel rated the control birds better than the birds fed on the fumigated food. 3. Growth of broilers was not affected by the treatment.

Sensory evaluation of pheasants hung at 10 °g for up to 15 days

1. Pheasants hung at 10 °G were found to become increasingly “gamey” in flavour and more tender in texture with length of hanging. 2. After 13 d they were strongly gamey and very tender.