D. G. Land

Preference and sensitivity to salt taste as determinants of salt-intake.

Total salt-intake was estimated in 33 normal subjects using urinary sodium excretion over 7 days, and table and cooking salt use were measured over the same period. Sensitivity to salt taste was measured for 31 of these subjects using a seven-category rating scale for intensity of saltiness with five concentrations of salt in water, bread and mashed potato. Preferences were assessed using a nine-category hedonic rating scale with the bread and mashed potato to determine the maximally-preferred concentration. No differences were found in the taste measures between subjects divided into high and low intake in terms of total salt-intake or total intake divided by body weight. However, differences were found in sensitivity and preferences between groups divided into high and low table salt use. This may be because the major proportion of total salt-intake arose from salt present in foods and this would not be so open to voluntary control as table salt use.

Rapeseed meal and egg taint: Association with sinapine

1. The “fishy” taint of brown‐shelled eggs from susceptible birds due to the presence of trimethylamine following the feeding of rapeseed meal has been shown to be associated with the presence of sinapine in the rapeseed meal.

THE RELATIONSHIP BETWEEN SALT INTAKE AND PREFERENCES FOR DIFFERENT SALT LEVELS IN SOUP

Two experiments are reported with subjects divided according to questionnaire responses into low and high total sodium intake, and low and high table salt use. The stimuli were tomato soup with varying salt concentrations. In Experiment 1 these were rated for salt intensity, pleasantness and intensity relative to ideal. In Experiment 2 the stimuli were presented in restricted concentration ranges or using a method designed to minimise range bias; relative-to-ideal intensity rating was again used. Subjects with a high total intake were found to prefer higher concentrations of salt assessed both with the hedonic and relative-to-ideal intensity ratings, though not with restricted stimulus ranges. Subjects with high table salt use were found to prefer higher concentrations only when assessed using the hedonic ratings. Sensitivity to salt taste was not found to differ between the groups.

Rapeseed Meal and egg taint

1. Certain rapeseed meals in the diet of hens laying brown eggs result in the production, from some birds, of eggs which have a “ fishy ” or “ crabby ” odour because of the presence of trimethylamine. 2. Such susceptible birds have been used to demonstrate that the activity can be extracted from rapeseed meal with appropriate solvents.

Estimation of salt intake by questionnaire

A questionnaire designed to assess salt intake was tested. This involved principal components analysis of responses from 155 subjects to find the underlying components related to the questions. Validation of the questionnaire used 7-day urinary sodium excretion for 33 subjects, along with table and cooking salt usage over 7-days. This gave comparatively good prediction for total intake (r = 0.66) and table salt use (r = 0.70) but not for cooking salt use (r = 0.17). Test-retest reliability for the estimate of total intake was r = 0.75. This method would therefore offer a useful estimate of total intake, especially where group means are required rather than accurate estimates of individual intakes.

Effects of Stimulus Context on Preference Judgements for Salt

An experiment is reported which confirms earlier findings that the range of stimulus concentration affects the estimate of ideal concentration. The method proposed by Booth et al for reducing range bias has been found to give satisfactory results.

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.

Measurement of sodium intake and its relationship to blood pressure and salivary sodium concentration

Abstract The mean daily sodium intake was determined for 33 normotensive subjects by analysis of a 7 day 24 h urine collection. The intake range was 1.75–5.77 g Na/day with an intra-individual standard deviation of 1.08 g Na and an inter-individual standard deviation of 0.80 g Na giving a ratio of intra-to inter-individual variance of 1.82, 79% of the subjects were correctly classified into the approapriate tertile for sodium intake after the 7 day collection. The intake range for potassium was 1.54 to 4.2 g/day. No relationship was observed between blood pressure and sodium or potassium intake. Salivary sodium levels (both stimulated and unstimulated) were positiviely correlated with sodium excretion of the day preceding saliva collection.

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.