Examination of chemical irritation and textural influence on food preferences in two age cohorts using complex food systems

The changes to the chemical senses of taste and smell that accompany ageing are widely documented, and there has been some evidence that these changes may influence food preferences of the older consumer. However, little is known about the loss of function of the residual senses of texture and chemical irritant perception and how such losses influence food preferences. A consumer panel comprising a young (20–35 years) and an older (>65 years) age cohort was recruited and sensory tests were conducted to determine perceived intensity, preferences and the possibility of cross modal interaction between the sensory modalities of chemical irritation and texture. Liquid, semi-solid and solid food systems were studied to enable comparisons to be drawn. Older consumers were less capable of discriminating between chemical irritation and texture stimuli, indicating loss of sensory function, but there was indication that higher levels of chemical irritation were preferred among older consumers in some texture types.     

Sensory evaluation of lightly preserved salmon using free-choice profiling

Summary In order to characterise a novel fermented salmon product, sensory evaluation by free-choice profiling was undertaken on three different types of salmon products (smoked salmon, gravlax and fermented salmon). Assessors could easily discriminate among all three types of products and common attributes were isolated from the set of individual assessments. Discrimination was made according to the appearance, odour and flavour attributes, while no clear consensus on texture was observable. The first discrimination factor between all products was the presence/absence of a smoky character. The novel fermented salmon was discriminated from gravlax as it appeared to have a distinct sour/ acidic odour and flavour.     

Development and validation of a tool to recall alcoholic beverage and wine consumption over consumers’ lifetimes

Different past experiences are likely to influence current preferences and consumption through learning processes, such as evaluative conditioning, leading to different flavour preference developments. The ability to measure past experience of alcoholic beverage consumption would be useful in order to understand the drivers of current wine consumption. The developed and validated tool provides reliable data for both past alcohol consumption recall and current wine consumption. Intraclass correlation coefficients (ICC) and F-tests indicated reliability, specifically, high internal consistency (lifetime drinking history and current wine consumption), internal validity and acceptable limits of agreement (current wine consumption relative to a 7-day diary), especially for the most frequently consumed wine (red), demonstrating that the measures taken were reproducible over time. In contrast to previous lifetime alcohol consumption studies, the present study included measures of type of wine consumed. Results justify and encourage the administration of the developed tool on a larger sample, aiming to seek associations between ‘drinking histories’ in order to understand current wine consumption.     

The effect of viscosity and volume on pleasantness and satiating power of rice milk

The present study examined the influence of two viscosity levels (62.3 and 3.2 mPa s relative) either matched for taste or non-adjusted, and two volumes (500 and 250 ml) in a rice milk beverage on satiety and pleasantness. The separate viscosity treatments were isocaloric. Seventy-one participants consumed one of the samples in a fasted state between the hours of 8:30–9:30 a.m. Participants rated thirst and hunger prior to consumption, and then thirst, hunger, overall pleasantness, pleasantness of taste, and pleasantness of viscosity immediately post-consumption. The time to consumption of lunch was measured using food diaries. This procedure was repeated for five consecutive days. Significantly greater reductions of hunger, and longer times to lunch were observed with the 500 ml treatments, but not with the thickened treatments. Results indicate that the volume of a rice milk beverage consumed in place of a breakfast has more satiating effect than the viscosity. Moreover, a change in overall pleasantness ratings, and pleasantness of taste ratings over time was found, demonstrating the importance of repeat testing for hedonic ratings of novel foods.     

Differential consequences of lateral and central fluid percussion brain injury on receptor coupling in rat hippocampus

We have identified alterations in the responses of muscarinic and metabotropic receptors in rat hippocampus that persist for at least 15 days after central fluid percussion injury. This study compares the effect of lateral fluid percussion and central fluid percussion on these responses. Moderate injury was obtained by displacement and deformation of the brain within the closed cranial cavity using a fluid percussion device positioned either centrally or laterally. Carbachol and (+/-)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (trans-ACPD)-stimulated polyphosphoinositide (PPI) hydrolysis was assayed in hippocampus from injured and sham-injured controls at 15 days following injury. At 15 days after central fluid percussion traumatic brain injury (TBI), the response to carbachol was enhanced by 30% and the response to trans-ACPD was enhanced by 75% compared to sham-injured animals. At 15 days after lateral fluid percussion TBI the response to trans-ACPD was enhanced by 40% both ipsilateral and contralateral to the side of injury. In contrast, the response to carbachol was enhanced by 29% contralateral to the side of injury but was diminished by 12% ipsilateral to the side of injury. Cresyl violet staining shows no hippocampal cell death after central fluid percussion injury or on the side contralateral to lateral fluid percussion injury but on the ipsilateral side cell death was identified in hippocampal area CA3. Thus, abnormal hippocampal cell signaling through the phosphoinositide pathway occurs in the absence of cell death and may contribute to cognitive impairment.     

Prediction of processed cheese instrumental texture and meltability by mid-infrared spectroscopy coupled with chemometric tools

The objective of this study was to determine the potential of mid-infrared spectroscopy coupled with multidimensional statistical analysis for the prediction of processed cheese instrumental texture and meltability attributes. Processed cheeses (n = 32) of varying composition were manufactured in a pilot plant. Following two and four weeks storage at 4 °C samples were analysed using texture profile analysis, two meltability tests (computer vision, Olson and Price) and mid-infrared spectroscopy (4000–640 cm⁻¹). Partial least squares regression was used to develop predictive models for all measured attributes. Five attributes were successfully modelled with varying degrees of accuracy. The computer vision meltability model allowed for discrimination between high and low melt values (R² = 0.64). The hardness and springiness models gave approximate quantitative results (R² = 0.77) and the cohesiveness (R² = 0.81) and Olson and Price meltability (R² = 0.88) models gave good prediction results.