No description available.

No description available.

No description available.

There are few empirical studies of food quality within hospital food service systems. Although it is widely accepted that food quality is a multi-faceted phenomenon, much attention has been paid to single component explanations in the past. The aim of this study throughout has been two fold - to develop a model suitable for evaluating the quality of food in conventional hospital food service systems; and to evaluate food quality in selected hospitals in the Trent Regional Health Authority and West Midland Regional Health Authority using the model. A key outcome in this study has been the development of a multifaceted measurement of food quality to help catering managers deploy resources effectively, in conventional hospital food service systems. This approach was achieved using a variety of qualitative and quantitative information to score six food quality components and 15 influencing variables. Food quality was defined as a multi-dimensional measure to include measures of satisfaction of patients and catering staff, productivity, safety, and nutritional adequacy. Measures of influencing variables were chosen or adapted from those available in food service operations insofar as was possible. Where none was available, methods were developed. The variables were grouped into two major categories: human resources and system resources. A survey of 12 hospital conventional food service systems in the UK was undertaken and detailed information was collected from each, including surveys of 933 patients and 327 catering staff. Patient satisfaction with the quality of hospital food and food-related service was evaluated by patient questionnaires. It was measured by assessing 14variables. Patients seem to be generally satisfied with the food served. In the regression analysis none of the influencing variables explained the component of 'patient satisfaction' at the level of P < 0.05, suggesting that it is a different kind of component from the other 4. Importantly the component 'patient satisfaction' appears to be explained predominantly by patients' own demographic and emotional variables rather than by objective catering system factors. Age and appetite were found to significantly correlate with patient satisfaction scores. The component of food waste was found to have a high negative correlation with patients' satisfaction. It may be possible to use food waste as an index of patient satisfaction in future research. Catering staff - satisfaction was evaluated by measuring employee job attitudes towards five aspects of their job using the Job Description Index (JDI). The JDI is directed toward specific areas of satisfaction rather than global or general satisfaction and was easily administered. The food service workers surveyed in this research were less satisfied with their jobs than are other types of workers in other industries. In the regression analysis total number of patients explains around 36% of the variation in staff satisfaction. The productivity level was based upon the total meal equivalents divided by the total labour hours required to produce and serve them. The regression analysis suggests that around 77% of the variance in productivity is explained by labour cost. The safety component was based upon two elements which were microbiological control and temperature control. The results of regression analysis suggest that the number of menu items and the subsidizing meal ratio explain around 74% of the variation in the safety component. Nutritional adequacy was evaluated indirectly by measurement of food waste. In the regression analysis more than 68% of food waste component can be explained by the variable occupancy rate. Correlations between the food quality components show that a non-significant relationship existed between all but one of the components of food quality studied. A significant negative correlation existed between the patients'satisfaction with the hospital meal and service and the food waste; this was expected. The non-significant correlations between the components of food quality showed the independence of components, confirming the need for a multi-dimensional model of food quality. The findings of this research support the notion that food quality is a multi-faceted phenomenon and have led to the development of a practical way of measuring it.

Procedures associated with Quantitative Descriptive Analysis were used to identify and subsequently train a panel to quantify the perceived textural attributes of Cheddar cheese. Seventeen types of Cheddar were assessed by the panel for creaminess, crumbliness (fingers), crumbliness (chewing), firmness, graininess, hardness (first bite), hardness (cutting), and springiness. Cluster and Principal Component analyses of the sensory data revealed that the cheese samples could be subdivided into young, mature and extra mature Cheddars in terms of the textural attributes measured. The panel was also able to distinguish between the low fat and genuine Cheddars. The percentage fat, moisture and salt contents and the pH level of the seventeen Cheddar samples were established. An inverse correlation between fat and moisture content and a positive correlation between pH level and salt content were observed. The rheological properties were measured using three tests performed on an Instron Universal Testing Machine - a compression test, a cutting test and a stress relaxation test - and, where appropriate, were reported in terms of true stress and true (Hencky) strain curves. The viscoelastic properties of Cheddar observed during stress relaxation tests were modeled using a Generalised Maxwellian model consisting of two exponential elements and a residual term. Considerable variation in all the rheological properties was observed amongst the Cheddar samples. The rheological parameters did not distinguish between the samples to the same extent as the sensory assessment. However, Cluster Analysis of the rheological data did differentiate between the rheological profiles of the young (mild & medium) and the remaining mature/extra mature samples. The relationships between the textural attributes and the chemical and rheological parameters were investigated. No relationship between chemical composition and texture was identified, but correlations between the rheological parameters and the textural attributes were not uncommon. Multiple regression techniques were employed to construct mathematical models to predict the textural attributes from the rheological data. Successful models were constructed utilising parameters from the compression and cutting tests for all the attributes apart from creaminess. More precise models were constructed for firmness, springiness and crumbliness (fingers) where the action of the instrumental test from which the rheological parameters were obtained resembled the test method used by the panel. The chemical, textural and rheological properties of an English Cheddar were determined at various stages during its ripening period to investigate any changes that occurred. A slight increase in pH was the only chemical change recorded. Progressive changes in the majority of the textural attributes were observed. The most dramatic changes included a decrease in springiness and an increase in creaminess. A changing rheological profile was also observed during maturation, a decreasing strain at fracture being the most notable development. The sequence of changes in both the textural and rheological properties was divided into three fairly distinct phases, the initial stage reflecting the developments necessary before the cheese would be suitable for retail sale and the final stage including the development of the necessary textural attributes characteristic of a Mature English Cheddar. It was evident that the timing of the maturation period was pertinent to the development of textural attributes characteristic of particular maturities of Cheddar cheese. The textural attributes of the maturing Cheddar were also predicted at each stage of maturation using the mathematical models constructed in the initial study. Accurate predictions were made for all the attributes except crumbliness (chewing) and graininess.

A gas chromatographic method for the routine analysis of volatile and semi-volatile sulphur compounds in beer was developed. Various selective and specific detectors, capillary columns and methods of sample preparation were compared. The combination offering the best sensitivity and stability consisted of solid phase microextraction (SPME) as the sample preparation step; a combined polar/non-polar chromatographic column; and a pulsed flame photometric detector (PFPD). All parameters were optimised to achieve maximum sensitivity. The system was linear for the range of sulphur compound concentrations found in beer, and displayed good reproducibility. The calibrated SPME-GC-PFPD system was used to analyse several different varieties of beer from a range of breweries, and to investigate the change in the concentrations of sulphur compounds when beer is subjected to illumination.

In this work laboratory-scale experiments were carried out to determine and quantify the mechanisms by which water, sugar and other solutes are transferred from vegetable tissue to blanch water. Samples of commercial potato and carrot varieties were studied and Fick's law of diffusion was applied to describe the mass transfer of solutes during blanching of cylinders and cubes of the vegetable tissues.

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The aim of this work was to evaluate the use of enzymes to accelerate the ripening of Cheddar cheese. Addition of preparations of β-D-Galactosidase to the cheese Milk. The ripening of Cheddar cheese produced from lactose-hydrolysed milk (e.g. up to 60% hydrolysis of the lactose) , was only slightly accelerated even though one of the β-D-galactosidase enzymes used contained some proteolytic enzyme(s). The numbers of starter bacteria at the end of the cheesemaking process were higher in cheese made from enzyme-treated milk than from untreated control milk. The level of soluble nitrogen gradually increases in Cheddar cheese as it becomes older. In these studies higher values for soluble nitrogen were observed in cheese made from lactose-hydrolysed milk compared with control cheese made from untreated milk after similar periods of ripening. This was true for both commercial lactase enzyme preparations - one of which was highly purified while the other contained substantial amounts of protease. Cheddar cheese manufactured from the latter enzyme contained the highest level of soluble nitrogen throughout the ripening period and this could be associated with appreciable acceleration of the ripening of the cheese. More extensive hydrolysis of the casein fractions was also evident in 6-month old Cheddar cheese made from milk treated with the lactase containing protease compared with the control and also the cheese made from milk treated with highly purified lactase. Other desirable effects were achieved as the result of lactose hydrolysis of the cheese milk: (i) Reduction in the cheesemaking time. (ii) Greater judge preference for cheese manufactured from lactose-hydrolysed milk. This effect could be due to the slight increase in protein degradation of this cheese. (iii) The increased level of glucose and galactose in the whey could be a desirable feature for further processing, i.e. in the production of a sweet syrup. Addition of a commercial brand of neutral proteinase to the cheese cord Cheddar cheese was manufactured by using direct-to-vat inoculation of concentrated frozen mixed strains of mesophilic starter culture. In preliminary experiments the enzyme was provided by the manufacturer as a powdered chemical and added to the milled curd at a rate of 0.001, 0.002, 0.005 and 0.01% (w/w). Separate lots of cheese were ripened at 10° and 13°C, and the enzyme activity in the cheese as assessed by monitoring the level of soluble nitrogen, hydrolysis of casein and organoleptically. The extent of acceleration of Cheddar cheese ripening depended on the level of enzyme added to the curd; for example, experimental cheese to which 0.001 and 0.01% enzyme had been added, had characteristics at 2 months similar to those of the control cheese at 4 and 8 months respectively. In enzyme-treated cheese there was a greater liberation of the more soluble nitrogenous compounds, and gel electrophoresis showed a high reduction in β- and αs1 -caseins compared with the control. All the enzyme-treated cheese had defects in "body and texture" characteristics, and had mottled, weak body and bitter flavour. The extent of the defect was associated with the enzyme level. The changes brought about by the addition of the enzyme did not increase to any large extent after four to six months ripening. The effect of the higher ripening temperature was enhanced enzyme activity. Follow up near-commercial scale trials the neutral proteinase was supplied by the manufacturer in the form of a coating on salt to enhance homogeneity of mixing with the curd. The addition of Neutrase, 0.002, 0.003 and 0.005% (w/w) to the cheese curd increased the proteolytic activity, i.e. greater liberation of more soluble nitrogen and more extensive casein hydrolysis compared with the control made from untreated curd. The flavour intensity of cheese made from enzyme-treated curd was greater than from untreated curd but the following quality problems were observed: - bitter and unacceptable flavour(s); - open and crumbly texture; - brittle and softer body cheese; - discoloured or mottled. The extent of these defects was related to the amount of enzyme added. In order to overcome these defects in the experimental cheese, the enzymatic activity had to be stopped when the desirable flavour intensity in the cheese had been achieved. Preliminary experiments have indicated that the use of Neutrase- treated curd which results in more rapid ripening and development of cheese flavour may have advantages in the production of processed cheese.

No description available.