Measuring dairy farm performance

To fully consider production impacts, this thesis adopts a systems perspective and uses a biophysical model, DairyMod, to measure the interactions between system components and gauge the environmental impact of dairy farming arising from nitrogen use. Performance from the perspective of both the individual farmer and society is examined.

Evaluation of novel dairy fatty acids in inflammatory muscle-wasting conditions

This work examined the effects of a novel dairy fatty acid conjugated linoleic acid (CLA) and its effects on muscle wasting in advanced cancer. Results showed a positive anti-inflammatory role of CLA on the supression of tumour growth and established a model for studying the action of CLA in human muscle-wasting conditions.

Identification and quantification of cholesterol oxides in foods

The types and levels of nine major cholesterol oxidation products was determined in a variety of foods. An estimate was made of the possible levels of cholesterol oxides in the Australian diet. These levels have been shown to cause endothelial damage in the coronary arteries of laboratory animals in previous studies. The health implications of these observations to humans is unknown.

The relevance of the Heart Foundation of Australia's dietary recommendations for adult Australians : a comparison of views of general practitioners, cardiologists and dietitians

PURPOSE: To compare the views of general practitioners, cardiologists and dietitians about the relevance of the Heart Foundation of Australia's dietary recommendations for adult cardiac patients.

BASIC PROCEDURES: Quantitative-cross sectional study. Postal questionnaires were self-completed by 248 Victorian general practitioners (30% response), 189 Australia-wide cardiologists (47% response) and 180 Victorian dietitians (45% response). Responses were represented as percentages and analyses of variance were conducted to explore the impact of the independent variables: age, work status and gender on the dependent variable: dietary recommendation.

MAIN FINDINGS: Approximately half of the recommendations were viewed as strongly important to implement; these related to lean meats, limiting takeaways and cakes/biscuits, and adjusting energy intake. Others of importance were eating fruits, vegetables and fish. However, most of these goals were seen as difficult to achieve. Dietitians appeared to share responses of doctors, except for greater importance of eating fruit and vegetables and a greater difficulty in limiting cakes and biscuits. There was a high level of agreement among the three groups (mean 87%) about patients having difficulty implementing adjusting energy intake.

CONCLUSIONS: There is agreement amongst these professionals that many of the recommendations lack importance, specifically those pertaining to unsaturated oils, low fat dairy products, cholesterol rich foods, intake of legumes and grains and the restriction of salt. This may reflect a need for further nutrition education.

The assessment of тт-тт selective stationary phases for two-dimensional HPLC analysis of foods : application to the analysis of coffee

Differences between alkyl, dipole–dipole, hydrogen bonding, and π-π selective surfaces represented by non-resonance and resonance π-stationary phases have been assessed for the separation of ‘Ristretto’ café espresso by employing 2DHPLC techniques with C18 phase selectivity detection. Geometric approach to factor analysis (GAFA) was used to measure the detected peaks (N), spreading angle (β), correlation, practical peak capacity (n_p) and percentage usage of the separations space, as an assessment of selectivity differences between regional quadrants of the two-dimensional separation plane. Although all tested systems were correlated to some degree to the C18 dimension, regional measurement of separation divergence revealed that performance of specific systems was better for certain sample components. The results illustrate that because of the complexity of the ‘real’ sample obtaining a truly orthogonal two-dimensional system for complex samples of natural origin may be practically impossible.

Major dietary patterns of young and middle aged women : results from a prospective Australian cohort study

Objective: The aim of this study was to assess the major dietary patterns of two age cohorts of women, to determine to the extent to which the dietary patterns differ between the cohorts and to assess whether they vary according to sociodemographic and behavioural characteristics and patterns of nutrient intake.

Method: Dietary intake was assessed using an 80-item food frequency questionnaire for women aged 50–55 years (n=10 150; ‘middle age’) in 2001 and aged 25–30 years (n=7371; ‘young’) in 2003, from the Australian Longitudinal Study on Women's Health. Factor analysis using principal component extraction was used to identify dietary patterns, and a pattern score was calculated from the consumption of the food items identified with each dietary pattern. Associations between the dietary pattern scores and sociodemographic and behavioural characteristics and nutrient intakes were investigated using regression analysis.

Results: Six dietary patterns were identified and were labelled: cooked vegetables; fruit; Mediterranean-style; processed meat, meat and takeaway; reduced fat dairy; and high-fat and sugar foods. Regression analysis revealed that healthier dietary patterns were significantly associated with other favourable health-related behaviours, higher socioeconomic status and living in urban areas (P-values <0.05).

Conclusions: In spite of differences in the level of consumption of individual food items, the similarity in dietary patterns across two generations of women suggests that policies and interventions to improve diet should focus on social and economic factors and general health-related behaviour rather than different age groups.

Trends in food and nutritional intakes of French adults from 1999 to 2007 : results from the INCA surveys

Two independent cross-sectional dietary surveys (the Individual and National Food Consumption Surveys, INCA), performed in 1998–99 (INCA1) and in 2006–07 (INCA2) on nationally representative samples of French people, were used to analyse trends in the dietary habits and nutritional intake of French adults. Food consumption was recorded through 7-d dietary records, and nutritional intakes were assessed using the French food composition database. After exclusion of under-reporters, analyses were performed on 3267 adults, aged 18–79 years: 1345 from INCA1 and 1922 from INCA2. The trends highlighted over the 8-year period showed a decrease in consumption of dairy products, meat, bread, potatoes, pastries/croissant-like pastries/cakes/biscuits and sugar/confectionery. In contrast, the consumption of fruits and vegetables, rice, ice cream and chocolate increased. Other food groups, like fish and snacking foods, remained stable. Food choices were mostly age specific. These age differences remained consistent over the years and underlined two opposite dietary trends: a ‘traditional’ one mainly followed by the elderly, and a ‘snacking and convenience’ one mainly adopted by young adults. The overall trends in food consumption did not influence the mean energy intake, but did slightly modify the contribution of each macronutrient to energy intake. These repeated surveys highlighted the fact that trends in French food habits have moved towards an average European diet at the crossroads between Mediterranean and Northern diets, and that food consumption changes impacted, to a lesser extent, nutritional intake.

Comparison of different maximum safe levels in fortified foods and supplements using a probabilistic risk assessment approach

Different European institutions have developed mathematical models to propose maximum safe levels either for fortified foods or for dietary supplements. The objective of the present study was to compare and check the safety of these different maximum safe levels (MSL) by using a probabilistic risk assessment approach. The potential maximum nutritional intakes were estimated by taking into account all sources of intakes (base diet, fortified foods and dietary supplements) and compared with the tolerable upper intake levels for vitamins and minerals. This approach simulated the consequences of both food fortification and supplementation in terms of food safety. Different scenarios were tested. They are the result of the combination of several MSL obtained using the previous models. The study was based on the second French Individual and National Study on Food Consumption performed in 2006–7, matched with the French food nutritional composition database. The analyses were based on a sample of 1918 adults aged 18–79 years. Some MSL in fortified foods and dietary supplements obtained independently were protective enough, although some others could lead to nutritional intakes above the tolerable upper intake levels. The simulation showed that it is crucial to consider the inter-individual variability of fortified food intakes when setting MSL for foods and supplements. The risk assessment approach developed here by integrating the MSL for fortified foods and dietary supplements is useful for ensuring consumer protection. It may be subsequently used to test any other MSL for vitamins and minerals proposed in the future.

Consumption of foods by young children with diagnosed campylobacter infection : a pilot case-control study

Objective: To determine whether parentally reported habitual intake of specific foods differed between children with diagnosed Campylobacter jejuni infection and children of a comparison group without diagnosed infection.

Design, setting and subjects: Information was collected from the parents or primary caregivers of South Australian children aged 1–5 years with diagnosed C. jejuni (cases, n=172) and an age- and gender-matched group of uninfected children (controls, n=173). Frequency of consumption of 106 food and drink items was determined for the preceding two months by food-frequency questionnaire. Four children in the control group had recorded diarrhoeal episodes during the assessment period and were excluded, so 169 responses were evaluated for this group. Information was gathered on possible confounders including socio-economic status. Response frequencies were classified into three levels of consumption (rarely, weekly or daily) and statistical comparison was made by frequency of consumption of foods versus the ‘rarely’ classification for cases and controls, respectively.

Results: Frequency of consumption of most foods, including starchy foods and fruits and vegetables, did not differ between cases and controls. However, reported consumption of eight food items (block and processed cheese (slices and spread), salami/fritz (a form of processed sausage), chicken nuggets, pasteurised milk, fish (canned or fresh) and hot French fries) was significantly higher by controls.

Conclusions: The hypothesis that reported consumption of starchy foods was lower by cases than by controls was not supported by the data. However, consumption of some processed and unprocessed foods was higher by controls. Some of these foods have established bactericidal actions in vitro that may indicate a possible mechanism for this apparent protection.

Stabilization of highly unsaturated fatty acids and delivery into foods

Highly unsaturated fatty acids derived from fish or algal oils, particularly EPA and DHA, are in high demand as healthy food ingredients in fortified foods. Due to their oxidative instability most food products incorporate stabilized microencapsulated EPA and DHA oils to avoid negative sensory impact associated with oxidation of these fatty acids. Complex coacervation has been particularly successful in stabilizing fish oil and providing an ingredient with a sensory shelf-life consistent with that of the food product. Overcoming the technical challenges associated with the instability of these oils will help drive growth of the omega-3 fortified healthy food ingredient market.

Reducing sodium in foods : the effect on flavor

Sodium is an essential micronutrient and, via salt taste, appetitive. High consumption of sodium is, however, related to negative health effects such as hypertension, cardiovascular diseases and stroke. In industrialized countries, about 75% of sodium in the diet comes from manufactured foods and foods eaten away from home. Reducing sodium in processed foods will be, however, challenging due to sodium’s specific functionality in terms of flavor and associated palatability of foods (i.e., increase of saltiness, reduction of bitterness, enhancement of sweetness and other congruent flavors). The current review discusses the sensory role of sodium in food, determinants of salt taste perception and a variety of strategies, such as sodium replacers (i.e., potassium salts) and gradual reduction of sodium, to decrease sodium in processed foods while maintaining palatability.