Longer guts and higher food quality increase energy intake in migratory swans

1.  Within the broad field of optimal foraging, it is increasingly acknowledged that animals often face digestive constraints rather than constraints on rates of food collection. This therefore calls for a formalization of how animals could optimize food absorption rates.

2.  Here we generate predictions from a simple graphical optimal digestion model for foragers that aim to maximize their (true) metabolizable food intake over total time (i.e. including nonforaging bouts) under a digestive constraint.

3.  The model predicts that such foragers should maintain a constant food retention time, even if gut length or food quality changes. For phenotypically flexible foragers, which are able to change the size of their digestive machinery, this means that an increase in gut length should go hand in hand with an increase in gross intake rate. It also means that better quality food should be digested more efficiently.

4.  These latter two predictions are tested in a large avian long-distance migrant, the Bewick's swan (Cygnus columbianus bewickii), feeding on grasslands in its Dutch wintering quarters.

5.  Throughout winter, free-ranging Bewick's swans, growing a longer gut and experiencing improved food quality, increased their gross intake rate (i.e. bite rate) and showed a higher digestive efficiency. These responses were in accordance with the model and suggest maintenance of a constant food retention time.

6.  These changes doubled the birds’ absorption rate. Had only food quality changed (and not gut length), then absorption rate would have increased by only 67%; absorption rate would have increased by only 17% had only gut length changed (and not food quality).

7.  The prediction that gross intake rate should go up with gut length parallels the mechanism included in some proximate models of foraging that feeding motivation scales inversely to gut fullness. We plea for a tighter integration between ultimate and proximate foraging models.

Future challenges in day-care centre food services : will benchmarking help?

Purpose – The aim of this study is to identify the methods used by providers to evaluate their food services and identify elements of their service that would benefit from adopting a benchmarking system.

Design/methodology/approach – In-depth interviews were conducted with 26 food services providers and key informants in day-care settings in Surrey.

Findings – Few providers formally evaluated their service provision and most had not considered benchmarking their services against other food service providers. Factors such as food variety, food quality, cost and environment have been identified as issues that could be benchmarked and may benefit from the adoption of this process.

Research limitations/implications – The study was conducted only in one country – in the UK – further research is needed into the evaluation practices of other local authorities. The benchmarking model that has been developed by the authors needs to be applied in a food service setting to establish its usefulness to food service managers.

Practical implications – A model has been developed from the outcome of this research, which could aid evaluation processes for food service providers to identify aspects of the service in need of improvement.

Originality/value – There has been little research conducted on the evaluation of food service provision for older people, especially for congregate meals. This paper provides a model, that food service providers may find useful, to identify areas of their food services that are suitable for benchmarking.

Effect of flour processing on the quality characteristics of a soy-based beverage

Four treatments (roasting, germination, autoclaving and an application of 0.5% EDTA+0.5% sodium hydroxide) were used to reduce the beany flavour of soya beans to produce a soy-based beverage. While germination significantly increased the protein level as compared to the other treatments, the maximum reduction of the beany flavour was achieved by the 0.5% EDTA+0.5% sodium hydroxide application. The soya beans that underwent this treatment were used during the second phase for optimized beverage formulation. During the second phase, a beverage was prepared according to different formulations and analysed for chemical composition and total viable count during a two-month storage period. During storage, the beverage samples exhibited variations in several parameters. The acidity, reducing sugars and total sugars increased, while the ascorbic acid, total soluble solids and pH decreased. Overall, chemical and microbial analyses showed the stability of the product during the storage period.

Bio-economical and ethical impacts of alien finfish culture in European inland waters

Since 1989, and in comparison to the global trend, inland aquaculture production of European finfish has declined. To date, the yearly European freshwater aquaculture production is 371,727 tons, valued at over US$1 billion. Indigenous species accounted for less than one-third of the production, whereas alien species (a species that has been moved beyond its natural range of distribution) accounts for the remainder. However, in general, indigenous species command a higher market price. Currently, food quality and food safety are leading concerns of consumers, and European consumers are also becoming alert to environmentally detrimental practices. Therefore, to aim at economic sustainability, the sector needs to satisfy consumer expectations of environmentally friendly practices. It is believed that farming alien finfish species can threaten local biodiversity through escapes, and this represents a current environmental concern relative to aquaculture. In this context, an attempt is made in this paper to understand and quantify the impacts of alien finfish cultivation in European inland waters, and to suggest remedial measures.

Provision of meals on wheels to the elderly : case studies in the era of local government reform

Australia’s ageing population is on the increase. It is predicted that by 2021 one quarter of Victoria’s elderly population will be aged 60 and over. Not only are people living longer, but they also wish to remain living in the community. The Home and Community Care (HACC) Program was established in 1985 to facilitate and assist the elderly and disabled to remain in their home. In Victoria around 51% of HACC funds are managed by local governments, a level of government that has recently undergone major reforms, which ultimately impacted on the manner in which services were provided. The HACC program funds Meals on Wheels, a service that provides meals for those elderly who no longer can prepare their own meals. The aim of this study was to assess the Meals on Wheels service provided by two Melbourne councils with different service philosophies. The study has four main components: (1) Menu analysis by food and variety; (2) Analysis of actual meals; (3) Clients assessment of Food Services; and (4) Client assessment of the organoleptic qualities of Meals on Wheels. Two Melbourne councils were chosen for their different approaches to service delivery. The City of South tendered out both meal production and delivery, while the City of North maintained its MOW service in-house. The case study method of research allowed for each council’s service to be assessed objectively and without comparison. Several methodologies were used for collecting data in this study. Menu analysis was carried out by comparing the MOW menus with the HACC menu planning guidelines together with general menu planning principles. Analysis of actual meals was in two stages. The weights of the meals were recorded and compared with the HACC recommended food serving portions and meal combinations over a five-day period were analysed for their nutrient contents. Face to face interviews were conducted with clients for their assessment of MOW and the assessment of the organoleptic qualities of the meals was carried out over a five-day period. The results concluded that both councils menus were based on sound menu planning principles, but did not conform with Home and Community Care menu planning guidelines fully and did not include a serve of bread, fruit and milk. The weight analysis of the meal combinations revealed some discrepancies between actual meals and Home and Community Care guidelines by not meeting the recommended serving sizes. Meal combinations generally met Home and Community Care standard for kilojoule and protein, but other nutrients, such as thiamin, riboflavin, magnesium, calcium and zinc were generally below the recommended levels for Meals On Wheels. The majority of study group lived alone and received four to five meals per week. Delivery times of meals, selective menus and food quality were issues raised by clients. Whilst the quality and variety of vegetables was raised by clients they generally rated the organoleptic qualities of the meals as satisfactory. This study examined the four components of the service. A simple method of evaluation the service was developed, which highlight discrepancies with HACC standards and encouraged the councils to set a customer satisfaction standard. A number of recommendations are made to ensure that meals are aesthetically pleasing, including a list of different methods for preparing vegetables. The provision of additional foods, such as a “snack pack” is recommended to improve the supply of essential nutrients that were below the Home and Community Care standards. Meals on Wheels is a vital support service for the elderly living in the community and as such should aim to provide a high quality service that meets the needs of its clients.

Prenatal environmental effects match offspring begging to parental provisioning

The solicitation behaviours performed by dependent young are under selection from the environment created by their parents, as well as wider ecological conditions. Here we show how mechanisms acting before hatching enable canary offspring to adapt their begging behaviour to a variable post-hatching world. Cross-fostering experiments revealed that canary nestling begging intensity is positively correlated with the provisioning level of their own parents (to foster chicks). When we experimentally increased food quality before and during egg laying, mothers showed higher faecal androgen levels and so did their nestlings, even when they were cross-fostered before hatching to be reared by foster mothers that had been exposed to a standard regime of food quality. Higher parental androgen levels were correlated with greater levels of post-hatching parental provisioning and (we have previously shown) increased faecal androgens in chicks were associated with greater begging intensity. We conclude that androgens mediate environmentally induced plasticity in the expression of both parental and offspring traits, which remain correlated as a result of prenatal effects, probably acting within the egg. Offspring can thus adapt their begging intensity to variable family and ecological environments.

Ecophysiology of avian migration in the face of current global hazards

Long-distance migratory birds are often considered extreme athletes, possessing a range of traits that approach the physiological limits of vertebrate design. In addition, their movements must be carefully timed to ensure that they obtain resources of sufficient quantity and quality to satisfy their high-energy needs. Migratory birds may therefore be particularly vulnerable to global change processes that are projected to alter the quality and quantity of resource availability. Because long-distance flight requires high and sustained aerobic capacity, even minor decreases in vitality can have large negative consequences for migrants. In the light of this, we assess how current global change processes may affect the ability of birds to meet the physiological demands of migration, and suggest areas where avian physiologists may help to identify potential hazards. Predicting the consequences of global change scenarios on migrant species requires (i) reconciliation of empirical and theoretical studies of avian flight physiology; (ii) an understanding of the effects of food quality, toxicants and disease on migrant performance; and (iii) mechanistic models that integrate abiotic and biotic factors to predict migratory behaviour. Critically, a multi-dimensional concept of vitality would greatly facilitate evaluation of the impact of various global change processes on the population dynamics of migratory birds.

Selective enumeration of dairy based strains of probiotic and lactic acid bacteria

Reliable methods for selective enumeration of probiotic and lactic acid bacteria (LAB) are required for improving the functional food quality of probiotics. Various methods were evaluated for selective enumeration of seventeen LAB and probiotic strains. Tested sugars failed to select any species however, improved recovery of total LAB count. The strains were viable and physiologically active within a range of oxygen tension levels, temperature and acidic conditions. Prior methods showed varied results such as De Man Rogosa Sharpe containing bile (MRSB), MRS containing nalidixic acid, paromomycin, neomycin sulphate and lithium chloride (MRS-NPNL), M17 and L. casei (LC) agar failed to select Lactobacillus acidophilus, Bifidobacterium, starter LAB and L. casei strains respectively. However, LC agar appears appropriate for L. paracasei and MRSB for yoghurt starter bacteria in the absence of L. reuteri and L. rhamnosus. The study suggests selective potential of culture media largely depends on target species.

Fat content of chips, quality of frying fat and deep-frying practices in New Zealand fast food outlets

Objectives: To collect baseline data on the fat content of hot chips, quality (degradation) of cooking fat, deep-frying practices and related attitudes in fast food outlets in New Zealand. To identify the key determinants of the fat content of chips and quality of cooking fat. Methods: A nationally representative sample of fast food outlets (n=150, response rate 80%) was surveyed between September 1998 and March 1999. Data collected included a questionnaire, observation of cooking practices and analysis of cooked chips and frying fat. Results: Only 8% of independent operators had formal training in deep frying practices compared with 93% of chain operators. There was a wide range of fat content of chips (5%-20%, mean 11.5%). The use of thinner chips, crinkle cut chips and lower fryer fat temperature were associated with higher chip fat content. Eighty-nine per cent of chain outlets used 6–10 mm chips compared with 83% of independent outlets that used chips ≥12 mm. A wide range of frying temperatures was recorded (136–233°C) with 58% of outlets frying outside the reference range (175–190°C). As indices of fat degradation, fat acid and polar compound values above the recommended levels occurred in 54% and 5% of outlets respectively. Operators seemed willing to learn more about best practice techniques, with lack of knowledge being the main barrier to change. Conclusions and implications: Deep frying practices could be improved through operator training and certification options. Even a small decrease in the mean fat content of chips would reduce the obesogenic impact of this popular food.

Takeaway food consumption, diet quality and abdominal obesity in young adults

Background - Takeaway food consumption is associated with a higher BMI and poorer diet quality in the USA but little is known about the association in Australians.
Objective - To examine if takeaway food consumption is associated with abdominal obesity and poorer diet quality in young Australian adults.
Design - A national sample of 1,277 men and 1,585 women aged 26-36 completed a self-administered questionnaire on demographic and lifestyle factors, a 127 item food frequency questionnaire, and usual frequency of fruit, vegetable and takeaway food consumption. Dietary intake was compared with the dietary recommendations of the Australian Guide to Healthy Eating. A pedometer was worn for seven days. Waist circumference was measured and moderate abdominal obesity was defined as ≥94 cm for men and ≥80 cm for women. Prevalence ratios (PR) were calculated using log binomial regression with eating takeaway food once a week or less as the reference group.
Outcomes - Consumption of takeaway food twice a week or more was reported by more men (37.9%) than women (17.7%). Participants eating takeaway food at least twice a week were less likely to meet the guidelines for vegetables (P<0.05 men and women), fruit (P<0.001 men and women), dairy (P<0.01 men and women), extra foods (P=0.001 men and women), breads and cereals (P<0.05 men only), lean meats and alternatives (P<0.05 women only) and overall met significantly fewer dietary guidelines (P<0.001 men and women) than participants eating takeaway less than twice per week. After adjusting for confounding variables (age, physical activity, TV viewing, and employment status) consuming takeaway food twice a week or more was associated with a 31% higher prevalence of moderate abdominal obesity in men (PR 1.31; 95% CI: 1.07, 1.61) and a 25% higher prevalence in women (PR 1.25; 95% CI: 1.04, 1.50).
Conclusion - Eating takeaway food twice a week or more was associated with poorer diet quality and a higher prevalence of moderate abdominal obesity in both young men and young women.

Takeaway food consumption and its associations with diet quality and abdominal obesity : a cross-sectional study of young adults

Background : Few studies have investigated the associations of takeaway food consumption with overall diet quality and abdominal obesity. Young adults are high consumers of takeaway food so we aimed to examine these associations in a national study of young Australian adults.

Methods : A national sample of 1,277 men and 1,585 women aged 26–36 completed a self-administered questionnaire on demographic and lifestyle factors, a 127 item food frequency questionnaire, usual daily frequency of fruit and vegetable consumption and usual weekly frequency of takeaway food consumption. Dietary intake was compared with the dietary recommendations from the Australian Guide to Healthy Eating. Waist circumference was measured for 1,065 men and 1,129 women. Moderate abdominal obesity was defined as ≥ 94 cm for men and ≥ 80 cm for women. Prevalence ratios (PR) were calculated using log binomial regression. Takeaway food consumption was dichotomised, with once a week or less as the reference group.

Results : Consumption of takeaway food twice a week or more was reported by more men (37.9%) than women (17.7%, P < 0.001). Compared with those eating takeaway once a week or less, men eating takeaway twice a week or more were significantly more likely to be single, younger, current smokers and spend more time watching TV and sitting, whereas women were more likely to be in the workforce and spend more time watching TV and sitting. Participants eating takeaway food at least twice a week were less likely (P < 0.05) to meet the dietary recommendation for vegetables, fruit, dairy, extra foods, breads and cereals (men only), lean meat and alternatives (women only) and overall met significantly fewer dietary recommendations (P < 0.001). After adjusting for confounding variables (age, leisure time physical activity, TV viewing and employment status), consuming takeaway food twice a week or more was associated with a 31% higher prevalence of moderate abdominal obesity in men (PR: 1.31; 95% CI: 1.07, 1.61) and a 25% higher prevalence in women (PR: 1.25; 95% CI: 1.04, 1.50).

Conclusion : Eating takeaway food twice a week or more was associated with poorer diet quality and a higher prevalence of moderate abdominal obesity in young men and women.

Impact of saltmarsh disturbance on seed quality of Sarcocornia (Sarcocornia quinqueflora), a food plant of an endangered Australian parrot

The article presents a study which evaluates the impact of saltmarsh perturbation on seed quality of Sarcocornia which is a food for the endangered Orange-bellied parrot in Australia. It notes the significant impact of grazing on the energy and availability of Sarcocornia seeds in saltmarshes and indicates that graze-free saltmarshes with regular inundation provide the highest potential for Sarcocornia seed availability. Further, the substantial factor of soil characteristics and salinity of flood water and inundation on the seed production of Sarcocornia is also discussed.