Evaluation of yield parameters and nutritional aspects of different strains of oyster (Pleurotus ostreatus) mushroom

The present study investigates the comparison between three different strains of oyster mushroom Pleurotus ostreatus (oyster (local), WC-537, WC-522) regarding to their yield and nutritional aspects. Four different kinds of substrates (corncob, wheat straw, rice straw, and sugarcane bagasse) were used for the growth of oyster. Oyster strain on corncob was found to be the fast mycelial run in comparison with WC-537 and WC-522. WC-522 on sugarcane bagasse showed the slowest mycellial run. Highest number of flushes was produced by oyster strain on each substrate. Number of days for period between flushes for oyster and WC-537 was about equal on corn cob, wheat straw and rice straw i.e. 4-6 days. Number of days taken for maturation of fruiting bodies of oyster and WC-537 was almost equal 6-7 days. In terms of nutritional aspects all strains have almost the same amount of moisture, fat, ash, fiber and protein with small variation. All the strains have protein content of about 20% by weight.

Nutritional aspects of food extrusion: a review

Extrusion cooking, as a multi-step, multi-functional and thermal/mechanical process, has permitted a large number of food applications. Effects of extrusion cooking on nutritional quality are ambiguous. Beneficial effects include destruction of antinutritional factors, gelatinisation of starch, increased soluble dietary fibre and reduction of lipid oxidation. On the other hand, Maillard reactions between protein and sugars reduce the nutritional value of the protein, depending on the raw material types, their composition and process conditions. Heat-labile vitamins may be lost to varying extents. Changes in proteins and amino acid profile, carbohydrates, dietary fibre, vitamins, mineral content and some non-nutrient healthful components of food may be either beneficial or deleterious. The present paper reviews the mechanisms underlying these changes, as well as the influence of process variables and feed characteristics. Mild extrusion conditions (high moisture content, low residence time, low temperature) improve the nutritional quality, while high extrusion temperatures (200 °C), low moisture contents (<15%) and/or improper formulation (e.g. presence of high-reactive sugars) can impair nutritional quality adversely. To obtain a nutritionally balanced extruded product, careful control of process parameters is essential.

Biometric, nutritional and organoleptic changes in intensively farmed Murray Cod (Maccullochella peelii peelii) purged for different time periods

A period of purging before harvesting is common practice in intensive aquaculture to eliminate any possible off flavours from the fish. The present study was conducted to evaluate the biometrical, nutritional and sensory changes in intensively farmed Murray cod (Maccullochella peelii peelii) after 0, 2 and 4 weeks of purging. After the main biometric parameters were recorded, fish were analysed for proximate, fatty acid composition and flavour volatile compounds. A consumer preference test (triangle test) was also conducted to identify sensorial differences that may affect the consumer acceptability of the product.

Fish purged for 2 and 4 weeks had a significant weight loss of 4.1% and 9.1%, respectively, compared to unpurged fish, whilst perivisceral fat content did not change. The concentration of saturated (SFA), monounsaturated (MUFA) and highly unsaturated (HUFA) fatty acids were not significantly affected by purging time, while polyunsaturated fatty acids (PUFA), n − 3 and n − 3 HUFA were significantly higher (P < 0.05) in purged fish compared to unpurged fish. Consumers were able to detect differences between the purged and unpurged fish (P < 0.05) preferring the taste of the purged fish. However, consumers were unable to distinguish between fish purged for 2 and 4 weeks.

This study showed that a 2 weeks purging period was necessary and sufficient to ameliorate the final organoleptic quality of farmed Murray cod. With such a strategy the nutritional qualities of edible flesh are improved while the unavoidable body weight loss is limited.

Biometric, nutritional and sensory changes in intensively farmed Murray cod (Maccullochella peelii peelii, Mitchell) following different purging times

A period of purging before harvesting is common practice in intensive aquaculture to eliminate any possible off flavours from the fish. The present study was conducted to evaluate the biometrical, nutritional and sensory changes in intensively farmed Murray cod (Maccullochella peelii peelii) after 0, 2 and 4 weeks of purging. After the main biometric parameters were recorded, fish were analysed for proximate, fatty acid composition and flavour volatile compounds. A consumer preference test (triangle test) was also conducted to identify sensorial differences that may affect the consumer acceptability of the product.

Fish purged for 2 and 4 weeks had a significant weight loss of 4.1% and 9.1%, respectively, compared to unpurged fish, whilst perivisceral fat content did not change. The concentration of saturated (SFA), monounsaturated (MUFA) and highly unsaturated (HUFA) fatty acids were not significantly affected by purging time, while polyunsaturated fatty acids (PUFA), n − 3 and n − 3 HUFA were significantly higher (P < 0.05) in purged fish compared to unpurged fish. Consumers were able to detect differences between the purged and unpurged fish (P < 0.05) preferring the taste of the purged fish. However, consumers were unable to distinguish between fish purged for 2 and 4 weeks.

This study showed that a 2 weeks purging period was necessary and sufficient to ameliorate the final organoleptic quality of farmed Murray cod. With such a strategy the nutritional qualities of edible flesh are improved while the unavoidable body weight loss is limited.

Relationship between alcohol abuse upper gastro-intestinal haemorrhage and nutritional status during acute hospital admission

This thesis is concerned with the effect of alcohol consumption on the pathogenesis of bleeding from the upper gastrointestinal tract via nutritional pathways. Altered nutritional status is a frequently recognised clinical accompaniement of heavy alcohol consumption in hospitalized patients. Similarly, upper gastrointestinal bleeding is frequently accompanied by the presence of heavy alcohol consumption. Nevertheless, the clinical quantification of alcohol intake is often descriptive, so that a link between alcohol use and upper gastrointestinal haemorrhage via nutritional mechanisms has been only generally defined. In the literature review, the methods of defining alcohol use and abuse, using interview, biochemical and haematological techniques are noted. The relationship between alcohol abuse and nutrient imbalances is reviewed, especially in relation to possible effects on the gastrointestinal tract, appetite and eating habits. A further section reviews the relationship between alcohol use and anatomical lesions of the upper gastrointestinal tract likely to lead to bleeding. Following the chapter in which the methods used in this thesis are described. Chapter 4 seeks to describe the study population and its subgroups in this thesis in relation to interview, biochemical and haematological methods. Alcohol use is defined in relation to (1) a clinical classification of heavy or light drinking, based on a questionnaire administered in Casualty, (2) a quantified method of determining alcohol consumption during a subsequent ward dietetic assessment, (3) in relation to a biochemical definition (recent drinking and non-drinking), and a classification of (1) and (2) called, for the purposes of this thesis, 'alcohol abusers' and 'nonabusers'. Heavy, regular and recent drinkers and alcohol abusers tend to be male and younger than light, infrequent and nonrecent drinkers and nonabusers. Chapter 5 relates the nutritional status of those patients admitted acutely to hospital in relation to the groups defined in Chapter 4, Nutritional status is defined in terms of food intake, anthropometry, biochemical and haematological parameters. Different methods of defining alcohol use give rise to different patterns of nutritional impairment. Chapter 6 relates the nutritional status of those patients admitted acutely to hospital in relation to the presence or absence of an endoscopically defined site of upper gastrointestinal bleeding. A difference is seen between those bleeding from a Mailory-weiss tear and other sites of bleeding, similarly, biochemical differences in nutritional status emerge between those patients who presented in shock, and those who did not. Chapter 7 explores the relationships between biochemical markers of nutritional status and haemostatic variables in the groups of abusers/non-abusers, the various sites of primary bleeding/controls, and shock/non-shock. Serum copper appears to be related to altered haemostasis in a manner not apparently described elsewhere.

A haemodialysis nutritional screening tool for nurses : a pilot study

The purpose of the study was to pilot a nurse-performed nutritional screening tool (NST) for dialysis patients in order to identify nutritionally at-risk patients. Haemodialysis (HD) patients are at risk of nutritional-related problems. Nutritional screening by nurses may assist in the early recognition of and response to these problems. An NST was developed using 9 screening parameters. (BMI, weight change, poor appetite, GI symptoms, albumin, pre-dialysis urea, K+, PO4++, HbA1c). The NST was compared with Standard Dietitian Assessment (SDA). 44 HD patients were screened with the NST and then with SDA. The tool showed sensitivity of 0.7 (95%CI+/- 0.21) and a specificity of 0.77 (95%CI+/-0.16). Reliability was low (alpha = .18). Alpha increased to 0.32 if pre-dialysis urea was removed from the tool and increased to 0.48 if weight loss, appetite, K+ and PO4++ were used alone. The pilot study showed a low reliability of the NST compared with SDA. With further analysis and modifications, the NST has the potential to assist nutritional screening by nurses in dialysis centres that have limited dietetic access.

A review of 16 years of quality control parameters at a mass-rearing facility producing Queensland fruit fly, Bactrocera tryoni

From 1996 to 2012, the mass-rearing facility at Camden (NSW, Australia) has been producing Queensland fruit flies, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae). During this time, the facility has regularly recorded fly quality parameters, creating a unique data set that provides an invaluable opportunity to evaluate the interrelationships among standard quality control (QC) parameters and test for redundant QC variables. Here, we conducted an exploratory data analysis to reveal relationships among the QC parameters. We found that pupal weight, adult lifespan, and longevity under nutritional stress (i.e., survival duration without food or water) had distinct monthly trends, suggesting that these QC parameters are sensitive to seasonal conditions. Furthermore, emergence percentage, flight ability, and adult lifespan were adversely affected by the dyeing/handling/irradiation process associated with sterile insect releases. Using a multivariate approach and controlling for monthly and yearly patterns, we showed that pupal weight and egg hatch are consistently negatively related and that percentage male and emergence rates are consistently negatively related. These results suggest that these correlation pairs measure similar quality information and hence one QC variable from each pair could be dropped. Flight ability was not strongly correlated with any of the QC variables, suggesting that this QC variable remains a useful QC metric. Finally, the longevity under nutritional stress QC appears to be fairly insensitive to QCs and we suggest that it should be replaced by the standard mortality under stress test.

Rapid effects of essential fatty acid deficiency on growth and development parameters and transcription of key fatty acid metabolism genes in juvenile barramundi (Lates calcarifer)

Barramundi (Lates calcarifer), a catadromous teleost of significant and growing commercial importance, are reported to have limited fatty acid bioconversion capability and therefore require preformed long-chain PUFA (LC-PUFA) as dietary essential fatty acid (EFA). In this study, the response of juvenile barramundi (47·0 g/fish initial weight) fed isolipidic and isoenergetic diets with 8·2 % added oil was tested. The experimental test diets were either devoid of fish oil (FO), and thus with no n-3 LC-PUFA (FO FREE diet), or with a low inclusion of FO (FO LOW diet). These were compared against a control diet containing only FO (FO CTRL diet) as the added lipid source, over an 8-week period. Interim samples and measurements were taken fortnightly during the trial in order to define the aetiology of the onset and progression of EFA deficiency. After 2 weeks, the fish fed the FO FREE and FO LOW diets had significantly lower live-weights, and after 8 weeks significant differences were detected for all performance parameters. The fish fed the FO FREE diet also had a significantly higher incidence of external abnormalities. The transcription of several genes involved in fatty acid metabolism was affected after 2 weeks of feeding, showing a rapid nutritional regulation. This experiment documents the aetiology of the onset and the progression of EFA deficiency in juvenile barramundi and demonstrates that such deficiencies can be detected within 2 weeks in juvenile fish.

Application of dried blood spots to determine vitamin D status in a large nutritional study with unsupervised sampling: the Food4Me project

An efficient and robust method to measure vitamin D (25-hydroxy vitamin D3 (25(OH)D3) and 25-hydroxy vitamin D2 in dried blood spots (DBS) has been developed and applied in the pan-European multi-centre, internet-based, personalised nutrition intervention study Food4Me. The method includes calibration with blood containing endogenous 25(OH)D3, spotted as DBS and corrected for haematocrit content. The methodology was validated following international standards. The performance characteristics did not reach those of the current gold standard liquid chromatography-MS/MS in plasma for all parameters, but were found to be very suitable for status-level determination under field conditions. DBS sample quality was very high, and 3778 measurements of 25(OH)D3 were obtained from 1465 participants. The study centre and the season within the study centre were very good predictors of 25(OH)D3 levels (P<0·001 for each case). Seasonal effects were modelled by fitting a sine function with a minimum 25(OH)D3 level on 20 January and a maximum on 21 July. The seasonal amplitude varied from centre to centre. The largest difference between winter and summer levels was found in Germany and the smallest in Poland. The model was cross-validated to determine the consistency of the predictions and the performance of the DBS method. The Pearson's correlation between the measured values and the predicted values was r 0·65, and the sd of their differences was 21·2 nmol/l. This includes the analytical variation and the biological variation within subjects. Overall, DBS obtained by unsupervised sampling of the participants at home was a viable methodology for obtaining vitamin D status information in a large nutritional study.