Cholesterol-lowering effects of plant sterol esters and non-esterified stanols in margarine, butter and low-fat foods

Objectives: To determine the efficacy on plasma cholesterol-lowering of plant sterol esters or non-esterified stanols eaten within low-fat foods as well as margarine.
Design: Randomised, controlled, single-blind study with sterol esters and non-esterified plant stanols provided in breakfast cereal, bread and spreads. Study 1 comprised 12 weeks during which sterol esters (2.4 g) and stanol (2.4 g) -containing foods were eaten during 4 week test periods of cross-over design following a 4 week control food period. In Study 2, in a random order cross-over design, a 50% dairy fat spread with or without 2.4 g sterol esters daily was tested.
Subjects: Hypercholesterolaemic subjects; 22 in study 1 and 15 in study 2.
Main outcome measures: Plasma lipids, plasma sterols, plasma carotenoids and tocopherols.
Results: Study 1¾median LDL cholesterol was reduced by the sterol esters (-13.6%; P<0.001 by ANOVA on ranks; P<0.05 by pairwise comparison) and by stanols (-8.3%; P=0.003, ANOVA and <0.05 pairwise comparison). With sterol esters plasma plant sterol levels rose (35% for sitosterol, 51% for campesterol; P<0.001); plasma lathosterol rose 20% (P=0.03), indicating compensatory increased cholesterol synthesis. With stanols, plasma sitosterol fell 22% (P=0.004), indicating less cholesterol absorption. None of the four carotenoids measured in plasma changed significantly. In study 2, median LDL cholesterol rose 6.5% with dairy spread and fell 12.2% with the sitosterol ester fortified spread (P=0.03 ANOVA and <5% pairwise comparison).
Conclusion: 1. Plant sterol esters and non-esterified stanols, two-thirds of which were incorporated into low-fat foods, contributed effectively to LDL cholesterol lowering, extending the range of potential foods. 2. The LDL cholesterol-raising effect of butter fat could be countered by including sterol esters. 3. Plasma carotenoids and tocopherols were not reduced in this study.

Wastewater reuse and treatment options for the dairy industry

Milk-processing plants generate significant quantities of wastewater with relatively high organic matter concentrations on a daily basis. In addition to environmental damage that can result from the discharge of these wastewaters into the natural waterways, the presence of products such as milk solids into wastewater streams represents a loss of valuable product for the plants. This paper presents a review of wastewater management practices employed by six milk-processing plants in Victoria, Australia. In all six plants investigated, milk powder represents a major product. During the milk powder production, water is evaporated, condensed and can be reused for various purposes with a significant impact on water usage. Other major products are anhydrous milk fat, cheese, butter, and UHT milk. The effectiveness of the practices was assessed through two main criteria: first through the water to milk intake ratio, and the waste volume coefficient. Both parameters characterise the plant efficiency in regard of water consumption and water reuse, Information on cleaning chemical usage and recovery was also assessed as part of the review. Significant discrepancies emerge between the plants first due to the products manufacturad and water reuse possibilities available in each plant. Second the type of treatment technologies used for condensate and cleaning solution influences the figures. One of the investigated plants is almost self-sufficient for water, emphasising the benefits gained from the use of technologies like membrane separations for condensate and cleaning solution treatment. In some cases, less cost-intensive technologies such as a clarifier are successful to improve cleaning agent recovery.

Input usage, output mix and industry deregulation: an analysis of the Australian dairy manufacturing industry

In this paper we estimate a Translog output distance function for a balanced panel of state level data for the Australian dairy processing sector. We estimate a fixed effects specification employing Bayesian methods, with and without the imposition of monotonicity and curvature restrictions. Our results indicate that Tasmania and Victoria are the most technically efficient states with New South Wales being the least efficient. The imposition of theoretical restrictions marginally affects the results especially with respect to estimates of technical change and industry deregulation. Importantly, our bias estimates show changes in both input use and output mix that result from deregulation. Specifically, we find that deregulation has positively biased the production of butter, cheese and powders.

Milkfat characteristics and functionality: opportunities for improvement

Manipulation of the composition of milkfat has the potential to improve the nutritional properties and physical functionality of milkfat and its acceptability in the market. The modifications that have been targeted from a nutritional perspective have included:
(a) reducing the ratio of saturated to unsaturated fatty acids;
(b) increasing the level of omega-3 polyunsaturated fatty acids; and
(c) increasing the content of conjugated linoleic acid.
From a physical functionality viewpoint, the outcome targeted has been an improvement in the spreadability of butter by altering milkfat composition to reduce the hardness of milkfat. Both on-farm strategies and the application of appropriate post-farm processing technologies may be used to alter the milkfat composition to enhance its nutritional image and its physical functionality for a range of product applications. However, changes in milkfat composition that are desirable for a specific nutritional purpose or for one type of milk-based product may not meet all the desirable requirements of another milkfat or dairy product. Furthermore, modification of the milkfat composition can also have an influence on the processing characteristics of milk and the quality of finished dairy products. It is essential to substantiate the benefits of specific target nutritional or physical functionality outcomes before the introduction of breeding goals, altered milk production systems or post-farm processing operations to manipulate milkfat composition. This paper reviews the variation in milkfat characteristics and the strategies that have been used to modify milkfat composition to achieve milkfat with altered nutritional and physical functional properties.

Macronutrient innovations: the role of fats and sterols in human health

Dietary intake of fats and sterols has long been known to play a critical role in human health. High proportions of saturated fat, which increase blood cholesterol levels, are mainly found in animal fat and some plant oil (e.g. cocoa butter, palm oil etc.). The predominant polyunsaturated fatty acid (PUFA) in the Western diet is linoleic acid (LA; 18:2n-6), an essential fatty acid, which is commonly found in vegetable seed oils. This is the parent fatty acid of n-6 series PUFA, which can be converted in vivo to C20 and C22 n-6 long chain (LC) PUFA. α‐linolenic acid (ALA; 18:3n-3) is less abundant than LA and is another essential fatty acid; ALA is also present in some vegetable oils such as perilla, flaxseed, canola, soybean and walnut oils, and is the precursor of C20 and C22 n-3 LC PUFA. Sterols are widely distributed in animal tissue and plants, with cholesterol being the major sterol in animal tissue and β-sitosterol, campesterol and stigmasterol being the main sterols in plants. It has long been recognized that an increased dietary intake of saturated fat and (to a lesser extent) cholesterol, raises plasma/serum total and low-density lipoprotein (LDL)-cholesterol, and PUFA decreases these levels. Results from recent studies have shown that plasma/serum levels of lipids and lipoprotein lipids can also be decreased by plant sterols (phytosterols) and diacylglycerol (DAG). Conjugated linoleic acid (CLA, cis-9,trans-11−18:2) has been reported to have anticancer and antidiabetic activities. Fat as the DAG form has also been reported to have anti-obesity effects. Omega-3 PUFA have a beneficial effect on increased heart rate variability, decreased risk of stroke, reduction of both systolic and diastolic blood pressure and may be effective in managing depression in adults. Gamma-linolenic acid (GLA) and phytosterols have an anti-inflammatory activity. The GLA, when combined with docosahexaenoic acid (DHA), have been reported to have a beneficial effect in hyperactive children. These data show that various lipids are powerful bioactive compounds.

The occurrence of trans-18:1 isomers in plasma lipids classes in humans

Objective: The aim of this study was to examine the distribution of trans fatty acids (TFA) in plasma lipid classes and the relationship with dietary intake of TFA.

Design: After a 2 week baseline (habitual) diet, all subjects consumed a moderate fat (MF) diet for 3 weeks with the fat being derived mainly from margarine and the rest from lean beef, and then a very low fat (VLF) diet for 3 weeks with the TFA being derived only from the lean beef. Blood samples were collected 2 days prior to the end and also on the last day of each dietary period.

Setting: Deakin Institute of Human Nutrition, Deakin University, Geelong, Australia.

Subjects: Ten free-living mildly hypercholesterolaemic subjects aged 22-66 were recruited in Geelong.

Outcome measures: TFA intake was calculated from analyses of Australian margarines, butter, lean meat and animal fat. The TFA in plasma lipid fractions were separated by AgNO3 thin-layer chromatography and quantitated by capillary gas-liquid chromatography using internal standards.

Results: The phospholipid (PL) fraction contained more than 60% of the trans-18:1 isomers in the plasma lipids in all subjects. On the baseline diet, the predominant positional isomer of trans-18:1 in PL was Delta11, whereas in the other lipid classes it was the Delta9 isomer. The concentration of the Delta9 isomer increased on the MF diet, particularly in the PL fraction, while the concentration of the Delta11 isomer decreased in all fractions. On the VLF diet, the total TFA level decreased by approximately 50%, mainly due to decreases in the TFA isomers in the PL and TG fractions. Changes in plasma total and PL TFA, PL Delta9, Delta10 and Delta11 were strongly correlated with dietary TFA intake (P<0.0001). There were also significant association between dietary TFA intake and PL Delta12 (P=0.003), triacylglycerol Delta9 (P=0.009), Delta11 (P=0.0005), total triacylglycerol (P=0.023) and free fatty acid TFA (P=0.042).

Conclusions: The results suggest that the measurement of trans-18:1 in plasma PL and TAG, and plasma total TFA could be used to estimate the intake of TFA.

'Hands-on' assessment: a useful strategy for improving patient safety in emergency departments

BACKGROUND: Patient assessment is an essential nursing intervention that reduces the incidence and impact of errors and preventable adverse events in emergency departments (EDs). This paper reports on a key finding of the ED nurse component of a larger study investigating how registered nurses manage 'discontinuities' or 'gaps' in patient care. METHODS: The larger study was undertaken as a naturalistic inquiry using a qualitative exploratory descriptive approach. Data were collected from a criterion-based purposeful sample of 71 nurses, of which 19 were ED nurses, and analysed using content and thematic analysis strategies. RESULTS: The component of the study reported here revealed that ED nurses used 'hands-on', head-to-toe assessment to manage gaps in patient care. Examination of the data revealed three key dimensions of patient assessment in the ED: (i) assessment is the 'bread and butter' of emergency nursing; (ii) 'hands-on' assessment techniques are irreplaceable and, (iii) patient assessment is undervalued in EDs. CONCLUSIONS: The findings of this study reaffirm the role of 'hands-on' observation and assessment in creating safety in EDs. Further research and inquiry is needed to determine how health care systems can provide the conditions for ensuring that 'hands-on' assessment occurs.