Optical coherence tomography velocimetry in controlled shear flow

Doppler-shift optical coherence tomography with infrared light was used to probe the velocity profiles of concentrated solutions of complex fluids with samples experiencing steady-state shear flow. The apparatus is sensitive to a velocity range of 0.7-330 mm/s probing very small volumes of material (quasicylindrical volume elements of 9-μm length and 11-μm radius with 3.4-picoliter volumes) inside a plate-plate rheometer with a total sample volume of ~100-1000 μL. The technique can scan the flow in the plane perpendicular to the shear direction, building up a two-dimensional map of the velocity flow field. The use of a coherence gate with a broad-band infrared source (9-μm coherence length, 1300-nm wavelength) allows opaque specimens, such as concentrated colloidal suspensions (2% w/w) and margarine, to be probed. We observe the phenomena of wall slip (margarine) and shear banding (polyacrylamide, a linear flexible polyelectrolyte) using this technique.

Plant sterols from rapeseed and tall oils: effects on lipids, fat-soluble vitamins and plant sterol concentrations

BACKGROUND AND AIMS

Data comparing the impact of different sources of plant sterols on CVD risk factors and antioxidant levels is scarce. We evaluated the effects of plant sterols from rapeseed and tall oils on serum lipids, lipoproteins, fat-soluble vitamins and plant sterol concentrations.

METHODS AND RESULTS

This was a double-blinded, randomized, crossover trial in which 59 hypercholesterolemic subjects consumed 25 g/day of margarine for 4 weeks separated by 1 week washout periods. The two experimental margarines provided 2g/day of plant sterols from rapeseed or tall oil. The control margarine had no added plant sterols. The control margarine reduced LDL cholesterol by 4.5% (95% CI 1.4, 7.6%). The tall and rapeseed sterol margarines additionally reduced LDL cholesterol by 9.0% (95% CI 5.5, 12.4%) and 8.2% (95% CI 5.2, 11.4%) and apolipoprotein B by 5.3% (95% CI 1.0, 9.6%) and 6.9% (95% CI 3.6, 10.2%), respectively. Lipid-adjusted beta-carotene concentrations were reduced by both sterol margarines (P<0.017). alpha-Tocopherol concentrations were reduced by the tall sterol compared to the rapeseed sterol margarine (P=0.001). Campesterol concentrations increased more markedly with the rapeseed sterol versus tall sterol margarine (P<0.001). The rapeseed sterol margarine increased while the tall sterol margarine decreased brassicasterol concentrations (P<0.001).

CONCLUSIONS

Plant sterols from tall and rapeseed oils reduce atherogenic lipids and lipoproteins similarly. The rapeseed sterol margarine may have more favorable effects on serum alpha-tocopherol concentrations.

Relationship between textural properties and sensory qualities of cookies made from medium- and long-chain triacylglycerol-enriched margarines

BACKGROUND

This study aims to investigate the textural properties and sensory qualities of cookies made from medium- and long-chain triacylglycerol (MLCT)-enriched margarines. Margarine with formulations of MLCT:palm olein:palm stearin, 60:30:10 and 70:20:10, were selected to produce cookies. The textural properties of cookies were determined using a texture analyser. Quantitative descriptive analysis (QDA) and acceptance test were carried out to describe the attributes and to evaluate the degree of liking of cookies, respectively.

RESULTS

Cookies made from MLCT-enriched margarines showed high values for hardness, fracturability, but also for cohesiveness and adhesiveness. Trained panelists rated the cookies made from MLCT-enriched margarines to be lower as compared to those made from commercial margarine for most of QDA attributes. However, cookies made from MOS 603010 and commercial margarines were scored similarly (P > 0.05) for all acceptance test attributes. Overall acceptability was found to be highly and negatively correlated for hardness, fracturability and cohesiveness (R(2) > 0.90). Principal component analysis showed that the taste attribute of cookies and the % solid fat content of margarine at 35 degrees C highly influenced the overall quality of the cookies.

CONCLUSION

Cookies made from MLCT-enriched margarines were not successfully produced. However, the findings obtained provide new perspectives in the production of low-calorie bakery fat.

Production of trans-free margarine stock by enzymatic interesterification of rice bran oil, palm stearin and coconut oil

BACKGROUND

Trans-free interesterified fat was produced for possible usage as a spreadable margarine stock. Rice bran oil, palm stearin and coconut oil were used as substrates for lipase-catalyzed reaction.

RESULTS

After interesterification, 137-150 g kg(-1) medium-chain fatty acid was incorporated into the triacylglycerol (TAG) of the interesterified fats. Solid fat contents at 25 degrees C were 15.5-34.2%, and slip melting point ranged from 27.5 to 34.3 degrees C. POP and PPP (beta-tending TAG) in palm stearin decreased after interesterification. X-ray diffraction analysis demonstrated that the interesterified fats contained mostly beta' polymorphic forms, which is a desirable property for margarines.

CONCLUSIONS

The interesterified fats showed desirable physical properties and suitable crystal form (beta' polymorph) for possible use as a spreadable margarine stock. Therefore, our result suggested that the interesterified fat without trans fatty acid could be used as an alternative to partially hydrogenated fat.

Trans fatty acids: current contents in Canadian foods and estimated intake levels for the Canadian population

Research conducted in the mid-1990s indicated that the levels of trans fats in Canadian diets were among the highest in the world. The consumption of trans fats raises blood levels of low-density lipoprotein (LDL)-cholesterol, while reducing levels of high-density lipoprotein (HDL)-cholesterol. In June 2007, Health Canada called on the food industry to voluntarily reduce levels of trans fats in vegetable oils and soft (tub)-margarines to < 2% of total fat, and in all other foods, to < 5%. Industry must show satisfactory progress by June 2009, or Health Canada might have to introduce legislation to ensure that recommended limits are achieved. Since 2005, Health Canada has been performing a national assessment of prepackaged and restaurant foods that likely contain trans fats. From 2005 to 2009, 1120 samples were analyzed, of which 852 or approximately 76% met the recommended trans fat limits. As a result of reformulation, most of the products had decreased trans + saturated fat content. The estimated average intake of trans fatty acids (TFA) in Canada significantly dropped from the high value of 8.4 g/day in the mid-1990s to 3.4 g/day (or 1.4% food energy) in 2008. However, this TFA intake of 1.4% of energy is still above the World Health Organization recommended limit of TFA intake of < 1% of energy, which suggests that the Canadian food industry needs to put more effort into reducing the TFA content in its products, especially in tub-margarines, donuts, and bakery products.

Investigation of the levels of some element in edible oil samples produced in Turkey by atomic absorption spectrometry

The element contents (Fe, Mn, Zn, Cu, Pb, Co, Cd, Na, K, Ca and Mg) in edible oils (olive oil, hazelnut oil, sunflower oil, margarine, butter and corn oil) from Turkey were determined using atomic absorption spectrometry after microwave digestion. The concentrations of trace element in the samples were found to be 291.0-52.0, 1.64-0.04, 3.08-1.03, 0.71-0.05, 0.03-0.01, 1.30-0.50, 84.0-0.90, 50.1-1.30, 174.2-20.8 and 20.8-0.60 microg/g for iron, manganese, zinc, copper, lead, cobalt, sodium, potassium, calcium, and magnesium, respectively. Cadmium was found to be 4.57-0.09 microg/kg. The high heavy metal and minerals accumulation levels in the samples were found in olive oil for Cu, Pb, Co, margarine for Fe, K, corn oil for Zn, Mn, butter for Na, Mg, sunflower oil for Ca and hazelnut oil for Cd, respectively.

[Application of extract from wild plants in guality antoxidants of oil production storage prolongs period]

In clause data on an opportunity of use of the natural antioxidants received from wild-growing vegetative raw material of Ussuriskaya taiga as antioxidants for a fatty basis of margarine. Is practically proved the role of entered antioxidants in change of periods of storage of oil production with biologically active substances.

The effect of a combination of plant sterol-enriched foods in mildly hypercholesterolemic subjects

BACKGROUND & AIMS

The purpose of this study was to evaluate the effect of low-fat products enriched with plant sterols in addition to a National Cholesterol Education Program step 1 diet on serum lipids and lipoproteins.

METHODS

This study was a double-blind, randomised, placebo-controlled cross-over design with a run-in period and 2 intervention periods, each lasting 4 weeks. A total of 46 mildly hypercholesterolemic subjects (age 50.6+/-9.8) completed the trial. The study products consisted of 20 g low-fat margarine (35% fat) and 250 ml low-fat milk (0.7% fat), in total delivering 2.3g plant sterols/d.

RESULTS

Serum total and low-density lipoprotein cholesterol were significantly reduced by 5.5% (p<0.001, 95% CI: 2.5; 8.3) and 7.7% (p=0.001, 95% CI: 3.4; 11.9), respectively, by plant sterol-enriched products compared to placebo. Serum apolipoprotein B was significantly reduced by 4.6% (p<0.05, 95% CI: 1.7; 7.5), and apolipoprotein B/apolipoprotein A-I by 3.4% (p<0.05, 95% CI: 0.1; 6.6) after plant sterol intake compared to the placebo supplement.

CONCLUSIONS

A combination of low-fat margarine and milk enriched with plant sterols significantly reduced low-density lipoprotein cholesterol, apolipoprotein B and the ratio of apolipoprotein B to apolipoprotein A-I in mildly hypercholesterolemic subjects, but had no effect on C-reactive protein and lipoprotein (a) concentrations.

SPONSORSHIP

Unilever Denmark A/S.

Dietary modeling shows that the substitution of canola oil for fats commonly used in the United States would increase compliance with dietary recommendations for fatty acids

OBJECTIVE

To examine the effect of substituting canola oil for selected vegetable oils and canola oil-based margarine for other spreads on energy, fatty acid, and cholesterol intakes among US adults.

DESIGN

Twenty-four-hour food recall data from the 1999-2002 National Health and Nutrition Examination Survey (NHANES) were used to calculate the effect of substituting canola oil for dietary corn, cottonseed, safflower, soybean, and vegetable oils described as "not further specified" and of canola oil-based margarine for other spreads at 25%, 50%, and 100% replacement levels.

SUBJECTS

Adult participants aged>or=20 years (n=8,983) of the 1999-2002 NHANES.

STATISTICAL ANALYSIS

Sample-weighted mean daily intake values and the percentage of subjects meeting dietary recommendations were estimated at the various replacement levels. Standard errors of the means and percentages were estimated by the linearization method of SUDAAN.

RESULTS

Significant (P<0.05) changes compared to estimated actual intakes included: saturated fatty acid intake decreased by 4.7% and 9.4% with 50% and 100% substitution, respectively. Complete substitution increased monounsaturated fatty acid and alpha-linolenic acid intakes by 27.6% and 73.0%, respectively, and decreased n-6 polyunsaturated fatty acid and linoleic acid intakes by 32.4% and 44.9%, respectively. The ratio of n-6 to n-3 fatty acids decreased from 9.8:1 to 3.1:1 with 100% replacement. Energy, total fat, and cholesterol intakes did not change.

CONCLUSIONS

Substitution of canola oil and canola oil-based margarine for most other vegetable oils and spreads increases compliance with dietary recommendations for saturated fatty acid, monounsaturated fatty acid, and alpha-linolenic acid, but not for linoleic acid, among US adults.

Use of margarine enriched in phytosterols by patients at high cardiovascular risk and treated by hypolipidemic drugs

BACKGROUND AND AIMS

The use of phytosterol-enriched margarines (PEM) in patients at cardiovascular risk has not been thoroughly explored. We determined the proportion of users of PEM in a population at high cardiovascular risk, and their characteristics. In addition, the correlates of using at least 25 g/d of PEM were identified.

METHODS AND RESULTS

Patients with at least two cardiovascular risk factors in addition to dyslipidemia (primary prevention) or with past cardiovascular disease (secondary prevention) were recruited by general practitioners (GPs). Baseline characteristics were collected from a computerized GP database linked to a survey. GPs recorded patterns of PEM use. First, users were compared with non-users. Then, analyses were conducted to identify characteristics of patients using PEM at a recommended dose (>or=25 g/d). Among 1631 patients with documented consumption, a minority used PEM (15.2%), and only 36.4% of consumers used it at recommended level. Overall, PEM users did not differ from non-users as to general characteristics, nor as to the level of cardiovascular risk in primary prevention. However, PEM users reported significantly more cardiovascular events among their parents (OR=1.4; 95% CI=[1.0-1.9]). Consumers who used at least 25 g/d of PEM were more likely to be men (OR=3.1; 95% CI=[1.6-5.8]), to be aged 60-74 (OR=3.0; 95% CI=[1.4-6.4]), or 75 or older (OR=4.0; 95% CI=[1.5-10.6]). Again, no difference was observed regarding the level of cardiovascular risk.

CONCLUSIONS

The level of use of PEM was low in this population of high cardiovascular risk patients. In addition, only a third of users consumed margarine at the recommended level. Our data suggest that pattern of use of PEM is not related to the level of cardiovascular risk.

Effects of margarine and butter consumption on distribution of trans-18:1 fatty acid isomers and conjugated linoleic acid in major serum lipid classes in lactating women

Trans FA (TFA) have at least one trans double bond and comprise several isomers and types, including many of the CLA (e.g., c9,t11-18:2 CLA). Some TFA may have adverse effects (e.g., cardiovascular disease), whereas some are thought to have beneficial effects (e.g., anticarcinogenicity). The presence of TFA in human tissues and fluids is related to dietary intake, although this relationship is not completely understood--especially in regard to serum lipid fractions. This study was conducted as part of an investigation designed to test the influence of butter (B), "low TFA" margarine (LT), and regular margarine (RM) on milk fat content. Here we tested the secondary hypothesis that consumption of B, LT, and RM by lactating women would result in differential distribution of TFA and CLA in major serum lipid classes. Breast-feeding women (n = 11) participated in this randomized Latin-square study consisting of five periods: intervention I (5 d), washout I (7 d), intervention II (5 d), washout II (7 d), and intervention III (5 d). Extracted serum lipid was separated into cholesterol ester (CE), TAG, and phospholipid (PL) fractions and analyzed for total and isomeric TFA and CLA concentrations. Data indicate that TAG consistently contained the highest concentration of total t-18:1. No interaction between treatment and fraction was found for any of the t-18:1 isomers identified. Absolute concentration of each t-18:1 isomer was greatest during the RM period, regardless of fraction. On a relative basis, concentrations of t10-18:1 and t12-18:1 were most responsive to treatment in the CE fraction. The concentration of c9,t11-18:2 CLA was highest in the TAG fraction and lowest in the PL fraction, regardless of treatment. In summary, these results indicate (i) that there is a differential distribution of some isomeric TFA and CLA among human serum lipid fractions and (ii) that dietary TFA intake influences absolute and relative concentrations of some of the isomers in selected fractions.

Phytosterol consumption and the anabolic steroid boldenone in humans: A hypothesis piloted

The presence of the anabolic steroid boldenone in animals has become a research topic as its occurrence is proposed to be a marker for illegal hormone administration. However, boldenone can also be formed from beta-sitosterol, a phytosterol present in animal feed, as well as from endogenous sources. The observations in animals together with the increased consumption of phytosterol-enriched foods in the Western population led the authors to the hypothesis that consumption of phytosterol-enriched foods might possibly lead to increased boldenone levels in humans. The authors performed a pilot study among female volunteers (n = 10) to investigate whether boldenone concentrations in urine were detectable after consumption of 25 g day(-1) of phytosterol-enriched margarines for 1 week. Urine samples were collected at days 0, 3 or 4, and 7. Urine of a sitosterolemia (a rare autosomal recessively inherited lipid metabolic disorder) patient was collected as a positive control case. No traces of boldenone were detected in either the volunteers or in the patient. In conclusion, there is no evidence of formation of boldenone in women after consumption of the recommended amount of phytosterol-enriched margarines.

Dose-response effects of different plant sterol sources in fat spreads on serum lipids and C-reactive protein and on the kinetic behavior of serum plant sterols

OBJECTIVE

To test the dose-response effect on low-density lipoprotein cholesterol (LDL-c) of plant sterols (PS) from different sources in a low-fat spread.

METHODS

Dose responses of soybean oil (BO), tall oil (TO) and a mix of tall oil and rapeseed oil (TO/RP) as fatty acid esters were tested in a parallel design in free-living subjects recruited from the general community who had elevated cholesterol concentrations. Subjects received either control for 6 weeks or 1.6 g PS per day for 3 weeks, then 3.0 g/day for 3 weeks.

RESULTS

LDL-c was lowered significantly by consumption of 1.6 g/day of PS (-10.4%, range -7.3 to -11.4%). Increasing the dose to 3.0 g/day modestly reduced LDL-c concentrations further to -14.7%. TO, containing 78% sitosterol, produced an increase in serum sitosterol of 6.5 nmol/ml, while BO, containing only 27% campesterol, produced an increase in serum campesterol of 9.5 nmol/ml in 6 weeks. After PS withdrawal, serum sterols declined by 50% within 2 weeks.

CONCLUSION

Different PS sources were equally effective in lowering serum LDL-c concentrations. The decrease in absolute concentrations of LDL-c was dependent on the baseline concentrations.

Effects of plant sterol and stanol ester consumption on lipid metabolism, antioxidant status and markers of oxidative stress, endothelial function and low-grade inflammation in patients on current statin treatment

OBJECTIVE

The present study was designed to examine for the first time, side-by-side, the effects of plant sterol and stanol consumption on lipid metabolism and markers of antioxidant status, oxidative stress, endothelial dysfunction and low-grade inflammation in subjects on stable statin-treatment.

DESIGN

Double-blind, randomized, placebo-controlled, intervention trial.

SETTING

University.

SUBJECTS

Forty-five patients on current statin treatment were recruited via newspaper advertisements. Data of 41 patients were used in statistical analysis.

INTERVENTION

Subjects consumed margarine with no added plant sterols or stanols for 4 weeks and were then divided into three groups of 15 subjects. For the next 16 weeks, one group continued with the control margarine and the other two groups with either a plant sterol- or stanol (2.5 g/day)-enriched margarine. Blood was sampled at the end of the run-in and intervention periods.

RESULTS

Plant sterol and stanol consumption significantly (P=0.026) reduced low-density lipoprotein (LDL) cholesterol by 0.34 mmol/l (95% confidence interval (CI), -0.67 to -0.04 mmol/l). No effects were shown on enzymatic and non-enzymatic antioxidants and markers of oxidative modification of lipids and DNA. In addition, no effect was found on soluble adhesion molecules, C-reactive protein and monocyte chemotactic protein-1 concentrations.

CONCLUSIONS

We conclude that 16 weeks of plant sterol or stanol consumption did not affect markers of antioxidant status, oxidative stress, endothelial dysfunction and low-grade inflammation in patients on stable statin treatment, despite a significant reduction of LDL cholesterol.

Customary use of plant sterol and plant stanol enriched margarine is associated with changes in serum plant sterol and stanol concentrations in humans

The consumption of products enriched with plant sterol or stanol esters lowers serum total and LDL-cholesterol concentrations, thereby most likely reducing the risk of coronary heart disease. However, using plant sterol (not plant stanol) enriched products elevates serum plant sterol concentrations in humans. This may be unwanted because health effects of elevated serum plant sterol concentrations are still controversial. Within postlaunch monitoring of functional foods, we compared serum plant sterol and plant stanol concentrations among users of plant sterol (n = 67) or plant stanol (n = 13) enriched margarines with those of matched nonusers (n = 81) in the ongoing Dutch Doetinchem cohort study. Subjects (aged 29-67 y) were examined in 1994-1998 (before the introduction of enriched margarines) and re-examined in 1999-2003. Serum concentrations of plant sterols and stanols were measured in samples from nonfasting subjects by GLC-MS. Intake of plant sterols was 1.1 +/- 0.6 g/d and was associated with a decrease of serum total cholesterol concentration of 0.25 +/- 0.91 mmol/L (4%, P < 0.05), a change that differed (P < 0.05) from the nonsignificant increase in nonusers (+2%, 0.12 +/- 0.78 mmol/L, P = 0.16). Cholesterol-standardized serum sitosterol and campesterol increased in plant sterol users by 22% (P < 0.0001) and 103% (P < 0.0001), respectively. Cholesterol-standardized serum sitostanol and campestanol increased in plant stanol users by 197% (P = 0.02) and 196% (P = 0.01). To our knowledge, these data are the first to show changes in serum cholesterol, plant sterol, and plant stanol concentrations after (long-term) consumption of plant sterol and stanol enriched margarines in a free-living population in a nonexperimental setting. Whether the increased serum sterol concentrations result in adverse side effects needs to be investigated in future postlaunch monitoring studies.

Correction of proton resonance frequency shift temperature maps for magnetic field disturbances using fat signal

PURPOSE

To improve the immunity of the proton resonance frequency shift (PRFS) method of MRI temperature mapping against magnetic field disturbances. Since PRFS is a phase-sensitive method, it misinterprets magnetic field disturbances as artifact temperature changes. If not corrected, the resulting temperature artifacts can completely obscure the true temperature estimation, especially if the temperature elevations are small.

MATERIALS AND METHODS

Since the fat protons experience the same magnetic field disturbances as the water protons, but no temperature-related frequency shift, the fat signal has been used for correcting PRFS temperature maps for the disturbances. A simple correction method is proposed that has either better compensation capability than the phase correction methods previously reported or higher spatial and temporal resolution than the spectroscopic correction methods previously reported. The evaluated method is based on the utilization of several gradient and spin echoes acquired within one repetition interval with water- and fat-selective scans.

RESULTS

In a series of phantom experiments, the improved method is shown to enable the reconstruction of accurate temperature maps in spite of interscan motion, suboptimal fat-water separation, and a wide range of magnetic field disturbances.

CONCLUSION

Our approach can be used for the guidance of thermal therapies involving tissues containing fat or surrounded by fat.

Similar serum plant sterol responses of human subjects heterozygous for a mutation causing sitosterolemia and controls to diets enriched in plant sterols or stanols

OBJECTIVE

We investigated the serum phytosterol responses of heterozygous relatives of sitosterolemia patients to diets enriched in phytosterols or stanols.

DESIGN

Randomized double-blind crossover design.

SETTING

Muenster, Germany.

SUBJECTS

Eight heterozygous and 13 control subjects were recruited. One heterozygote and three controls dropped out.

INTERVENTIONS

Seven heterozygotes and 10 controls received daily portions of margarine containing 2 g of plant sterols, 2 g of stanols or a control margarine for 6 weeks each in a randomized order. These phases were intercepted by wash-out periods of 6 weeks each.

RESULTS

Compared to the control period, serum phytosterol concentrations increased overall by more than 20% when subjects consumed the plant sterol margarine (F((1,15))=8.719, P=0.01), with no significant difference between heterozygotes (mean +14.5 (s.d. 17.2) micromol/l, +23.0%) and controls (+4.9 (9.9) micromol/l, +20.5%; F((1,15))=2.168, P=0.162), but decreased when subjects consumed the stanol-enriched margarine (F((1,15))=12.124, P=0.003), again to a similar extent in heterozygotes (-34.2 (41.2) micromol/l, -54.2%) and controls (-12.2 (9.2) micromol/l, -50.6%; F((1,15))=2.729, P=0.119). The lowest total serum concentrations of cholesterol and phytosterols were seen after the diet enriched in stanols. Serum stanol concentrations increased on this diet, but on a very low level and never exceeded 0.05% of serum cholesterol levels in any subject.

CONCLUSIONS

Serum phytosterol concentrations increased only moderately in heterozygotes consuming a diet enriched in phytosterols, indicating that they retained considerable capacity to excrete phytosterols even at higher intakes.

Consistency of use of plant stanol ester margarine in Finland

Objective:

The aims of this study were to investigate the consistency of use of plant stanol ester margarine and to characterise consistent and inconsistent users.

Design:

A cohort of plant stanol ester margarine users was established based on 14 national surveys conducted by the National Public Health Institute in Finland between 1996 and 1999. A follow-up study questionnaire was developed and sent to 1294 users in 2000.

Setting:

Subjects who reported using plant stanol ester margarine in both the original survey and the follow-up study were classified as consistent users, and the rest as inconsistent users.

Subjects:

The study population consisted of 1094 subjects aged 18–87 years, 590 men and 504 women.

Results:

There were 357 (33%) consistent and 737 (67%) inconsistent users of plant stanol ester margarine in the study population. Consistent users were more likely to be men and to have a higher household income than inconsistent users. Both consistent and inconsistent users were predominantly middle-aged persons with a healthy lifestyle and diet as well as a history of cardiovascular disease. Healthfulness was the main factor affecting bread spread choice among 94% of the consistent users and 59% of the inconsistent users.

Conclusions:

The use of plant stanol ester margarine is more often inconsistent than consistent. There is nevertheless a relatively large subgroup of long-term users of plant stanol ester margarine. It is important to examine the health effects especially among these regular users.