فصلنامه علوم تغذیه و صنایع غذایی ایران
سال چهارم شماره 3 (پیاپی 14، پاییز1388)

Hypercoagulability is an important risk factor for thrombosis and its complications such as ischemic heart disease, stroke and arteriovenous fistula failure in hemodialysis patients. The present study was designed to investigate the effects of L-carnitine supplement on plasma coagulation and anticoagulation factors in hemodialysis patients. The study was a double-blind randomized clinical trial. Fourty-two hemodialysis patients (25 females and 17 males) were randomly assigned to either a carnitine or a placebo group. The patients in the carnitine group received orally a vial containing 1000 mg L-carnitine daily for 12 weeks, while the placebo group received a corresponding placebo vial. At baseline and at the end of week 12 of the study, 8.5 ml blood was collected from each patient after a 12- to 14-hour fast before dialysis and plasma fibrinogen concentration, activity of plasma protein C, coagulation factors V, VII, IX, and serum concentrations of tPA, PAI-1, free carnitine and CRP were measured. In the carnitine group the mean serum free carnitine concentration increased significantly 150%, while the plasma fibrinogen and the serum CRP decreased 98 mg/dl and 41%, respectively, at the end of week 12, as compared to the baseline value (P<0.001). The reductions were significant as compared to the placebo group (P<0.05). No significant differences were observed between the two groups with regard to mean changes in the activity of plasma protein C, coagulation factors V, VII, IX, and serum PAI-1-to-tPA ratio. The results of the present study indicate that L-carnitine supplement can reduce serum CRP, a systemic inflammatory indicator, and plasma fibrinogen, an inflammation-related coagulation factor, in hemodialysis patients, while it has no effect on coagulation and anticoagulation factors not related to inflammation.

Probiotic dairy products with their valuable nutritional and therapeutic properties, whose positive effects on human health have been confirmed, present one of the most controversial issues globally in the current domains of industry, nutrition and medicine. In order to have an upward trend in the promotion of the production and consumption of such products, it is essential for them to have desirable sensory and textural characteristics and preserve the probiotic strain at the defined level during shelf life. Doogh, an Iranian milk drink, is a popular fermented drink in Iran, the probiotic content of which can promote community health. The objective of this study was to determine the effects of Lactobacillus acidophilus La-5, as the probiotic bacterium, on microbial characteristics, post-acidification rate, and overall sensory acceptability of Doogh. In this research, in addition to commercial yoghurt culture (YF-3331), Lactobacillus acidophilus La-5, a probiotic bacterium, was used to produce probiotic Doogh, and alteration of probiotic bacterium and yoghurt culture bacteria (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus), acidification, phase separation, and its sensory acceptability were evaluated during its twenty one-day storage at 4 °C and compared with the blank produced without probiotic strain. The bacterial counts of the three bacteria reduced during cold storage. However, the probiotic bacteria, having the reduction of 0.93 log cycle/ml, could stand above the optimum level during the given time. Comparison between the probiotic Doogh and the blank showed that this bacterium could enhance the bacterial population reduction rate, reduce post- acidification, and improve the overall acceptability during storage. The addition of L. acidophilus did not have any significant effect on the textural stability of the probiotic sample, as compared to the blank. The percentage phase-separation of the 2 samples was high on days 1 to 7 of storage and then slowed down. The results demonstrated that Lactobacillus acidophilus La-5, as a probiotic bacterial strain, can be used in the production of Doogh with a pH=4.30, a salt content of 0.8 % (w/v) and a total solid content=7.4 % and it could enhance the yoghurt bacterial population reduction during storage. Thus, the probiotic Doogh produced was assessed as desirable with regard to the L. acidophilus viability, post-acidification reduction, overall sensory acceptability, and textural stability.

Nutrition transition in developing countries leads to coexistence of stunting and overweight. This study aimed to determine the prevalence of stunting-cum-overweight and its association with socio-demographic characteristics of parents in the Iranian Khoy City school children. This cross-sectional analytical study was conducted in two phases. In the first phase, 4400 students, 6-12 years old, in Khoy City, Iran were recruited by the stratified random sampling method. In the second phase, based on CDC2000 standards, 54 students suffering simultaneously from overweight (body mass index≥85 percentile) and stunting (height percentiles ≤15) were chosen as the case group and 115 non-overweight and non-stunted students as controls. The case and control students were matched with regard to age, sex and school. Socio-demographic status of the families was determined by interviewing the student's mothers. The prevalence of overweight, stunting and overweight-cum-stunting was 15.4%, 19.5% and 1.2%, respectively. The case and control group students were similar with regard to parent's age, height, educational level, occupation, familial diabetes history, and father's BMI. The logistic regression model, after adjusting other variables, suggests that familial stunting history compared with non-familial stunting history (OR=2.2; P<0.05), mother's BMI ≥30 compared with BMI<30 (OR=2.8; P<0.01), and owning a house compared with having a rented house (OR=2.3; P<0.05), had positive associations with stunting-cum-overweight status. All together, stunting in school-age children in Khoy City is more prevalent than overweight and is associated with genetic, environmental and economical factors. Further, prospective investigations are required to confirm such associations and find causal relationships.

Edible coatings are thin layers of edible biopolymers applied on the surface of foods as protective coatings. There has been a great interest in production of edible films and coatings from biopolymers in recent years. The most widely used edible and biodegradable films are cellulose derivatives. The objective of this research was to investigate the effects of adding 4 plastisizers, namely, glycerol (Gly), polyethylene glycol400 (PEG400), palmitic acid (PA) and GLY+PA, on some mechanical and physicochemical properties of edible methylcellulose (MC) films.

Edible films were prepared from methylcellulose (MC) and plasticized with Gly, PEG400, PA or GLY+PA. Then the water vapor transmission rates (WVTR), tensile strength (TS), percent elongation (E), and percent soluble matter (SM) of the plastisized films were measured.

Tensile strength of the plasticized MC films was significantly lower than that of the pure MC films (p<0.05), while percent elongation of MC films containing Gly or PEG400 was significantly higher than that of the pure MC films and films containing PA (p<0.05). WVTR and percent SM of the films plasticized with PA roPA + GLY were significantly lower than those of the pure MC films and the films containing Gly or PEG (p <0.05).

The results of the present study indicate that pure MC films were very brittle. Plasticizers with low molecular weights (Gly) were most effective with regard to decreasing TS and increasing percent elongation of the MC films. On the other hand, plasticizers with higher molecular weights (PA) produced the greatest effect as regards decreasing WVTR of the MC films. PA + GLY is more suitable for applications that require a lower permeability to water vapor, such as coatings on the surface of fruits.

Proteins, as antioxidant compounds, can protect cells against free radical-induced damages. This study was conducted to investigate the protective and antioxidant effects of soy protein isolate (SPI) in acute liver failure in rats. In this experimental study, 48 rats were randomly divided into 3 groups. Groups 1 and 2 were put on a 20 % casein- and group 3 on a 20 % SPI-diet. Liver injuries were induced by injection of dimethylnitrosamine (DMN) (30mg/ml per kg, ip) in groups 2 and 3. Biochemical parameters [serum aspartate amino-transferase (AST), alanine amino-transferase (ALT), alkaline phosphatase (ALP), total protein, albumin, total bilirubin, and malondialdehyde (MDA)], as well as histopathological changes in liver tissue, were assessed at the end of the study. Dietary SPI resulted in decrease in ALT (270.2±493.6 IU.L-1) (P<0.05) and increase in serum albumin (4.3±0.7 g.dl -1) and MDA (8.5±1.7 nmol.ml-1) levels (P<0.05). SPI did not have significant effect on other factors. Histopathological findings indicated that SPI led to improvement of the damage and rapid hepatocyte regeneration. Results of our study suggest that an SPI diet can improve acute liver damage and reduce DMN-induced complications.

There usually are energy intake reporting errors in dietary assessment methods. Therefore, it is important that such methods be validated for energy intake. In this study, we identified energy intake misreporting among women based on the Goldberg formula [the ratio of reported energy intake (EI) to resting metabolic rate (RMR) measured by indirect calorimetry (EI/RMR)] and compared dietary patterns of all the participants with those of plausible reporters. This cross-sectional study included 187 healthy women aged 18 to 45 years. The ratio EI/RMR was used as an indicator of reporting accuracy (EI/RMR<1.35 was considered to represent underreporting, and an EI/RMR≥2.4 as over reporting, of EI). Dietary intake was assessed by a semi-quantitative 125-item food-frequency questionnaire. The food items were classified into 39 food groups. In addition, lifestyle and anthropometric data were gathered using questionnaires. A cluster analysis and ANOVA were used for data analysis. Under-reporters (n=66), with a low consumption of most food groups, were more likely than plausible reporters (n=107) to be overweight and older. Three dietary patterns, i.e., healthy, unhealthy, and mixed, were identified for all reporters and named according to their most recurrent food groups, while two dietary patterns were determined for plausible reporters, i.e., healthy and unhealthy. The proportion of under-reporters was 16.9% in the healthy cluster, 49.4% in the unhealthy cluster, and 34.7% in the mixed cluster (P<0.01). Individuals may not accurately report dietary intake. Age and body mass index may influence the relative accuracy of energy intake reporting among Iranian women. Researchers conducting dietary pattern studies should consider the possibility of misreporting errors before making decisions about dietary adequacy.

Cardiovascular diseases (CVD) are one of the major causes of death. High blood cholesterol increases CVD risk. Consumption of high-cholesterol foods increases blood cholesterol. Therefore, limiting consumption of such foods, or reducing their cholesterol content, will lead to a reduction of CVD risk. Different methods have been presented for cholesterol reduction in foods. The objective of this study was to reduce the cholesterol content of butter oil by using soybean lecithin. Twenty ml distilled water and different amounts of lecithin (5, 7.5, 10, 12.5, 15, 17.5 and 20%) were added to 100g melted butter oil, and the resulting mixtures were stirred. The hydrated lecithin thus obtained was then removed by centrifuge. In addition to the lecithin concentration, effects of stirring speed (200, 400, 600, 800 and 1000 rpm), stirring time (15, 30, 45, 60, 75 and 90 minutes), centrifuging speed (2000, 2200, 2400, 2600 and 2800 rpm), and centrifuging time (5, 10, 15, 20 and 25 min) on the magnitude of cholesterol reduction were studied. Chemical (acid, peroxide, and saponification values) and physical (refractive index and melting point) characteristics of the low- cholesterol butter oil were compared with those of untreated butter oil. Increasing the lecithin concentration up to 17.5% and stirring time up to 75 minutes led to a higher cholesterol reduction. However, longer stirring time decreased significantly the magnitude of cholesterol reduction (p<0.05). The data showed a linear relationship between the magnitude of cholesterol reduction on the one hand and the stirring speed and centrifuging speed and time on the other. As regards the chemical and physical characteristics, only the acid value of the low-cholesterol butter oil was higher than that of the untreated butter oil. Other characteristics of the 2 butter oils were not significantly different. Based on the findings of this study, the optimum conditions for cholesterol reduction of butter oil are a lecithin concentration of 10%, a stirring speed of 600 rpm, a stirring time of 45 min, a centrifuging speed of 2400 rpm, and a centrifuging time of 15 minutes. Under these conditions, the cholesterol content of butter oil can be reduced by 78.6%.