JOURNAL OF NUTRITION SCIENCES & FOOD TECHNOLOGY
Year:2007 | Volume:2 | Issue:2|Papers Count:11

Background and objectives: Lipid abnormalities, especially high serum Lp(a) concentrations, are one of the major causes of cardiovascular diseases in hemodialysis patients. The present study was designed to investigate the effects of L-carnitine supplementation on serum lipids and apoproteins in hemodialysis patients with Lp(a) hyperlipoproteinemia.Materials and methods: The study was a randomized clinical trial in which 36 hyper Lp(a) hemodialysis patients (23 males and 13 females) with serum Lp(a) more than 30 mg/dl were randomly assigned to receive either a daily oral carnitine supplement of 1000mg (carnitine group) or no supplement (control group) for 12 weeks. At the baseline and the end of the period 5ml blood were collected after a 12 to 14-hour fast from each patient before dialysis and serum free carnitine, triglyceride, total cholesterol, HDL-C, LDL-C, apoAI, apoB100, Lp(a), IL-6 and albumin were measured. Results: As compared to the initial values, the mean serum free carnitine concentration increased significantly in the carnitine group at the end of the period (P<0.001), while serum triglyceride (P<0.05), total cholesterol (P<0.001) and IL-6 (P<0.001) decreased significantly. No significant changes were observed in the serum concentrations of free carnitine, triglyceride, total cholesterol and IL-6 in the control group. In addition, there were no significant differences between the 2groups as regards mean changes of the serum HDL-C, LDL-C, apoAI, apoB100, Lp(a), and albumin levels.Conclusion: The results of the present study indicate that an L-carnitine supplement has no effect on serum Lp(a) concentration in hemodialysis patients with Lp(a) hyperlipoproteinemia, but it may be effective in preventing cardiovascular diseases by reducing serum triglyceride and total cholesterol concentrations in these patients.

Background and objectives: Annual production of Doogh (a yoghurt drink) in Iran exceeds 120000 metric tons. Iran is probably a leading producer and consumer of this type of dairy-based product in the world. Separation of Doogh into 2 phases (serum separation) during storage is a major problem which affects its market share. The present study was undertaken to investigate the stabilizing effects of salep and tragantin gums (as local gums) and guar gum (as a commercial gum), added individually or in combination, to Doogh (containing 40% yoghurt).Materials and methods: Various gums (salep, tragacantin and guar), individually (concentrations 0.1–0.5%) and in combination (at ratios 50:50, 20:80 and 80:20) over a range of 0.1 to 0.2%, were added to samples of Doogh (composed of 40% stirred yoghurt, 59.3% tap water, 0.7% NaCl), and their physical stability (serum separation percent) were monitored over a period of 30 days at various storage temperatures (5 and 25 °C). In addition, some mechanical parameters, namely homogenization (up to 200 bars) and agitation speed (9000 and 11000 rpm for up to 2 min) of the samples, as well as their biphasic separation and rheological properties were determined. Sensory evaluation was also performed using semi-trained panelists and the 9-point hedonic scale procedure. Results: Our findings revealed that the individual gums could significantly reduce phase separation during storage (p <0.01). Gum tragacantin was the most effective, resulting in full stability of Doogh at a concentration of about 0.3%. Generally speaking, increasing the concentration of gums caused changes in the rheological behavior of the Doogh samples. Samples containing salep, tragacantin and guar gums showed a pseudo-plastic flow behavior, whereas in their absence, the Dooghs behaved as a Newtonian fluid. Mechanical operations, particularly agitation speed, led to a considerable reduction in the apparent viscosity of Doogh and, consequently, a significant increase in serum biphasic separation (p <0.01). In the organoleptic tests, the Doogh samples containing tragacantin and tragacantin-guar combinations received the highest scores.Conclusions: It is probable that the stabilizing effects of the gums, being non-absorbent hydrocolloids, were due to their viscosity-raising and water-holding properties. Moreover, mechanical operations (stirring and homogenization) could have disrupted the colloidal structure, leading to a decrease in viscosity and an increase in the biphasic separation.

Background and Objectives: Knowledge, attitude, and practice of bakers, as direct producers of bread, are considered as one of the factors that can be reflected ultimately in the quality of bread and the magnitude of bread wastage in the country. In an attempt to determine the causes of high bread wastage in the country, this study was conducted to assess the knowledge, attitude, and practice (KAP) of bakers in the city of Tehran regarding preparation, storage, and consumption of bread. Methods and Materials: The study included 472 bakers, from 236 bakeries in the city of Tehran chosen by systematic random sampling proportional to the populations of the 19 districts of the city. Data were collected through interviews using a KAP questionnaire.Results: Most of the bakers were aware of appropriate storage condition for flour (78.2%), importance of flour quality assessment (78%), importance of not adding baking powder to the dough (99%), most appropriate container for dough (72%), and appropriate methods of bread-baking (74%). More than half of the sample did not give correct answers to questions regarding yeast and sourdough. The bakers’ attitude towards using both types of yeast was negative in two-thirds of the cases. More than 50% were not satisfied with the appearance and price of bread they were producing; they believed that the price is high. About 24% were familiar with the two-stage baking process, and 41.5% did not perceive it as the preferred method. The bakers’ attitude regarding the different aspects of bread production and processing was significantly associated with their education level and service record, but not with their age. As regards the bakers’ practice, the findings showed that 25% actually used baking powder, while 34% did not give a clear answer to the questions on this subject. On the other hand, despite their indifferent (39%) or positive (27%) towards the use and storage of sour dough, 45-55% did not use industrial yeast or sour dough. The use of baking powder was related significantly with the type of bread, it is being highest in the case of, in ascending order, lavash, barbari, and taftoon, and lowest in the case of sangak and white bread. Conclusion: The bakers’ knowledge regarding preparation and leavening seems to be low, so they need to be educated about appropriate methods of dough-making and baking. Training programs for bakers in proper bread-baking methods and standards is required. Also, to ensure better practice, improving baking conditions and provision of better ingredients and equipment is a priority.

Background and objectives: Adolescence is a critical period of growth and development. Inadequate nutrition during adolescence may increase the incidence of non-communicable diseases in adulthood. This study was conducted to determine the prevalence of underweight, at-risk-of overweight, overweight, and stunting in adolescents, as part of a project entitled “Nutrition and health education intervention program to improve the school buffets and nutritional behaviors of guidance school students".Methods: A descriptive, cross-sectional study was carried out on 780 students from 12 public guidance schools in East Tehran. Schools were chosen based on their population size and students’ gender in north, south, east, west and central areas of the zone 4. Samples were selected using the systematical random method in each grade. A questionnaire was completed about demographic characteristics for each subject. Weight and height were measured and body mass index (BMI) was calculated. The Percentiles of underweight (( £5th), at-risk-of-overweight (85-95th), and overweight (³95th) were determined, and stunting was calculated based on height for age (£10th ) using the US CDC2000 BMI standards. Data were analyzed employing SPSS, the statistical tests being c 2, Fisher exact test, and T-test. Results: The mean age (years) of girls and boys were 13.3±1 and 13.3±0.95, respectively. Family size in 53.5% of the adolescents was £4. 43% of their fathers were employees, while the majority of their mothers (88%) were housewives. The highest level of parents’ education was high school diploma (34% and 39% of the mothers and fathers, respectively). The mean weight and height of the girls and boys were 48.3±11.9 Kg and 47.9± 13.3 Kg and 153.6±7.0 Cm and 153.4±10.1 Cm, respectively, and the mean BMI was 20.2±4.2.The data showed that 6% of the subjects were underweight, 12% at risk of overweight, 13% overweight, and 14.5% stunted.Conclusion: The prevalence of overweight and stunting among public guidance schools in East Tehran are high, which not only may affect their health but also will cause the community to confront problems as regards development, with serious challenges due to increased risk of non-communicable disease in future. Therefore, nutritional intervention programs using modern technology for this age group is required as one of the main priorities to obtain sustainable development in the country.

Background and objectives: The consumption of meat products is increasing in Iran. The use of sodium nitrite as an antioxidant, preservative and color fixative is very common in the meat industry, which is a cause of concern due to its hazardous effects in humans; it may also be considered as a toxicant and carcinogenic compound due to conversion into nitrosamine compounds. Considering these alarming facts, this study was designed to determine the changes of sodium nitrite residue in four types of processed red meat products during storage at 40C.Materials and methods: In this descriptive study triplicate samples of four types of heated red meat, with meat contents of 40%, 55%, 80%, and 90%, and containing 120 ppm added sodium nitrite, from an Iranian meat processing plant were investigated. During processing and storage at 40C for 87 days, the samples were analyzed for nitrite sodium residues, in duplicates, at 21 time points, according to AOAC method.Results: The initial sodium nitrite residue in all the 4 product types decreased significantly by the end of the 87-day period, as follows: in the 40%-meat sample, from 66 ppm to 21 ppm; in the 55%-meat sample, from 63 ppm to 20 ppm; in the of 80%-meat sample, from 53 ppm to 4 ppm; and in the 90%-meat sample, from 51 ppm to 3 ppm. The data also showed that, as regards the final nitrite residue levels, there was no significant difference between samples with 40% and 55% meat content, or between those with 80% and 90% meat content. However, significant decreases were observed between the 40%- or 50%-meat samples and the 80%- or 90%-meat samples.Conclusion: With respect to the hazards that may be caused by nitrite and its derivatives for human health, it is recommended that the acceptable level of nitrite be based on meat content of the processed products, taking into consideration its anti-microbial and organoleptic characteristics.

Background and objective: The third and the last stage in human growth and development is adolescence. Adequate nutrition of adolescent girls, these future mothers, is very important. The purpose of this survey was to determine association of such variables as age, age of menarche, nutritional awareness, physical activity, and family size, with the body mass index (BMI) in 14-18 year-old adolescent high school girls’ in Sari, north of Iran.Materials and methods: The sample size was 240. Weight and height were measured, and BMI was calculated and compared with the 2000 US Centers for Disease Control and Prevention (CDC) standards. Nutritional status was determined based on BMI, the categories being underweight, normal, at-risk-of-overweight, and overweight. Information on the nutritional knowledge, physical activity, age, family size, and age of menarche were obtained using questionnaires. ANOVA and Post Hoc were used to determine differences between the variables. Results: The nutritional status of adolescent girls had no significant association with the age of menarche, nutritional knowledge, or physical activity. However, significant relationships with family size and girls’ age were found.Conclusion: The results of this survey showed that in Iran, a developing country, family size has a considerable effect on the nutritional status of adolescent girls; furthermore, age was assessed to be an important factor influencing the nutritional status of adolescent girls.     

Background and objective: To test the hypothesis that an n-3 fatty acids (n-3) plus vitamin E supplementation is more effective than n-3 supplementation alone in improving the clinical, laboratory and inflammatory indices in patients with rheumatoid arthritis (RA).Materials and methods: A total of 55 RA patients (50 female, 5 male; mean age = 47±11y), in 3 groups, were included a double-blind randomized clinical trial. The groups were assigned to treatments as follows: group 1 (G1), placebo (2 g/d MCT oil + vitamin E placebo); group 2 (G2), n-3 fatty acids (1/2 g/d EPA/DHA) +vitamin E placebo; group 3 (G3), n-3 fatty acids (1/2 g/d EPA/DHA) + vitamin E (100 IU/d). Clinical, inflammatory, and laboratory indicators were determined at the baseline and at the end of the 6the and 12th weeks. Intra- and inter-group comparisons of the values obtained were made using repeated measure-ANOVA and ANOVA, respectively (p<0.05).Results: In G2 and G3, improvements in clinical, biochemical, inflammation, and oxidative indicators, as well as in the score of health status assessment (by interview) were more pronounced than in G1 (P<0.01). Also, compared to G1, at the end of week 12 there were higher improvements in morning stiffness and the score of health status assessment in G2 and G3 groups (P<0.05).Conclusion: Combination of n-3 fatty acids with vitamin E improved most of the clinical and laboratory indices in RA patients. However, there were no significant differences between G2 and G3 other than decreased oxidation and ESR.

Recently, nutrition scientists have tended prefer to assess diet-disease relations through dietary pattern approach rather than previous traditional approaches (nutrient- or food-oriented approach). Identifying dietary patterns allows us to consider the whole diet, not ingredients; a relationship helps to find associations beyond those described based on foods or nutrients. This approach is also beneficial when traditional analyses in nutritional epidemiology show weak associations. Dietary pattern approach is more realistic than the food- or nutrient-based approach. Inter-correlations and biological interactions between foods and nutrients confound the associations of single foods or nutrients with a certain chronic disease. Several studies have provided evidence supporting the use of dietary pattern approach in nutritional epidemiology. Most of these studies have indicated that dietary patterns identified by factor or cluster analysis are significantly associated with chronic diseases. Data on major dietary patterns in developing countries, including Iran, are scarce. This review aims to provide more detailed information about methods of measurement, as well as the advantages and disadvantages of dietary pattern approach to help and encourage nutrition scientists in the country to use this approach in future investigations.