فصلنامه علوم تغذیه و صنایع غذایی ایران
سال سوم شماره 4 (پیاپی 11، زمستان 1387)

Essential fatty acid deficiency has been found in diabetic patients. Omega-3 fatty acid supplementation could be beneficial in alleviating diabetes complications and glycemic control. However, it may increase oxidative stress. In this study the effects of omega-3 fatty acid supplements on glycemic control, total antioxidant capacity and antioxidant enzymes (superoxide dismutase and catalase) activities were investigated. In a double-blind, randomized, controlled clinical trial, 81 type-2 diabetic patients were divided into 2 groups. The experimental group took 2714 mg/day omega-3 fatty acids (1548 mg EPA, 828 mg DHA, and 338 mg other omega-3 fatty acids), and the control group took sunflower oil as a placebo, for 8 weeks. Dietary intakes were assessed by a 24h dietary recall, before and after intervention, and analyzed using food processor II. In addition, fasting blood samples were collected for analysis and height and weight were measured, initially and at the end of the trial. At the start of the study there were no statistically significant differences between the two groups with regard to mean weight, height, body mass index (BMI), daily intakes of energy, carbohydrate, protein, total fat, polyunsaturated fatty acids, fiber, vitamins A, B, C, E, folate, cobalamine, zinc, or biochemical parameters. Neither were there any difference in weight, BMI and dietary intakes before and after intervention in either group. The supplementation brought about a significant decrease (P<0.00) in HbA1c% in the experimental group, while in the control group the HbA1c level actually increased (p<0.02). Furthermore, the magnitudes of HbA1c changes were significantly deferent between the two groups (P<0.00). Changes in the fasting blood sugar (163.88 ± 10 vs. 165.6 ± 7.9 mg/dl), total antioxidant capacity (3.79 ± 0.07 vs. 3.62 ± 0.7 mg/dl), and activities of super oxide dismutase (449.22 ± 14.14 vs. 417.16 ± 11.9 U/gHb) and catalase (150.72 ± 9.6 vs. 151.86 ± 12.6 k/gHb) were not statistically significant. Omega-3 fatty acid supplementation may be helpful in glycemic control in type-2 diabetes, but it has no significant effect on the antioxidant enzyme activities.

Many studies have been carried out on structural and functional properties of gums from different sources. However, there is not much information available on the properties of gum exudates from different species of Astragalus. The objective of this study was to investigate and compare the chemical composition and rheological properties of two species of Astragalus under different conditions with regard to concentration, temperature and ionic strength.

Moisture, ash and protein contents of the samples were determined according to the Iranian official standards, while determinations of minerals were done using ICP-AES. All rheological measurements were made using Physica MCR 301 rheometer (Anton Paar). In addition, the flow behavior index (n) and consistency index (m) as parameters of power law model were computed, and the temperature dependency of consistency coefficient was assessed by fitting the Arrhenius model.

The moisture and ash contents of A. floccosus were higher, and its protein content was lower, than those of A. rahensis. At all concentrations and temperatures, the results of apparent viscosity versus shear rate for each two species were found to exhibit a clearly shear thinning behavior. At all concentrations and temperatures and shear rates, A. floccosus had a higher apparent viscosity. At similar concentrations and temperatures, the magnitudes of parameters (m) and (n) for the A. floccosus was, respectively, higher and lower than that of the A. rahensis.

In different food processing operations (stabilizing of soft drinks, using fat replacers, microencapsulation, and appropriate mouthfeel), the use and application of gums is based on the exact knowledge of their functional properties. In this study, it has been shown that different species of gum tragacanth have different characteristics. Therefore, in the processing of different foods (dairy, cereal, soft drinks, sauces, etc.), appropriate species of gum tragacanth should be selected and used.

As previous studies on the association between obesity and cardiovascular (CVD) risk factors have been made in limited populations, this study was performed to determine the association in 3 cities in the central parts of Iran. In this cross-sectional study, data collected in the1st phase of the Isfahan Healthy Heart Program (IHHP), involving 12514 subjects ≥19 years old, conducted during 2000-2001, in Isfahan and the Central Provinces of Iran, were analyzed. Fasting blood sugar (FBS), 2-hour post-load plasma glucose (2hpp), serum lipid profile, anthropometric parameters and blood pressure were determined by standard methods. FBS, 2hpp, serum lipids fractions (except for HDL-C) and blood pressure had significant positive relations with body mass index (BMI) and waist circumference (WC) (all p-values<0.001). As compared to the 1st quartile of WC, odds ratios (OR; 95%CI) of hypertension, diabetes and dyslipidemia in the 4th quartile were 2.8 (1.2-3.3), 3 (1.6-4.3) and 2.4 (1.9-3.1) in men and 2.5 (1.8-3.4), 2.7 (1.3-3.8) and 2.5 (2-3.2) in women, respectively. Also, ORs (95%CI) of hypertension, diabetes and dyslipidemic in 4th quartile of BMI, as compared to the 1st, were 1.6 (1.2-2), 2.8 (1.7-3.9) and 3 (2.4-3.8) in men and 1.9 (1.4-2.4), 2.6 (1.4-3.7) and1.6 (1.2-2) in women, respectively. ORs of these risk facrors increased with increasing WC and BMI. Therefore, it is concluded that both obesity indicators increase the chance of CVD risk factors.

Multi-purpose shortenings are of high importance in food processing technology due to their applications in manufacturing bakery and confectionary products and frying. Since shortenings are one of the main dietary sources of trans fatty acids, which have been shown to increase risk of coronary heart diseases, the aim of this research work was to produce, at a lab-scale, a zero-trans fatty acid multi-purpose shortening by chemical interesterification. A 40:60-blend of fully hydrogenated soybean oil (soy flakes) and sunflower oil was prepared and dried for 30 minutes at 110ºC and 30 mmHg. The blend was then subjected to chemical interesterification reaction at 90 ºC with 0.2% sodium methoxide as catalyst for 45 min. To inactivate the catalyst and end the reaction, an aqueous 20%-citric acid solution (2%) was added. The interesterified blend thus obtained was dried in 3 steps, including filtration under vacuum, drying at 110ºC for 10 min and, finally, centrifuging at 3500 rpm for 15 minutes. After bleaching and deodorization of the interesterified blend, its physical and chemical characteristics were determined, and two samples of a multipurpose shortening were formulated by adding 10% and 20% palmolein to the interesterified blend and the qualitative characteristics of the final products were evaluated. Interesterification reaction significantly lowered the melting point and SFC in the oil blend. The reaction also brought about randomization of the triglyceride structure. The trans fatty acid content of the shortening samples was about 1%, which can, thus, be categorized as zero-trans. In addition, the melting point, SFC, peroxide value, oil stability, moisture and volatile contents, color, smoke point, and other characteristics of the shortening samples conformed with the multi-purpose shortening standards. Results show that by chemical interesterification zero-trans multi-purpose shortenings can be produced, which could be used a substitute for hydrogenated vegetable oils in manufacturing a variety of food products.

The translation of estrogen receptor-α (ERα) is vital in therapeutic regimens in breast cancer. The repression of its expression could be attributed to regional CpG island methylation in exon1. We aimed to explore the association of plasma levels of folate, vitamin B12 and total homocysteine (tHcy) with the hypermethylation status of ERα genes in breast cancer patients. The hypermethylation status was determined in dissected tissues from 137 primary breast cancer patients aged 28-85 years, using methylation-specific PCR. In addition, the plasma levels of folate and vitamin B12 of the patients were assessed by automated chemiluminescence, and their total plasma homocysteine was determined by HPLC. The logistic regression analysis was used for analyzing the data after adjusting for potential confounding factors. Hypermethylation at ERα was observed in 51.1% of the participants. It was related positively to smoking history and duration of exposure to estradiol, and inversely with ER translation. After adjustments for confounding factors, an inverse association was also found between the hypermethylation status of ERα gene and the plasma levels of folate (OR=0.187; 95%CI, 0.052-0.668) and vitamin B12 (OR=0.185; 95%CI, 0.036-0.953). The data also showed that the risk of hypermethylation at ERα gene increased with the high plasma levels of tHcy (OR=9.61; 95%CI, 1.26-73.2). It may be concluded that a high plasma tHcy level can potentially increase the risk of hypermethylation of the ERα gene, while plasma folate and vitamin B12 levels may reduce the risk, in cancer patients

A key target of the Millennium Development Goals (MDG) toward eliminating poverty and hunger is to reduce malnutrition among children less than 5 years. Over the past 20 years developing countries have experienced accelerated urbanization and an increase in the incidence of overweight and obesity as a consequence. Monitoring progress of countries toward the MDG requires reliable data on the growth status of children at the national level. The purpose of this study was to determine the prevalence of stunting, underweight, wasting, overweight and obesity among under-five-year-old children of the Iranian households included in the National Comprehensive Study on Household Food Consumption Patterns and Nutritional Status (2000-2002). Data from 7158 households, with a total of 2562 under-five-year-old children, selected through random systematic sampling from 28 provinces, were included in the study. Trained nutritionists measured weight (with Seca digital balance, to the nearest 100gr) and height (using tape, to the nearest 0.1 cm) of all the household members during three consecutive days, using standard protocols. Age was documented in months, based on birth certificates. For children under two years, weight was based on the mean of two weighings, and recumbent length was measured. Undernutrition was defined as less than 2 standard deviations (2SD) of weight-for-age, height-for-age and weight-for-height z-scores, and overweight+obesity as higher than 2SD. The results were expressed based on weighted means of the total country, rural, and urban areas, and for both sexes. The total prevalence of stunting was 13.1% (CI 95%: 11/8%-14.4%) and of underweight 7.6% (CI 95%: 6.6%-8.6%). Prevalences of stunting and underweight in rural areas were twice those in urban areas. There were statistically nonsignificant gender differences: the prevalences of stunting and underweight were, respectively, 14.2% and 7.3% among boys, and 11.8% and 8.0% among girls. Wasting and overweight were less prevalent–the proportion of wasting was 4.5% and of overweight+obesity 5.2%; the prevalence of the latter was similar in rural and urban areas but it was higher among girls. Finally, the prevalence of wasting in urban areas was twice that in rural areas. According to the WHO classifications based on underweight, stunting and wasting rates, Iran is grouped with the countries having low prevalence rates. The high prevalence of overweight in children must be taken seriously, and it is absolutely esential to pay sufficient attention to both ends of the malnutrition spectrum. The findings of this study indicate that in order to achieve the millennium goals, improvements in living standards and the quality of diets is essential.

Iron deficiency anemia is one of the most prevalent nutritional deficiencies in the world, as well as in Iran. A solution to this problem is fortification of foods with iron. In this study the possibility of milk fortification with microencapsulated iron was investigated. Two kinds of iron salts were microencapsulated by two novel methods, and the efficiencies and optimum conditions of the methods were compared. Then, milk fat oxidation, color indices and sensory characteristics of the fortified milks during storage for 3 days at 4 OC were studied. Maximum efficiency (ME) was obtained with microcapsules with a ratio of iron ion-to-lipid (0.04) and a 5 molar % of Tween 80 in the liposome method (ME=85.5%), and at ratio of polyglycerol monostearate-to-iron salt of 15 to 1 in the F.A.E. method (ME=81.8%). The minimum and maximum milk fat oxidation was observed in milks fortified with irons microencapsulated by F.A.E. and plain iron, respectively. From a sensorial point of view, there was no difference between milks fortified with iron microencapsulated by F.A.E. at a concentration of 7 mg L-1 and control. Based on the findings of the present study, it can be concluded that the F.A.E. method, due to its simplicity, low cost, reasonableness, rapidness of the process, as well as higher stability of the microcapsules obtained, is an appropriate method for iron microencapsulation and fortification of pasteurized milk.

There is growing evidence indicating the benefits of Lactobacilli and Bifidobacteria in attenuation of colitis. On the other hand, some studies have shown that n-3 fatty acids can ameliorate inflammation in colitis. The aim of this study was to examine the interaction between different dietary oils and intestinal microflora in an experimental model of colitis. Eight week-old BALB/C mice (n=9) were fed isocaloric diets varying only in fat composition for 4 weeks. A group fed the chow diet served as control. The diets contained 20% fat from fish oil, canola oil, safflower oil, or beef tallow. Colitis was induced by intracolonic administration of acetic acid on day 21. Inflammation, fecal microflora and serum lipid profile were compared among the groups one week after induction. The highest degree of inflammation was seen in the chow-diet group, followed by safflower-, canola-, and fish oil-fed groups (p<0.05). As compared to the experimental groups, the number of fecal bacteroideceae was significantly higher (p<0.05), and the number of fecal bifidobacteria significantly lower, in the control group (p<0.05). Moreover, fish oil could reduce the plasma level of triacylglycerole significantly (p<0.05). These results indicate that n-3 fatty acids can affect intestinal microfloral populations in favor of increasing the number of bifidobacteria. They might be recommended as an adjunct therapy to patients with colitis.