فصلنامه علوم تغذیه و صنایع غذایی ایران
سال ششم شماره 2 (پیاپی 21، تابستان 1390)

High prevalence of obesity is closely associated with a prominent rise in the incidence of hypertension, both of which result in a major increase in cardiovascular disease risk. Several studies also suggest obesity as a major risk factor for systemic inflammation. The purpose of this study was to determine associations between metabolic and anthropometric indicators on the one hand and serum levels of high-sensitivity CRP (hsCRP) and blood pressure in overweight and obese women on the other hand, as well as determine the predictors of hsCRP level and blood pressure in this population. Subjects were recruited by convenience sampling from health care centers and schools in Tehran in winter. From among volunteers 200 women meeting the study criteria were selected and their fasting blood samples collected. Dietary intake was assessed, anthropometric measurements were made, and the related laboratory tests (total cholesterol, triglycerides, glucose, and hsCRP) were performed. Pearson and Spearman correlation coefficients and multiple linear regression were used for statistical analysis. Serum levels of hsCRP were significantly associated with those of glucose(p=0.015, triglycerides (p=0.005), total cholesterol(p=0.002), body mass index (BMI)(<0.0001), waist circumference (WC)(p<0.001), and fat mass (FM) (p<0.0001). Also, systolic blood pressure (SBP) was significantly associated with serum levels of glucose(p=0.018), triglycerides (p=0.011), BMI (p<0.0001), WC(p<0.0001), FM(p=0.005) and WHR(p=0.049). In different regression models, WC and FM were found to be predictors of hsCRP (p= 0.020, 0.015), wheras BMI was a strong predictor of SBP (p <0.0001). This study demonstrates that waist circumference and fat mass are the predictors of hsCRP, while body mass index is the main predictor of systolic blood pressure, in Tehrani obese and overweight women with waist circumference more than 88cm.

Plant extracts are rich sources of natural antioxidant and antibacterial compounds. In recent decades, the need for using natural antioxidants in foods, pharmaceuticals and cosmetics has promopted extensive scientific research. The purpose of this investigation was to determine the antioxidant and antibacterial activities of shallot extract on shelf-life of vacuum-packaged gutted rainbow trout stored at 4±1˚C. Prepared fish were divided into two batches. One batch was treated by dipping in an aqueous solution of shallot extract, vacuum-packaged, and kept at 4±1˚C, serving as the treatment sample, and one batch was vacuum-packaged and served as control. Chemical (TVN, TBA, PV) and microbial (total viable count, psychrotrophic) tests were performed, pH measured, and sensory analysis done on all the samples kept for 20 days. Shallot extract delayed significantly (p<0.05) lipid oxidation in the treated sample, in which the psychotrophic bacteria and total viable counts also remained lower than the proposed acceptable limit (7 log cfu/g). Furtehrmore, microbial spoilage decreased significantly (p<0.05) in the treated, in comparison with the control, sample. According to sensory analysis results, treated samples were acceptable even at the end of the 20-day storage. The findings indicate that shallot extract exerts antioxidant and antibacterial effects on vacuum-packaged rainbow trout during storage and increases its shelf life.

Substituting dietary saturated fatty acid (SFA) with monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA), especially omega-3 fatty acids, both found in canola oil, can reduce the risk factors of cardiovascular diseases, particularly in postmenopausal women. The aim of this study was to compare the effects of canola oil with sunflower oil on blood pressure, lipid profile, apoproteins, lipoprotein (a), total antioxidant capacity, and CRP in hyperlipidemic postmenopausal women. We performed a double-blind randomized clinical trial on 44 hyperlipidemic postmenopausal women randomly divided into two groups receiving, daily for 8 weeks, either 30gr of canola oil or 30gr of sunflower oil. Blood samples were collected at baseline and after intervention and analyzed for serum triglyceride (TG), total cholesterol (TC), LDL-c, HDL-c, lipoprotein a [Lp (a)], apoproteinB (APOB), apoprotein A-I [APOA-I]، CRP, and total antioxidant capacity (TAC). Systolic and diastolic blood pressures were also measured and compared between the 2 groups at baseline and after intervention. There was a statistically significant decrease in diastolic pressure in the canola group, as compared to sunflower group, at the end of the period. The treatment also brought about a significant increase in HDL-c and significant decreases in the systolic blood pressure and TG/HDL-c in the canola group, whereas in the sunflower group mean serum LDL-c, TAC, and ApoB decreased significantly. The levels of ApoA-I, TC/HDL-c, and LDL-c/HDL-c decreased significantly in both groups. Further analysis of the data showed that there were no significant differences in Lp (a), CRP, and TAC between the two groups at the end of study. As compared to sunflower oil, canola oil has more desirable effects on diastolic blood pressure in hyperlipidemic postmenopausal women.

Doogh is an Iranian traditional beverage based on yoghurt. In this product, serum separation occurs during storage due to its low pH. In recent years, studies have been conducted on the stabilization of doogh using hydrocolloids. The objective of this study was to compare the effects of different species of gum tragacanth (Astragalus gossypinus, Astragalus rahensis, and Astragalus fluccosus) on the stabilization and rheological properties of this typical Iranian dairy drink during storage. Gum solutions were added to Doogh samples prepared from yoghurt made with skim milk. Phase separation was measured using graduated cylinders during storage (30 days), and particle size distribution at ambient temperature was determined by laser diffractometery. Furthermore, steady and unsteady rheological tests were carried out using a controlled shear rate rheometer (CSR) at 3°C. Finally, sensory analysis was performed with 30 panelists familiar with the product, using a 5-point hedonic scale. In the samples containing 0.3% (w/w) A. gossypinus no phase separation occurred during the 30-day period. The data on particle size distribution indicated that addition of gum tragacanth resulted in a reduction in the size of aggregated particles, specially in the sample containing A. gossypinus. The apparent viscosity in this sample was higher than in the other samples. Also, its sensitivity to frequency (range = 0.01-10 Hz) was much less, which is very important from an industrial point of view. In addition, based on the sensory evaluation data, the sample containing A. gossypinus was the most acceptable product. The higher content of uronic acid and insoluble part of A. gossypinus can be the most probable reasons for the stabilized dispersion caused by A. gossypinus as compared to that caused by the other two species at the same concentration (0.3% w/w) in doogh.

The risk of cardiovascular diseases among hemodialysis patients with energy-protein malnutrition (PEM) is higher compared to well-nourished hemodialysis patients. Traditional risk factors for cardiovascular diseases such as a high body mass index and serum total cholesterol cannot explain the high prevalence of cardiovascular diseases in hemodialysis patients with PEM. Therefore, the present study was designed to study the association of PEM with nontraditional risk factors of cardiovascular diseases in hemodialysis patients. A total of 291 hemodialysis patients were selected with systematic randoml sampling from among 2302 eligible adult hemodialysis patients in Tehran hospitals. The nutritional status of the patients was determined by subjective global assessment (SGA). In addition, dialysis malnutrition score (DMS) and malnutrition inflammation score (MIS) of the patients were determined and their dietary intakes assessed using a 4-day dietary recall including 2 dialysis days and 2 non-dialysis days. Also, after a 12- to 14-hour fast, an 8 mL- sample of blood was taken from each patient before dialysis and serum urea, creatinine, albumin, CRP, sICAM-1, sVCAM-1, sE-selectin, MDA, NO, endothelin-1, and Lp(a) were measured. The serum concentrations of CRP and sICAM-1 were significantly higher in hemodialysis patients with PEM as compared to those without PEM (p<0.01), whereas there were no significant differences in serum concentrations of sVCAM-1, sE-selectin, MDA, NO, endothelin-1 or Lp(a) between the two groups. In addition, compared to hemodialysis patients with PEM types IIa or IIb, those with PEM type I had significantly lower serum CRP and sICAM-1 levels (p <0.01). There were significant direct correlations between DMS and MIS, as two PEM indicators, with serum CRP and sICAM-1 (P <0.01). The results of the present study indicate that nontraditional risk factors of cardiovascular diseases do not increase in hemodialysis patients with PEM type I, whereas serum CRP and sICAM-1, two risk factors of cardiovascular diseases, increase in PEM type II, which is accompanied with inflammation.

In the recent years, the application of microwave–vacuum drying as a novel, effective, and low-cost method for dehydration of various foods has been investigated. Therefore, the objective of the present study was to evaluate the potential of this method in drying sour cherry, as well as to select an appropriate mathematical model for describing its drying kinetics. The experimental drying trials were performed at 4 nominal microwave power levels (360, 600, 840, and 1200 Watts) and 4 absolute pressures (200, 400, 600, and 800 mbar) using a microwave–vacuum dryer designed in our laboratory. The drying parameters were determined as functions of absolute pressure and microwave power. Moreover, the fitting rates of experimental data with seven semi-theoretical and empirical models based on R2, χ2 and RMSE values were determined and the most appropriate mathematical model was selected. The findings showed that the microwave power and the vacuum level play the major role in the drying rate of sour cherry, such that increasing microwave power and decreasing the drying chamber pressure reduce the drying time significantly. Moreover, the drying process occurred in the falling rate period. Comparison of different models showed that the Middili and co-workers model can be the most suitable model due to its having the highest R2 and lowest χ2, RMSE values. The findings of this study indicate that the drying process of sour cherry does not show any constant drying rate during dehydration using a microwave–vacuum dryer. Thus, microwave–vacuum drying has a high potential for dehydration of sour cherry and other food and agricultural products due to high efficiency and reasonably short proceesing times.

In order to prevent obesity it is essential to identify its determinants. This study aimed to assess the association between duration of breastfeeding and subsequent obesity among female adolescents in Najafabad, Isfahan, Iran.

In this cross-sectional study, data were collected on 550 female adolescents aged 15-18 years selected by multistage cluster random sampling from Najafabad high schools. Anthropometric measurements were made and the body mass index (BMI) was calculated. Information on duration of breastfeeding and other required variables was collected by interviewing parents using questionnaires. Overweight and obesity were defined on the basis of TOTF cut-points.

The mean (± SD) duration of breastfeeding was 19.7±8.1 months, and the prevalence of overweight and obesity 20.5% and 6%, respectively. Breastfeeding as such (that is, without considering its duration), was significantly associated with a reduced risk of overweight or obesity (25.8% for breastfed, vs 50% for non-breastfed, adolescent, P = 0.02). However, no statistically significant association was found between duration of breastfeeding and either overweight or obesity in the subjects (r= -0.007, P=0.87).

Our findings indicate that breastfeeding may reduce subsequent risk of obesity and overweight in female adolescents, although we found no association between duration of breastfeeding and adolescent overweight or obesity.

The use of edible coatings is a suitable method to reduce oil uptake in fried foods. In this research, the effects of soy-protein isolate (SPI) coating plasticized with sorbitol on oil uptake reduction and sensory and physical properties of deep-fat fried French fries were investigated.

Potato strips were coated with SPI plasticized with sorbitol at different concentrations. The effect of coating on oilp uptake reduction, water retention, crispiness and color change of French fries were determined, using response surface methodology. Moreover, the sensory acceptability of the tried potato samples was assessed.

The results showed that the protein and sorbitol concentrations are the major factors affecting water retention, oil uptake reduction, crispiness, and color of the fried potato samples. Coating resulted in oil uptake reduction and water retention up to 40%±2 and 80%, respectively. Nonsignificant differences in sensory characteristics of coated and uncoated samples were observed. The results showed that the models based on the response surface methodology are quite suitable for the evaluation of the effects of coating on the properties of french fries.

The application of soy-protein coating reduces oil uptake, while it does not affect the sensory characteristics, of fried potato strips. It is concluded, then, that SPI coating can improve the organoleptic and nutritional properties of fried food products.