فصلنامه علوم تغذیه و صنایع غذایی ایران
سال نهم شماره 2 (پیاپی 35، تابستان 1393)

Type-2 diabetes is a prevalent metabolic disorder characterized by both insulin deficiency and peripheral insulin resistance. This study was undertaken to determine the effects of omega-3 fatty acid-fortified soymilk fermented with bifidobacterium lactis on the body weight, blood glucose and lipid profile of diabetic rats. Diabetic rats were divided into four groups (one being diabeteic control); a fifth group was added as a normal control. The two control groups (normal control and diabetic control) received, by tube-feeding, 1 mL/day of distilled water, while the three diabetic groups received 1 mL/day of soymilk (SM), fermented soymilk (FSM) and fermented soymilk fortified with omega-3 fatty acids (FSM+omega-3). Body weight and blood glucose were monitored weekly and the lipid profile was measured at the end of the 28-daty period. As compared with the diabetic group, administration of SM, FSM and FSM+omega-3 for 28 days led to statistically significant (p<0.05) reductions in blood glucose, total cholesterol and triglyceride concentrations, with the maximum reduction in the FSM+omega-3 fatty acid group. In addition, as compared to the diabetic group, body weight in the 3 treated groups receiving the SM, FSM and FSM+omega-3 fatty acids increased significantly (p<0.05), the maximum weight gain being in the FSM+omega-3 fatty acid group. The findings suggest that fermented soy milk fortified with omega-3 fatty acids may be beneficial in preventing or delaying the progression of type-2 diabetes.

By using molecular methods, e.g., polymerase chain reaction (PCR), it is possible to detect and differentiate the milks of closely related species (such as sheep and cow) in dairy products. The aim of the present study was to develop a specific PCR method for identification of cow's milk fraudulently used in making sheep cheeses (Lighvan Brand). Eighteen different samples of sheep cheeses (Lighvan Brand) claimed on the label to be 100% sheep cheese were collected from supermarkets in Tehran city. Total genomic DNA was extracted from all the samples. PCR was optimized for detection of specific cow's DNA in the sheep cheese samples based on amplification of mitochondrial cytochrome b gene (using the specific cytochrome b gene primer). The results were tested on a 2% agarose gel. Using the optimized PCR reaction based on amplification of the mitochondrial gene, 274 bp fragments of cow's DNA and 336 bp fragments of sheep’s DNA were obtained. The results demonstrated that cow's milk could be detected in 11 of the 18 brands tested. Thus, adulteration by the company was confirmed. The proposed PCR assay is a rapid, robust and reproducible method for the detection of adulterations in sheep cheese and other dairy products.

Although whole-grain foods have been reported to affect the metabolic profile, limited data are available in this regard on children. The present study aimed to determine the effects of whole-grain consumption on fasting blood glucose and lipid profile of overweight or obese children. This randomized cross-over clinical trial included 44 overweight or obese (BMI>85th percentile for age and sex) girls aged 8-15 years. After a 2-week run-in period, the subjects were randomly assigned to either an intervention or a control group. The subjects in the intervention group were given a list of whole-grain foods (dark bread (sangak and barbari), brown rice, whole-meal biscuits, wheat germ, wheat bran and cornflakes) and asked to choose and consume 50% of their daily grain servings, for 6 weeks, from among whole-grain foods. Those in the control group were given similarly a list of whole-grain foods and asked not to consume any of those foods during the intervention phase of the study. A 4-week washout period was applied following which the subjects were crossed over to the alternate arm for an additional 6 weeks. Fasting blood samples were taken before and after each phase of study for biochemical measurements and metabolic profile determination. Mean (±SD) age, body mass index, systolic and diastolic blood pressures of the subjects were 11.2±1.49 years and 23.5±2.5 kg/m2, 111.4±9.7 and 66.4±9.1 mmHg, respectively. After 6 weeks we found significant effects of consuming whole-grain foods on plasma glucose (changes from baseline in the intervention group -1.9 vs. 3.8 mg/dL in the control group, P=0.01), serum triglycerides (changes from baseline in the intervention group -16 vs. 7 mg/dL in the control group, P=0.01), and serum HDL-cholesterol levels (changes from baseline in the intervention group 6.3 vs. -5.6 mg/dL in the control group, P=0.05). Whole grain intake had no significant effect on serum total and LDL-cholesterol concentrations or blood pressure. This study provides evidence supporting the beneficial effects of consuming whole-grain foods on the serum levels of fasting blood glucose and lipid profile (TG and HDL) in obese or overweight children.

Food gums are a class of food additives playing various roles, such as thickening, gelling and stabilizing of the food aqueous solutions. In this study, the best conditions for quince seed gum extraction and its rheological characteristics were determined. The effects of temperature range (25-80 ºC), pH (3-11) and water-to-seed ratio (50-120 w/w) on the yield of quince seed gum extraction were optimized by statistical analysis using response surface methodology (RSM). Rheological properties of the quince seed gum, such as strain sweep and frequency sweep, were determined with a rheometer (Anton Paar, MCR300, CC27), while for determination of intrinsic viscosity and Huggins constant capillary viscometer was used. Based on the response surface methodology, temperature and water-to-seed ratio affected the quince seed gum extraction yield significantly (p< 0.05). The maximum extraction yield occurred at a temperature of 60.77 oC, a water-to-seed ratio of 96.2 (w/w), and a pH of 6.6. The Cross model fitted the data with a regression more than 0.98. The slopes of the lines for the dilute and semi-dilute regions and critical concentration occurred at a concentration of 0.6%, 2.0% and 0.077%, respectively. The linear viscoelastic range of the gum solution (0.3%) deviated from linear route at strain 11.4%. Loss and storage moduli of the gum solution (0.3%) were frequency dependent. The intrinsic viscosity and Huggins constant were found to be 1530 and 0.31, respectively. Quince seed gum has a high extraction yield, strong gelling structure, and hydrodynamic volume. It can, therefore, be used as a thickener in food products.

Breastfeeding has desirable effects on many risk factors of cardiovascular diseases. Therefore, it seems necessary to investigate the effect of breastfeeding on cardiovascular fitness. The aim of present study was to determine effects of breastfeeding and its duration on cardiovascular health in children aged 7-8 years old. In this historical cohort study, 246 children aged 7-8 years old in both sexes with no history of cardiovascular, renal, or liver diseases were recruited. Based on the type of feeding in infancy, they were divided into 3 groups − children breastfed for more than 6 months, those breastfed for less than 6 months, and those formula-feed. Cardiovascular fitness was determined by treadmill ergometric test and VO2max. The SPSS software version 16 was used for all data analysis. Breastfeeding for more than 6 months was correlated significantly with more cardiovascular fitness (p<0.001). The correlation was statistically significant (p<0.001) even after adjusting for confounders (birth weight and body mass index (BMI) of the children; BMI of their mothers; smoking, physical activity, dietary intakes and fat mass of parents) (p<0.001). Breastfeeding (for more than 6 months) can increase cardiovascular fitness in children aged 7-8 years old. Considering that action can be taken regarding dietary patterns when a child is at a low age, these findings confirm, once again, the importance of paying particular attention to breastfeeding.

The existing literature reinforces the idea that social physique anxiety and eating attitudes differ in obese and normal weight adolescents. The purpose of the present research was to compare social physique anxiety and eating attitudes in obese and normal weight adolescents by examining the moderating role of sociocultural influence in weight loss and body change.

In this cross-sectional-descriptive study, 70 obese adolescent girls and 72 adolescent girls with normal weight were selected from among Tabriz City high school students. Data were collected on social physique anxiety (SPAS, Motle and Conroy), eating attitudes (EAT-26, Garner et al.), and sociocultural influence on weight loss and body change (SCIQ, McCabe and Ricciardelli) using questionnaires and analyzed using multivariate two-factor ANOVA.

Based on the results obtained, there was no significant difference between obese adolescents and normal weight adolescents with regard to eating attitudes, while social physique anxiety in the obese adolescents was much more than in the normal weight adolescents. Analysis of the data showed further that a high sociocultural influence on weight loss and body change had a significant role in the rise of the social physique anxiety and danger of disturbed eating attitudes. However, it did not have any significant moderating role in the social physique anxiety or the danger of disturbed eating attitudes.

High level of sociocultural influence on weight loss and body change is an important factor in elevating the social physique anxiety and dangers of disturbed eating attitudes. However, obesity, though an important factor in elevating the social physique anxiety, has no significant effect on elevating the dangers of disturbed eating attitudes.

Microbial lipid production has attracted the attention of researchers for several reasons − inexpensive substrates, a valuable fatty acids content, and rapid growth of microorganisms. In this study, the efficiency of total lipid and fatty acids production by Mucor hiemalis PTCC 5292 using a carbohydrate source and oil wastes was compared. Spores of Mucor hiemalis (n = 1×107) were inoculated in 50 ml of culture media in the presence of one of three carbon sources, namely, glucose, chicken oil waste, or fish oil waste, and cultivated at 28°C for 72h. The media included medium A containing exclusively a carbon and a nitrogen source and medium B containing a more limited nitrogen source than medium A. The fatty acid profiles of the lipids produced were determined by gas chromatography. The yield of lipid production was 33%, 66% and 68% in the glucose, chicken oil waste and fish oil waste, respectively, in medium B. The yield was higher than that in medium A because the limitation of nitrogen source in medium B would cause microorganism to reach the production phase in the logarithmic phase of growth more quickly. In addition, in medium B fatty acids, such as, for example, linoleic acid, were produced with glucose as the carbon source. Discussion and The findings show that using oil wastes, which are easily accessible and less expensive, could increase lipid production by Mucor hiemalis. Another advantage is production of valuable microbial lipids with a high essential unsaturated fatty acid content which has wide applications in the food industry. Furthermore, the data show that limitation of the nitrogen source has a significant effect on the production of microbial lipid by this fungus.

Primary dysmenorrhea is a common problem among women in the child-bearing age. This study was designed to compare the analgesic effects of extra virgin olive oil and Ibuprofen in primary dysmenorrhea. In a crossover randomized controlled trial (IRCT2013051110804N2), 60 university girl students (17-30 years old) in Boroojerd Islamic Azad University dormitory with the diagnosis of primary dysmenorrhea were enrolled based the CONSORT guidelines and divided randomly into 2 groups receiving either extra virgin olive oil (Group 1) or Ibuprofen (Group 2). Screening for primary dysmenorrhea was done by a visual analog scale. The participants were followed up for 4 menstruation cycles. The subjects in Group 1 took 25 cc of extra virgin olive oil daily for 2 months (starting two weeks before the start of the menstruation cycle) and completed a questionnaire containing items on pain visual analogue scale for two consecutive cycles. After a 4-week washout period they received 400 mg Ibuprofen three times a day in the first 3 days of menstruation. Group 2 was treated basically similarly, except that they received Ibuprofen during the first cycle and extra virgin olive oil during the second cycle. A self-reported checklist was used to collect information on menstruation. Data were analyzed using the Student's t-test and the linear mixed method model (SPSS 16). Although before the intervention, both groups were similar (P > 0.05) in terms of demographic variables and the outcome measures, the results showed that there were significant differences in the severity of pain during the pre- and post-treatment periods between the Ibuprofen and extra virgin oil groups (P=0.001). In addition, the severity of pain was less in the extra virgin olive oil as compared to the Ibuprofen group. Extra virgin olive oil is effective in treating primary dysmenorrhea and it seems that it can be used as a substitute for nonsteroidal anti-inflammatory drugs.

So far there is no report in the literature on bleaching vegetable oils by using ultrasonic waves in Iran. The aim of this study was to bleach soybean oil by ultrasonic waves and attempt to reduce the temperature and length of time required for the bleaching process. Bleaching of the oil was carried out by adding 1% w/w acid-activated bleaching earth to the soybean oil sample, followed by operating an ultrasonic bath (150 W, 20 kHz frequency) at two temperatures (45 and 60 °C) for 10, 20 and 30 minutes. Several tests, including chlorophyll and carotenoid measurements, peroxide value, acidity, fatty acid composition (with GC), and induction periods measuring the resistance to oxidation were carried out on both the unbleached and bleached samples. The results were compared using a factorial design with random blocks with 3 iterations. Bleaching by ultrasonic waves could reduce the chlorophyll and carotenoid contents of the soybean oil to a desirable level, the magnitude of reduction being 94.5% and 74.4%, respectively, when the ultrasonic waves were applied at 60 °C for 30 minutes. The induction periods of resistance to oxidation increased due to a reduction in the peroxide value and uptake of peroxides in the bleaching earth. Finally, the bleaching process produced no noticeable changes in the acid value or the fatty acid composition. Based on the findings, it can be concluded that ultrasonic wave treatment can be used as a safe method in bleaching vegetable oils without effecting their fatty acid composition.

Overweight and obesity is increasing because of changing food consumption patterns as well as our industrial life. Because of this, the prevalence of cardiovascular diseases and premature death have increased. The main goal of this study is to determine the effect of controlled diet as well as aerobic exercise on weight loss in fat men. In this study 40 fat men were randomly selected and then divided into four groups of ten men.1.Ten men along with exercise. 2. Ten men along with controlled diet. 3. Ten men along with exercise as well as controlled diet. 4. Ten men along with controls. Their height, weight and thickness of subcutaneous fat were measured before starting the exercise and diet intervention. The researcher did the exercise and controlled diet for eight weeks. After four weeks and at the end of the eight weeks of training and diet intervention their weight and thickness of subcutaneous fat were measured. Software of food processer was used to control the subjects dietary intake.In order to analysis the data, the researcher used analysis of variance by repeated measures (ANOVA). In all tests the significance level was considered as p < 0.05. The results showed that eight weeks of aerobic exercise and controlled diet significantly decreased the levels of weight and body fat percentage in different groups. (p< 0.05). So that aerobic exercise along with controlled diet group with four percent reduction in weight had the greatest effect compared to the other groups. In conclusion, based on the findings of this study, we can recommended exercise programs with caution and certain intensity along with low fat dairy foods to weight loss in obese men (BMI>30) to community health centers.

Considering the harmful effects of oil from a nutritional point of view on the one hand, and high oil uptake in fried products on the other, reducing the amount of oil in frying is essential. In this study, feasibility of producing low-fat kiwi chips based on aloe vera gel and the influence of various pre-treatment methods on reducing oil uptake of the product were investigated. To produce low-fat kiwi chips, the effect of coating type (CMC gum and aloe vera gel) and pretreatment (osmotic dehydration and osmo-ultasound) on the mass transfer of fried kiwi chips were investigated. The qualitative tests carried out on the samples included determination of moisture content, oil uptake, fried yield, coating percentage and water loss during frying. The result indicated that, as compared to the control (blank) and osmo-ultrasound samples, osmotic dehydration pretreatment in the experimental sample could reduce oil uptake of kiwi chips. The results of optimization of the method of kiwi chips production showed that kiwi chips prepared with osmotic dehydration pretreatment and coated with 1% CMC in aloe vera gel (i.e. C3T1) was the best treatment for production of low-fat kiwi chips. The result of this study show that aloe vera gel as a hydrocolloid compound can reduce oil uptake during deep fat frying.