فصلنامه علوم تغذیه و صنایع غذایی ایران
پیاپی 3 (زمستان 1385)

Urinary stones are common throughout the world, usually caused by supersaturated urine. The quantity of water intake and its mineral and trace elements have been reported to influence the urolithiasis. This study was carried out to compare the effects of Tehran tap water (TTW, with a low degree of hardness) and Damavand Ala-Spring Mineral Water (DMW, with a high degree of hardnes) on urinary mineral elements in men with and without kidney calcium stones at Hasheminejad Hospital, Tehran. This single-blind clinical trial included 29 15-62-year old male subjects, 14 with, and 15 without urinary stones, hospitalized in Hasheminejad Hospital, Tehran. The patients without urinary stones did not suffer from renal disorders or urinary stones, but had been hospitalized for rupture. None of the subjects was taking citrate, vitamin D, vitamin C, or Ca supplements, and showed no symptoms of pyuria or hematuria. Based on ideal weights of the subjects, their diets were prepared,weighed, packed and offered to them. Morning and 24-hour urine samples were collected before and after the intervention for oxalate, citrate, phosphate, uric acid, creatinine, Mg, Ca, specific gravity, and pH determinations. All the subjects were offered distilled water, 30-36 ml/kg/day, for 2 days (days 1 and 2), followed by the. same volume of TTW for 2 days (days 3 and 4) and, finally the same volume of DMW for the last 2 days (days 5 and 6). Data were analyzed using SPSS11.5, the statistical tests being ANOVA (repeated measures) and t-test. The age, weight, height, and BMI of the 2 groups of men showed no statistically significant differences. The urine volume increased significantly after taking distilled water and TTW (P<0.01) and mineral water (P<0.05). Distilled water and TTW reduced the urine specific gravity significantly (P<0.05). The specific gravity after consumption of TTW and DMW was lower after distilled water (P<0.01). Calcium levels after intake of distilled water and TTW were significantly different between the two groups (P<0.05). The data also showed that, as compared to distilled water, TTW increases urinary citrate, magnesium, phosphate, and the urine volume in men with nephrolithiasis and DMW increases urinary magnesium, phosphate and pH in men without nephrolithiasis; however, the differences were not significantly different. Conculsions: Results of this study showed that increasing water intake increases urinary volume and decreases specific gravity, irrespective of the degree of water hardness. Consumption of TTW is more beneficial (and may potentially prevent recurrence of stone formation) than that of the harder mineral water for patients with urinary stones, while consumption of the latter may be more beneficial for people without urinary stones. People should drink more water in order to reduce stone formation.

Globally, potatoes are the fourth main food item after wheat, rice and corn. Potato chips are a very popular snack However, due to the high content of oil (40%), consumption of this product is not desirable from a nutritional point of view. The aim of this study was to produce low-fat potato chips by coating with hydrocolloids and investigate the effects of the hydrocolloid coating on chemical, sensory, and shelf-life of potato chips. Potatoes (Agria variety) were sliced, and the slices were then coated by immersion in 1%, 3%, and 5% pectin, 0.5%, 1.0%, and 1.5% sodium alginate, and 0.5%, 1.0%, and 1.5% carboxymethylcellulose (CMC) solutions. The coated samples, as well as an uncoated control sample, were fried in a frying oil. The moisture content, oil uptake, and the total acceptability of all the samples were determined, and then their acid and peroxide values were measured after zero, 2, 4, 6, and 8 weeks of storage. The results showed that hydrocolloid coating caused an increase in moisture content and a reduction in oil uptake in potato chips (p<0.05). Coating with 5% pectin brought about the highest reduction of oil uptake (28.6% oil and 34.4 % reduction), while treatment with 1.5% CMC resulted in the highest retention of moisture (6.06%). Based on the sensory evaluation of the total acceptability and the oil uptake reduction, concentrations of 5% pectin, 1% sodium alginate and 1% CMC for each type of hydrocolloids were selected. The results also showed that hydrocolloid coating causes significant reductions (p<0.05) in peroxide and acid values during 2 months of storage: the lowest peroxide value (61.32% reduction) and the lowest acid value (42.1% reduction) were due to treatment with 5% pectin and 1.5% CMC, respectively. The 5%-pectin coating was selected as the most suitable coating because it brought about the highest reduction in oil uptake, the highest total acceptability, the highest reduction in peroxide value, and a considerable increase in the shelf-life of potato chips.

The objective was to study the effect of red-seed grapes on the serum levels of total cholesterol (TC) and low-density-lipoprotein-cholesterol (LDL-C) in hypercholester- olemic subjects. In a clinical trial 43 hypercholesterolemic subjects (cholesterol>200mg/dl) were randomly divided into two groups of red-seed grapes (RG) and control (CG). The RG group included 22 subjects (18 female, 4 male) with a mean age of 50 years, taking 500gr red-seed grapes per day for 4 weeks, while the 21 control subjects (17 female, 4 male) with a mean age of 52 years received no treatment. At the beginning of the study, physical activity and BMI were determined. Serum lipid levels (TC, LDL-C, HDL-C and TG) were measured at the beginning and at the end of the period. Dietary intake was also determined before and after the period, in both cases for 3 conseutive days, using the 24-hr recall questionnaire. The fiber and flavonoid contents of the grapes were also determined.The data were analyzed (paired t-test), using SPSS 11.5. The experimental and control groups were matched with regard to age, sex, BMI, and physical activity. As compared to the CG the mean level of TC in the RG significantly decreased after the 4 week-period (-24.2±6.3 mg/dl in the RG vs 2.8±6.1 mg/dl in the CG, p<0.05). The grapes also, caused a significant decrease in LDL-C in the RG, compared to the control group (-24.3±6.0 mg/dl in the RG vs 4.1±7.5 mg/dl in the CG, p<0.01). There were also reductions in the ratios and in RG compared with those in CG (p<0.05); however, the differences between the 2 groups with regard to HDL-C and TG were not statistically significant. Red-seed grapes might have beneficial effects on the serum total and low-density-lipoprotein-cholesterol in hypercholesterolemic subjects. Further studies are needed to determine tth effects of these grapes on HDL-C and TG.

The antimicrobial effects of green tea have been shown in many studies. However, there are not any reports in the literature on the inhibitory effects of black tea. This study was undertaken to determine the antibacterial effects of black and green teas against the pathogenic Escheriachia coli in vitro. Extracts from both green and black tea (Camellia sinensis) were made using the percolation method. Then different concentrations were prepared from the dried extracts. Viability of E. Coli was assessed by exposing the bacteria to different concentrations of the tea extracts in aqueons media, transferring the culture onto the solid media, and counting the colonies at different times. This was followed by determining the interactions between black or green tea extracts with some of the antibiotics rountinely used against Gram negative infections using the disc diffusion method (11 times on different days). The data were analysed by the Wilcoxon sign and Kruskal Walis tests. Both Black an green tea extracts showed either synergistic or antagonistic effects with the antibiotics in a selective dose-dependant manner. The total antioxidant capacity (TAC) of the green tea extract was significantly higher than that of black tea extract (p<0/001). It is concluded that the antimicrobial effects of tea are likely to be dependent on its TAC. Moreover, it seems that under certain conditions tea polyphenols act as pro-oxidants and exert their cytotoxic effects in this way. Potentially tea or its polyphenol supplements may be used along with antibiotics in infections.

Findings of several studies on animals have shown the beneficial effect of garlic on the blood glucose level. However, there have been few studies conducted on humans. Thus, this study was performed to determine the effects of garlic consumption with breakfast on the blood glucose and insulin responses in type 2 diabetic patients recruited from the Iranian Diabetes Society, Tehran.. This clinical trial was performed, 2 days per week with a 1-week interval, on 24 type 2 diabetic patients (13 men and 11 women, with a mean age of 49.4±7.4 years and a mean disease duration of 6.9 ±5.05 years) with a fasting blood glucose concentration ranging between 126 to and180 mg/dl. Each day the patients received one of the test breakfasts, namely, regular breakfast (containing bread, cheese, yogurt and cucumber) and garlic breakfast (regular breakfast plus 20 grams garlic). Blood glucose and insulin were measured by glucose oxidase and RIA (Radio Immuno Assay) methods, respectively, on a 2-ml blood sample taken at time zero (fasting) and 60, 120 and 180 minutes after ingestion of the breakfasts. The results were compared using ANOVA with repeated measures, and a P<0.05 was considered statistically significant. As compared to the regular breakfast, the garlic breakfast caused a significant reduction in the glucose level (P<0.05) and a significant increase in the insulin level (p<0.05). Taking garlic with breakfast reduces postprandial glucose response and increases insulin response significantly in type 2 diabetic subjects. Therefore, it seems that inclusion of garlic in the daily diet may have beneficial effects on glycemic control in type 2 diabetic subjects. Further long-term studies are needed to throw more light on the subject.

Lycopene and -carotene, two strong antioxidant carotenoids, enter our bodies mostly through vegetables and fruits. Determination of the serum carotenoid levels may be used both to assess body antioxidant status and to validate vegetable and fruit consumption questionnaires. The aim of this study was to design and setup a rather simple, reliable and less expensive high-performance liquid chromatography (HPLC) -based method for simultaneous determination of serum lycopene and -carotene levels. After examining various chromatographic conditions, the following method was found to be most reliable. َAfter protein precipitation with ethanol, the carotenoids were extracted using n-hexane, which was then evaporated under nitrogen flow at 40°C. The sediment was reconstituted with a mixture of mobile phase (methanol: acetonitrile: tetrahydrofurane, 50:45: 5, v/v/v) and diethyl ether (2:1, v/v), 20µL of which was injected to the column Novopack C18. With a flow rate of 1. 5mL/min at 472nm, retention times of lycopene and -carotene were 5. 1 and 8. 6 minutes, respectively, and the run time was 11 minutes. The percent recoveries (mean±SD) of lycopene and beta-carotene were 95. 5%±7. 8 and 95. 2±7. 0, respectively, and their intra- and inter- measurement variations 1. 6% and 5. 75% and 3. 0% and 3. 5%, respectively Quality control tests indicated high sensitivity and precision of the method. The method is quite suitable for use in research and, particularly, in population studies, although it has, like any other method, its own limitations. Furher studies are needed in this area.

Malnutrition among adolescents is not only an important health problem but also an economic development issue in Iran and other developing countries. High incidences of nutritional deficiencies and poor eating habits during adolescence may lead to undesirable concequences in later years, including osteoporosis, obesity, hyperlipidemia, sexual maturation delay, and a shorter adult stature. The objective of this study was to determine the relationship between some food factors with the weight status in high school adolescent girls in Semnan. In a cross-sectional study, using the two-stage random sampling method, 256 girl students 14-18 year old were randomly selected from 8 Semnan high schools. Weight and height were measured and BMI was calculated. The weight status was defined on the basis of BMI-for-age, using the CDC 2000 standards. Data on 24-hours recall, food record, and food frequency were collected using standard questionnaires. Underweight, overweight, and obesity were present in 5.9% (expected 5%), 11.7% (10%), and 4.7% (5%) of the subjects, respectively. The data also indicated that there were significant relationships between the BMI percentile and the daily fat intake (p=0.003, r=+0.18), energy percent from fat (p=0.04, r=+0.01) and weekly fast food frequency (p= 0.026, r=+0.139). Similarly, there was a significant relationship between the daily snack frequency and weight status (p=0.023). The daily energy, carbohydrate, and protein intakes, energy share of macronutrients except fat, meal frequency, and the fruit and vegetable, red meat, dairy products except cheese, and cocoa intakes had no significant relationships with the weight status. Daily fat intake, percent of energy from fat, frequency of fast food intake, and snack intake had significant relationships with the weight status of high school adolescent girls in Semnan. Nutrition education and correction of food habits could help to improve the nutritional status of adolescent girls.