فصلنامه علوم تغذیه و صنایع غذایی ایران
سال سوم شماره 2 (پیاپی 9، تابستان 1387)

Few studies have investigated the association between dietary patterns and socioeconomic and demographic factors. The aim of this study was to detect major dietary patterns and assess their relationship with socioeconomic and demographic factors among 20-50 year-old women living in the north of Tehran. In this cross-sectional study 460 women, aged 20-50 year-old, living in the north of Tehran were selected by stratified random sampling. Dietary data (for the previous year) was collected by a semi-quantitative food frequency questionnaire, and information on the socioeconomic and demographic factors was obtained by interview. Factor analysis was used for identifying major dietary patterns. The association between major dietary patterns and socioeconomic and demographic factors was assessed by covariance analysis. Two major dietary patterns were detected: 1. Healthy Pattern (high in, fruits; yellow vegetables, cruciferous vegetables, tomatoes and other vegetables; yogurt drink and low-fat dairy products; poultry; olives; nuts; fruit juice; potatoes; garlic; coffee; dried fruits; and legumes), and 2. Unhealthy Pattern (high in processed meat; mayonnaise; soft drinks; sweets; refined grains; snacks; industrial juice; red meat; nuts; French fries; hydrogenated fats; egg;, butter and high-fat dairy products; sugars; and organ meats). After adjustmnent for confounders, the Azari ethnic group in comparison with the Fars ethnic group (B= 0.44; p<0.01), and living in District 7 in comparison with living in District 3 (B= 0.39; p<0.05) were positively, and age (B= - 0.04; p<0.01), university education (B= -0.34; p<0.05) and total monthly family income (B= - 0.25; p<0.05) negatively, associated with the unhealthy diatery pattern.On the other hand, age (B= 0.03; p<0.01) and housing surface area (square meters_ per head) (B= 0.21; p<0.01) had a positive, and duration of residence in Tehran, a negative, association with the healthy pattern (B= - 0.01; p<0.01). Socioeconomic and demographic factors influence dietary patterns of the women. It is suggested that these factors be considered in the future assessments of associations between dietary patterns and disease.

The prevalence of obesity and cardiovascular diseases in the world has prompted production of low-fat and low-trans-fatty acid margarine-like products or low-fat and low-trans spreads. An increase in water content of such products can affect their sensory characteristics and shelf-life. The aim of this study was sensory evaluation and shelf-life determination of low-fat and low-trans spread samples produced at a laboratory scale.

Six samples of low-fat (40%) and low-trans (<1%) spreads were produced at a laboratory scale (2kg) by combining three oil phases and two stabilizers, i.e., F1 and F2 formulas with palm stearin and canola oils (40:60) and sodium alginate (F1), or modified waxy maize starch or MWMS (F2); F3 and F4 formulas with fully hydrogenated soybean oil (flake) and soybean oil (25:75) and sodium alginate (F3), or MWMS (F4); F5 and F6 formulas with palm, cottonseed and canola oils (40:40:20) with sodium alginate (F5), or MWMS (F6), and full fat spread or F7 (80%fat) with palm stearin and canola oils (40:60), without stabilizer, as a control. Sensory evaluation (surface texture, spreadability, flavour and mouth feel, and overall acceptance) was carried out by 30 in-house panelists (ranking method). Shelf-life of the spread samples stored in refrigerator (5°C) was determined by measuring peroxide value, oiling off and microbial characteristics (total aerobic bacterial count, and mold and yeast counts).

There were significant differences among the samples as regards overall acceptance (p<0.05). Sensory evaluation showed similar results for F2 and F7, and samples with MWMS had better acceptance compared to samples containing sodium alginate. Peroxide value did not reach the discard point (5meq/kg), even after 10 weeks of storage. Results of oiling off tests were satisfactory for most samples; oiling off was found only in F5 and F6 after six weeks of storage. All samples reached the discard point after 10 weeks of storing at 5°C, taking into account total bacterial and mold and yeast counts.

The final ranking of the spread samples based on the nutritional value (P/S+T), physical characteristics, sensory evaluation and shelf-life was as follows: F7>F2>F1>F6>F5>F3>F4. Considering the necessity of production of low-fat and low-trans-fatty acid products from a nutritional and public health point of view, the F2 formula is recommended for further research.

breakfast is recommended as the most important meal of the day, but not all studies show positive effects of breakfast consumption on the cognitive performance. Differences in breakfast composition may account for some of the contradictory results reported so far. There are limited studies investigating the effect of breakfast composition on cognitive performance. This study was designed to compare the effect of two common Iranian breakfasts (high-carbohydrate vs high-protein) on the cognitive performance of elementary school children Fifty-one well-nourished children (27 girls, 24 boys) aged 9-11 years participated in the this study. They consumed one of 2 breakfasts (60%carbohydrate or 25%- protein), or took no breakfast, as controls (the fasted state) in a randomized cross-over design with one week apart as the wash-out period. The breakfasts were similar with regard to the energy and fat contents, but differed in carbohydrate and protein composition. Cognitive performance was assessed prior to, and 30 and 120 minutes after, taking breakfast, using the standard computerized CDR assessment tests. Statistical analysis was conducted using SPSS (version 15), and P<0.05 was considered as the level of significance. No statistically significant differences were observed among the 3 groups (high-carbohydrate breakfast, high-protein breakfast, and control) with regard to most of the tasks. However, the high-carbohydrate breakfast significantly impaired the simple reaction time (P<0.023), the choice reaction time (P<0.018), and the power of attention (P<0.013) in girls. The choice reaction time improved in the control boys (P<0.003). Breakfast composition had no effect on the healthy boy's cognitive performance, but a high-carbohydrate breakfast reduced the power of attention in healthy girls. It is recommend that the effect of quality and quantity of breakfast on the mood of the children be also assessed in future studies.

Presently the consumption of sausages in Iran is on the increase. Considering the importance of hygienic/microbial aspects of their production, this study was conducted to determine the growth patterns of aerobic mesophilic and psychrotrophic microorganisms, moulds and yeasts in four heated red-meat product groups during storage for a period of 87days. This will be helpful when revising the respective national processed meat product standards. Methods and materials: The heated red-meat products were divided (based on percent meat content), according to the existing national standards, into 4 groups of 40%, 55%,8 0%, and 90%. Three samples of each group were produced in a meat processing plant. During processing, as well as during storage at 4°C for 87 days, the samples were tested for the microorganisms at 21 steps, twice at each step, according to National Standards No.5272, 2629 and 997.

The aerobic mesophilic bacterial count did not exceed the permitted limit (National Iranian Standards) during the study. However, other bacterial counts did exceed the respective limits in different samples at different time points as follows: 1. The psychrotrophic bacterial counts in the 90%-, 80%-, 55%-, and 40%-meat samples on days 32, 36, 44, and 52, respectively; 2. The mould and yeast counts in the 90%-, 80%-, 55%-, and 40%-meat samples on days 59, 66, 80, and 87, respectively.

An increase in the meat content of the processed products causes an increase in the loads of all the three types of microorganism during storage. The psychrotrophic bacterial count can be used as an indicator of spoilage during storage.

It is usually expected that food-insecure people have an inadequate food intake, less body fat, and body weight. However, several studies in developed countries have shown a higher prevalence of overweight/obesity among food-insecure household members, especially women. This study aimed to assess the association between food insecurity and body weight status and socio-economic factors affecting it in adult members of Iranian households. This cross-sectional study was conducted in the framework of the Comprehensive Study on Household Food Consumption Patterns and Nutritional Status of I.R. Iran during 2001-2003. Households were selected by the Iranian Statistical Center by systematic cluster sampling in urban and rural areas. Heights and weights of all household members over 20 years of age (7960 women and 6083 men) were measured based on standard protocols, and body mass index (BMI) was calculated. Weight status (classified into underweight, normal weight, overweight, and obesity subgroups) was defined based on cut-off values recommended by NIH. Socio-economic status (SES) of the household was assessed by a questionnaire through structured interviews. Assessment of food consumption patterns was made using the weighing method and three consecutive 24-hour diet recalls completed by trained nutritionists. Food insecurity (FI) was defined on the basis of daily energy intake (as percentage of WHO/FAO RDA) as follow: mild FI, 80-89% RDA; moderate FI, 70-79% RDA,; and severe FI, lower than 70% RDA. Logistic regression was used to test the simultaneous effects of SES and food security variables on weight status. A total of 7158 households, including 2496 (34.9%) rural and 4662 (65.1%) urban, were included in the study. The findings showed that 5.2%, 7.6%, and 9.9% of them were severely, moderately, and mildly food-insecure, respectively. On the whole, 30% and 34.3% of the men and women were overweight, and 9.9% and 26.7% obese, respectively (P<0.001). Logistic regression in 6083 men did not show any significant association between weight status and food insecurity after controlling for the SES variables. However, overweight increased at higher educational levels, good housing condition (ownership) (P<0.01), and a higher score of facilities in the home (P<0.001) in men. On the other hand, in severely and moderately food-insecure women (n=7960) overweight was 1.5 times (CI: 1.22-1.94 & CI: 1.27-1.88, P<0.001), and in mildly food-insecure women 1.2 times, (CI: 1.04-1.43, P<0.001) that in their food-secure counterparts. Overweight decreased with higher educational levels and increased with being married, urbanization, score of facilities in the home (P<0.001), and better housing conditions (ownership) (P<0.05) in women. Food insecurity is associated with overweight in Iranian women in food-insecure households. This association is not clear in men.

In the meat industry, carcass cooling rate is very important due to its effects on meat quality and economic aspects. Rapid cooling of carcasses causes cold shortening of muscles and, therefore, results in meat toughening. Electrical stimulation is used in developed countries as an effective treatment for reducing carcass cooling time and preventing cold shortening. Electrical stimulation can also increase tenderness of meat. The purpose of this study was evaluation of the effect of low-voltage electrical stimulation on tenderness and water-holding capacity in veal. Eighteen Holstein steers,12–14 months of age, with a carcass weight of 243 ± 13 kg (mean ± SD), were stimulated, immediately after exsanguinations, by low voltage (110 V,1 A, 20 s). After splitting of the carcasses, from each side a sample of about 1kg of M. Longissimus dorsi was removed. Shear force, sensory tenderness and juiciness were determined at 1, 3 and 7 days post mortem (PM). Water-holding capacity, drip loss and cooking loss were determined at 7 days PM. Shear force of the stimulated samples was lower, and their tenderness and juiciness scores were higher, than the respective control (non-stimulated samples) values at 1, 3 and 7 days PM (P < 0.05). (P < 0.05). Ageing resulted in a decrease in the shear force and an increase in the sensory tenderness and juiciness scores 1 and 7 days PM (P<0.05 in both the stimulated and non-stimulated samples. Electrical stimulation had no significant effect on the water-holding capacity, drip loss and cooking loss. According to the results of this research, application of electrical stimulation is an effective treatment for improving tenderness and juiciness of veal.

Zinc (Zn) is an essential trace element found in a wide spectrum of metalloenzymes,. It participates in many metabolic processes, including normal metabolism of vitamin A. On the other hand, vitamin A affects zinc absorption and utilization. Recent investigation has shown that vitamin A plays a role in the secretion of insulin by the pancreas. There is evidence that the metabolism of zinc and vitamin A is altered in type 1 diabetes mellitus (DM). The objective of the present study was to investigate the effects of simultaneous zinc and vitamin A supplementation on serum lipoproteins, apoproteins A-I and B and glycemic status in patient with type I DM.

Fifty-two 7-20 year-old patients with at least 2 years of DM history, not suffering from any other metabolic disease, and not taking any medicine, but under insulin treatment, participated in a 12-week randomized double-blind clinical trial. They were divided,, after matching for sex, age and DM duration, into 2 groups: a Zn- and vitamin A-supplemented group (10 mg Zn-sulfate syrup per day and half of a 25000-IU vitamin A tablet every other day) and a control group (taking a zinc and vitamin A placebo). Forty-eight patients completed the study. Nutrients intakes were estimated using a 24-hour recall and analyzed by Food Processor III. The serum contents of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), triglyceride (TG), apoproteins B and A-I, fasting blood sugar (FBS), insulin, and glycosylated hemoglobin (HbA1c) were determined at the beginning and at the end of the trial. The independent sample t-test was used for comparisons between the two groups and the paired sample t-test was used to compare the differences between different time points in each group. A P-value £ 0.05 was considered significant.

The final mean serum TC, TG, LDL-c, HDL-c, FBS, insulin, HbA1c and apoprotein B values were not significantly different between the 2 groups.As compared to the control value, only the apoprotein AI level significantly increased in the experimental group (p<0.0001).

It seems that simultaneous zinc and vitamin A supplementation may increase the serum ApoA-I level, which can reduce the atherogenic risk factor in patients with type 1 DM.

Sourdough fermentation with interactions between lactic acid bacteria and yeasts, is considered to play a key role in producing bakery products with improved flavor, texture and shelf-life properties. This research focused on evaluation of acidification properties of different starter cultures in liquid sourdough fermentation and selecting an appropriate inoculum based on quality and shelf-life properties of the resultant bread. Liquid sourdough samples were fermented by cultures including L.casei and S.cerevisiae (T1), L.fermentum and S.cerevisiae (T2), L.casei, L.fermentum and S.cerevisiae (T3) and adde to bread doughs (15% w/w). Technological properties (moisture content, specific volume and organoleptic properties) and shelf-life of the sourdough breads were compared with those of a control bread. Sourdoughs fermented by inoculums T1 and T3 had a similar pH-lowering rate (there were only small differences). Inoculum T3 showed the highest acidification rate. In comparison, inoculum T2 showed a lower acidification rate (pH> 4). Liquid sourdough breads had higher specific volumes as compared to the control bread, and sourdough bread T3 ranked first organoleptically. Sourdough breads (T1 and T3) had a lower staling rate than the control value, and bread T3 showed a higher staling rate than T1 (p< 0.05). Sourdough addition can improve organoleptic properties–specific volume and shelf-life–of the breads.. Based on acidification properties and sensory analysis, inoculum L.casei, L.fermentum and S.cerevisiae produce the most desirable effects.

Salmonella enteritidis is an important food-borne enteric pathogen. It is very resistant in the environment and remains an important cause of gastroenteritis in humans world-wide. It forms biofilms on many food contact surface materials. Development of biofilms on these surfaces is a potential source of contamination of foods which may lead to spoilage or transmission of food-borne pathogens. In this project biofilm formation by the Iranian species of Salmonella enteritidis RITCC 1624 on food and medical contact surfaces was assessed. Firstl the hydrophobicity of S. enteritidis RITCC 1624 was measured by the Microbial Adhesion to Hydrocarbon method (MATH). Then biofilm formation by the organism was assessed after a lapse of 2, 4, 8, 16 and 20 hours on stainless steel type 304 no 2B, polyethelene, and on glass by the drop plate method. Resultes indicated that this organism, with 73% hydrophobicity, can form biofilm on all the three surfaces. Biofilm formation on glass and stainless steel surfaces within 2 hours was more than on polyethylen (P<0.05).increasing time to 20 h did not result in biofilm formation to a larger extent (P>0.05). Biofilm formation by S. enteritidis was most extensive on the interface between air and liquid phases. Biofilm formation ability of S. enteritidis on the 3 surfaces increases the possibility of its transmiision, important from a hugienic and disease spreading viewpoint.