فصلنامه علوم تغذیه و صنایع غذایی ایران
سال هفتم شماره 2 (پیاپی 25، تابستان 1391)

Preliminary studies have shown reductions in apoptosis in brain ischemia following treatment with antioxidants. In this study, the relationships between consumption of olive oil and apoptosis in hippocampal neurons and changes in memory following brain ischemia in mice were determined. Three groups of 7 mice each were included in the study: healthy, ischemic control, and treatment groups. The mice were treated with olive oil as a pre-treatment for a week (tube-feeding). Ischemia was then induced by common carotid artery occlusion. This was followed, after the inflammation in the ischemic area was reduced, by furher treatment for a week with olive oil. Histological examinations were made using Nissl staining for counting necrotic cells, TUNEL kit was used to quantify apoptotic cell death, and short-term memory scale was determined by the shuttle box test In the ischemic group high rates of necrosis and apoptotosis were seen, which were associated with short-term and spatial memory loss. Apoptosis rate in the treatment group was much less than in the ischemic group, confirming results of the memory tests. Ischemia-reperfusion for 15 minutes induces vast and permanent cell death in the hippocampus in mice, particularly in the CA1 region. Olive oil consumption significantly reduces cell death and decreases memory loss.

Phenylketonuria (PKU) is a genetic disease. Patients suffering from PKU must adhere to a lifelong low-phenylalanine diet. Glycomacropeptide (GMP) is a unique source of protein for PKU patients, because it contains no phenylalanine. The objective of this study was to extract GMP from whey and purify it in order to obtain a product with a minimum phenylalanine content. The ultrafiltration membrane technology was used to separate GMP from the whey protein concentrate solution at different pH values. Two ultrafilteration disc membranes with 50 and 10 kDa cut-off were used to extract glycomacropeptide from a solution of whey protein concentrtae (10% protein w/v).The experiments in triplicates were performed at the ambient temperature (25±2 °C) and a pH of 3.5, 4 or 4.5. The diafilteration technique was used for purification of glycomacropeptide in both ultrafilteration phases; the protein, phenylalanine, and non-protein nitrogen (NPN) contents were measured. The phenylalanine and NPN contents of the ultrafiltered whey at a pH of 4 were at the lowest and highest level, respectively, indicating the high purity and recovery rate of glycomacropeptide. Sweet whey, the major type of whey produced in the country, is the best alternative available for producing a new food source for phenylketonuria patients.

The increasing trend of prevalence of diabetes mellitus, a diet-related chronic disease has prompted research to find ways to control it. Brewer's yeast may have a potential role because its glucose tolerance factor (GTF) may have beneficial effects on insulin receptors in diabetic patients. This study was conducted to investigate the effects of brewer's yeast supplementation on serum lipoproteins and blood pressure in patients with type-2 diabetes mellitus (T2DM) patients. In a randomized double-blind controlled clinical trial 84 adults (21 men and 63 women, 46.3 ± 6.1 years old) with T2DM were recruited and divided randomly into 2 groups of 42 subjects each, one receiving brewer's yeast (six 300-mg capsules/day, total 1800 mg) and one (control group) receiving a placebo (6 capsules/day) for 12 weeks. Body weight, height, body mass index (BMI), food consumption (based on 24-hour food recall), fasting serum lipids and lipoproteins (total cholesterol, triglyceride, LDL-c and HDL-c), and systolic and diastolic blood pressure were measured before and after the intervention. Data analysis was performed using the Statistical Package for Social Sciences (SPSS-Ver 18.0), the statistical tests being the independent t-test, paired t-test, Kolmogorov-Smirnov test, and analysis of covariance. Brewer’s yeast supplementation brought about statistically significant reductions in diastolic and systolic blood pressures (5.7±0.6 mm Hg, p=0.001 and 4.1±1.5 mm Hg, p=0.007, respectively) after 12 weeks. Changes in LDL-c, HDL-c, triglycerides and total cholesterol were no-significant. Further analysis of the data showed significant differences between the brewer’s yeast and control groups with regard to diastolic (p<0.03) and systolic (p<0.05) blood pressure at the end of the period. Dietary supplementation with brewer's yeast can reduce systolic and diastolic blood pressure in type-2 diabetes mellitus patients.

Today dietary deficiency of selenium (Se), an important mineral in human nutrition, is common in many regions and communities. Se-enriched yeast, obtainable by growing Saccharomyces cerevisiae in Se-rich media, is considered as a source of organic Se suitable for alleviating its deficiency due to its high bioavailability, stability, digestability, and absorbability. Using a Plackett-Burman design, the effects of various culture medium conditions, including temperature (28 and 30 °C), initial pH (4.5 and 5.8), shaking speed (130 and 160 rpm), fermentation duration (24 and 48 h), size of inoculum (30 and 60 g/l), Se concentration (15 and 25 µg/ml) and time of Se addition (0 and 9 h), on the bioaccumulation of Se in the yeast were investigated.. The Se content in the yeast was determined by graphite-furnace atomic-absorption spectroscopy. The results showed that Se concentration, size of inoculums, temperature, time of Se addition and fermentation duration were, in ascending order, the most significant factors on the yield of total Se accumulation and organic Se formation in the yeast. Manipulating these conditions/variables could markedly affect the magnitudes of incorporation of Se and formation of organic Se in the yeast, the ranges being 107.9 to 287.6 mg/kg and 93.27 to 269.05 mg/kg, respectively. The most suitable culture medium conditions to attain the highest level of total and organic selenium Se biotransformation in yeast are a concentration of 25 µg/ml sodium selenite, an inoculum size of 30 g/l, a temperature of 28 °C, an initial pH of 5.8, a shaking speed of 130 rpm, an incubation time of 48 h, and adding the selenium source to the culture medium 9 hours after the start of fermentation.

Limited studies have been conducted on the effect of resistance training plus protein supplements on weight control, muscle growth and body composition. The purpose of this study was to evaluate the effects of a whey protein supplement combined with a 6-week strength training on weight loss, body composition, strength, and muscle hypertrophy in overweight young men. Thirty individuals with a body mass index between 25-30 kg/m2 participated in the study. They were randomly divided into three groups of 10 persons each as follows: 1. Experimental group 1 (whey supplement + 6 weeks of strength training (W); 2. Experimental group 2 (placebo + 6 weeks of strength training (D); 3. Control group (C). Maximum strength and muscle volume of the subjects were measured by the 1-RM test in bench press, biceps curl, Squats and chest, arm and tight limb. Skinfold thickness (triceps, supraillium, abdomen and thigh) were measured with Lange skinfold calipers. Repeated measure ANOVA and Bonferroni post hoc test were used for data analysis. No significant changes occurred in body weight and BMI (p>0.05). The waist-to-hip ratio (WHR) also remained unchanged in all groups (p>0.05). In both the experimental and placebo groups significant reductions in percent body fat and fat mass and significant increases in the lean body mass, strength, and muscle hypertrophy were observed (p<0.05) after 6 weeks of strength training. Strength exercise training alone increases strength, hypertrophy and muscle mass and improves body composition in sedentary, overweight young men. Our results suggest that protein supplementation is not needed for strength improvement or body composition changes.

Prevention of physical instability of chocolate milk is an important challenge in the field of food science, particularly dairy technolohy. In this study, the effects of high-intensity ultrasound treatment on stability of cocoa particles in chocolate milk, with or without the presence of stabilizers, was investigated. Chocolate milk was exposed to ultrasound (maximal nominal power 600 W at 20 kHz) at various levels of power intensity (24, 72 and 120 W), exposure times (2, 6 and 10 minutes) and temperatures (25, 45 and 65ºC) for 30 days. κ-carrageenan at concentrations of 0.000, 0.010, 0.015 and 0.020 %, with or without sugar (7.0% and 0.0%), was added to the samples. Increasing power intensity and exposure time led to a significant increase in physical stability of the milk samples − the milk phase volume decreased and the cacao phase increased. Moreover, the phase separation and cacao particle sedimentation were effectively prevented in the treated samples (ultrasonic power 120W, exposure time 2 min, temperature 45ºC, κ-carrageenan 0.02%, and sugar 7%) after 30 days of storage at 4ºC, while phase separation and cacao particle sedimentation occurred in the control sample (containing 0.040% κ-carrageenan). The findings also showed that sugar improved cacao milk stability. The milk phase volume in the presence of 0.02% κ-carrageenan, kept at a temperature of 45 ºC for 30 days, was less than that of samples kept at other temperatures. Based on the findings of the present study, it seems that ultrasound can increase the stability of cacao particles in milk. In addition, ultrasound treatment possibly degrades the κ-carrageenan network, particularly at higher temperatures. Furthermore, cavitation, probably due to entrapment of air in the κ-carrageenan network, may weaken the gel network

Creatine and sodium bicarbonate are energizer supplements used by sportsmen to reduce fatigue and increase power output in sprints − short, strenous excecises − such as rapid running and explosive movements.The purpose of this study was to compare the effects of creatine monohydrate, sodium bicarbonate and their combined administration on anerobic performance and blood lactate level in wrestlers.

A group of 24 national Iranian junior male wrestlers with a mean age, height, weight and body mass index (BMI) of 17.7±4.76 years, 179.6±7.39cm, 1±9.94 kg and 23.17+1.92 kg/m2, respectively, participated in this this tudy. They all took a placebo for 2 days (20 g maltodextrin/day) and then completed six 10-second Wingate sprints, with a 60-second active rest between each 2. After a lapse of 10 days, the subjects were randomly assigned, on the basis of base power and body weight, to a creatine (Cr; 20g creatine/day), sodium bicarbonate (Sb; 0.065 g/kg sodium bicarbonate/day) or creatine-plus-sodium bicarbonate (Cr + Sb; 5g Cr + 0.065 g/kg sodium bicarbonate/day) supplement, using a double-blind design. They took the supplements and the placebo 4 times daily at 9 AM, noon (12’oclock), 6 PM and 10 PM and drank large amounts of water. In the next phase of the study, 2 days after taking the supplements/placebo, the Wingate tests (six 10-second tests) were repeated and relative peak powers (PP), relative mean power (MP) and fatigue index (FI) were assessed. Blood lactate was measured in a hand-finger blood sample before, immediately and 3 minutes after the last Wingate sprint. The data were analyzed, the statistical tests being repeated measures, t-test and ANOVA. An alpha of p≤0.05 was used to determine statistical significance.

The data show statistically significant increases in PP, MP, and blood lactate level in the Cr+Sb, Cr and Sb supplement groups as compared to the placebo group (p0≥.05). Also blood lactate level and fatigue index immediately and 3 minutes after the last Wingate sprint increased; however, no significant differences were found among Cr+Sb, Cr and Sb groups.

It can be concluded that short-term consumption of Cr-Sb, Cr or Sb brings about a statistically significant increase to the same extent in both anaerobic power in Wingate 10 s-repeated performances and blood lactate level of wrestlers.

Inhibition, even reduction, of acrylamide formation during processing of foods, can help produce more healthy food and, consequently, promote food safety. The objective of this study was to investigate the effects of rosemary extract (RE) and vitamins niacin (B3) and pyridoxine (B6) on acrylamide formation in potato chips. Samples of potatoes, to which RE, vitamin B3 or vitamin B6 had been added at 3 levels, namely, 0.2, 1.0 and 2.5 g/kg, in a deeping system for 15, 30, and 60 minutes, were fried for 4 minutes, the frying temperature being 180 C. The acrylamide level in potato chips was determined by gas chromatography (GC/MS). Addition of RE and the vitamins at a level of 1 and 2.5 g/kg potatoes, respectively, resulted in acrylamide reduction by 82.7% and 50.9%. The antioxidant effect of RE and the vitamins at these levels preventing acrylamide formation was considerable. The magnitudes of acrylamide reduction in the fried potato samples with any given content of reducing sugars, asparagine and acrylamide were significantly different. The findings indicate that both rosemary extract and the vitamins B 3 and B 6 could significantly reduce the acrylamide content produced in potato chips, with no change in flavor and crispness. The use of these 3 additives to reduce acryamide formation is recommended for potato chips, fried and other potato products, as well as for otherv high-carbohydrate foods, such as bread and biscuits.

Breakfast, considered to be the most important meal, is skipped more ferquently than other meals by children and adolescents. ‏This study aimed to determine breakfast consumption and its predictors among Qom school girl students based on the Pender`s health promotion model constructs.

This descriptive-analytical study was carried out on 100 secondary school girl students selected by classified random sampling from among secondary schools of the City of Qom, Iran. The Pender`s health promotion model (HPM) constructs were used as the theoretical framework. Data were collected using questionnaires. Statistical analysis of the data was performed by SPSS (version 17) software, the statistical tests being correlation and regression analysis.

The average number of breakfasts consumed per week was 3 (± 1.5). Body mass index, time of waking up in the morning, and interpersonal influences had no significant correlations with the average number of breakfasts consumed per week. On the basis of the Pender`s health promotion model constructs and personal factors having a potentially significant correlation with behavior, 69% of the variability in breakfast consumption by the girl students (R2 =0.69, F =12.68, p< 0.0001) was predicted by the folowing variables: prior related behaviors, perceived barriers, self-efficacy, and competing demands and preferences.

In designing nutritional interventions aiming at increasing breakfast consumption in school girl students, it is better to put more emphasis on strategies to promote self-efficacy and reduce perceived barriers. Also, paying due attention to prior related behavior and competing demands and preferences can be beneficial in designing effective interventions.

Types and contents of the chemical compounds found in olive oil, including fatty acids, antioxidants and pigments, indicates the oil quality, which in turn depends on several factors, including cultivar, climate, extraction method, and maturity of he olive fruit. Research has shown that tocopherol and polyphenol contents depend on cultivar and the cultivation region, respectively, while fatty acid content depends on both of these factors. Iranian olive oils have a different chemical composition and, consequently, different oxidative stability. Therefore, the aim of the present study was to investigate the chemical composition and physicochemical chartacteristics of commercial types of Iranian virgin and refined olive oils.

Iranian olive oils, including four virgin (C, D, F and H) and five deodorized (A, B, E, G and I) samples, as well as two foreign virgin samples (1 and 2) were purchased from local stores. To determine fatty acid compoition and compositional, chemical and physical indicators, national and international laboratory methods were used. All determinations were performed in triplicates.

The results showed that the main fatty acids in the Iranian commercial olive oils were monounsaturated fatty acids (MUFA), particularly oleic acid (C18:1); saturated fatty acids (SFA), particularly palmitic acid (C16:0); and polyunsaturated fatty acids (PUFA), particularly linoleic acid (C18:2). However, the compositional, physical and chemical characteristics, such as peroxide value, acid value, polar compounds, the unsaponifiable matters, phenolic compounds and tocopherols, which affect the oxidative stability of fats and oils, were significantly different among the different olive oils.

The available literature shows that no comprehensive research has been conducted on the physicochemical properties of commercial olive oils in Iran, despite the fact that the domestic production of olive oil, because of its special importance with regard to its more desirable fatty acid composition compared to other edible oils, as well as its unique microstructure, has had an increasing trend. Hence, investigation into the effects of climate and agricultural conditions on the properties of olives and a better knowledge of raw material characteristics will make it possible to produce edible oils with higher quality and greater stability.

Short storage life of loquat fruit and its high susceptibility to water loss and browning are the main factors limiting its marketability.The purpose of this study was to investigate the effects of cellophane-film packaging and cold storage on the keeping quality and storage life of loquat fruit (Eriobotrya japonica). Samples of sorted loquat fruit were placed in packages either coated with cellophane film (experimental) or non-coated (control) and stored for 28 days at 7ºC and a relative humidity of 85% ± 5. The following variables were determined in the experimenrtal and control samples: weight loss, outside tissue browning, total soluble solids, titratable acidity, vitamin C, total phenol, antioxidant capacity, and flavonoid (quercetin and catechin) contents. In the experimental sample the browning index was lower and general quality appearance more desirable at the end of the storage period, while the control sample lost marketability after a short time. In addition, weight loss of the sample packaged with cellophane film was significantly lower than that of the control sample. Furthermore, the increase in the soluble solid content and decrease in titratable acidity were statistically significantly higher in the control sample compred to the cellophane-film packaged sample during storage. In both the experimental and control samples the ascorbic acid content, total phenol and antioxidant capacity in loquat fruit were lower at the end of the storage period; in the experimental sample the reductions were smaller. Finally, the magnititude of reduction in the flavonoid (quercetin and catechin) contents at the end of the storage was lower in the fruit sample packaged with cellophane film. Packaging with cellophane-film, with stotage at low temperatures, can be a new method for extending storage life of loquat fruit.

One of the major problems in a research work is the lack of previously published comprehensive and updated information. Development of Iranian Food Science and Technology Data Bank (IFSTDB; 1978-2001) and its subsequent updating has made possible quick access to the existing information sources in Persian by researchers and specialists. In this paper, methods of collection and classification of documents used in preparing IFSTDB during the period 2002-2006 is described, together with analysis of the documents. Bibliographic information on seven types of documents published during the period 2002-2006 was collected by a trained team, the members of the team consulting directly the educational, research and executive institutes active in the area of food science and technology and filling worksheets especially prepared for the purpose. The documents types were as follows: journal articles, conferences articles, M.Sc. and doctorate theses/dissertations, research project reports, books, food standards and patents. The documents were classified into main groups and subgroups, using the international Food Science and Technology Abstracts (FSTA) database as a model, followed by coding and selecting proper keywords. Data entry was carried out making use of a programmed software (using Visual Basic). The data were processed and the compact disk (CD) of the Iranian Food Science & Technology Data Bank was produced for the period 1978-2006. Relative frequency distribution of the documents was determined according to the type of document, publication time, subject, and also the role of journals and conferences. Finally, the contribution of universities and research institutes in publishing the documents during the 2002-2006 was determined. The total number of documents collected for the period 2002-2006 was 5428, consisting of 767 (14.1%) journal articles, 2083 (38.4%) conference articles, 421 (7.8%) research projects, 939 (17.3%) theses/dissertations, 263 (4.8 %) books, 693 (12.8%) food standards, and 262 (4.8%) patents. During this period, the total number of documents was found to have an increasing trend. The highest numbers of documents were on fruits, vegetables and nuts (17.1%), milk and milk products (13.7%), and food additives, spices and condiments (11.0%) groups, while the lowest numbers were on cocoa, chocolate and confectionary products (0.5%), eggs and egg products (0.6%), and food economics (1.2%) groups. Journals, conferences, educational and research centers with the highest contribution in producing scientific documents were identified. The data revealed the important role and contribution of universities in publishing articles. Tehran, Tarbiat Modarres, Shahid Beheshti Medical Sciences, Shiraz, and Ferdowsi Mashhad universities ranked 1 to 5 with regard to publishing articles in journals. This investigation on the Iranian Food Science and Technology Data Bank not only showed the present status but also helped identify the needs and gaps in this field. This information will make it possible to plan better educational and research programs in the field of food science and technology in Iran.