Journal of Food Technology and Nutrition
Year:2013 | Volume:10 | Issue:3 (39)|Papers Count:12

Introduction: Arabic gum is a high applicable substance in the food industry as it has good functional properties as well as worthy health characteristics. In this study, it was aimed to compare the rheological properties of arabic gum in aqueous solutions and oil in water (O/W) emulsions containing different concentrations of arabic gum.Materials and Methods: Solutions and emulsions with different concentrations of Arabic gum (0.1, 5, 10 and 20%) were prepared and their viscosities were determined. The emulsion stability of the prepared emulsions was also measured and their microstructures were evaluated using optical microscope.Results: The viscosity of solutions and emulsions containing arabic gum was increased with gum concentration. Arabic gum showed Newtonian behavior in the tested mediums, although a shear thinning behavior was observed for emulsion stabilized with 20% arabic gum. According to ‘‘Ostwald–de Waele’’ model, the consistency (k) of all samples, both solutions and emulsions was increased and the flow index (n) values were near to 1 indicating a Newtonian behavior. Rheological behaviors of all samples were modeled with Power law and Casson models with great correlation coeffients. Addition of arabic gum increased the emulsion stability of O/W emulsions. This stability was increased with increasing gum concentrations.Conclusion: The rheological behavior of arabic gum was similar to both solutions and emulsions. According to the results of this study, arabic gum can be used as an effective stabilizer as well as a very efficient emulsifier as it emulsified the emulsions well in low concentration (0.1%).

Introduction: Presence of dietary fibre in food has beneficial health effects namely reduction of blood sugar and cholesterol and reducing the prevalence of cardiovascular and chronic diseases. Rice bran that is a byproduct during milling process is a product rich in dietary fiber. This study reveals some compositional and functional analysis of dietary fiber extracted from rice bran using chemical and enzymatic methods.Materials and Methods: Rice bran that is provided from Gillan barns was employed for fibre extraction using both enzymatic and chemical methods after fat was extracted. Two different dietary fibres obtained were compared for extraction yield, chemical composition such as (moisture, protein and ash) and functional properties such as (Water Binding Capacity and Fat Binding Capacity) and comparisons were also made with fibre extracted from wheat.Results: The results showed higher yield from enzymatic method (67.53%) as compared to the chemical method (33.97%). Protein content of fibres extracted by chemical method was higher and the ash content was lower than enzymatic method. Water Binding Capacity and Fat Binding Capacity in enzymatic fibres had significant increases as compared to the fibres extracted by the chemical method and wheat fibre.Conclusion: Rice bran had 67% dietary fibre using enzymatic extraction method. This fibre has more WBC and FBC than fibers extracted by chemical method and might be employed in development of value added foods known as functional foods.

Introduction: Many products that are produced today are the result of a multi-stage process. This means that a multivariate process is carried over several successive stages. In each stage, one or several different qualitative characteristics in accordance with process specifications might be selected as a key to qualitative control.Materials and Methods: The line of refining raw sugar in Hamedan sugar factory was reviewed during a month. All effective quality variables were measured in the process based on an autocorrelation model. Regression analysis was taken to evaluate the product quality.Results: A new method is presented for statistical quality control of multi-stage process (refining raw sugar) based on cause selecting control chart and autocorrelation. The quality of sugar produced might be evaluated during the process with respect to regression analysis. Thereby the production of poor quality sugar can be prevented with corrective action. The application of this method and its implementation can produce white sugar in different arbitrary quality.Conclusion: Among the variables examined, highest correlation coefficient exists between pH of second cooking, polarization of Molasses, brix of raw syrup with quality of final product (set of footprints). Autocorrelation for product quality (set of footprints) was also observed.

Introduction: Cakes containing cream filling are consumed by a large number of people. The quality of this improving this product as a food containing functional properties might have important roles in human health promotion. The objective of this study is to evaluate the survival of free and microencapsulated B. bifidum in water-based filling.Materials and Methods: Bifidobacterium bifidum ATCC 29521 was encapsulated with calcium alginate and chitosan via emulsion technique and inoculated in cream filling individually in three different forms; non-encapsulate, encapsulated with calcium alginate and calcium alginate coated with chitosan. The survival and effect of free and encapsulated bacteria on pH and sensory attributes of cream-filled cake were monitored during 30 days storage at 4oC and 25oC. The morphology and size of microcapsules were measured by SEM technique and particle size analyzer.Results: The survival of microencapsulated probiotic bacteria in calcium alginate and chitosan coating was increased significantly (P<0.05). Microencapsulated B. bifidum did not change the pH of cream-filled cake during storage. The probiotics survived better at 4oC (P<0.05). The addition of probiotic cultures either in the free or encapsulated forms did not significantly affect texture, colour and flavour of the product over the storage period (P>0.05).Conclusion: Microencapsulation with calcium alginate and chitosan coating helps to enhance the survival of probiotic bacteria in product during storage.

Introduction: Vegetables and fruits are susceptible to spoilage due to their high moisture content. Increasing drying time might be regarded as the major cause of losses in agricultural products. The aim of this research is to decrease drying time by using combination of FIR and convective drier.Materials and Methods: This study is concerned with a mathematical modeling based on thin layer drying model in convective drier and evaluates the combined convective and radiation drying methods and also investigates the effects of air inlet conditions on the moisture content and on the drying time. The mass and energy balance of the system were solved simultaneously using a numerical technique. The model was applied to air temperatures of 30 to 60°C and air velocity of 1 to 3m/s to evaluate the model. The model equation was solved numerically by using MATLAB software.Results: The results of the model were compared with the reference data and showed a good agreement. The drying rate was increased with increases in the temperature and velocity, therefore reducing the total drying time. The prediction of the average moisture content, air temperature and drying time as compared with the experimental results are in good agreements.Conclusion: In order to increase the efficiency, FIR and convective drier were combined and applied. The results indicated that the drying time in combined method is reduced by 58%.

Introduction: Mango seed kernel oil might be considered as nutritive and healthy oil, free of unwanted impurities and to some extent regarded as a replacement for some fat employed in food industry. The object of this study is to evaluate the physico-chemical characteristics of the oils extracted from three different varieties of mango seed kernel cultivated in Iran.Materials and Methods: The oil was extracted by application of Soxhlet procedure using hexane as the extracting solvent. The extracted oils were subjected to a series of physical and chemical tests consisting of acid value, iodine value, peroxide value, saponification value, induction period determination, fatty acid composition, reflective index determination, color measurement and isolation and fractionation of nonsaponifiable matter.Results: Mango seed kernel constitutes 6.7 to 7.0% of the total weight of the fruit. The kernel contains 10% oil where the total saturated fatty acid constitutes approximately 55% of the fatty acids present in the oil. The results indicated that the Payvandi variety was more resistant to oxidation and had higher concentration of nonsaponifiable matter and higher refractive index as compared to other varieties.Conclusion: It might be concluded that all the varieties had similar composition however the Payvandi variety had higher concentration of nonsaponifiable matter meaning that higher concentration of tocopherols or sterols might be present in this valuable fraction affecting the stability of the oil.

Introduction: Osmotic dehydration is a viable process for the partial removal of water from plant tissues such as fruits and vegetables. The main advantage of this process is its influence on the principal drying method, shortening of the drying process, resulting in lower energy requirement. Considering that heat is not applied in this stage, osmotic dehydration offers higher retention of food characteristics, such as color, aroma, nutritional constituents, and flavor compounds.Materials and Methods: The effects of temperature (30-55 C), concentration of osmotic solution (40-60, w/w), time of contact (120-300 min), initial vacuum (100-300 mbar for 15 min) at the beginning of the process (pulsed vacuum osmotic dehydration, PVOD) and drying temperature (40-70oC) on color changes and WL (water loss) to SG (solid gain) ratio of orange slices were studied. The optimization of combined process was carried out by Response Surface Methodology with Central Composite Design.Results: The analysis of variance showed that a linear model predicted well the experimental data. The applied temperature of osmotic solution and drying temperature had the main effect on responses. Optimization conditions were based on the higher water loss to solid gain ratio and lower changes of color.Conclusion: The followings; 35oC for osmotic temperature, 60% for sucrose concentration,180 min for osmotic time, 240 mbar for pressure and 41.5oC for drying temperature were considered as optimal conditions for the above investigation.

Introduction: The role of the food and its supply to deprived people in an emergency situation particularly during armed conflict and the concern of international community in respect to such situation from the point of international humanitarian law is a dominant subject. It is therefore necessary that such issue to be investigated thoroughly.Materials and Methods: The method applied for this research is based on common methods of descriptive social sciences and analysis.Results: Regarding documental studies connected with the international humanitarian law in relation to the right to food, it is indicated that conventions and related protocols have identified the situation and have stated the commitments of all sides of the conflict concerned with the people in need of food.Conclusion: In respect of international humanitarian law and conventions and agreed protocols, during international armed conflict and hostilities as well as occupation the use of food as a tool in the conflict to provide hunger that might lead to genocide is considered as a war crime, a crime against humanity. Therefore the international humanitarian law insists on provision of food aids to civilian during armed conflicts.

Introduction: Selenium is an effective inorganic element that plays an important role in human body. It is essential for the prevention of cancers, e.g. liver cancer. It is dangerous to use selenium as a food complement by itself; therefore it is necessary to be taken in regular diet.Materials and Methods: In this research, total selenium, selenium (IV) and selenium (VI) are extracted with three different methods (Acid digestion, Microwaves, Ultrasonic) and are measured in 10 different vegetables (garlic, onion, thyme, date, cabbage, carrot, cucumber, parsley, dill and lettuce) using VGA-AAS.Results: All three extraction methods have shown that selenium has the least concentrations in carrot and cucumber, also selenium (VI) is present in trace quantity in date kernel. The total selenium has the highest concentration in parsley and the least quantity in date and thyme. The amount of selenium (IV) is high in parsley and is low in thyme and dill and also selenium (VI) is present in high concentration in cabbage and in trace quantity in thyme.Conclusion: It is concluded that Selenium (VI) is the predominate form as compared to selenium (IV). Only in the parsley Selenium (IV) has higher concentration than Selenium (VI). Among the extraction methods examined, ultrasonic method was proved to be superior to others.

Introduction: Campylobacter jejuni and C. coli are among the most common causes of acute bacterial enteritis disease in human throughout the world. The veterinary use of antimicrobial drugs has been suggested to be largely responsible for resistance in human isolates of this zoonotic pathogen.Materials and Methods: This study was conducted to determine the antimicrobial resistance pattern of Campylobacter spp. isolated from retail raw meats in Shahrekord, Iran. Antimicrobial susceptibility testing for 193 C. jejuni and 20 C. coli isolated strains from raw chicken, turkey, quail, partridge, ostrich, beef, sheep, goat and camel meat samples were performed by disc diffusion method according to the Clinical Laboratory Standards Institute.Results: Overall, 191 of 214 Campylobacter isolates (89.3%) were resistant to one or more antimicrobial agent. Thirty six strains (19.3%), 64 strains (34.2%) and 84 strains (44.9%) of Campylobacter strains were resistant to single, two and three or more of drug tested, respectively. Resistance to tetracycline was the most common finding (72.4%), followed by resistance to nalidixic acid (48.6%) and ciprofloxacin (40.2%). All Campylobacter isolates were susceptible to gentamicin and one of the Campylobacter coli isolated from chicken and turkey meat samples was resistant to chloramphenicol and erythromycin, respectively.Conclusion: Due to the increased reports concerned with the antimicrobial resistance of Campylobacter worldwide, attempts should be made to control the use of antimicrobial drugs in animal husbandry.