Journal of Food Technology and Nutrition
Year:2016 | Volume:13 | Issue:2 (50)|Papers Count:11

Introduction: Dried vegetables such as mint are usually prepackaged irradiated to prevent the post contamination and reduce the microbial population. This process might affect the type and the amount of natural volatile essential oils of the product and also some ions, free radicals and low molecular weight volatile compounds might be released from the packaging materials due to radiolysis reactions migrated into the package and might be adsorbed onto product.Materials and Methods: Dried mints, the mixtures of two species (spearmint, peppermint) were packaged in pouch of three layers of polypropylene film and were irradiated at 8, 10 and 15 KGy. The changes in the natural volatile compounds of the product and those that were released from packaging and were isolated by distillation-extraction technique were analyzed using gas chromatography equipped with flame ionization detector.Results: 59 different compounds were identified which might be classified into the following groups: a) the essential oils which were completely destroyed at three different doses (Sabinene, 7-myrcene). b) The essential oils which their concentration were increased by increasing the irradiation dose (Trans sabinene hydrate, cis-jasmone). c) The essential oils which were safe in the lower doses but partially lost at 15KGy. d) Chemical volatile compounds from polymeric packaging material which migrated into the package (tert-butyl benzene).Conclusion: The results indicated that essential oils from spearmint were more sensitive to irradiation than peppermint. To save the functional quality and also safety of prepackagedirradiated dried mint, processing dose may not exceed from 8KGy and more resistant mint species such as peppermint should be packaged in polymeric materials with lower sensibility to irradiation, i.e. polyethylene terephthalate.

Introduction: Fermented ice cream is a new dairy dessert with low amount of fats and sweeteners as compared to the typical ice creams. Since kefir contains collections of various bacteria and yeasts with unique nutritional, sensory and desired functional properties, it is considered as an unique product in dairy industry. The aim of this study is to use kefir in ice cream formulation and investigate the substitution of sugar by the date syrup and in addition study the effect of arabic gum as a stabilizer on the physicochemical and sensory properties of the ice cream.Materials and Methods: In this study, kefir is first produced and then used in the ice cream formulation. Then effects of sugar substitution by date syrup (0%, 25%, 50% and 75% w/v) and arabic gum (0%, 0.1%, 0.2% and 0.3% w/v as stabilizers) on physicochemical (acidity, pH, viscosity, overrun, melting rate and first dripping time) and sensory properties of orange kefir ice cream were investigated.Results: The results indicated that the application of date syrup and arabic gum caused increases in the acidity, apparent viscosity, overrun, first dripping time and decreases in melting rate and pH of the ice cream samples. Organoleptic scores were decreased by increasing the date syrup and arabic gum concentrations.Conclusion: By considering the kefir microbial flora activity on the physicochemical properties of the product, it might be concluded that 25% date syrup and 0.2% arabic gum concentrations are the most suitable sugar and stabilizer substitution in the production of kefir ice cream.

Introduction: Helicobacter pylori is a common infectious disease that has numerous side effects. The impact of these infections because of decreased iron absorption in reducing gastric acid secretion and the consequent anemia has been mentioned. In this study, a comparative study concerned with the prevalence of iron deficiency anemia in infected and non-infected persons with Helicobacter pylori in the city of Kashan have been studied.Materials and Methods: The people who were referred to the laboratory to evaluate the antibody IGg were 412 people of whom 229 were infected and 183 were non-infected.3 ml of blood samples were taken to measure the serum ferritin (SF) and complete blood count (CBC).Results: The mean and standard deviation of competing blood counts based on the status of infection with H. pylori showed that the serum ferritin (SF) in the infected patients was less than the non- infected persons (p=0.04) and this difference based on gender was significant in women (p<0.001). The indices showed that the SF in all age groups of infected persons is Less than non infected persons and this difference in persons over 60 was also significant (p<0.001). Also in the women over 30, the mean of SF in infected persons was less than the non infected persons and this difference was significant (p<0.05).Conclusion: The results showed that the amount of SF of H. pylori infected women especially in those over 30 significantly has decreased that might be due to the impairment of iron absorption in the infected persons.

Introduction: Extra virgin olive oil represents the popular source of oil in the Mediterrian countries. The price of extra virgin olive oil is increasing rapidly in the world market, due to many factors namely special organoleptic and health attributes. Therefore this popular oil might be subjected to adulteration. In this research, the application of Differential Scanning Calorimeter (DSC) and fatty acid profile methods to detect the adulteration of sunflower seed oil in extra virgin olive oil has been studied.Materials and Methods: Refined sunflower seed oil was added to extra virgin olive oil at different portions (5, 10, 15 and 20 percent) and the thermal analysis of the samples were performed using DSC and the fatty acid composition of the samples were determined by GC apparatus.Results: The results of the thermal analysis showed that the addition of sunflower seed oil created significant changes in cooling and heating thermograms of DSC. The enthalpy, onset and maximum temperature of major crystallization peak for at least 10% adulteration and the enthalpy and maximum temperature of minor melting peak for 5% adulteration indicated significant differences as compared to the extra virgin olive oil (P<0.05). The results also indicated that the major fatty acids in the mixture with at least 5% sunflower seed oil showed significant differences as compared to extra virgin olive oil (P<0.05). The quantities of behenic and linoleic acids in the mixtures of 15 and 20 % added sunflower seed oil to olive oil indicated higher amounts than those defined as standard values. maximum limit of standard value.Conclusion: The DSC method might be evaluated as a valuable method to detect the adulteration of refined sunflower seed oil in extra virgin olive oil however this method has its limitations regarding the percent of added oil.

Introduction: Processed cheese is the resulted of the combination of natural cheese with dairy and non-dairy elements. A simple type and production technology of processed cheese is based on the application of low quality cheeses with wide extent of flavor and texture that has resulted in the increased production of this product as a suitable substitute for the natural cheese. The aim of this study is to optimize the replacement of milk fat with the sunflower oil at different times and temperatures of cooking through the slow cooking method concerned with the physical properties of the processed cheese.Materials and Methods: In this study, response surface methodology (RSM) was employed to investigate the effect of vegetable oil concentration (20, 30 and 40%), cooking temperature (65, 75 and 85oC) and time (5, 10 and 15 min) on the physical properties of the cheese that consisted of hardness, meltability and oiling-off through the slow chilling method.Results: As the vegetable oil concentration increased, the cheese hardness decreased (P<0.01) and there were no significant differences in the oiling off and meltability of the cheese. The effect of time and temperature of cooking was inversely related to the vegetable oil concentration.Conclusion: The optimum conditions for the production of the processed analogue cheese were the vegetable oil concentration of 20%, cooking temperature of 85oC and time of 15 min under which the optimum values for the hardness, meltability and oiling-off were 23.337, 237.5 and 228.2% respectively.

Introduction: Due to the problems concerned in urban life and the consequences of noncommunicable diseases such as diabetes, cardiovascular disease and cancer, it is necessary to change the eating habits as a way to help and slow down the diseases. Camel milk is a healthy valuable sourcethat can be presented on the consumers table and can be fermented to extend its shelf life. This research has studied the thermal process of camel milk with producing Exololysaccharide bacteria which in addition exhibits antioxidant activity and is effective in improvement of the sensory characteristics of fermented process.Materials and Methods: Camel milk has been heated at 85oC for 15 minutes and then is impregnated with Exopolysaccharide bacteria including lactobacillus casei TD4, lactobacillus casei T20, and lactobacillus plantarum.After incubation periods of first, seventh, fourteenth and twenty first days the physico-chemical characteristics particularly the antioxidant and sensory properties were evaluated.Results: The findings determined that the thermal process apart from the safety increased the shelf life of the product. Strains producing Exopolysaccharide beside the products as the result of fermentation like lactic acid give the product more acceptability from consumer viewpoint and also have significant role in increasing the antioxidant activity. These products at refrigerator temperature after 14 days have the highest antioxidant property.Conclusion: This research work indicated that the thermal process did not exhibit significant effect on the chemical composition and antioxidant activity of the product. In fact fermentation by suitable lactic bacteria makes it valuable due to the increase in the shelf life.

Introduction: Optimum machinery and equipment designing for transportation, harvest and processing of agricultural products need the knowledge of physical and mechanical properties of the products.Materials and Methods: In this research, the physical properties consisting of dimensions, mass, average geometrical diameter, sphericity, surface area, volume and the process of moisture attraction and the mechanical properties including force, deformation, rupture energy and power of almond the variety of Rabi were determined and evaluated.Results: The average of geometrical diameter for the whole almond was 22.37 mm and for its kernel was 13.42 mm. The sphericity for the almond and its kernel were 0.654% and 0.523% respectively. By placing some samples of almond kernel in the water, the process of moisture absorption of almond kernel was studied and the mathematical models were presented. The moisture absorption of the kernel when placed in the water for a period of 9-13 hours was 36-41% and this raised to 44% after 18 hours.Conclusion: Statistical coefficient of friction of almond and its kernel on glass and galvanized iron was the minimum, respectively. Study of the effect of moisture on the statistical coefficient of friction showed that by increasing the moisture, this coefficient increased.Investigation concerned with mechanical properties showed that the effect of loading speed and direction on rupture force, energy and power in probability level of 1% were significant. Power consumption to rupture almond was increased by increasing the speed from 50 to 200 mm/min. By increasing loading speed the rupture force was significantly decreased and deformation in rupture point was increased. Rupture force of almond in loading in the direction of axis was minimum.

Introduction: The use of gluten free flour is gradually gaining prominence worldwide due to the nutritional reasons for bread making. The most common disease caused by the protein, prolamin ingestion is celiac and the only effective treatment is to strict the diet free of prolamin.Materials and Methods: This paper examines the effect of two different hydrocolloids, Qodume shahri (QSG) and xanthan gums (XG) at the concentrations of 0, 0.5 and 1% (w/w flour basis) on the rheological properties of dough and sensory characteristics of bread produced from gluten free sorghum flour. The crumb cell structure was also studied using digital image analysis technique.Results: The results showed that the hydrocolloids QSG and XG had positive effects on the bread quality and sensory acceptability of fresh gluten free bread. The results indicated that the addition of either of the two cited hydrocolloids could improve the quality of the dough and bread produced.Conclusion: According to the results it might be concluded that Qodume shahri gum acts quite similar to xanthan gum. The work also indicated that the bread produced by wheat flour has slightly higher acceptability by consumer as compared to the gluten free bread produced but the production of latter is quite possible.

Introduction: Preservation of natural colour, as a quality attribute and characteristic of beetroot concentrate might be considered as a possibility if the knowledge of kinetic of color change is studied thoroughly.Materials and Methods: Three different heating/evaporation processes were employed for the production of beetroot juice concentrate. The juice was concentrated to a final 40o Brix from an initial °Brix of 10 by microwave heating, rotary vacuum evaporator and evaporating at atmospheric pressure.Results: The concentration of the final juice at 40o Brix was achieved in 40, 43 and 70 minutes by using microwave, rotary vacuum and atmospheric heating processes, respectively.The changes in colour during the concentration processes were investigated. Total colour differences (DE) and L, a and b parameters were used to estimate the extent of colour changes by using Hunter Lab equipment. All colour parameters were decreased with time. The zeroorder, first-order and a combined kinetics model were applied to the changes in colour parameters.Conclusion: The results indicated that the variation in TCD followed both first-order and combined kinetics models, and parameters L, a and b followed only the combined model.This model implied that the colour formation and pigment destruction occurred during concentration processes of beetroot juice.

Introduction: Dried garlic with various nutritional and medicinal values is used in food industry as flakes or powder. The nutritional and medicinal properties of garlic are attributed to Allicin. This substance (a compound of Tyosulfinates) is produced enzymatically after crushing. Since the temperature affects the enzymatic action that results in pirovic acid and allicin. The size and temperature are two critical factors to prevent color change and reduce allicin and pirovic acid present in garlic during drying process.Materials and Methods: This study investigated the effects of sample size and temperature on qualitative characteristics such as color of powder and pirovic acid and alicin retention in a convective hot-air dryer. For this reason whole and half and minced Shushtar garlics (Allium sativumL.) were dried at air temperatures of 50 and 70oC with the relative humidity of 22%.Results: According to the obtained results by increasing the temperature from 50 to 70 °C the color of half garlic have changed and allicin and pirovic acid have been increased. The quantity of pirovic acid and color of the minced samples were not affected significantly by the temperature of drier but allicin content of minced samples were reduced by increased temperature. Whole garlic dried at 70oC was not affected by change in color but the quantities of present allicin and pirovic acid were reduced considerably.Conclusion: According to the findings in this research work the condition that the halved samples were dried at 70oC could be regarded as the best condition for producing garlic powder.