Food Technology
Maryam Khosravani; Seyyed Moein Nazari; Gholamhasan Asadi
Abstract
Introduction In recent years, increasing consumer awareness of the dangers of consuming high-fat products, sensitivity to proper nutritional patterns and the impact of health factors has increased consumer demand for low-fat or free-fat foods. Scientific researchers have provided a great quantity ...
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Introduction In recent years, increasing consumer awareness of the dangers of consuming high-fat products, sensitivity to proper nutritional patterns and the impact of health factors has increased consumer demand for low-fat or free-fat foods. Scientific researchers have provided a great quantity of evidence between the consumption of high-fat products and the development of diseases such as obesity, hardening of the arteries, chronic hypertension, etc. Fat removal is not an easy task because fat, in addition to nutritional aspects, affect rheological and sensory properties such as mouth feel and texture properties of the final product. Using alternative materials that can be completely or partially replaced fat in the formulation of low-fat products by imitating the properties of fat is great important. Unlike fat, which its high consumption causes many problems; fiber can play a vital role in many of the nutritional, functional, and sensory properties of food products, Some types of fiber act as fat substitutes, while producing less energy, provide a large effect of fat function properties. Increasing consumption of easy-cook meat products such as sausages induced replacement the fat content in the formulation of these products, by fat substitutes such as maltodextrin. The aim of this study was to evaluate the chemical and sensory properties of low fat German sausages produced by maltodextrin. Materials and Methods In this study, 0, 6, 12, and 18% of fat was replaced by maltodextrin in the formulation of German sausage. The chemical and sensory properties were then investigated. Chemical properties including moisture, protein, ash, and fat were accomplished according to the ISIRI standard. Evaluation of sensory properties was done by 5-point hedonic method according to Click et al. (2006). Data analysis was performed using SPSS software in a completely randomized design with a 95% confidence level. Results and Discussion The results showed that with increasing the level of maltodextrin, the amount of moisture, ash, and starch of sausage samples increased significantly. As the concentration of maltodextrin increased, the protein content of the samples decreased. The highest protein content observed in the control sample and the sample contained 6% maltodextrin and in contrary, the lowest protein content was in the sample containing 18% maltodextrin and there was no statistically significant difference between the test samples (p>0.05). Changes in maltodextrin concentrations had a significant effect on the fat content of sausage samples so that with increasing the concentration of maltodextrin in the sausage formulation, the fat content of the samples decreased (p≤0.05). Also, with increasing the percentage of maltodextrin replacement in German sausage samples, the cooking yield decreased significantly (p≤0.05). In the evaluation of sensory properties, it was found that the use of maltodextrin reduced the score in all parameters studied so that the lowest score in terms of color, texture, flavor, and total acceptance of sausage samples was related to sample with 18% maltodextrin replacement. Conclusion The vital role of the effect of dietary fiber on improving and managing the health has been proven by researchers for many years. Due to the need to reduce fat in products such as sausages, which considered as a popular meat product and based on the results observed in the present study, it is recommended to use maltodextrin fiber at the level of 6% as a fat substitute in the formulation of German sausages.
Food Chemistry
Shaghayegh Mirehsanpazir; Maryam Gharachorloo; Gholamhasan Asadi
Abstract
Introduction: Today, in developed countries, where there is a deep dependence on processed foods, food fortification has played a major role in the health of these communities over the past 40 years and has led to the eradication of malnutrition in these countries. Omega-3 is a type of unsaturated fatty ...
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Introduction: Today, in developed countries, where there is a deep dependence on processed foods, food fortification has played a major role in the health of these communities over the past 40 years and has led to the eradication of malnutrition in these countries. Omega-3 is a type of unsaturated fatty acid that is composed of a carboxyl group (COOH) and a carbon chain with several double bonds. Clinical trials have shown that omega-3 deficiency can increase the risk of diseases such as mood problems and anxiety, psychosis, attention deficit disorders, obsessive-compulsive disorder, personality disorders, depression, dementia and autism. In fact fatty acids have a protective effect against psychiatric disorders, especially in people at high risk. The use of fatty acid compounds directly in food enrichment causes problems such as autoxidation, malnutrition, reduced bioavailability as well as instability against light and heat, which has led to the use of various techniques to encapsulate. Microencapsulation is the process of employing a carrier for sensitive microorganisms and compounds with high instability as well as high cost to protect the external environment, thus reducing cell damage. Natural polymers are based on available materials for their biodegradability, food compatibility and viability of controlled transmission systems. The structure of emulsions consists of scattered droplets of one liquid (suspended phase or internal phase) in another liquid (continuous phase or external phase). Emulsions with a particle diameter of nanometers and, according to most authors, a maximum of 500 nanometers are called microemulsions. There are different techniques for producing microemulsions, each of which produces microemulsions with different properties, and each has advantages and disadvantages. In this study, semi-fat spread butter was prepared with omega-3 microemulsion. Materials and Methods: The aim of this study was fortification of half-fat spread butter with microemulsion containing omega-3 based on emulsification/ gelation microemulsification method. Microemulsions were prepared according to the method of (Chen and Subirade, 2006) with some modifications. From each of the microemulsions containing omega 3 with concentrations of 400, 500, 600 and 700 mg of omega 3, 10 mg per 100 g of butter sample was added and rubbed until a homogeneous mixture was obtained and stirred thoroughly. After that, the product was packaged at a maximum temperature of 16 ° C and transferred to a refrigerator below zero (-18) ° C, and then evaluated at the time production day and the first, second, third and fourth months. Evaluation of size, polydispersity index of microemulsions morphological characteristics, omega-3 trapping rate in microemulsion and omega-3 release rate on the basis of the method (Chen and Subirade, 2006) was done. The amount of peroxide was measured idiometrically - the end point was determined visually according to National Standard No, 4179. Butter acidity was done by titration method according to National Standard No, 4178. Sensory characteristics such as taste, color, odor and general acceptance were assessed using 15 trained evaluators based on a 5-point hedonic test. Results were analyzed with analysis variance and (α = 0.05) with software SPSS version 22. Results demonstrated that the average size of microemulsion was between 95 -119 nm. The loading efficacy of omega 3 was between 65-79%. Results and Discussion: Fish oil is the main food source of long-chain unsaturated fatty acids that have healing effects on the body. Studies have shown that eating fish oil-fortified foods has potential health benefits, especially protection against heart disease, cancer and improved brain function. In this study, omega-3 microemulsions were used to enrich half-fat spread butter. According to the results of the present study, the particle size of the microemulsion was between 95 and 119 nanometers. The omega-3 trapping rate was between 65 and 79 percent. The results showed that peroxide, acidity and sensory indexes of butter treatments during storage showed a significant increase until the end of the fourth month of storage. The least amount of changes in sensory and physicochemical indices were observed in the treatment of butter with microemulsions with 500 mg omega 3 and the highest amount of changes was observed in the pasteurized control butter. Finally, the treatment of pasteurized semi-fat spread butter with 500 mg of omega 3 was selected and introduced as the optimal treatment.
Marjan Haji Bagher Naeeni; Behjat Tajeddin; Gholamhasan Asadi; Babak Ghiassi Tarzi
Abstract
Introduction : Over the past 30 years with population growth, plastics have played an important role in the people's lives and its consumption is increasing. However, the most important problem of synthetic packaging materials is their total non-biodegradability that is causing environmental pollution.In ...
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Introduction : Over the past 30 years with population growth, plastics have played an important role in the people's lives and its consumption is increasing. However, the most important problem of synthetic packaging materials is their total non-biodegradability that is causing environmental pollution.In recent years, concerns about the environmental problems caused by packaging materials and plastic derived from petroleum products as well as consumer demand for qualitative food products, hascaused researchers to find alternative materials with high biodegradability, which has led to the development of biocomposites.Therefore,wheat straw-low density polyethylene composite (as a renewable material) was prepared in order to reduce the consumption of plastics in the packaging industry and the effect of two different compatibilizers, maleic anhydride polyethylene (MAPE) and polyethylene glycol (PEG) on mechanical and physical properties of obtained biocomposites was investigated.Materials and Methods: Wheat straw (WS) was first dried at 30 ℃ for 24 hours. It was then manually cut to 2-3 cmpieces manually and then was milled. The ground wheat straw was screened through 40 mesh sieve. After that, all materials including WS flour, LDPE, MAPE , and PEG were blended to prepare the different biocomposites by twin-screw extruder. The extruded materials were cut into smaller pieces proper for the next processing step by grinder.grinded. The obtained granules were then placed in the injection-molded machineto create the test samples.so combinations, respectively, were considered : WS, LDPE, MAPE (sample 1) WS, LDPE, PEG (sample 2) , LDPE (sample 3) and WS, LDPE (sample 4).Water absorption test was performed according to ASTM D 570-98 in order to study the amount of moisture absorbed by the composite samples. The samples were weighed for 9 weeks, the first time, after 24 hours, then once a week. For this purpose, samples were taken out of the water then surface moisture was dried, finally moisture absorption was calculated according to weight changes.Biodegradability test was carried out based on soil burial method for 4 monthsaccording to ASTM 6400-99. In this test, samples were taken out of the soil and washed by water every 15 days. They were thenplaced in an oven at 100℃ for 24 hours. Subsequently, samples were weighed by a digital scale with an accuracy of 0.1 mg.The amount of degradation was calculated by controlling weight changes over the time.The tensile strength, the maximum amount of force taken by a material before its failure was performed to evaluate the effect of natural fiber on the composite characteristics. It is measured with units (Pa) and (Mpa). The test was done according to ASTM D 638-08by Instron machine.The flexural strength of a material is defined as its ability to resist deformation under load. The test was done according to ASTM D790-10by Instron machine.It wasalso measured with units (Pa) and (Mpa). Result and Discussion: The results showed that the use of PEG compare with MAPE greatly increased the rate of water absorption and biodegradation of samples. It may be because of PEG's hydrophilic property that cannot act well as MAPE. Therefore, it creates an improper and weak interface adhesion between the wheat straw and polyethylene, resulting in gaps and cracks in this section. Thus, water absorption is higher in composites containing PEG. These factors also caused faster degradation in samples containing PEG. However, the use of MAPE in the composites improved surface adhesion between the wheat straw fiber and polyethylene, and therefore less water absorption and degradationwas observed.In terms of mechanical properties samples containing MAPE had greater tensile and flexural strength compared to samples containing the PEG.Because MAPE creates an ester bond in composite, which improves the interfaceadhesion of wheat straw particles and polyethylene, but when the PEG used, adhesion between wheat straw particles and polyethylene is not enough to increase the efficiency of stress transfer from the matrix to the fibers.Since almost all properties of materials are associated with each other, it cannot be introduce a combination that all properties is best. Therefore, when high biodegradability is desired, sample containing PEG is suitable but in terms of mechanical properties and resistance to water absorption, the sample containing MAPE is best combination.
Bahareh Davarnia; Ali Motamedzadegan; Gholamhasan Asadi; Abdolmohammad Abedian Kenari; Mahmoudreza Ovissipour
Abstract
Enzymatic hydrolysis of Yellowfin tuna visceral protein with Neutrase has been carried out by response surface methodology using factorial design. Peptide chain length was estimated as the response surface to the hydrolysis conditions (enzyme activity, reaction temperature, and reaction time). The tuna ...
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Enzymatic hydrolysis of Yellowfin tuna visceral protein with Neutrase has been carried out by response surface methodology using factorial design. Peptide chain length was estimated as the response surface to the hydrolysis conditions (enzyme activity, reaction temperature, and reaction time). The tuna visceral protein hydrolysate had relatively high protein (74.56%) and low lipid content (1.86%). R2 of 0.85for the mathematical model indicated that 85% of the variability within the range of values studied could be explained by the model. Enzyme activity of AU/kg protein, temperature of 50°C, and hydrolysis time of min were the optimal conditions of hydrolysis. The electrophoresis pattern of the Yellow tuna hydrolysate showed no peptides size bigger than 10 KDa. The chemical score of the hydrolysate indicated that it fulfils the nutritional requirements of children with age 10-12 except Lysine and Methionine. Lysine and Methionine were the first and the second limiting amino acids, respectively and in case of children with age 2-5 lysine was predominant amino acid in the hydrolysates. It could be concluded that by application of enzymatic hydrolysis of Yellowfin tuna viscera protein, the properties of protein hydrolysate was improved.
Zahra Emam-Djomeh; Rasoul Ghaheri; Gholamhasan Asadi
Abstract
In this research the effect of substituting sugars (glucose and sucrose) by low caloric sweeteners (sorbitol and isomalt) on the physical properties of Gazz was studied. Textural properties of Gaz were investigated using Instron and micro-structure was studied by Scanning Electron Microscope (SEM). The ...
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In this research the effect of substituting sugars (glucose and sucrose) by low caloric sweeteners (sorbitol and isomalt) on the physical properties of Gazz was studied. Textural properties of Gaz were investigated using Instron and micro-structure was studied by Scanning Electron Microscope (SEM). The results of texture investigation showed that the sample containing 25% of sorbitol and 65% of isomalt had the most similarity with the control sample. Increasing the content of sorbitol will soften the texture. Micro-structural studies showed that the texture of control sample has lots of bubbles inside, and this will decrease its density in comparison with dietary Gazz. No bubbles were observed when low caloric sugars were replaced which can be explained by the functional properties of sorbitol including its lubricant characteristics. This fact can led to a decrease in the density of the product in comparison with the control one.
Keywords: Gazz, Low caloric sweeteners, Isomalt, Sorbitol, Texture
