جستجوی مقالات مرتبط با کلیدواژه « physical » در نشریات گروه « صنایع غذایی »

In recent years, natural polymers such as quince seed mucilage  have received much attention for their replacement with plastics derived from petroleum derivatives in the production of packaging films. Polyols are one of the most important plasticizer to increase the efficiency and mechanical properties of biological films. The aim of this study was the effect of different concentrations of sorbitol (20, 35 and 50% w /w) on physical (water solubility, moisture, water vapor permeability, color, hydrophobicity), mechanical properties of quince seed mucilage based film. The results showed that with increasing sorbitol concentration, the water vapor permeability, tensile strength, water solubility, the moisture content and contact angle was decreased. By increasing sorbitol concentration, L* b* and a* index of films decreased, increased, increased, respectively.  The water vapor permeability of produced films was affected by the relative humidity of the environment. Comparison of the effect of glycerol and sorbitol at the same concentration (35%) on the properties of mucilage based film showed that water vapor permeability and contact angle of films containing sorbitol was decreased about 33 and 19.4%, respectively. Therefore, sorbitol suggested to incorporate in quince seed mucilage based films to obtaining advanced bio-films with low affinity to water for packaging of food products. Incorporate of sorbitol to produce biofilms based on quince seed mucilage is suggested to obtaining bio-films with low affinity to water for food packaging products.

Although fish oil is a very important source of omega-3 and its consumption is recommended in terms of nutrition, it cannot be used directly in the food system due to its instability. Therefore, its stability can be increased by converting the particle to the nanoscale. The aim of this study was to investigate the physical and chemical stability of omega-3 nanoemulsion at different temperatures and its antibacterial properties. For this purpose, fish oil containing omega-3 fatty acids was produced by high energy method in nanoparticles and its physical (particle size, zeta potential, viscosity, and physical stability) and chemical properties (pH and turbidity) were evaluated during storage at 4, 25 and 40 o C during 7 days, as well as antibacterial properties of fish oil nanoemulsion against two gram-positive and gram-negative bacteria. The results showed that the omega-3 nanoemulsion produced had the optimum stability at 25 o C. the optimal concentration of 4% of omega-3 nanoemulsions also showed antibacterial properties against the studied bacteria, especially Staphylococcus aureus.

The ostrich (Struthio canelus) is the largest and oldest bird in the world and belongs to the Ratite family, which is unable to fly and is adapted to living in hot areas and barren lands. Birds of this family are characterized by low-fat meat and low cholesterol. Ostrich oil makes up about 15% of their total body weight (Basuny et al., 2017) that is mainly composed of triglycerides and is free of phospholipids. Ostrich oil is a relatively new and very valuable source of animal fats, which in recent years has received special attention to the use of it in pharmaceutical and food industries. Today, ostrich oil is mostly used for health, cosmetic and also medicinal purposes. Little researches has been carried out on its use orally and there is no comprehensive information about the properties of adipose tissue oil in different parts of ostrich body. Therefore, the aim of this study was to investigate the physical and chemical properties of oil extracted from different parts of ostrich body and introduce it as a new source of edible fat.

In this study, adipose tissue from 3 parts (front of the heart, front of the chest and lower abdomen) were obtained from ostrich breeding farm (Karaj, Iran). Oil extraction was carried out according to wet melting method by using rotary evaporator at 80°C for 2 hrs. Then some physical and chemical properties of the extracted oil such as fatty acid composition, cholesterol and total sterol, tocopherol composition, melting point, refractive index, color and induction period were investigated. The fatty acid composition of oils was determined by employing a gas chromatograph equipped with a DEGS capillary column (60 m × 0.25 mm i.d.) and a flame ionization detector. Sterols and tocopherols were identified by gas chromatography and high performance liquid chromatography methods respectively. Refractive index of oils was determined by using a refractometer and color of samples were analysed by application of Lovibond. The induction period was performed on a Metrohm Rancimat apparatus model 743 at 110 °C with an air flow of 20 L/h. All the experiments and/or measurements were carried out in triplicate order. The data were statistically analyzed using the Statistical Analysis System software package on replicated test data. Analyses of variance were performed by application of an ANOVA procedure. Significant differences between the means were determined using the Duncan multiple range test.

Based on the results, the highest amount of oil extracted from the abdominal parts (62.45%), front of the chest (40.35%) and front of the heart (38.58%) respectively. The main saturated and unsaturated fatty acids of extracted oils were palmitic and oleic acids respectively. The results of total saturated and unsaturated fatty acids in oil samples indicated that the highest amount of total saturated fatty acids was observed in oil obtained from the front of the heart (34.59%) and the lowest amount was observed in lower abdominal oil (33.72%) (P<0.05). The highest amount of unsaturated fatty acids was related to the lower abdomen oil (66.28%) and the lowest amount was in the front of the chest oil (65.44%) (P<0.05). The ratio of polyunsaturated fatty acids to saturated fatty acids (PUFA/SFA) in the oils of front of the heart, front of the chest and lower abdomen were 0.59, 0.61 and 0.65, respectively. The results of total sterol and cholesterol in the oil samples showed that the highest amount of total sterol (125.91 mg/100 g) and cholesterol (95.82 mg/100 g) were obtained in the oil of front of the heart. The highest levels of delta tocopherol (0.98 mg/100 g) were in the oil of anterior cardiac. The highest levels of alpha tocopherol (2.45 mg/100g) and beta tocopherol (0.87 mg/100g) were obtained in anterior thoracic oil. The samples were not different significantly in terms of gamma tocopherol and gamma tocotrienol. Melting point (29.31°C in all samples), refractive index (1.45 in all samples), yellow (35 Lovibond) and red (2 Lovibond) colors in the oils of the front of the heart, front of the chest and lower abdomen did not show significant differences. The highest induction period was obtained in the oil of front of the heart (11.58 hours) and the lowest stability was related to abdominal part (11.44 hours), Therefor no significant difference was observed between the induction period of the samples (P<0.05).

In this study, the results of the analysis of fatty acids in the studied oils showed that the composition of ostrich oil fatty acids in the lower abdomen, front of the heart and in front of the chest are the same and only their amounts were evaluated differently. According to the obtained results, ostrich oil can be considered as a valuable oil in the food industry due to its high content of essential fatty acids and tocopherol compounds, low cholesterol and good stability.

Doughnut is one of the high-calorie confectionary products that are popular among consumers as a snack due to its desirable sensory properties. Thus, studies aimed to investigate the feasibility of producing such products with lower calorie are necessary because of the relationship between high-calorie foods consumption and overweight, and disorders such as diabetes and cardiovascular disease. In this regard, the feasibility of reduced-calorie doughnut production using a mixture of maltodextrin-sucralose was investigated. The effect of maltodextrin-sucralose mixture substitution at the levels of 25, 50, 75 and 100% (w/w) was evaluated on some physical, chemical, and sensory properties. The results revealed that the amount of oil absorption decreased significantly (p<0.05) with the replacement of maltodextrin-sucralose mixture. Also, the replacement of the maltodextrinsucralose mixture reduced the specific volume, porosity, and redness of the doughnut crust, while the firmness of the crumb and the brightness of the crust increased. Finally, based on the results obtained, producing reduced-calorie doughnut which can compete with the control sample in terms of physical, chemical and sensory properties is feasible by replacing the maltodextrin-sucralose mixture by 50%.

Tomato and tomato based product are widely used as fresh, paste, juice, puree, sauce, etc. Canned tomatoes are an important product worldwide. Peeling is one of the important operations in the tomato industry to ensure good final product quality. In tomato peelings, steam and wet-lye are usually used which is associated with high-energy consumption and environmental degradation, respectively (Wongsa-Ngasri and Sastry 2016b). Thermal treatments are known as the most common method to process the food product. Considering the adverse effect of long thermal process on the chemical and physical aspects of the food, novel heating methods are developed to overcome these limitations. Ohmic heating is a quick thermal method which is known as Joule heating, electrical resistance heating, direct electrical resistance heating, electro-heating and electroconductive heating (Aghajanzadeh and Ziaiifar 2018). In batch ohmic heating system, the food is placed between two electrodes and its temperature increases due to electrical current exposure. In fact, it is used to generate heat uniformly throughout food matrices by controlling the electrical conductivities of food components (Wongsa-Ngasri 2004). Considering the ionic concentration of the food, the increase in the temperature could be rapid resulting in better preservation of the nutritional values and physical aspects of the product. Electroporation is the non-thermal phenomenon which occurs during ohmic heating. This produces the pores with different sizes in the cell walls as a result of alteration in the natural dielectric strength of the cells. In general, ohmic heating has been expanding to other applications to the edge of hybrid technologies such as thawing, blanching, extraction and drying. However, to reach its ultimate benefits for new and higher quality products, further insightful research, on other applications, needed. In this study, ohmic heating system was developed to peel the tomatoes and study the effect of this method on different physicochemical properties of the product.

In this study, laboratory scale ohmic peeling system designed and manufactured at Gorgan University of Agricultural Sciences and Natural Resources. The distance between the electrodes (made of stainless steel 314) was 7 cm. In our study, tomatoes ohmically heated in salt solution under various conditions. After initial weighing, the sample placed in salt solution in the ohmic system. Preliminary tests performed to determine the range of operating parameters (salt solution concentration and electric field intensity). The effect of electric field (range from 1500 to 4500 V/m) and concentration of salt solution (range 0.1 to 0.3% w/v) investigated in tomato peeling. After cracking in the tomato skin, the tomato skin easily separated by hand (Wongsa-Ngasri 2004). Hot water peeling at 100° C selected as a control treatment. T-type thermocouple was applied to control the temperature of the cold point of the tomato and the heating medium. The weight loss of the samples was measured considering the difference between the weight of fresh and the peeled tomato vs. the weight of the fresh sample according to Wongsa-Ngasri and Sastry (2016b). Ascorbic acid content of the samples was determined using iodine titration method (Kashyap and Guatam 2012). To study the effect of the peeling methods on the texture, the firmness of tomato was estimated based on the compression percentage as Wongsa-Ngasri and Sastry (2016b) suggested. The optimization of the ohmic peeling was performed using Design Expert software to suggest the best processing condition.

Tomato skin cracking involves thermal, electrical, chemical, biochemical and physical effects. The increase the fruit temperature caused alteration in different physical and chemical properties. During hot water peeling, the process time lasted for 523.33 s. This method brought 16.08% weight loss, 36.08% degradation of the ascorbic acid and 30.86% alteration in the firmness of the sample. The obtained results showed that peeling using the ohmic heating method resulted in faster skin cracking (82s), the less weight loss (10.7%), less ascorbic acid degradation and more stiffness (19.47% compression). The initial temperature of the tomato was 22°C which increased to 40 and 33.22°C after hot water and ohmic heating peeling methods, respectively. It was found that the electric filed intensity and the salt solution concentration had significant effects on the raise in the cold point temperature of tomato. Considering the thermal sensitivity of the ascorbic acid to thermal treatments, it can be mentioned that the ohmic heating peeling was more effective in preserving this vitamin. As, the least vitamin degradation was observed during the tomato processing at 2500 V/m in 0.2% salt solution due to the lower alteration in the sample temperature.
The change in the weight of the ohmic heated tomato resulted from de-esterification of pectin especially in mesocarp and electroporation effect on the skin destruction. To determine the optimum ohmic peeling conditions was determined based on obtaining the highest level of ascorbic acid content and the least cracking time, weight loss, firmness and alteration in the cold point temperature

It could be concluded that the quick rise in the tomato temperature as well as electroporation phenomena enhanced the peeling process in which the product with high nutritional value and quality was produced. In fact, weight loss and compression of the hot water peeled tomato were respectively 6.08% and 11.39% higher than the ohmic heated sample; however, the ohmic peeling brought a higher (4.1%) ascorbic acid content in comparison to the control method. The optimum ohmic peeling condition was processing the tomato in 0.2 W/V salt solution at 2500 V/m. These conditions have shown the potential to be good for processing because they require a reasonably short time. Ohmic heating method can be introduced as an effective method in peeling process of the fruit and vegetable with thin skin such as tomato to produce the high quality product. However, more studied should be performed to investigate other operational parameter affecting the process performance especially using different solution as heating medium and also combining the ohmic heating with other thermal, non-thermal and even chemical peeling methods based on hurdle concept. Besides more physical and chemical properties of the samples could be studied to have a comprehensive view of the effectiveness this novel method.

Today one of the most important concerns of the world is the significant volume of waste accumulation associated with the synthetic polymers used in food packaging. Therefore, biodegradable edible films are the best alternative for synthetic polymers and plastics. In this study, biodegradable films of corn zein containing two levels of olive leaf extract (10 and 15% w/w) are produced and their physical, mechanical, colorimetric and micro straucture properties were investigated. The results showed that the effect of treatment on physical, mechanical and colorimetric properties was significant (p <0.05). The results showed that by adding 15% extract, the thickness and moisture absorption increased compared to the control sample. Also, by increasing the percentage of olive leaf extract, there was a significant decrease in solubility and vapor permeability in all three relative humidity (33, 50 and 75%) compared to the control sample. In conclusion, it can be concluded from the results of this study that the combination of olive leaf extract with polymeric zein improves some physical and mechanical properties of edible film

According to the disadvantages of solid fats in baking products such as cakes in terms of Health, in this study, the effect of sesame oil and Psyllium seed mucilage were investigated on the physical properties of dough and textural properties of the cake. Fat replacement with sesame oil and emulsifier replacement with Psyllium seed mucilage in the formulation of oil cakes, were used in the ratio of 0, 50 and 100%. Moisture, protein, gluten and flour particle size measurements for flour, acidity, peroxide, melting point and iodine index measurements for shortening and sesame oil based on national standards and determining the dough special density and viscosity and the volume and texture of the produced cakes test were conducted on the cake samples. Data analysis was conducted by factorial test in a completely randomized design and Duncan's Multiple Range at 5% and was analyzed by SPSS software. dough samples containing 100 percent sesame oil had a much lower viscosity than other mixed treatments. According to the texture analyzer tests, mixed and 100% shortening treatments, when used by psyllium gum, due to the ability of the gum to retain moisture and prevent starch retrogradation, retain their freshness. Shortening treatments, induced a softer texture than liquid oils. During storage, enhanced staling found from the first two-week to the forth two-week. Samples with 100 percent shortening and psyllium gum, showed the lowest staling. Control treatment had the second score. Finally, by eliminating 50 percent of solid oil and replacement of 50% sesame oil together with psyllium gum or emulsifier, low-fat cake was produced with high nutritional properties.

In this study, quince seed mucilage(Qsm) was extracted in the best optimal way and composite edible films based on quince seed mucilage and whey protein isolate(Wpi) were prepared in different proportions of 0:100,30:70, 50:50, 70:30 and 100:0. In the following, the effect of the addition of the different proportion of quince seed mucilage and whey protein isolate on physical, mechanical and barrier properties of edible films resulted from them was studied. Qsm and Wpi were totally good compatible to make solutions and films. The results showed that increasing of the percentage of Wpi in produced films caused to increase thickness, moisture and solubility of produced films. However, the amount of water absorption decreased mechanical properties of the films showed when the percentage of Qsm is increased, maximum force at rupture of the film is increased and distance elongation at break is decreased. In color measurement of produced films, lightness(L) was significantly improved as Wpi content increased, but yellowness (a) decreased. When the Qsm content and also, water vapor permeability was lowered by the growth of the Qsm content.

Evaluation of physical characteristics of wheat grain during transportation, separation and storage of this valuable product plays a critical role. In this study, in the first step, effects of cleaning, moisture content, storage temperature and time, on some physical (hectoliter, thousand seed weight, and bulk density) and microbial (total count of microorganisms and mold counts) properties of wheat grain variety n-80 was determined and then obtained data were simulated by two Artificial Neural Network models including multilayer perceptron and radial basis function with different threshold functions and the data predicted by the ANNs were compared with experimental data. Our results revealed that multilayer perceptron network model with one hidden layer, and a TanhAxon – TanhAxon function of stimulus for the physical characteristics, with a structure of (5-11-3) including 5 inputs, 11 neurons in the hidden layer, and 3 outputs, with epoch of 3000, and also for microbial characteristics, with a structure of (5-4-2) including 5 inputs, 4 neurons in the hidden layer, and 2 outputs, with epoch of 4000, were the best ANN models for data predicting compared with radial basis function networks. Determination coefficients (R2) of hectoliter, thousand seed weight, bulk density, total count of microorganisms and mold count in multilayer perceptron network were 0.95, 0.989, 0.908, 0.908, and 0.938, respectively. The hectoliter and bulk density decreased with increasing levels of moisture content, storage time and temperature while they were increased with the rise of cleaning level. Also, the total count of microorganisms and mold count increased with increasing levels of moisture content, storage temperature and time and decreased with increasing levels of cleaning.

Wheat grain has an important value in the world nutrition. Physical and microbial properties of agricultural products (such as wheat, ...) play an important role during harvesting with machines, cleaning process and waste reduction. In this study, the first research in Iran, the optimized effects of cleaning and moisture content at 40 °C on the physical (Useful besatz, Unuseful besatz, hectoliter, weight thousand seed) and microbial (total count of microorganisms and mold counts) properties of wheat grain (n-80 variety) in Golestan province, were modeled.
After determining the basic moisture content, samples with three levels of cleaning (0-100%), and different moisture content (10-14% wet basis) at 40 °C were studied and modeled by response surface methodology using central composite design (face center) includes 21 tests with five repeats at the central point.
The results showed that by reducing moisture content and increasing cleaning levels, useful and unuseful besatz were decreased and hectoliter was increased. Also increasing the percent of cleaning was more effective than reduce the moisture content in reducing useful besatz and unuseful besatz. The lowest rate of hectoliter was 72.58 (0.01kg. lit-1) at 40 °C. The highest weight of thousand seed at moisture content 14% (wet basis) and cleaning level 100%, was 36.80 gr. Increase in weight of thousand seed in the higher moisture content was more effective than the higher level of cleaning. With increasing moisture content and reduction in cleaning, total count of microorganisms and mold counts were increased. Linear parameters of cleaning and moisture, in the linear model had a significant effect (p For all studied properties, due to non- significant lack of fit and high values of R2 and R2 adjusted, our selected models could accurately predict the experimental values.

Use of soy products in sesame cream composition led to produce nutritious and healthy product with better quality and quantity. In this study, the effect of replacing soy meal instead of sesame in producing sesame cream to reduce fat and increase the protein content and the use of lecithin as emulsifier to improve rubbibility on chemical, physical properties and sensory evaluation was examined. Replacement percent of soy meal (0, 20, 30 and 40 percent) and lecithin (7,5,0 and 10 % w/w) was considered in the formulation. By increasing soya meal and lecithin replacements, changes in fat, protein, hardness, color (l *, b *, a *) was significant. In soy meal replacing, significant moisture difference( p

Extensive researches into native plants as a source of functional food have been conducted over the resent years. Meanwhile, barberry has been utilized as one of the main medicinal plants in Iran and many other countries, from the past decades. Currently, it has been known pharmaceutical active ingredients like berberin have wide application in pharmaceutical industry. The genus of Berberis includes about 450–500 species of deciduous or evergreen shrubs in which four species B.integerrima, B.crataegina, B.vulgaris and B.orthobotrys are found in Iran. Iran is the first largest producer of barberry (B.vulgaris) in the world. Apart from that, other species in different parts of Iran grow in wild conditions. B. Integerrima is a thorny shrub with fragile branches to a height of 1 to 3 meters. Its fruits are small and red with a mild sour taste. There are 1-4 small oblong seeds inside. The changes in this species are important and can produce hybrid with other species. B. Integerrima fruits are consumed fresh or used in the preparation of traditional foods. Barberry fruit, which contains large amount of anthocyanins, can be used as an alternative to synthetic colorants. In addition, aqueous extract of barberry has beneficial effects on both cardiovascular and neural system suggesting a potential use for treatment of hypertension, tachycardia and some neuronal disorders, such as epilepsy and convulsion. The physical properties of barberry genotype are important to design the equipment for sorting, transportation, separation, processing and packaging. Identification of the chemical characteristics of Berberis genotype can lead in using them in the pharmaceutical or food industries. Therefore, in order to introduce these native species, physicochemical characteristics of three wild barberries were evaluated
Three native seed genotypes from Semnan province were manually collected from Research Institute of Food Science and Technology (Mashhad). The harvested fruits were instantly stored inside ice box to minimize damages and transported to the laboratory. Over ripened and damaged fruits were separated. Some physical properties (size, geometric mean diameter, sphericity, area, mass and the weight ratio of seeds to fruit) of fruits were determined using 100 repetitions at the natural moisture content of fruits. Chemical properties of samples were determined as follows: total anthocyanin content by the pH differential, total phenolic content by modified Folin–Ciocalteu method, mineral elements amounts such as Potassium(K), Sodium (Na) and Calcium (Ca) by Flame Photometer and microelements (Fe, Cu, Mg, and Zn) by Atomic Absorption Spectrophotometer, Moisture, crude oil, crude protein, ash, reducing sugar, water-soluble extract, pH and acidity were determined according to Indrayan et al,1989 and Iranian National Standard No. 2685. All experiments (except physical properties) were repeated at least three times and results were expressed as mean ± SD. The significant differences between mean values of juice samples were determined by analysis of variance (one way-ANOVA) using Duncan’s test at a significance level of p Results showed that in physical properties such as, fruit length there was statistically difference between genotypes. The number of seeds in the three genotypes varied between 1 and 4 numbers. The weight ratio of seeds to fruit was 11.88%, 10.84% and 10.68 in Noshin, Negarin and Parchin genotypes, respectively. All three genotypes contained high amount of protein, total carbohydrate, fat and ash (3.82-5.255%, 21.68-23.97%, 2.04-2.70% and 0.94-1.27%). Noshin contained the highest reduced sugar (8.03±0.222). So, it is sweeter taste than others. In accordance with result, the amount of anthocyanins (950.17-3927.60mg/L) and total phenol (9.75-12.35gr/L) were higher than these fruits in comparison to the other fruits like mulberry and blueberry that represents the health benefits of these wild plants. All the three genotype emerged as good source of minerals, especially K, Ca, Mg and Zn.

Nowadays, one of the most important nutritional problems in different societies is the protein mal-nutrition. Since bread is the main food material being consumed in all over the world, bread enrichment using the grains rich in protein such as sesame seeds would be an appropriate alternative. However, addition of sesame products such as Tahini meal would cause some technical difficulties such as dough stability, water absorption, dough extension time, etc. in bread manufacturing processes.In this study the effect of addition of xanthan gum to on physical and textural properties of Baguette bread containing tahini meal was investigated.

Wheat flour and tahini meal were supplied from Damghan and Ardakan cities, respectively. They were then refrigerated prior to baking process and different chemical tests were carried out according to standard methods. Protein was measured based on Kejeldahl method. Moisture content as well as ash content were determined using oven method.Raw fat was calculated according to AACC-No. 30-10 and raw fiber was measured using appropriate instrument (Scientific velp-FIWE6 F30530201). Starch determination was carried out using Small universal polarimeter (SUP-Germany). Xanthan gum was purchased from Provisco Ltd. (Switzerland) in food grade quality. Bread yeast (Saccharomyces cerevisiae) was also supplied in dried form. All other chemical enhancers were purchased from Merck Ltd. (Germany). Baguette dough was produced from mixture of wheat and Tahini meal flour based on protein content and the amount of protein in final dough was increased from 10.28% in flour free of tahini meal to 12, 14 and 16% in different treatments. The rest time for all flour samples was fixed at 15 min and the baking process was carried out for 15 min at 300°C. Baked breads were exposed to room temperature for two hours and then were packed using poly-ethylene (PE) film for further tests. Specific volume of bread samples was measured using rapeseed displacement method (AACC, No. 54-30, 2000). Samples porosity was determined using image processing techniques. Samples were cut to 2cm×2cmcubes and an appropriate scanner (Canoscan 8800F, Japan) with 300 pixel resolution was used to acquire the images for further process using Image J(1.6r, 2010). Apparent color for the baguette samples (in terms of CIE ‘L*’- lightness,“a*” - redness and greenness, and “b*”- yellowness and blueness) were also measured using image processing techniques (Image J, 1.6r, 2010).Texture profile analysis (TPA) test was carried out using a texture analyzer (QTS Texture Analyzer, CNS Farnell, Hertfordshire, UK) to study the effect of xanthan gum and tahini meal on parameters such as hardness, gumminess and cohesiveness in all baguette samples.

ANOVA test showed the significant effect of xanthan gum and tahini meal on the porosity of samples. The porosity of samples containing less than 0.5% xanthan gum at all tahini meal levels, was significantly less than control sample.Similar results were obtained in the case of specific volume meaning that the employed treatments have significant effect on bread’s specific volume. Increasing tahini meal from 9.45% to 14.53% caused significant decrease in specific volume. This could be due to the weakness of dough gluten matrix. These results are in agreement with other works reported by other researchers (Paraskevopoulouet al., 2010; Mohammad Idrisset al., 2012; and Guardaet al., 2004). The results obtained for apparent color of bread core also showed the effect of xanthan and tahini meal. The only exception was found in case of a* value when studying the effect of xanthan gum, meaning that xanthan gum has no significant effect of this parameter. In the case of apparent color in bread crust, the studied treatments (xanthan gum and tahini meal) showed significant effect on all color parameters. Different textural properties of baguette samples including hardness, gumminess and cohesiveness were also measured.

The results indicated obvious effect of xanthan gum and tahini meal levels on these mentioned parameters. Increasing tahini meal and xanthan gum levels would increase hardness as well as gumminess. However, addition of xanthan gum and tahini meal cause significant decrease in cohesiveness. This could be due to dilution effect of these substances which decrease the concentration of protein matrix existed in flour’s gluten.

Effect of heat treatment of soft wheat flour (with low and high gluten contents) was investigated on batter characteristics and cake quality. Physical properties of cake batter such as specific gravity and consistency, cake properties (volume, specific volume, apparent density, solid density, apparent porosity, moisture, symmetry and uniformity, color and firmness and the final score of sensory evaluation were evaluated. Results showed that increasing time and temperature of dry heat led to a decrease in specific gravity of cake batter, cake moisture content and an increase in the batter consistency, cake volume, specific volume and cake apparent porosity. However, moist heat (steaming) application on the flours decreased the latter parameter. Control and heat treated samples had similar solid densities. The best cake symmetry and uniformity were obtained for product obtained from heat treated flours at temperatures of 110 and 120 °C for 120 min. Higher crust color values were obtained for cakes prepared from steamed flours. Crumb color for all treatments was almost similar. At 7th and 14th day of evaluation, control cakes showed the firmest crumbs, while cakes prepared from steamed flours and heat treated flours (at temperatures of 110 °C and 120 °C for 120 min) showed the softest crumbs. Overall, sponge cakes prepared from dry heat treated flours presented better acceptability for the sensory judges. All the results in high and low gluten treatments had similar trends.

External and internal changes in fruits during storage time are affected by the various factors that some of them can by studied by measuring the qualitative parameters (physical and mechanical). The effects of storage time on some physical and mechanical properties of Valencia orange were investigated. The experiment was performed as factorial based on completely randomized design. Analysis of experimental results showed a significant effect of storage time on all the physical parameters of Valencia orange. With increasing time، the true density of oranges increased while other physical parameters decreased. Rind ratio and moisture content increased and true density decreased with increasing the size of fruit. Also the effect of storage time and fruit size on the rupture force and deformation was significant at the level 0. 01. The mean failure load for 2، 32 and 62 days storage were obtained 206. 05، 139. 64 and 221. 07 N، respectively. Rupture force and deformation values were followed by increasing fruit size.

Mayonnaise is one kind of salad dressing used widely all over the world and is highly appreciated because of its texture and flavor. In this study, reduced fat mayonnaise samples (45% oil) were produced using pre-gelatinized corn starch (2-4%), xanthan (0-0.3%) and guar (0-0.3%) as fat replacer by central composite design and their viscosity, stability and sensory properties were analyzed and were compared with those of full fat mayonnaise sample (70% oil) as control experiment. Results showed that the most stability and viscosity values were related to the sample made of 4% pre-gelatinized corn starch, 0.3% xanthan and 0.3% guar and the least values were observed for the sample made of only 2% starch. Sample containing 3% starch, 0.15% xanthan and 0.15% guar (central point) showed the highest score for sensory total acceptability. Most of the samples demonstrated sensory characteristics better than those of the control sample (P<0.05) hence describing high performance of used hydrocolloids. Modeling and satisfactory coefficients of determination revealed goodness of the models to predict data.

In this research, thin-layer drying of tomato slices was simulated via a laboratory scale hot air dryer. The drying process was carried out at two different temperatures (60 and 70 oC). Drying data were fitted to 8 drying kinetic models. The goodness of fit was determined by means of R2, RMSE and χ2, it was concluded that Logarithmic model represented the best performance. Also, physicochemical properties of tomato slice such as shrinkage, acidity, pH and color were determined during drying. The result indicated that drying air temperature had a significantly affect on the color change of tomato slices. Furthermore, in this research, tomato slice favorite is evaluated by sensory evaluation. In this test sense qualities as color, aroma, flavor, appearance and chew ability (tissue brittleness) are considered. The results revealed that air temperature had a significant effect on the appearance (P<0.01). The results showed that perceptron neural network with logsig activation function as a goodness activation function can be estimated moisture ratio with R2 value 0.996.

In this study, the effect of heat treatment on soft wheat flour with low gluten content on cake batter characteristics and the quality of final product was investigated. Physical properties of cake batter such as specific gravity and consistency, properties of cake such as volume, specific volume, apparent density, solid density, apparent porosity, moisture, symmetry and uniformity, color and firmness (at 1st, 7th and 14th days after production) and the final score of sensory evaluation were evaluated. Results showed that increasing time and temperature of dry heat led to a decrease in specific gravity of cake batter, cake moisture content and an increase in the batter consistency, cake volume, specific volume and cake apparent porosity. However, moist heat (steam) application on the flours (even at a very short steaming period) decreased the latter parameters. Control and heat treated samples has similar solid densities. The best cake symmetry and uniformity were obtained for product obtained from heat treated flours at temperatures of 110 and 120 °C for 120 min. Higher crust color values were obtained for cakes prepared from steamed flours. Crumb color for all treatments was almost similar. At 7th and 14th days of evaluation, control cakes showed the firmest crumbs, while cakes prepared from steamed flours and heat treated flours (at temperatures of 110 and 1200c for 120 min) showed the softest crumbs. Overall, sponge cakes prepared from dry heat treated flours presented better acceptability for the sensory judges.

Non-alcoholic beer (Ma-al-Shaeer) is a commonly consumed and popular beverage in Islamic countries. Its popularity originates not only from the pleasurable sensory attributes and relatively low cost، but also from its health beneficial effects when consumed in moderate amounts. Qualitative aspects of non-alcoholic beer from the consumer point of view، which is so-called here as “functional qualitative aspects” (flavor، color، foaming property، body، viscosity and mouthfeel، colloidal stability، nutritional and medicinal aspects as well as hygiene) play a crucial role in its acceptability. This article reviews these qualitative aspects، in physical and chemical categories.

Knowledge of physical and mechanical properties of agricultural products، such as vegetables، is needed for their processing. The objective of this study was to find the physical and mechanical properties of squash، related to head cutting process. The physical properties such as length، mass، headfirst diameters، head diameters، volume، density، sphericity and geometric mean diameter were determined. Material testing machine was used to measure mechanical properties by applying shear test on the sample. The experiments were carried out at three mass levels (m<95g، 95g120g)، loading speed of 50mm/min and loading direction (vertical to headfirst diameter direction) of preprocessing squash. Mechanical properties such as maximum force and energy of shear and bio-yield point were determined. Result of physical properties of squash showed that the averages of length، mass، volume، density، sphericity، headfirst diameters، head diameters and geometric mean diameter were 121. 34 mm، 110. 09 g، 110. 77 cm3، 994. 85 kg/m3، 48. 72، 25. 51mm، 37. 48 mm، 59. 05 mm، respectively. Result of mechanical properties showed that mass had significant effect on maximum shear force and energy. Moreover، the biggest squashes had the highest shear force and energy.