مجله علوم و صنایع غذایی ایران
سال دوازدهم شماره 2 (پیاپی 47، تابستان 1394)

Ahvaz, Iran Orumiyeh, Iran Date paste as an important date products, has found many applications in food industry in recent years. After production color change and solidifying of the date paste and aggravation during maintenance are considered as the major problems facing the date paste processing factories. This research has carried out in order to overcome the solidification of date paste (Kabkab cultivar) in a full factorial experiment with three factors of: date paste preparation method (two levels of immersion in hot water or steaming), added oil (sesame and olive oil as a preservative) and three type of packaging (cellophane, nano silicone and multi-layered) in a split plot design with preparation method as the main plot. Textural properties including hardness, Young's modulus, shear modulus, and the penetration work done were measured at 0, 1, 2, 3, 4, 5 and 6 months of storage using a texture analyser. The result confirms the positive effect of steaming for 10 minutes to maintain the softness paste during the test period. Date paste of firmness made from method of steaming and immersion in hot water is 0.02 N and 19 N respectively. The results confirmed positive effect of steaming for 10 minutes on date paste softening during storage at.

Reduce the quality of traditional breads in recent years related to the type of flour and bread production process is not hidden from anyone. Traditional Iranian breads are prepared from flour with high extraction rate, which contains high amount of minerals, vitamins and fibers, but the presence of high levels of phytic acid prevent absorbing precious minerals in the body and are irreparable harm to the consumers. The purpose of this study was to assess the level of phytic acid in the flour marketed in Ahwaz to bake traditional flat breads, Lavash, Taftoon, Sangak and Barbari, and effect of processing on the content of the primary phytic acid. The results showed that phytic acid of flours was high (91.464 mg/100 gr. flour) and prepared dough and baking bread conditions had not a significant reduction in phytic acid so that the maximum reduction was observed in Barbari bread (33.4 %) and the lowest decrease in Lavash bread (15.79 %), respectively. On the other hand, the mean level of zinc was 592 mg in hundred grams of flour and average of phytic acid mole ratio to zinc was shown 63.67, so bioavailability of zinc was deteriorating. The results indicated that the present baking procedures had not an appreciable effect on reduction of the amount of phytic acid in breads. Due to the high level phytic acid in flours is recommended to considering the amount and type of fertilization in field conditions, baking conditions of bread to be reformed in Ahwaz.

Xylitol is a naturally five – carbon polyol with a high sweetening power. Owing to its physicochemical and technological properties, make it of high value to pharmaceutical, food and chemical industries. The biotechnological method of producing xylitol by microorganisms has been studied as an alternative to the chemical method. This method is of interest because it requires little energy and is very specific. Among the microorganisms, yeasts are considered as the best xylitol producer. In this study xylitol was produced by Rhodotorola mucilaginosa that isolated from leaf of Benjamina. The produced xylitol by R. mucilaginosa was determined and measured by thin layer chromatography, kit and colorimetric methods. This strain produced 6.42 g l-1 xylitol after 48 hours in medium congaing of 40 g l-1 xylose. Consequences of increasing the initial xylose concentration from 60 to 140 g l-1, the final xylitol concentration and yield were also increased. Maximum concentration of produced xylitol by R. mucilaginosa was 49.28 g l-1 (yield of 0.59 g g-1) at 140 g l-1 initial xylose concentration. However further increasing of xylose concentration to 160 g l-1, led to a drastic decrease in xylitol production and yield.

According to theresearchersfocused onthe roleof bread in thenational economyandtheuse ofnaturaladditivesto reducestalingrateand improvethe quantitative and qualitativeproperties ofstrategic products, So The aim of thisstudy was to investigatethe effect ofdifferent levels ofwatermelon(0, 1, 2, 4, 8 and 16%) on dough farinographypropertiesandmoisture content, specific volume, porosity andfirmness of semi volume Barbari bread. Inthis study, Image J software was used for porosity measurement. The resultsshowed thatwith the increasing ofwatermelonin the bread formulation, water absorption anddegree of softening increased butthe amount of dough stability decreased. While the mostdoughdevelopment timewas observedinsamples containing2% water melon. Also theresultsshowed thatthemelon water as a natural additive canincreases the amountof moisture content,porosity andspecific volumeanddecreased firmnessoftexture. So the highest moisture, specific volume andporosity were observed in ofthesamplescontainedrespectively16, 4and8% water melon. It should be notedthatsamples containing4% water melonhadthe lowestfirmness.

Effects of addition of each plasticizers (sorbitol, glycerol or lactic acid) having concentration of 0-40% on mechanical properties and water vapor permeability (WVP) and oxygen permeability (OP) of casein composite films have been studied. The best formulation for each composite film having optimum amounts for mechanical properties, WVP and OP have been determined. The amounts of WVP, OP and mechanical properties for the composite films with optimum formulation at three different relatives humidity (RH =32, 52, 75 %) have been also compared. The value of WVP has been measured using a vial coated by a film. The value of OP for a film was determined from measurement of peroxide value for a definite amount of oil that is placed in a vial and coated by the film. Mechanical properties were measured using a tensile machine. The results showed that addition of 20% each plasticizer to casein was the best concentration to achieve optimum mechanical properties (elongation, tensile strength and elastic modulus). Further increase in concentration of plasticizer led to a decrease in tensile strength and elastic modulus and negligible increase in elongation and significant increase in WVP. Thin films containing sorbitol at RH 32% and thin films containing glycerol at RH 75% had WVP greater than that of two other RH. Thin films containing sorbitol at three RH had OP smaller than that of the films containing lactic acid and glycerol.

Fried foods are favored by consumers because of the crispy crust, desired flavor and color, but these properties are accompanied by some undesirable effects to the consumers due to the considerable amount of oil absorption during frying process. Nowadays, the main challenge is to enhance the frying process by controlling and lowering the final fat frying of the fried foods. In this study, the effect of hydrocolloids (methyl cellulose, pectin and methyl cellulose- pectin) on the quality of deep- fat fried Falafels at 150, 170 and 190 ˚C for 1, 2, 3, 4, and 5 min were evaluated. Moisture content decreased whereas oil content, hardness, volume and color of potatoes increased with increasing fried time, fried temperature. The lowest oil content values are given for samples coated with methyl cellulose- pectin. The control samples had the highest percentage of fat content in all the frying time range.

Mango is a tropical crop that has been originated from south east areas of Asia. Mango has high decayed nature because it climacteric property. In order to investigate the effect of Putrescine and cold water treatments on post-harvest quality of mango, an experiment was done as factorial design in 2012. So local mango fruit was prepared at maturity stage, were treated with treatment combinations of Putrescine solution (0, 0.01, 0.1 mM) and cold distilled water (non-soaking and soaking for 30 and or 60 minutes). Quantitative and qualitative traits of fruit (like fresh and dry weight, length and width, firmness, total soluble solid, acidity, pH, taste and aroma, skin and pulp color) and also observation of rot symptoms have been measured. Results showed Putrescine and cold water treatments were affected fruit taste, acidity, and TSS/acidity ratio, also rot symptoms were reduced. Both concentrations of Putrescine affected the firmness and total soluble solids significantly. In all treatments combination of cold water and Putrescine fresh and dry weight was higher than control. The results indicated a positive and significant impact of mixed fruit dipping treatments in cold water and Putrescine in keeping appearance quality and improving storage life of mango fruit. Therefore the greatest concentration of Putrescine (0.1 mM) with immersion in cold water is recommended.

In recent decades, as the result of the expansion of industrial life, fast foods and fried foods consumption has increased significantly. Consumption of fried foods including saturated fat and trans fatty acids is one of the important factors which endangers human health and the risk of heart disease, weight gain, cancer. With increasing consumer awareness of the health effects of dietary fat, tend to produce low-fat food consumption is increasing. Nowadays, the main challenge is to enhance the frying process by controlling and lowering the final fat frying of the fried foods. In this study the effect of microwave pretreatment levels 360, 600 and 900 W), on moisture and oil content, color and hardness of fried zucchini at three temperatures, 130, 160 and 180 ° C were studied. The results showed that the moisture content decreased with increasing frying time and oil hardening rate increases. The moisture content with increasing frying temperature is reduced and the amount of oil absorption is reduced. The highest oil uptake in control samples, and the lowest in samples treated with microwave 900W was observed respectively.

Reduction of bread loss and wheat consumption have particular importance in the national economy, has attracted many researcher’s mind. Thus in this study sorghum flour was used as a substitution for the part of wheat flour in bread making. On the other hand, the purposes of this study were investigation on the effects of steaming time (three levels of 0, 90 and 180 second) and baking time (three levels of 10, 15 and 20 minute), on moisture content, water activity, crust color, firmness and overall acceptability of composite bread (wheat- sorghum). Based on the result, the steaming and baking time were effective on staling rate and bread shelf life at P.

Because of importance of bread, shelf life and quality control be noticeable for bread specialist, cause of this research was assaying synergistic effect of apple pomace and sodium stearoyl -2-lactylate on rheological properties and the shelf life of oven based Barbary bread. three percent of dried apple pomace (%5,%8,%11) was ready on cabinet drier on 58°c, and SSL was added up to %1,%5 (w/w of flour). rheological properties of dough was studied with two experimental method (farinograph, extensograph) and texture of the bread sample analyzed for shear by instron (Universal Testing Mashine) at, 0,24,48,72 hours at room temperature sensory evaluation of bread for sample and control wasstimated in 1,2,3 days with 5 panelist. respect to rheological properties,sample with %8 apple pomace and %0/5 SSL was acceptable to panelist. all sensory evaluations was upper than control. and analytical resultsby instron indicated that this sample delay staling than control. results indicated by the use of apple pomace in flat breads delayed the staling rate and addition of Appropriate emulsifier has synergistic effect and itimproved the rheological properties.:

Potato (Solanum tuberosum) is one of the most important agriculture products which damage soon because of inappropriate storage and processing conditions. Drying process causes to increase the shelf life of potato. In current research, potato slices dried in a parallel flow dryer and its kinetics of drying and shrinkage was studied. The experiments were accomplished in three levels of slices thickness; 3, 6 and 9 mm and three levels of temperature; 50, 60 and 70 c. Air flow was considered as 0.012 m3/s in all tests. Drying rate, moisture reduction, variation of area and roundness of samples were investigated during drying period. Results showed the maximum drying rate has been occurred when temperature was 70 c and thickness was 3 mm. Area and roundness variation was increased while temperature increased and thickness decreased.

Manufacturing of low-fat spread products due to the prevalence of obesity and cardiovascular disease in the world is expanding. Utilization of silver carp (Hypophthalmichthys molitrix) waste as a cultured species with high abundance and relatively low price, gelatin was prepared from the waste.The aim of this study was to in vitro production of the fat spread samples containing the three formula 1-3%with different cultured silver carp gelatin to pectin ratio (1:1 and 1:2) and evaluating the color and texture characteristics of the fat spread samples prepared by different fish gelatin to pectin ratio using colorimeter and texture analyzer.Firmness (69.75±1.767 g), compressibility (767.26±28.41 g.s) and adhesiveness (262.03±13.852 g.s) attributes were found at the highest level in the treatment contains fish gelatin to pectin ratio of 1:2 withformula 3% (p≤0.05). The highest yellowness index (39.70±0.027%) and the lowest whiteness index (71.54±0.014%) were measured in the treatment contains 1:1 (fish gelatin to pectin) with formula 1% (p≤0.05). Significant positive correlation between the shear test (kg) and firmness results of the samples was observed (r2=0.973). It was found that decreasing with higher substitution of fish gelatin with pectin leads to increase firmness, compressibility, adhesiveness and elasticity properties of fat spread samples significantly. With respect to low-fat productions due to their importance in society health and the results of this investigation, applying a formula with fish gelatin to pectin ratio of 1:1 (3%) at a larger scale is recommended.

Simple and corresponding impacts of adding acidic improvers (Lactic Acid, Acetic Acid and Citric Acid) on bread staling has been researched twice in 3 levels(0%, 0.25 % and 0.5 %) by factorial experimental method. There was an orthogonal comparison between the two treatments (acidified treatments and sourdough groups) in the second stage. The effect of lactic acid on bread staling was significant 24 hours after baking the bread. Different levels of lactic acid and citric acid had significant effect on bread staling 48 hours after bread baking. Finally -24 and 48 hours after bread baking- orthogonal comparison among our 6 selected treatments showed that there was a significant differences between two groups.The sourdough treatments had the least scores. Among the final treatments, containing 0/25% acetic acid had the most scores, the treatments containing 0/25% lactic acid and the control sample had gradually a better score(from 24 to 48 hours).According to these results, the sourdough can be processed, in a way that the bread has enough amount of acetic and lactic acid.

Apple fruit is one of the most worthy garden Product with high nutritional Value and its production in Iran makes more job and Exchange technology. From different apple Non-destructive quality control methods, machine vision technology achieves the more speed, quality, greater productivity and higher valuation for the product. Usually, apple bruise overlaps with Peduncle and in these causes, serious problems of recognition for quality sorting occurs. In this research work it was tried to work out this problem and to increase the sorting systems performance precision. In order to accomplish this, two separate algorithms based on color to identify bruise and pedicle was designed in Matlab. It was achieved 97.14% accuracy for the bruise algorithm and 100% accuracy for the pedicle algorithm. Then with integration of these two algorithms, an algorithm was achieved with 94.29% accuracy. Further experiments to investigate the possibility of increasing the accuracy in detecting bruise with time maintenance was performed by the bruise algorithm. The results indicate that the bruise detection quality by this algorithm gradually increased and after two to three days it reaches the desired consistency. Another algorithm with special properties of bruise and pedicle pictures shape such as roundness value, ratio of area to Perimeter square and also coefficient of variation (cv) of distances of spaced points on the edge from center of gravity of picture was designed. Then bruise and pedicle were distinguished from each other with an accuracy of 100% with this algorithm along with the ANN which it proving the importance of using these techniques, combined with machine vision techniques to increase the accuracy of sorting machines performance.

Nowadays, the importance of brand concept is so high that some researchers believe that brand is a perfect product and argue the most of the time customers instead of buying a product buy the brand. Therefore recognizing the factors influencing brand choice and investigating the specific features of brand is of importance and requires various studies. the present study aimed at investigating into factors that affect brand choice in food industrial companies. the methodology of this study was applied. research and for data collection. Survey approach was used. The statistical population consisted of buyers in Tehran and statistical sample based on factor analysis were 400 buyers. Based on statistical analyses, 19 factors that affect brand choice were categorized in 4classified: 4 factors namely the simplicity of brand pronunciation, personality and psychological factor, recognition quality and services and famous. further based on qualitative analyses based on qualitative analysis result revealed that "personality and psychological factor" for responding effects in brand choice to great extent.

Iran is one of the most important fig producer countries around the world. Intermediate moisture fig is a processed product. One problem about intermediate moisture fig is that the color will be changed and transmute to brown during storage after processing. The purpose of this research was to study soaking temperature and time effects and to evaluate the effects of calcium chloride, cysteine, sodium metabisulphite and citric acid in various concentrations on prevention of semi-moisture fig browning at room temperature. Chemical compounds (protein, total sugar, fat, fiber and moisture) of fig samples were determined. In order to prepare product five different periods of time(3, 6, 9, 12, 15 min) and five different degrees of temperature (20, 40, 60, 80, 100°C) based on central composite rotational design were used. Samples were kept in room temperature for 2 weeks to evaluate the effects of soaking parameters on color and texture of product. After that moisture, color and texture of samples were determined. First different solution of calcium chloride (0.6, 1, 1.5, 2% w/w), citric acid (0.5, 1, 2, 3%w/w), cysteine (0.05, 0.07, 0.2, 0.5%w/w) and sodium metabisulphite (500, 800, 1000 and 1200 ppm) were prepared. Dried figs were dipped in prepared solutions and water was used to evaluate control samples to optimize the time and temperature, then color of the samples were measured in specific period of time during four months. Results showed that temperature of 60°C and 3min interval provided 20% moisture in the product which assessed as the best moisture content for preserving color and texture. The most desirable L value was obtained using citric acid (1, 2, 3%w/w) and Calcium chloride (1.5%w/w). However sodium metabisulphite and cysteine in concentration of 0.07%, 0.05%, 0.2% showed significant difference with control, the results were not satisfactory. Results showed that using suitable temperature in rehydration of fig to inactivate poly phenol oxidase and chemical treatments to postpone and reduce the browning reaction rate were effective.

In this research, response surface methodology was used to investigate the influence of improver gel components on the dough farinographic properties and quality of Barbari bread and optimization of gel formulation. Gel samples were prepared using sodium stearoyl-2-lactylate (SSL), diacetyl tartaric acid esters of monoglyceride (DATEM) and propylene glycol (PG) in the range of 0-0.5 g/100g. The results showed that addition of all three components to the gel formula caused decrement in the water absorption, dough characteristics i.e. development time and mixing tolerance index and bread hardness at first day but all of these parameters except of water absorption affected by their interaction. Dough stability and valorimeter value increased by increasing the gel components addition and were affected by their interaction. Although bread properties i.e. specific volume, moisture content, water activity, sensory score and ΔE increased by addition of SSL and DATEM but the decrease of moisture content, water activity and ΔE was observed by increasing the propylene glycol. The represented models have high determination coefficients and could be used for prediction of all investigated characteristics. The results for optimization using central composite design suggested that a mixture containing 0.5 g/100g of SSL, 0.25 g/100g of DATEM and 0.5 g/100g of PG could be a good improver gel to achieve the best characteristics.

Wheat flour has many proteins in which gluten is an important protein in it and this protein has important role in dough formation and bread making.Thus, Uses of different materials must be considered to improve gluten quality as well as wheat flour enrichment. In this study the effects of adding chickpea protein isolate in range of 3 to 7 g and ascorbic acid in ‎range of 0.05 to 0.15 % in wheat flour formulation on gluten stability and extensibility were investigated by response surface methodology. Therefore, The results showed that increasing of chickpea protein and ascorbic acid concentration had significant effect (p<0.01) on farinograph parameters texture analyzes (dough extensibility). The results of optimization in the case of 3 gr of chick pea protein isolate and 0.15% of ascorbic acid were as follows; water absorption 57.7%, dough development time 2.8 minute, dough stability 6 minute, mixing tolerance index 58 FU, farinograph quality number 91.3, toughness (area under curve) 3.3 N/mm, maximum resistance 0.02 N and dough extensibility 22.9 mm. Therefore, chickpea protein weakens strong flours gluten and it can be uses for making biscuit.

Nowadays, additives are commonly used in cooking industry. Emulsifiers are one of the important materials generally used to improve the quality and efficiency of dough, to make the usability of dough easier, and to reduce dough wastage through delaying the staling time. The purpose of this study is to investigate the influence of adding two kinds of emulsifier including DATEM and Glycerol mono stearate In 3 levels of %0,% 0/2, and %0/4 and Lipase Enzyme in 3 levels of 0, 100, and 200 PPM(activity 25KLU/g). The influence of adding above-mentioned materials was sought in qualitative and quantitative features of doughnut made from solid dough (texture, moisture, activity water (AW), specific volume, porosity, and general acceptability). According to the random statistical study and the obtained significant difference (p<0/05) among treatments, it was shown that the combinations with %0/2 of Datem, %0/2 of GMS and 100 PPM of Lipase Enzyme presented the most specific volume, porosity, moisture and the least hardness level, and consequently low speed staling 2 hours after cooking and 4 days after maintenance. This instance won the highest grade from tasting judges. The result indicated that after the experiment the qualitative and quantitative features of doughnut improved in comparison with the instance case. The case with %0/2 of Datem, %0/2 of GMS and 100 PPM of Lipase Enzyme showed lower speed of staling. Other parameters such as moisture level, activity water (AW), volume, porosity level, and general acceptability also presented better condition in this case.

The effect of the addition of various gelatin with different gel strength and changes in total solid non-fat on physicochemical and textural properties of non-fat yogurt evaluated, and addition of high bloom (HBG) and low bloom (LBG) gelatin in different concentrations (0.25%, 0.5%, 0.75% and 1%) impacts on textural properties of yogurt compared. According the results during gel formation and after that, gelatin interacted with milk casein network, as basis of the yogurt gel structure and revival water bands, thereupon plummet syneresis dramatically specially in samples with higher gelatin amount. On the other hand textural properties such as gel firmness of yogurt hardly affected by gelatin and SNF content; and samples contain 12.5% SNF and 1% HLB had firmest gel. Also, viscosity increased with addition of gelatin and solid nonfat. This feature can reduce the deficiencies of fat removed.

In this research, the effect of vacuum pressure and storage time were investigated on the postharvest quality of tomato and carrot. Three levels of vacuum pressure, 0.6, 0.4 and 0.2 bar were considered and during 12 days of carrot storage every three days and during 20 days of tomato storage every five days the sampling were performed. The effects of these treatments on the factors such as weight loss, firmness, soluble solids, titrable acidity and pH in carrots and tomatoes were investigated as factorial test based on Completely Randomized Design. Analysis of variance results showed that the effect of vacuum pressure and storage time on all mentioned factors were significant. Weight loss of both products was low at vacuum pressure of 0.4 bar. Also, tirable acidity and pH of these products were preserved better at vacuum pressure of 0.4 bar. The highest firmness was observed at vacuum pressure of 0.4 bar. Based on the results, storage of these two products at high vacuum pressure (0.6 bar) reduced the quality. In general, vacuum pressure of 0.4 bar was resulted in higher storage time of tomato and carrot.