مجله علوم و صنایع غذایی ایران
سال یازدهم شماره 1 (پیاپی 42، بهار 1393)

Sponge cake is one of the cereal products which has a shelf-life about 4 weeks and contains 15 to 25 % fat. Moisture migration and staling are of most problems related to this product leading irreversible changes in its physical and sensorial properties and finally diminished shelf-life. In this study the effects of tragacanth addition on quality properties and staling pattern in order to improve the quality of cake and increase its shelf-life was investigated. Hence، cakes containing different concentration of tragacanth were prepared and then their volume index، sensory attributes، and physical properties (softness using the texture analyser) were determined. Results showed that cakes contained up to 0. 4 % tragacanth had significantly more volume index، softer texture، and better sensory attributes than the reference cake.

In this research In order to use the rice bran extract in the formulation of Fruit Drinks، Three varieties of rice، including tarom، anbar bo and hashemi were selected and heavy metals of them were analyzed and then In order to select the appropriate method of bran extract، Four extraction methods including using subcritical water at a temperature of 100 and 120 ° C، microwave and oven at 100 ° C for the extraction of rice bran were used. After choosing the best method of extraction، physical، chemical، and rheological characteristics of samples were measured and compared. Results of data using SPSS software and one-way ANOVA and the Duncan test were evaluated. Results showed that in using of subcritical water extraction method، increasing temperature increases the amount of extraction of compounds found in rice bran So that Most of the compounds extracted from the above methods is related to using subcritical water at 120° C And the least amount of compounds extracted from rice bran is related to using oven at 100° C. Investigate the rheological properties of the extracts also suggests that All extracts show the behavior of a Newtonian fluid. According to the characteristics of extraction produced from subcritical water at 120° C This method is the best method of extraction Among the extraction methods.

The aim of this study was evaluation of sensory properties and color parameters cantaloupe pastille. Independent variables was pectin in range 0. 2-0. 5% and xanthan in 0-0. 3%. Effect of pectin and xanthan on sensory properties evaluated by multivariate ANOVA. The results showed only total pectin levels on sensory properties was significant (Hotelling Trace، p £0. 05). The percentile distribution showed that the sample containing 0. 2 % pectin and xanthan 0. 3 % had highest score of favor color and appearance acceptability. The sample containing 0. 5% pectin and no xanthan had lowest score of flavor. The sample containing 0. 5% pectin and xanthan 0. 3 % had highest score adhesiveness. Effect of pectin and xanthan on color parameters (L*a*b*) was significant (p £0. 05). The assessment of relationships between color parameters and color sensory evaluation with using PCA method indicated that maximum of a* and L* values cause to acceptance score were decreased.

Packaging is one of the most important factors in the field of marketing. By developing industries and emerging new technologies in different aspects of production the packaging industry was not divested as well and has its own effect on this crucial industry. Product packaging is the combination of various elements which can be effective in creating a vivid image on the consumer’s mind. The current research investigates the visual and informational effects of packaging on customers buying trends in food industries in Semnan. For this purpose، questionnaires have been designed to collect data and regression analysis and path analysis methods were used for hypotheses testing. Among the visual and informational factors، the information on package، shapes and size have the most influence on the repurchasing tendency of customers it should be mention the visual and informational factors have also significant and direct impact on customer’s perceived quality which has its own direct effect on tendency to buying. Considering the results of this study and its compatibility with the previous studies، researchers suggest that these factors should be applied in sales promotions in order to make customer loyal through the sales which guarantee future profit.

Mayonnaise is a kind of oil in water emulsion that generally contains 70-80% oil. Increasing knowledge of people about full fat food products has made manufacturers solve the problems related to the health concerns. In this research reduced fat mayonnaise samples (45% oil) were produced using xanthan (0-0. 3%)، guar (0-0. 3%) and preglatinized corn starch (2-4%) as fat replacer by central composite design and their textural attributes (firmness، consistency، adhesive force and adhesiveness) were measured and compared with those of full fat mayonnaise (70% oil) as control sample. The highest textural values were observed for the sample which was made with 0. 3% xanthan، 0. 3% guar and 4% preglatinized corn starch and the lowest values were found for the sample containing only 2% starch as fat replacer. Most of the samples demonstrated textural values higher than those of control sample، describing high performance of the used hydrocolloids in developing thickness. Besides، synergistic interaction was observed between xanthan and pre gel corn starch that consequently resulted in improved textural properties. Modeling and high coefficients of determination revealed high satisfaction of the models to predict data.

One of the most important researches areas in food industry is setting parameters in an optimal level to improve process functions. A literature research in food science and technology databases reveals that in recent years many optimization methods have been developed to improve food processing. However، most of these methods have only dealt with a single objective problem. In many situations the quality of a manufactured product is often evaluated by several quality characteristics and multiple objectives must be optimized simultaneously. In this article we propose a method that integrates design of experiments، response surface technique and Signal-to-Noise (SN) ratio concept for optimization of a kind of yoghurt، called Whey Less، with three TS، Acidity and cost per unit. The proposed method considers both the mean and the variation of quality losses associated with several objectives، and ensures a small variation in quality losses among the objective functions، along with a small overall average loss. Moreover، this method can be used for both kinds of decision variables (discrete and continuous) and its implementation is easy.

The present study was established to evaluate the efficacy of formol titration test in detecting the protein and milk solid non fat (MSNF) values in ice cream. A total of 41 ice cream samples and constituents such as fresh milk، skim milk powder and whey powder were tested. The dry matter، fat، ash، total proteins، sugars and MSNF (by calculations) of the samples were measured. The MSNF were also measured by formol titration method. Regression coefficient between total proteins of ice cream، measured by Kjheldal and formol titration was 0. 07 (p>0. 6). This value was 0. 11 (p>0. 5) between true MSNF and measured by formol titration. Our results revealed that the formol titration test was not a valid procedure to estimate the protein values of ice cream، and we were not been able to assess the MSNF values based on the measurement of proteins using formol titration and also Kjheldal method. As a final result، we propose the replacement of “percent of total MSNF” by “the lowest values of total proteins” in the number 2450 rule، of the Iranian national standard regulations.

Quality enhancement and shelf life extension of bread as main meal in Iran is one of the particular importance to people’s health and national economy. So that the purpose of this study were planned to investigation on the effects of emulsifiers (E471، DATEM and SYTREM) in levels of 0، 0. 25، 0. 5 and 0. 75 % and final fermentation time in 30، 45 and 60 minute on dough rheology (Amylogram and Farinogram) and quantitative and qualitative properties (texture، volume، porosity، crust color and overall acceptability) of composite bread. Porosity and crust color were estimated and analyzed by image J software. The results showed viscosity، dough development time، stability and valometervalue increased by increasing the amount of emulsifierswhereasgelatinationtemperaturewas decreased. AlsoDATEM and SYTREM were more effective as compared tocontrols inwaterabsorption. Experiments showed that the sample with 0. 5% DATEM and 45 minutes final fermentation time had the lowest firmness and the highest overall acceptability. On the other hand DATEM، E471 and SYTREM and 30، 45 and 60 min the final fermentation time respectively had the pronounce effect on increasing volume and porosity of the bread samples. Regarding to color estimation the L* value was increased by addition of emulsifiers especially DATEM to the bread formulation. However the highest L* value was observed in samples 45، 60 and 30 min final fermentation time respectively.

Rheological behavior of fig juice concentrates was studied with the objective of defining suitable models for use in evaporation and other processing procedures. The flow properties were determined for juice concentrate with solid content of 70° Brix containing different concentrations of pectin from 0. 2 to 0. 8% over the temperature range of 5 to 65°C using response surface methodology. A rotational viscometer was used to characterize the flow behavior of concentrates. Samples were subjected to a programmed shear rate increasing from 0-100 s-1 in 10 min. The flow of all combinations was adequately described by Herschel Bulkely model and the consistency coefficient (m)، the flow behavior index (n)، yield stress (τ0) and apparent viscosity (η) were obtained. m and τ0 increased with pectin concentration and decreased with temperature، while pectin concentration and temperature had opposite effects on n and (η). All parameters were sensitive to changes in temperature and pectin concentration.

Probiotic yogurt is one of the most common and important probiotic products in the market. Researchers have revealed that the survival of probiotic organisms in yogurt during storage has often been low. An appropriate technique to preserve the survival rate of these organisms is to prepare yogurt powder using spray drying. The objective of this study was to investigation the effect of ingredient supplementation on survival of bacteria in probiotic yogurt during spray drying process. Effect of supplementing milk before preparing probiotic yogurt with various of ingredient (including whey protein concentrate، maltodextrin powder (DE=10-12)، lactose، sodium caseinate and skim milk powder at a level of 1. 5% (w/v) on survival of bacteria in probiotic yogurt powder after spray drying using inlet air temperature of 150 ˚C، air flow rate of 478 m3/h and feed flow rate of 2 L/h was investigated. The results indicate that supplementing milk with various ingredients prior to preparing probiotic yogurt not only enhances the growth of bacteria in fresh yogurt but also improve the survival rate these bacteria following spray drying and preparation of probiotic yogurt powder.

This study aimed to investigate the quality characteristics of fish protein powder (FPP) from common carp raw surimi and its mince prepared by application of freeze-drying technique. To prepare test samples، either distilled water or 0. 5M NaCl solution was used and parameters such as water holding capacity (WHC)، emulsion capacity (EC)، emulsion stability (ES) and oil absorption (OA) were determined. According to the results، WHC did not show any significant differences in samples prepared either by distilled water or 0. 5M NaCl solution. In terms of EC، after 6، 12، 24، 48 and 72 h in samples prepared by use of 0. 5M NaCl، no significant differences was observed between treatments. However، by use of distilled water، the differences became significantly (P<0. 05) different. In this study، FFP from raw surimi showed higher and significant OA capacity compared to the one from fish mince. Finally، among color indices، L* and a* values showed significant difference between FFP from raw surimi and fish mince. It can be concluded that as there was no significant differences between FPP from common carp raw surimi and unwashed mince in terms of functional properties، therefore، if we expect lighter and whiter color in enriched product with protein powder، surimi FPP would be an appropriate choice، however، it needs to be confirmed by sensory evaluation test.

Gluten-freebakeryproductsisan important rolein the diet ofcoeliac diseaseandshould besupplied a part ofdailyenergy، protein،mineralsandvitaminsofthese patient''s needs. Therefore the aim of this study was evaluation of adding BalanguShirazi gum (0، 0. 25، 0. 5، 0. 75 and 1%) on moisture content، specific volume، porosity، crust color (L*، a* and b* values) and sensory properties (overall acceptance) of sorghum gluten-free semi volume Barbaribread. Crust color and porosity were estimated and analyzed by Image J software. The results showed the moisture content and L* value were increased by adding this gum. However the highest specific volume and overall acceptance in sensory evaluationwere observed in sample including 0. 5% BalanguShirazi gum. On the other hand the lowest firmness (2hr after baking) was observed in this sample. Also the samples containing 0. 25 and 0. 5% BalanguShirazigum had the highest porosity and the lowest firmness (72hr after baking).

In recent years، there has been an increased consumer interest and demand for low fat food products. Chocolate is a product with high fat and energy، therefor calorie reduction and partial replacement of cocoa butter is one of the efficient solution in this way. This study investigates the effect of collagen hydrolysate (Instant Gel Schoko) as a partial replacement of cocoa butter on the rheological and sensory properties of milk chocolate. Chocolate samples prepared with collagen hydrolysate having replacement levels of 15، 20، 25، 30% investigated and compared to control (contaning cocoa butter) group. The result showed that moisture content increased with increasing replacement levels، but water activity didn’t show significant difference with control group. The values of hardness، tixotropy، plastic viscosity and apparent viscosity increased with increasing the percentage of replacement، as a result، samples by least replacement levels (15، 20%) had less diffrence with control group. The amounts of yield value had increasing trend with enhancing of replacement percentage as the least yield value was related to M15. In spite of reducing total acceptance with increasing the levels of replacement in sensory evaluation، there was no significant difference with control group and in five levels hedonic test the most acceptance alloted to M20. In conclusion، according to results of rheological and sensory evaluations، in most cases، samples up to 15، 20% replacement had the least difference with control group and can be counted as optimum level for cocoa butter replacement.