Research and Innovation in Food Science and Technology
Year:2016 | Volume:5 | Issue:3|Papers Count:9

In this study, Barbari flat bread was prepared by two methods, including part-baking and conventional baking and then stored at 4oC for 7 days. Part-baking was done for 4, 6 or 8 minutes and conventional bread were prepared for 10 minutes (control). The samples were evaluated for the crust color, porosity and mean particle size by using ImageJ software during the storage time. Also, image texture features of samples were extracted using MATLAB software. Before acquiring images, the baking time of Barbari part-baked bread was completed to the baking time of control bread (10 minutes). Crust color of part-baked samples did not significantly change during 7 days, but the lightness of control bread decreased significantly. In addition, because of less porous and more compact texture of control bread and also, stronger changes in their image texture characteristics compared to part-baked bread during storage time, part-baking was a successful method for production of Barbari flat bread. Part-baked breads with different initial baking times were not completely similar. On the other hand, the results showed that the part-baked bread with different initial baking times were not similar in terms of quality characteristics. By comparing three quality features of the sample images after the second baking, the part-baked Barbari bread with initial baking for 6 minutes had higher quality and stability than other treatments.

The main aim of this study was to determine the effects of acetylated wheat starch (AWS) addition in different levels on the properties of dough and bread. Therefore, Syneresis and Pasting properties of Nativewheat starch (NWS) and acetylated wheat starch (AWS) was investigated. Effects of incorporation of 5, 10 and 15% of those starches on properties of wheat flour were determined by using a Rapid Visco Analyzer (RVA). Then, Rheological properties of dough were determined by Farinograph and Extensograph. After measuring mass, volume and sensory evaluation, staling analysis was done by seven trained panelist, texture analyzer and moisture content was determined in 1, 3 and 5 days. Measuring syneresis and pasting properties indicated that best viscosity properties and Lower syneresis observed in AWS. The farinograph results showed a decrease in the water absorption in comparison to control but no significant difference was observed in arrival time and development time. According to Extensograph results, resistance to extension of samples containing starch was significantly more than control sample and extension ability in all treatments was significantly lower than control. Addition of both of starches resulted in reduction of bread volume and specific volume compared to control. Data obtained from sensory evaluation showed, AWS significantly resulted in the highest score in quality properties. According to the results of staling tests (sensory evaluation, texture analysis and moisture content determination), addition of AWS was successful in retarding of staling. Overall results revealed that the incorporation of 5% AWS improves the quality of Barbari bread.

Nowadays, using the fat replacers is a common method to produce low-fat cheeses. Employing these ingredients improves the texture, yield and functional characteristics of these products. To achieve the low-fat cheese formulation with desired gum concentration that resembles to its full-fat characteristics a lot of experiments is required. Therefore, this technique is a costly and time consuming process. Response Surface Methodology (RSM) is an appropriate approach to optimize formulation of new products. The effects of addition of Persian and almond gums as fat replacers on traditional Iranian white cheese were investigated and the best low-fat cheese formulation with favorable texture characteristics was obtained. The experiments were designed according to 3-level-3-factor box-Behnken design through RSM. The independent variables were including Persian gum (0-0.2%), almond gum (0-0.2%) and milk fat content (0.4-1.4%) and the responses were textural characteristics of cheeses. A predicted optimum formulation was gained with 1.4% milk fat, 0.18% Persian gum and 0.13% almond gum. Microstructure analysis of cheeses showed that the traditional low-fat Iranian-white cheese with optimum formulation like full-fat cheese sample had a more open structure in comparison with low-fat control.

In this study, the composition, color attributes and functional properties of watermelon, melon, cantaloupe and cucurbit flour were evaluated. Significant differences were observed in proximate composition, color attributes and functional properties (P <0.05) except for water binding capacity. Foam expansion was higher for the cantaloupe and cucurbit flours.Cucurbit flour had more foam stability, water/oil binding capacity, water holding capacity and more protein solubility; Moreover, it had a significant lower L* value (P<0.05). Also, emulsifying stability was higher for the cucurbit flour and a strong gel was formed at 6% (LGC) for this flour. In this research cantaloupe flour appeared to have the least gelling properties and the highest emulsifying capacity. The rheological data were fitted with the Power Law model. The flow behavior index was less than 1 for all flour types, which indicating shear-thinning behavior. Furthermore, the most consistency coefficient and flow behavior index were attributed to the cucurbit flour suspension and the least to the watermelon and cantaloupe flour.

Response surface methodology (RSM) is a collection of statistical and mathematical techniques for designing experiments, modeling, improving, and optimizing processes. The aim of the present study was to optimize osmotic dehydration process ofRosa canina L. fruit by RSM. For this purpose, the effects of independent variables including temperature (20, 30 and 40oC), concentration of osmotic solution (40, 50 and 60% w/w) and dehydration time (2, 3 and 4 h) on the responses or dependent variables including water loss (WL), solid gain (SG), and weight reduction (WR) were evaluated. The results showed that all models obtained for WL, SG and WR were suitable to describe the experimental data. Moreover, the desirability function showed that optimum conditions of osmotic dehydration process of Rosa canina L. fruit were osmotic solution temperature of 31.78oC, solution concentration of 60 (% w/w) and dehydration time of 3.59 h. Under these conditions, the amount of parameters of WL, SG, and WR were obtained to be 27.38, 3.53 and 23.85 g per 100 g of sample, respectively.

According to the importance of expanding the use of clean energy, especially solar energy, in this study a solar cooker was designed, built and its performance in terms of the angle of the side mirrors at the same time and working time on the amount of energy absorbed was investigated by response surface methodology (RSM). The total amount of solar radiation as a measure of energy intake and increased water temperature inside the container was taken as an indicator of the amount of energy absorbed. The model on the basis of response surface methodology was used to validate the test and had a good validation (R2=0.89, R2adjusted=0.74 and lack of fit: no significant). Analyzing the results of a mathematical model was obtained for investigation of the effect of the side mirrors angle and time on the performance of the system. The amount of absorbed energy by theory and laboratory has been also compared and the average of error at all tests was 2.75%. Based on this model in the optimal condition, energy absorption was increased by 22.56%. This study was done at Institute of Food Science and Technology located in Mashhad with latitude 54 and 36 degrees and a height of 985 meters above sea level.

Nowadays, new systems that are be able to measure the characteristics of the quality of food products for nondestructive testing and can be installed on the grading lines are very important. Analysis of the acoustic response is a non-destructive method for measuring fruit quality characteristics. Therefore, the potential of acoustic impulse response for non-destructive classification of Red Delicious apple was examined. In this study, sound signals in both time and frequency domains were analyzed using wavelet transform. Signals are decomposed into three levels using Daubechies 4. Eight statistical features were selected: maximum, minimum, mean, standard deviation, energy, kurtosis, skewness and third moment. Apples are classified according to changes in the acoustic response during storage time using multilayer perceptron neural network algorithm. According to results, classification performance of artificial network with 4-1-2 topology in time domain is better than the other networks. The classification accuracy and harmonic mean of precision and sensitivity for this topology were 82.1% and 0.81, respectively.

In this study the ability of Saccharomyces cerevisiae PTCC 5052 to adsorption of aflatoxin M1 was assessed. In order to improve operational efficiency, Alumina ceramic was analyzed as a potential support for immobilization of yeast cells. In immobilization process, results indicated that the binding abilities of AFM1 by live cells of Saccharomyces cerevisiae were higher than non-live immobilized cells on alumina ceramic within 48 hours (P<0.05). Then, the aflatoxin M1 solution (0.2 ppb) was passed through a ceramic substrate containing immobilized saccharomyces cerevisiae (both of live and non-live immobilized cells) in 5, 10 and 20 minutes. The results showed that the residual aflatoxin M1 in the solution after 20 minutes of circulation was minimal and the highest percentage of AFM1 reduction was 75. Alumina beads containing live immobilized yeast cells compared non- live yeasts, significantly reduced aflatoxin M1. The results of this study showed that the alumina ceramic can be used as a suitable bed for immobilization of saccharomyces cerevisiae to remove aflatoxin M1.