mohammad shahedi - Academia.edu (original) (raw)

Papers by mohammad shahedi

Isfahan University of Technology - Journal of Crop Production and Processing, Oct 15, 1999

Journal of Food Processing and Preservation, Sep 16, 2011

Nanocomposite low-density polyethylene (LDPE) films containing Ag and ZnO nanoparticles were prep... more Nanocomposite low-density polyethylene (LDPE) films containing Ag and ZnO nanoparticles were prepared by melt mixing process through the twin-screw extruder. Packages prepared from nanocomposite films were then filled with fresh orange juice, pasteurized (at 55 and 65C for 16 s) and then stored at 4C. Microbial stability, ascorbic acid (AA) content, browning index and color value of the juice were evaluated after 7, 28, 56, 84 and 112 days of being stored. The two-way interaction between heat treatment and packaging type on the characteristics of the orange juice was investigated. Consequently, application of LDPE nanocomposite packaging containing Ag markedly decreased the pasteurization temperature (65C) of orange juice by 10C. Moreover, the reduced degradation of AA was observed in orange juice, which was filled in nanocomposite packaging containing nano-ZnO. PRACTICAL APPLICATIONS Development of the novel technologies that offer reduced energy consumption and increased quality of fruit juice are of the interest in the food industry. Compared with pure packaging, antimicrobial nanocomposite packages containing Ag and ZnO as an alternative nonthermal-processing technology can reduce the temperature of orange juice light pasteurization while produce juice with higher quality.

Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment, 2017

ABSTRACT This study mainly focuses on a strategy for reducing acrylamide content in whole-wheat b... more ABSTRACT This study mainly focuses on a strategy for reducing acrylamide content in whole-wheat bread by combining lactobacilli and yeast in sourdough breadmaking. Combinations of sourdough (fermented dough using different Lactobacillus strains including Lactobacillus plantarum PTCC 1896 [probiotic], L. sakei DSM 20,017, L. rhamnosus DSM 20,021, and L. delbrueckii DSM 20,081) and yeast, in comparison with yeast alone, were used for breadmaking. The results showed that acrylamide levels in breads fermented using sourdough+yeast were in all cases much lower (6.9–20 μg/kg on a dry weight basis [d.b.]) than those in the yeast-only fermented bread (47.6 μg/kg d.b.). Significant (p < 0.05) correlations were also found between pH, total titratable acids (TTA) and lactic acid, and acrylamide content. Furthermore, the obtained results showed that the moisture content of dough directly influenced the formation of acrylamide in bread (r = 0.925, p < 0.0001). In addition, no significant correlations were observed between acrylamide content in breads and either the reducing sugar or free amino acid contents in dough samples. According to the different effects of Lactobacillus strains, it could be concluded that the acrylamide reducing potential of lactobacilli was strain-specific, with L. rhamnosus being the most effective. This suggests that sourdough fermentation with appropriate Lactobacillus strains can be used as an advantageous technology to reduce the acrylamide content of whole-wheat breads. Graphical Abstract

Food Additives & Contaminants: Part A, Sep 27, 2017

Journal of Food Measurement and Characterization, Oct 28, 2015

Food Control, Mar 1, 2011

Nanocomposite LDPE films containing Ag and ZnO nanoparticles were prepared by melt mixing in a tw... more Nanocomposite LDPE films containing Ag and ZnO nanoparticles were prepared by melt mixing in a twin-screw extruder. Orange juice was sterilized and was inoculated with 8.5 log cfu/mL of lactobacillus plantarum. Packages prepared from nanocomposite films were then filled with this orange juice and then stored at 4 C. Microbial stability of the juice was evaluated after 7, 28, 56, 84, and 112 days of storage. The results showed that microbial growth rate significantly reduced as a result of using this nanocomposite packaging material. Reduced numbers of L. plantarum were observed (p < 0.05) in nanocomposite packages of orange juice containing nanosilver and nano-ZnO. Moreover, packaging made from nanocomposite film containing nanosilver showed a more pronounced antimicrobial effects, as compared with nano-ZnO during 112 days storage of inoculated orange juice. However, LDPE þ 5% P105 packages, showed a significant antimicrobial activity compared with others.

Journal of Agricultural Science and Technology, Jan 10, 2019

Cellular Automaton (CA) was applied, for the first time, to model mass transfer during the drying... more Cellular Automaton (CA) was applied, for the first time, to model mass transfer during the drying process. CA is a discrete model with powerful potential application for simulating complex systems. In this paper, a two-Dimensional (2D) model was applied to simulate drying process of banana slices. The system was designed for a grid with size of 30×90 square cells, four possible states, and von Neumann neighborhoods. The logical trends of the model results were examined by running program for different process conditions such as various temperatures, air relative humidity values, air flow velocities, and sample thicknesses. Validation of the model was performed by comparing estimated and experimental data of banana drying for three temperatures (60, 70, and 80°C). The model showed high accuracy for predicting moisture content (R 2 values higher than 0.99). Notable accuracy based on simple rules to pattern the complexity of the system and flexibility indicated the superior application of cellular automaton for modeling food processes.

Journal of Agricultural Science and Technology, Mar 1, 2018

Since the microwave technology is well considered in food processing due to the speed and mechani... more Since the microwave technology is well considered in food processing due to the speed and mechanism, in this study, cupcake was baked at different levels of MicroWave (MW) power (150, 300, 450 and 600W) and the effects of different kinds of operational time (3.5, 5, 8, 16 minutes) and power on physical properties (density, porosity, colour and height) and textural properties (crispness, hardness, cohesiveness, springiness, resilience, gumminess and chewiness) of cupcake were investigated. Results showed that the MW baking time to obtain desirable baking properties was affected by MW power. The obtained results showed that the total differences in colour from the reference batter (∆E) and colour intensity increased with increasing of MW power. Moreover, the MW cupcake baked at a power of 600W had the least hardness, density, chewiness, gumminess values, the shortest baking time, and the highest values of cohesiveness, resilience, porosity, height, and browning index. Also, it had the highest cohesiveness, resilience, porosity, height and browning index, compared to the other powers. Therefore, the best operational power for desirable quality obtained during baking was 600W.

Isfahan University of Technology - Journal of Crop Production and Processing, Oct 15, 2001

Iranian Food Science and Technology Research Journal, Aug 26, 2014

The best PH for getting Millard reaction started and Acrylamide formation ranges 7 to 8. PH below... more The best PH for getting Millard reaction started and Acrylamide formation ranges 7 to 8. PH below the range slows the reaction speed down and the resultant Acrylamide formation delayed. This research assess how Acetic Acid in 0.05, 0.15, 0.25% concentrations together with sourdough may promote acidity in bread dough and how they can cause a reduction of acrylamide content in Sangak bread [an Iranian traditional bread]. Here the acrylamide is assessed after it was derived and then transferring it to gaseous chromatography with ion indicator. The concentration of acrylamide in Sangak breads made of sourdough with 0.05, 0.15 and 0.25% of acid acetic showed a decrease of 73.47, 81.50 and 82.10% and also a 90.55, 92.80 and 95.96 % decrease when the bread has been made of the same compounds and yeast. The acidity of compounds with acidity rate of 0.05, 0.15 and 0.25% in Sangak bread made of yeast equates to 0.12, 0.14 and 0.17% (normal) respectively; while these values for Sangak breads made of sourdough stand at 0.16, 0.18 and 0.21% (normal). Therefore, decreased acrylamide can be attributed to increased acidity of dough.

Pistachio processing is one of the ways to increase the value added of pistachio. Production of p... more Pistachio processing is one of the ways to increase the value added of pistachio. Production of pistachio butter is for this purpose. Pistachio butter is a paste form product that contain mainly milled, roasted pistachio kernel with sugar. The aim of this investigation is to produce ...

Microbial transglutaminase (MTG) catalyzes the formation of ε-(δ glutamyl-)-lysine cross links in... more Microbial transglutaminase (MTG) catalyzes the formation of ε-(δ glutamyl-)-lysine cross links in proteins via an acyl transfer reaction. In this study, the impact of microbial transglutaminase (MTG) on dough rheological properties of wheat flour supplemented with 20, 35 and 50% of hullless barley flour was investigated. The MTG was added at five different levels (0. 0.5%, 1%, 1.5% and 2%; w/w) to increase the concentration of lysyl residues and possibly enhance the extent of cross-linking of protein matrix by MTG, a commercial soy protein isolate (SPI) was added at a level of 3% (w/w) in combination with MTG. Extensography results showed that increasing MTG concentration increases the resistance to extension and decreases the extensibility. Farinography results indicated that in flours with 35 and 50% of hull-less barley flour, with increasing MTG doses, dough development time was increased. Addition of MTG in a concentration of 1% in 20% of hull-less barley led to an increase in dough stability time in farinograph. In 50% of hull-less barley treatment, addition of MTG in concentration up to 1.5% and 2% caused an increase in dough stability time. Mixing tolerance index was decreased with increasing MTG up to 0.5%. In overall, MTG can improve the rheological properties of dough when it is used in an optimum level.

Food Additives & Contaminants: Part A, 2017

Renewable Energy, 2016

In this study, a new method was proposed for the preparation of a stable Al 2 O 3-paraffin nanoco... more In this study, a new method was proposed for the preparation of a stable Al 2 O 3-paraffin nanocomposite phase change material (NCPCM). Sodium stearoyl lactylate (SSL) was used as the surfactant to improve the dispersion of Al 2 O 3 nanoparticles (2.5, 5, 7.5, and 10 wt.%) in paraffin with a SSL/Al 2 O 3 mass ratio of 1:3.5. After preparation, one group of the samples was placed in an incubator at a temperature of 60 C for one week to evaluate its stability during the time elapsed. The other was left alternately in two incubators, one at 60 C and the other at 25 C over time intervals of 1 h in order to evaluate the stability of the sample after given numbers of melting/freezing cycles. This latter treatment has been seldom ever reported elsewhere. For NCPCM stability evaluation, the samples were broken into two parts equal in volume and the change ratios of surface layer Al 3þ concentration are determined. Also, image analysis is used for evaluating the stability of nanofluids. The results obtained from the two methods are found to be in good agreement. Image analysis is, therefore, proposed as a nondestructive method with good accuracy, especially for evaluating the stability of high concentration nanofluids.