Food Engineering
Setereh Ramezani; Mohammad Shahedi; Milad Fathi
Abstract
Global concern about human health and the increase the prevalence of chronic diseases in recent years lead to growing appeals for nutritious and healthy compounds, such as coenzyme Q10. Susceptibility to heat and lipophilic properties of coenzyme Q10 limit its utilization in food. Encapsulation is a ...
Read More
Global concern about human health and the increase the prevalence of chronic diseases in recent years lead to growing appeals for nutritious and healthy compounds, such as coenzyme Q10. Susceptibility to heat and lipophilic properties of coenzyme Q10 limit its utilization in food. Encapsulation is a technology that protects bioactive ingredients from harsh environmental conditions and extends shelf life. The purpose of this study was to encapsulate coenzyme Q10 using complex coacervation by gelatin–basil seed mucilage and characterize physical, thermal and chemical properties of produced microcapsules. Response surface methodology was applied to determine the optimum level of the four formulation variables for maximum encapsulation efficiency, loading capacity and turbidity and minimum supernatant absorption. The optimum microcapsules had encapsulation efficiency of 83.69%, encapsulation load of 16.32%, turbidity of 0.979 and supernatant absorption of 0.227. The microcapsules were assessed by scanning electron microscopy, Fourier transform infrared spectroscopy, and differential scanning calorimetry. The results of FTIR confirmed the formation of coacervates. The thermogram of Q10 loaded microcapsule melting point was not observed at its melting point (50°C) due to its solubility in the oil phase and appropriate entrapment. Release behavior of Q10 was studied by different mathematical models. Microencapsulated Q10 was used to fortify milk and the results showed that the developed protein-carbohydrate microcapsules can be applied for protection of hydrophobic compounds.
Food Technology
Mahya Hosseinzadeh; Mohammadyar Hosseini; Mohammad Shahedi; Mehdi Kadivar
Abstract
IntroductionThe most important component of wheat proteins is gluten, and the most prominent bonds in gluten are disulfide bonds, which bind glutenin subunits. Therefore, oxidizing and reducing agents with great effects on the thiol-disulfide system of the dough can change the mechanical and rheological ...
Read More
IntroductionThe most important component of wheat proteins is gluten, and the most prominent bonds in gluten are disulfide bonds, which bind glutenin subunits. Therefore, oxidizing and reducing agents with great effects on the thiol-disulfide system of the dough can change the mechanical and rheological properties of the dough. Due to the positive effects of ascorbic acid on the properties of the dough, it is used as a flour improver. To weaken the structure of the dough, reducing agents such as cysteine-L can be used, and by adding organic acids, increasing the specific volume and decreasing the moisture, the pH and hardness are observed in comparison with the control. This study is performed to evaluate the effect of adding reducing compounds, vitamin C and organic acids during the conditioning of wheat and their effect on the yield of the resulting pulp.Materials and MethodsFirst, Physical properties of wheat include: specific density, colorimetry, estimation of grain length, width and thickness, grain hardness, hectoliters, 1000-grain weight, grain moisture, degree of extraction were measured for the tested wheat. Moisture, pH, ash, particle size, fat, protein and zeal number tests were performed on wheat flour. From elementary cleaned and weighed wheat, 13 samples of 240 g each were weighed separately and poured into plastic bottles. One sample was conditioned with only 30 ml of distilled water and the other 12 samples were conditioned with the following solutions, respectively:1- Cysteine solution at three levels of 0.25, 0.5 and 0.75% by weight2- Citric acid solution in three levels of 0.3, 0.4 and 0.5% by weightVitamin C solution in three levels of 100, 150 and 200 ppm4- solution of 80 ppm vitamin C and 0.1% cysteine, solution of 100 ppm vitamin C and 0.2% cysteine, solution of 120 ppm vitamin C and 0.3% cysteineAfter 24 hours, the conditioned wheat samples were milled by a laboratory waltz mill, and then subsequent tests including gluten, sulfhydryl-disulfide, glutathione, and solvent retention capacity (SRC) were performed on the samples.Statistical analysis was performed using SAS statistical software in a randomized complete block design. Each measurement was performed in at least three replications and the means were compared at 95% confidence level with the least significant difference in LSD.Results and DiscussionThe results of physical tests on wheat grain and chemical tests on flour obtained by milling the wheat samples without adding additives during conditioning are presented in tables. The results of gluten, glutathione, sulfhydryl-disulfide and solvent storage capacity tests on samples of conditioned wheat flours are also presented. Based on the results of gluten and glutathione test, it was shown that ascorbic acid is oxidizing and strengthening the dough, but cysteine is reducing and weakening the dough. Simultaneous addition of cysteine and ascorbic acid strengthened the dough, adding citric acid to certain level strengthened the dough as exhibited in the gluten test. However, byond that level, weakened the dough, but in the glutathione test it was almost ineffective. The results of sulfhydryl-disulfide test showed that increasing the amount of vitamin C at three levels of 100, 150 and 200 ppm increases the number of disulfide bonds, although this increase was not in linear trend, which can be due to the limited number of groups of sulfhydryl with a suitable spatial arrangement for oxidation. Accordingly, the number of sulfhydryl groups is significantly reduced, although it does not reach zero. With the addition of reducing cysteine, the opposite trend was the case, as the number of thiol groups increased, the number of disulfide bonds and bridges decreased. The addition of organic acid had no significant effect on both parameters and showed that the performance of these two variables is independent. By adding both reducing and oxidizing compounds, it was found that the oxidizing effect of vitamin C is far greater than the reducing effect of cysteine. Regarding the solvent retention capacity test performed with 4 solvents of deionized water, 50% sucrose, 5% sodium carbonate and 5% lactic acid, the expected results are that the addition of cysteine has a reducing and weakening effect on the dough, adding vitamin C and cysteine + vitamin C strengthens the dough and the addition of citric acid initially strengthens the dough, but by increasing its level weakens the dough, but this effect is small and can beneglected . The results obtained by comparing the samples conditioned with cysteine, vitamin C, citric acid and cysteine + vitamin C, with the sample conditioned with distilled water in some additive levels matched the expected results, but in some cases did not.
Zeynab FarhaniNejad; Milad Fathi; Mohammad Shahedi
Abstract
Introduction: Banana is one of the most popular tropical fruits in all over the world with notable post-harvest losses. Due to its high moisture content preventing long preservation period. So, it needs a proper preservation method to prevent product lost especially in main produceing countries. Since ...
Read More
Introduction: Banana is one of the most popular tropical fruits in all over the world with notable post-harvest losses. Due to its high moisture content preventing long preservation period. So, it needs a proper preservation method to prevent product lost especially in main produceing countries. Since banana is an un-freezable fruit, thermal processing such as drying or canning could be more appropriate for prolonging its shelf life. On the other hand, high energy consumption and being cost intensive are two most important disadvantages of thermal processing. In order to decrease the side effects of thermal process on quality parameters, pretreatment of samples could be applied to reduce time of main process.Osmotic dehydration is a non-thermal pretreatment which provides partial removal of water by immersing sample in an osmotic solution.But this process also takes a long immersion time to enough reduction of moisture. So this leads to undesirable effect on texture and colors.This study was performed to eliminate some side effects of osmotic dehydration on quality and finally introduce an optimized condition resulting best performance of process.A novel all-knowing method for optimization of process is genetic algorithm (GA) which is a search heuristic that mimics process of natural selection. It generates solutions for the optimization of problems using techniques inspired by natural evolution, such as inheritance, mutation, selection, and crossover. In this research, genetic algorithm was applied to predict optimum condition of osmotic dehydration.Material and methods: Osmotic dehydration was performed using aqueous solution of sucrose in concentration of 45% (w/w) for immersion time of 3 hr. The first challenge was improving mechanical properties of banana slices by adding calcium lactate to sucrose solution in concentrationsof 0, 2, 3 and 4%.For the next step in order to protect samples from enzymatic browning mixture of ascorbic acid (0.25 %) and citric acid (0, 0.5, 1, and 1.5%) were used.The pH of solution was measured for each level of adding citric acids. The efficiency of operation was estimated by computingwater loss and solid gain. Firmness of dehydrated samples wasmeasured using a texture analyzer (INSTRON, 1140, Singapore) and penetration test. Image acquisition technique was applied to measure L*, a* and b* indices.The coefficient of efficiency was defined as the ratio of water loss to solid gain and calculated to estimate performance of treatment in new condition. Finally, optimized conditionsfor maintaining the lowest solid gain and color changes, the highest water loss and firmness waterlosswere predicted by genetic algorithms method. The accuracy of model was investigated using statistical parameters such as mean absolute error (AME), normalized mean square error (NMSE),mean square error (MSE).Results and discussion: The results of experiments showed a significant increase of firmness by adding lactate calcium. This observation was due to complex formation between calcium and cell wall ingredients. Thesecomplexes have a decreasing effect on solid gain.Because complexes preventedmacromoleculesentering such as sucrose to the cells.On the other hand,calcium lactate and citric acid had interaction on mentioned parameters.Firmness showed less firmness when citric acid was added to the solution. Because citric acid as a chelating agents can blockdivalent cations and prevent from effective reaction with plant cells.Also citric acid can disconnect methoxyl groups from protopectinproducing softer texture.However, treated samples still showed firmer texture than control sample. It could be due to the additional effect of citric acid which makes carboxyl groups available for divalent calcium cations during conversion of protopectin to the pectin.For color parameters,only use of citric acid could not decrease the total change of color because yellow index increased due to the hydration of citric acids. But for the use of two factors, a significant decrease of total change of color was observed.For water loss, increase of solvents in each treatment led to raise of water loss due to the increase of osmotic pressure.In this circumstance determination of suitable concentration for each factorresulting best performance is complex, so it is necessary to apply a system canpredict optimized conditions. Genetic algorithms estimated optimum condition formaximum firmness and water loss, minimum solid gain and total change of color.In this condition the concentrations of lactate calcium and citric acid were %3.99 and %0.86, respectively. Also predicted values for water loss, solid gain, firmness and total change of color were earned %18.01, %5.07, 1.47 N and 11.37.MAE, NMSE and AME parameters (2.062, 0.021, and 1.099 respectively) were used for investigation of difference between estimated and experimental data which showed high efficiency of genetic algorithm for optimization of osmotic dehydration of banana.Investigating the efficiency ofcoefficient of treatments showed that application of both factors (calcium lactate and citric acid) significantly had more efficiency in comparison to the control samples regarding quality factors.
Reza Farhoosh; Mohammad Shahedi; Ali Sharif
Abstract
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 ...
Read 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.
Kiana Poormohammadi; Mehran Alami; Mohammad Shahedi; Alireza Sadeghi Mahoonak
Abstract
barley is a kind of cereal that contains high amounts of β-glucan. β-glucan is a major component of soluble fiber implicated in hypocholesterolemia, hypoglycemia, diabetes and heart attacks. Investigations show that hull-less barley has more β-glucan than hulled barley. In this study the physical ...
Read More
barley is a kind of cereal that contains high amounts of β-glucan. β-glucan is a major component of soluble fiber implicated in hypocholesterolemia, hypoglycemia, diabetes and heart attacks. Investigations show that hull-less barley has more β-glucan than hulled barley. In this study the physical and chemical properties of hull-less barley (EHDS 18), wheat (zarrin) varitiese, barley flour, and the impact of substitution of hull-less and hulled barley flour to wheat flour at 20, 35, and 50% levels on the physicochemical properties and the staling of bread were carried out. the staling of bread, was analyzed by Instron texture analyzer machine, colorimetry, by hunterlab and volume by rapeseeed displacement. The results of phisicochemical tests showed that the properties of hull-less barley is significantly (p
Ali Najafi; Reza Shokrani; Mohammad Shahedi; Leila Nouri
Abstract
Iced tea is a world popular beverage,for example about 80% of people in Italy and United States, consume iced tea as a thirsty-quenching beverage. However, it is also believed that iced tea contains health benefit components. Process of iced tea involved tea solid extraction and then mixing with edible ...
Read More
Iced tea is a world popular beverage,for example about 80% of people in Italy and United States, consume iced tea as a thirsty-quenching beverage. However, it is also believed that iced tea contains health benefit components. Process of iced tea involved tea solid extraction and then mixing with edible acids, flavors, sugar or non-nutritional sweeteners. In this research, regarding to the demand market for new beverage, the possibility of production iced tea beverage using green tea leave was investigated and was extracted under predetermined conditions. The effects of extraction temperature and time on the extractability were examined. The results of extraction at various temperatures in sample demonstrated that the extracted solid yield increased steeply during the first 5-10 min of extraction, but gradually in next 10-30 min and after 30 min the extraction continued slowly. Tea cream and haze extract was also determined using gravimetry and spectrophotometric methods, respectively. The extraction components, which cause tea cream and haze formation in extract increased with increasing of temperature. A sharp increase was observed when extraction temperature increased from 50 to 60oC. There was no significant difference (p
