JOURNAL OF INNOVATIVE FOOD TECHNOLOGIES (JIFT)
Year:2017 | Volume:4 | Issue:15 |Papers Count:12

Drying is one of the most common techniques for agricultural production processing which improves shelf life of the final product. Corn (Zea mayz) is a high nutritional value food and is an essential source of minerals and vitamins; thus it makes a substantial contribution to human nutrition. In this study the effects of hot air drying temperature (35, 50, 65 and 80°C), drum rotation speed (2, 6 and 10 rpm) and final moisture content of kernels (13 and 17 %) at constant air velocity (0.8 m/s) on drying time, percentage of broken kernels of corn, and percentage of crack of corn kernels were investigated. For this propose, the laboratory batch rotary dryer is designed. The results showed that increasing the temperature form 35 °C to 80°C, the percentage of broken grains and percentage of cracked grains increased and the drying time was decreased. Increasing the rotating cylinder rotation speed increased the drying time and the percentage of broken grains, but not significant effect in percentage of cracked grains. The drying time, percentage of broken grains and percentage of cracked grains is lower in grain with 17 % db than the sample with 13 % db To obtain the desired quality parameter, the optimum drying for production of dried corn was determined as 65°C for 2 rpm and 17 % db.

Calcium alginate micro hydrogels loaded with niosomes and liposomes were used to encapsulate caffeine as a model low molecular weight hydrophilic bioactive compound. To load niosomes and liposomes into alginate hydrogel network and to reduce the size of gel particles the feed solution was electro sprayed into calcium chloride solution. Successive freeze-thaw cycles were employed with a view to slow the release rate of caffeine from niosomes and liposomes. The results showed that niosomes was more efficient in caffeine encapsulation than liposomes. The release profiles confirmed the positive effect of freeze-thaw cycles on sustainable release of caffeine and that the niosome-loaded hydrogels had slower rate of caffeine release. Also, liposomes made of highly pure lecithin revealed more encapsulation efficiency as well as better release profile compared to those of commercial lecithin. Korsmeyer-Peppasmodel was found to appropriately describe the release of caffeine from particles based on Fickian diffusion. The findings of this study clearly demonstrated that niosome- and liposome- loaded micro hydrogels could potentially be used to encapsulate food and pharmaceutical compounds for slow release applications. Moreover, electro spraying technique owing to its capability of producing uniform fine particles could be used as an alternative method for hydrogel preparation from natural polymers.

Response surface methodology is a collection of mathematical and statistical techniques for empirical model building. In this study, response surface methodology based on Box Behnken design was applied for investigation, optimization and modelling of ultrasound assisted extraction independent variables including amplitude (25, 50 and 75%), temperature (30, 45 and 60 ºC) and sonication time (20, 40 and 60 min) to maximize the radical scavenging activity of Eryngium caucasicum Trautv leaf extracts. The radical scavenging activity was measured using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide (H2O2) radical scavenging activity methods. Based on results obtained linear, quadratic and interaction effects of three independent variables had significant effect on DPPH and H2O2 free radical scavenging activity. Quadratic polynomial model was obtained for each response using multiple linear regression analysis. By using numerical optimization the optimized condition was obtained as 50% amplitude, 42 ºC temperature and 51 min sonication time. The radical scavenging activity of extracts under these optimal conditions was predicted as 50.20% DPPH free radical scavenging activity and 26.55% H2O2 free radical scavenging activity. The models obtained for prediction of dependent variables has a good closeness with experimental results. Finally, the results obtained were compared with conventional Soxhlet extraction results. Based on the results, by applying ultrasound waves it is possible to obtain more compounds with radical scavenging activity during short time.

Drying fruits is one of way to increase the shelf time and use it in different seasons of the year. One of these fruits is apple that for increasing shelf time it must either be refrigerated or dried and used as potato chips. In this research was investigated the effect of various pretreatments including osmotic dehydration, ultrasound, blanching and microwave pretreatment different levels and at three temperature levels (45, 55 and 65 °C) in convective dryer on drying time, curve slop of moisture ratio and constant drying rate coefficient. The results of applying this pretreatment at different temperatures showed that the maximum value of drying time was 345 min at 45 °C and in control treatment occurred and minimum value of drying time was 75 min at 65 °C by using microwave pretreatment with power 360 W occurred. Also the highest value of drying rate constant was 0.1020 min-1 in microwave pretreatment at 65 °C and the lowest value this coefficient was 0.0091 min-1 in control treatment at 45 °C. Change of drying rate constant show that using the microwave and ultrasound pretreatment cause tissue degradation and remove moisture from the product could be faster and this coefficient increased than control treatment. Also using the osmotic and blanching pretreatment due to little effect on moisture migration from the product causes reduction of drying curves slope and then coefficient of constant drying rate than the control treatment and followed by constant drying rate coefficient decreases.

Milk and dairy products as an animal protein source with a high nutritional value has a particular importance in human diet. Development of non-destructive and quick methods for assessing the quality and freshness of milk is of particular importance in ensuring product safety before consumption. The aim of this study was to measure the dielectric power with the use of a parallel-plate sensor to develop a new method for rapid assessment of milk freshness. Three milks with commercial names of Pak, Kaleh and Damdaran and a milk from dairy farm were dielectrically measured during seven storage days. Sinusoidal voltage wad applied to the milk samples and capacitor power within the frequency range of 0-150 MHz was measured using a spectrum analyzer. Results proved that the frequency range of 75-100 MHz varied considerably with storage time so that the frequency of the valley within this frequency range increased with storage time. The frequency of the valley as a spectrum characteristic predicted the storage day by a linear regression model with R2 and RMSE of 0.84 and 0.8, respectively. The correlation of milk pH and the frequency of the valley showed that during the first four days of storage with a minor change in pH, the frequency of valley varied significantly indicating further physico-chemical changes in milk with storage that affects the dielectric properties of milk. The dielectric power at the frequencies of 2.7 and 89.4 as the most effective frequencies, predicted the storage day and pH, respectively with RMSEs of 0.4 and 0.22. Multiple linear regression models decreased the errors of prediction to 0.26 and 0.11 for storage day and pH, respectively. Based on the findings of this study, dielectric power spectroscopy can be implemented as a non-destructive, simple and accurate method to milk pH and freshness determination.

Ostrich meat has much more benefits than other meat, it defined as 21th century meat. Osmotic dehydration is processing multi-component of mass transfer, in which synchronized water loss from foods, osmotic agent penetrate the texture that is low in comparison to water loss. Whereas high watery level activity during storage time causes chemical and microbiological changes, that have negative effect on food and lead to disadvantage decayed of foods. So using of osmotic dehydration and decrease in texture water and facility in mass transfer during drying is useful. Dehydration of the ostrich with the osmotic solutions containing (10, 20, 30 %) salt, the ratio of meat to osmotic solution (1: 4, 1: 6, 1: 8) and immersion time (30, 45, 60 min) on the water loss, solid gain and shrinkage were calculated by response surface methodology and the optimum sample was obtained, dehydrated sample in optimum conditions then dried with hot air (65, 75oC). were obtained the moisture content during drying kinetics and comparison of 10 mathematical models and select the best model to describe the kinetics of mass transfer. At the optimum point the concentration of salt 30%, the ratio of meat to osmotic solution 1: 6 and immersion time 60 min water loss, solid gain and shrinkage were found to 5.50 (g/100 g initial sample), 5.45 (g/100 g initial sample) and 6.99 respectively. The most convenient model to describe the kinetics of mass transfer during drying meat, Two-term model were determined.

In this research, the ability of a machine vision system was evaluated to monitor the oxidation period of olive oil. For this purpose, the olive oil samples studied during accelerated storage for 24 days in an oven and then image processing processes was carried out to extract parameters related to color spaces RGB, HSV and L*a*b*. The performance of artificial neural network and decision tree techniques compared to determine the olive oil oxidation rate. In each of the models color parameters were used as inputs and different stages in the olive oil oxidation period were considered as output. According to the results, the highest classification accuracy (94.44%) and the lowest RMSE (0.0696) are related to the decision tree technique. The proposed machine vision system combined with artificial intelligence techniques as non-destructive and efficient tool will offer for monitoring and quality control during oil storage.

In the present study, potato starch nanobiocomposites films plasticized with glycerol and containing four different montemorrillonite loading (0, 1, 3 and 5 wt% starch) were prepared via solution casting method. Differential scanning calorimetry (DSC) confirmed that the melting point and glass transition temperatures were increased and heat stability of the nano composites were improved. Upon 5% MMT loading, the glass transition and melting point of PS film were increased from 185.6 and 282.9 to 203.5 and 304.6, respectively. Colorimetry and UV-Vis spectroscopies were employed to evaluate the UV and visible-shielding efficiency of the PS-MMT nano composite films. Incorporation of 5% MMT did not have significant effect on color parameters (L*, b* and a*), color differences (E) and whitness index, but decrease yellow index of the films. Presence of 5% MMT in film formulation successfully blocked more than 82, 38 and 11% of UV-A, UV-B and UV-C lights, while opacity and transparency of the films were unchanged. Investigation of chemical structure of nanobiocomposite films by Fourier-transform infrared spectroscopy (FT-IR) and Atomic force microscopy (AFM) and revealed the hydrogen bonds interactions between MMT and starch and uniform dispersion of MMTplatelets in the starch matrix, respectively. Also, AFM topography images were used to study the surface morphology and roughness of starch films. Plasticized starch (PS) film had smoother surfaces and a lower roughness parameter. Adding MMT to starch matrix caused to increase the average roughness (Ra) and the most frequently quantitative parameters of roughness (Rq) from 32.4 nm and 39.9 nm in PS film to 119 nm and 147 nm in PS-5%MMT, respectively. The AFM phase images described the uniformity of the starch-MMT mixtures.

Cake, because of various tastes and ease of use, is the most important baking product after bread. Considering the mechanism of celiac disease, which develops because person's body can' t digest the gluten proteins, producing gluten free cake is increasing across the world. The goal of this research is to analysis using of sweet almond protein concentrate (SAPC) in four levels (0, 5, 10, 15) and xanthan gum in three levels (0, 0.2, 0.4) (rice flour basis) on physical characteristics of dough and chemical and textural properties of free-gluten cake. Results show that by increasing the level of SAPC, protein, moisture, and ash of cake increase. By adding xanthan gum and SAPC, Special weight and Consistency of dough increase too. According to these results, the sample containing 0.4% xanthan and 15% SAPC has the most hardness and sample with 0.4 % xanthan and without SAPC has less hardness. Besides, xanthan decreases gumminess and increases springiness and cohesiveness. SAPC increases gumminess and decreases springiness and cohesiveness. Finally level of 2.0% for xanthan and 5% for SAPC due to suitable quality properties were accepted.

Antimicrobial packaging is a type of active packaging that provides the continuous migration of antimicrobial agents to the surface of food products. In this study, chitosan bioactive films containing Eucalyptus globulus essential oil (EGOs) (at concentrations of 0.5, 1 and 1.5 % v/v) were produced by casting method and their antibacterial, physical, mechanical and microstructural properties were examined. The results of disc diffusion test revealed that chitosan film containing 1 and 1.5 % essential oil was able to reduce the density of bacteria. The addition of EGO into chitosan based films reduced the moisture content, solubility in water, water vapor permeability and tensile strength of bioactive films to 41.28 %, 39.08 %, 25.36 % and 27.3 % respectively, while increased elongation at break (65.61 %) as well as its thickness. It seems that physical and mechanical properties of chitosan films containing EGO is related to the formation of bonds between the essential oil compounds and functional groups of chitosan, which consequently improved the physical properties but decreased the mechanical properties. Also, the electron microscopy images confirmed the results obtained in this study. The results of this study indicated that these natural compounds have a great potential to be applied in active packaging materials due to their effective antimicrobial and physical properties.

Pumpkin is important cucurbit with very high nutritional value. In this study, the effect of osmosis - microwave combination drying of pumpkin slices with a thickness of 5 and 7 mm, sucrose osmotic solution concentrations of 45, 55 and 65% and at times of 15, 30, 45, 60, 90, 120, 150 and 180 min and power of 100, 300 and 500 watts were used as complementary drying. Physical parameters such as texture, shrinkage, color and chemical parameters such as protein, ash, moisture, β-carotene, fat, iron, calcium, sodium, potassium, phosphorus, fiber and vitamin A were studied. Osmotic treatments have reduced the resistance and firmness. The lowest amount of shrinkage was related to dried pumpkin at 100 watt power (71.09%) and significantly difference was observed between samples. The amount of β-carotene for pumpkin with thickness of 0.5 and 0.7 cm dried at a concentration of 55% was between 2.6-3.5%. According to the statistical results there was no significant difference of fiber in the dried samples at power of 100 and 300 watts, but dried samples with the power of 500 watts were significantly different. Amount of pumpkin sodium with thickness of 0.5 and 0.7 cm dried at the 100 watt in microwave oven was between 0.01-0.02%. Calcium content of pumpkin with 0.5 cm thick dried under the powers of 100, 300 and 500 watts were between 1.05-1.08%. The dried pumpkin slices with microwave with 100 watt power had lower darkness related to 300 and 500 watt. A total time of 150 minutes for the osmosis process and power of 500 w was selected for the microwave dryer.

In this research, the combination of two levels of tragacanth gum (15 and 30%) on chitosan film 2 % were studied and produced film characteristics checked out. The results are proved the best properties in tragacanth 30% in combination with chitosan. Moisture and solubility was not significantly increased by adding tragacanth to chitosan (p>0.05). There was a significant difference between water vapor permeability of chitosan (control) and composite (p-1 s-1 p-1. Tensile strength of chitosan did not change significantly with the addition of tragacanth (p>0.05) but the lowest tensile strength showed in the composite 15%. Elongation percentage was reduced by addition of tragacanth. Add tragacanth to chitosan did not cause significant changes in its transparency (p>0.05) but the degree of transparency was reduced, so that the lowest transparency was observed in the composite 30%. The results of the present study demonstrated that the addition of tragacanth into the chitosan improve the physical and mechanical properties of this polymer in the film and increase its efficiency for fish packaging.