نشریه پژوهش های علوم و صنایع غذایی ایران
سال پنجم شماره 2 (پیاپی 10، نیمه دوم سال 1388)

In this research, attention is focused on the resistantance of packages containing silver nanoparticles to gases such as oxygen as well as to the antimicrobial property of these packages. The effect of these packages on increasing quality and shelf time of the barberry was investigated in comparison with the current polyethylene packages. To do this, different microbial factors and the color of the barberry were investigated. The microbial experiments were done according to the national standards of Iran. The data obtained from microbial tests statistically considered by SPSS15 software. They showed decreasing microbial capacity, especially in the case of mold and counting total bacteria, packages containing silver nanoparticles had between 1% and 2% concentration of nanoparticles in comparison with the samples of polyethylene packages. Investigation of the apparent color of the samples was also done according to an average red color and brightness of the images taken from barberry seeds by Photoshop CS3 software, version10. The data obtained from these investigations statistically considered by SPSS15 software. The results showed that the apparent color is qualitatively better in the samples of packages containing 2% and 3% silver nanoparticles, compared with samples of polyethylene packages. However, a low concentration of nanoparticles, in the range of 200 part per million (ppm), did not produce a great effect on increasing either the quality or the shelf life in barberry, compared with ordinary polyethylene packages.

Due to medical and dietary properties of the Plantago Major L. seed, it is necessary to know engineering properties in order to design post harvest equipments. Engineering properties of Plantago Major L. seed was determined only at the moisture content of 7.98% dry basis, because of it produces mucilaginous components when it is soaked in water. The average of length, width, surface area, sphericity, perimeter, roundness and aspect ratio were determined 778.9 m, 514.8m, 29.6344 × 104 m2, 0.996, 1874.8 m, 0.620 and 1.53 respectively by means of image processing technique. The average thousands seeds mass, bulk density, true density and porosity were 147 mg, 701.8 kg/m3, 1283 kg/m3 and 45.3% respectively. Coefficient of friction was measured on the 5 surfaces of plywood, rubber, glass, fiberglass and galvanized sheet and the average value were 0.51, 0.46, 0.36, 0.35 and 0.33 respectively. Angle of emptying repose and angle of filling repose were 36.1˚ and 18.1˚ respectively and terminal velocity was determined 1.86 m/s.

The preferred colour for surimi is white, but surimi prepared from light fillets of common carp (Cyprinus carpio) is slightly pink. Hydrogen peroxide (H2O2; 1-3% v/v) with and without sodium tri-polyphosphate (STP; 1-2% w/v) was added to a sodium carbonate bath (pH 7.0-11.5) resulting in a final pH range of 4.4 to 10.1 which was injected into carp fillets. After soaking and tumbling for 30 min at 4-10ºC, the fillets were evaluated for colour and water holding capacity (WHC). Fillets tumbled with treatment solution at different pH levels (7.0-11.5) without H2O2, had improved colour with significantly (P < 0.05) higher L* compared with untreated fillets as the control. However, the colour improvement [(L* and colour deviation (ΔE)] was not significantly different (P > 0.05) within the pH levels (7.0-11.5) trialled. With increasing H2O2 levels (1-3%), fillets became lighter and ΔE increased significantly (P < 0.05), especially with a 3% H2O2 treatment at pH of 10.5. The whiteness (L*-3b*) of surimi produced from treated (3% H2O2, pH 10.5) common carp fillets was compatible with that of Alaska Pollock and significantly (P < 0.05) higher than that of surimi from threadfin bream. On the contrary, WHC of treated fillets and its resultant kamabok gel significantly decreased in comparision with other samples. This was investigated by scanning electorn microscopy (SEM) technique. It was concluded that application of 3% H2O2 has possibly denatured the myofibrillar proteins which caused lower number of polygonal structure at the gel matrix of kamaboko prepared from treated fillets. It is recommended to improve the colour of common carp surimi while keeping the myofibrillar proteins intact by application of lower concentration of H2O2 on either chopped fillets or mince.

In this study, the possibility of microwave finish drying for two types of dried grapes (Natural and Sultana) was investigated. The samples were washed in water bath at given temperature ranges (25 and 45 C) for 30 to 60 minutes. After dewatering the samples, they were dried using microwave (at two powers: 270 and 450 W) and hot air convective dryer (at 50 C). Water gain (%), effective moisture diffusivity and Hunter values (L as lightness and a/b ratio) were determined. To determine a suitable model for describing finish drying behavior, ten commonly used mathematical models were compared according to the three statistical parameters: coefficient of determination (R2), chi-square (χ2), and root mean square error (RMSE). Results showed that water gain for sultana samples was 3-4.5 times more than that for natural raisins. Based on experimental drying rate data, drying took place in falling rate period. Among the models, two term model was most adequate showing highest R2 and lowest χ2 and RMSE. It was found that the drying method affect color indices of product and also the application of microwave finish drying technique depends on used microwave power and type of dried grape.

Osmotic dehydration, as a minimal processing method, has found increasingly wide prospects during the past few decades. This process involves mass transfer which is commonly modeled by applications of different procedures, mostly based on Fick's law. In this research, we approached the modeling process by first obtaining experimental measurement of potato’s solid gain, water loss and moisture content under different conditions of solution concentrations (5, 10 and 15% w/w), temperatures (30, 40 and 60oC), potato to solution ratio (1:6, 1:8 and 1:10) as well as time intervals (1, 2, 3 & 4h). In order to evaluate the effect of changes in operational parameters on mass transfer kinetics, sensitivity analysis was performed. Artificial neural networks (ANN) was applied for modeling. The results exhibited how much powerful the model is in prediction of the system’s outputs, and high sensitiveness of these outputs to the ratio of potato to osmotic solution.

Safflower (Carthamus tinctorius L.) is one of the oilseed plants that can influence strongly on oilseed security because it is extremely compatible with environmental conditions. Safflower is cultivated as second cultivation after combining cereals in Isfahan. Nowadays many attempts are performed to improve safflower oil quality to use in edible oil industry. In this study, quantity and quality of oil extracted from 20 safflower genotypes were investigated. Results indicated that there were significant differences between (p

The effects of pulsed electric field (PEF) on the cell disintegration of sugar beet were studied. Field strength (0.5kV/cm to 6kV/cm), pulse number (1 to 100 pulses) and capacity of capacitors (0.5 F to 32 F) were evaluated on degree of cell disintegration and consumed energy in PEF treatment. The field conditions of 1 and 2 kV/cm, 8 F with 20 and 10 pulses respectively disintegrated the cell membrane in less than 1 minute. The most important parameters during cell permeabilization were the total energy input followed by field strength. At energy input of 3.2 kJ/kg, the higher the field strength resulted the higher cell permeabilization. Mass transfer with determination of sugar and ion leaching for PEF pretreated sugar beets at room temperature were compared to moderate and high heat treatment (50, 75 and 80C, 15minutes). Comparison between PEF pretreatment and conventional thermal cell disintegration (average 75C) method showed that high values of sugar may extracted after PEF pretreatment (2kV/cm, 8µF) at ambient temperature while 75C or more with long time thermal duration is needed to achieve the same extracted sugar. In addition, the energy consumption for thermal treatment is approximately 20 times more than PEF pretreatment. Optimization of field condition (Field strength, capacity of condensers, and number of pulses) as well as treatment chamber conditions are very important factors to achieve high yield of sugar from sugar beet when using PEF.

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

Consumer’s demand for functional foods is increasing, however, production of such food is not an easy task, and sometimes the sensory aspects of food are affected adversely. To ensure the customers of the quality of food, it is necessary to label the product with accurate nutrition information in order to make people aware of the positive nutrition effects of such foods. The aim of this research was to study the effects of giving nutrition information to the customers on their perception of quality of a wheat germ cake. Therefore, some cakes containing 15% wheat germ were packed in two different packages, one with and the other without nutrition label. These cakes were evaluated by taste panel in terms of color, flavor, taste, texture, general acceptability and possibility of buying. The results showed that despite the similarity of the product, the cake with nutrition information received higher score in many sensory aspects, general acceptability and the possibility of buying than the other one. The results stressed the impacts of giving information and making the culture of the people on the marketing of healthy food products and the costumer's perception of the food quality.