جستجوی مقالات مرتبط با کلیدواژه « خواص فیزیکوشیمیایی » در نشریات گروه « پزشکی »

Due to the high content of unsaturated fatty acids in soybean oil, the possibility of oxidation occurrence in this product is high and its application in the food industry is limited. Therefore, to increase oxidative stability and extend food applications of soybean oil, various modification processes have been investigated. Among modification processes, the hydrogenation process using the cold plasma technology has been considered to produce the partially hydrogenated oil with very low trans fatty acids.

this research evaluated the effect of surface dielectric barrier discharge cold plasma on physicochemical properties of soybean oil at 15 kV voltage and 50% hydrogen- 50% nitrogen gas composition for 13-hour treatment. The samples were taken at the certain intervals to measure fatty acid composition, iodine value, refractive index, carotenoid content, melting point, peroxide value, tocopherol content, and sterol content during the treatment.

After a 13-h treatment, the results showed an decrease in the content of unsaturated fatty acids, carotenoid content, refractive index, iodine value and total sterol content from 58.62% to 40.24%, from 26.38 ppm to 6.32 ppm, from 1.4672 to 1.4400, from 129.64 to 100.45 and from 2636.51 ppm to 2315.86 ppm and an increase in peroxide value from 2.4 to 5.8 meq O2/kg oil and melting point to 7°C, respectively (p<0.05). In addition, the content of trans fatty acids was detected in very small content (0.85%).

According to the obtained results, surface dielectric barrier discharge cold plasma treatment can be used as a new technology for the hydrogenation of oils along with bleaching oil.

Greenhouse cucumber is one of the most important summer crops of Iran. Quality of the product is immediately lost after harvest due to physicochemical changes. Thus, use of special pre-processes (especially use of edible coating) to delay their maturity and increase the shelf-life of the product is important.

To decrease weight loss, preserve nutritional value (protects against the breakdown of vitamin C) and texture brittleness (corresponding to the higher acceptability of consumers), greenhouse cucumbers were processed with various edible coatings; control (I), Shiraz gum (II) and Shiraz gum containing 1000 ppm peppermint essential oil (III). Then, physicochemical characteristics (pH, weight loss, vitamin C and hardness) and color parameters (L*, a* and b*) of the samples were assessed at storage days of 1, 8 and 16 at 4 oC.

While the vitamin C and firmness of uncoated greenhouse cucumbers (control) respectively decreased to 4.8 and 2.26 times during 16 days of storage, the highlighted parameters decreased at rates of ~3.85 and ~1.20 times in samples treated with coating (III) at similar conditions, respectively. Moreover, strong positive correlations between vitamin C and firmness factors (r = +0.9654 and R2 = 0.932) included significant effects on the perception of consumer mouth feels.

Regarding that the control sample achieved only 57.5% of the maximum organoleptic score (flavor, aroma, color and texture), greenhouse samples treated with coating (III) achieved up to 94% of these characteristics and have been recommended as the best edible coating for the shelf-life extending of greenhouse cucumbers.

Use of natural coatings with various capabilities provides the opportunity to produce healthier and more acceptable materials, especially for higher value-added products such as dates. The objective of this study was to investigate effects of date coatings on the fruit various characteristics for the purpose of a longer shelf-life.

Mazafati dates were coated with natural polymers (zein, chitosan and pimpernel essential oil). Effects of coating on various characteristics of dates, including moisture content, total soluble solids, acidity, sugar content, pH and sensory characteristics (color, taste, firmness and brightness), were assessed at 4 and -18 oC for the first year and at 10 oC for the second year. Data were analyzed using factorial experiment in a completely randomized design. Comparisons of the means were carried out using Duncan method.

In organoleptic characteristics, the highest color score belonged to the fruits with chitosan after three months of storage and the lowest color score belonged to chitosan and oil and to control and oil treatments after 12 and 9 months of storage, respectively. Zein and chitosan treatments included better tastes and textures, compared to those other treatments did. In chemical assessments, zein treatments include the highest and chitosan treatments included the lowest moisture contents. The lowest sugar contents were reported in control. No significant differences were seen in acidity and pH contents of the treatments.

Based on the results of sensory and physicochemical assessments, use of the highlighted coating treatments to preserve physicochemical characteristics of the fruit dates as well as chitosan coating to minimize color and zein coating to minimize flavor changes in dates are recommended.

Starch and its derivatives have several applications in food and other industries. Changes in the structural properties of starch affect their physico-chemical and functional properties.

In this study, after determination of starch, amylose and amylopectin contents of three Iranian wheat varieties (Alvand, light bak kras and Sirvan), modification of their characterizations were accomplished with cross linking creation with “epichlorohydrin” in (0.1%, 0.3%, 0.5% v/w) level and physical modification by ultrasounic waves in 28 KHz frequencies in two times (15 and 30 minutes) at 20 °C. Qualitative properties of the samples such as paste clarity, water binding capacity, viscosity, solubility, swelling power and freezing thawing stability (Syneresis) of native and modified samples were examined.The results were analyzed in a completely randomized design-factorial test and the means were compared based on the least significant difference.

The results indicated the solubility, swelling power, paste clarity and water binding capacity of physically treated starch varieties were increased as compared to the native granules. Whiles, starch modification with epichlorohydrin decreased solubility and consistency of treated starches. The changes of paste clarity and water binding capacity in chemical modified starch in comparison to the native samples are different in varieties. Viscosity of all modified samples in comparison to the native form was decreased and their synersis were increased.

  Modification treatments are effective in many qualitative properties of starch and effectiveness of different starch varieties on physical and chemical treatments are different due to difference in genetic characteristics of starch.

The bacterial Asparaginase is used in the treatment of asparagine-dependent tumors, particularly lymphatic sarcoma and acute lymphoblastic leukemia. However, the instability of the enzyme increases the number of injections that are accompanied by high immune responses. The aim of this study was to investigate the conjugation of L-asparaginase with nanochitosan glutaraldehyde (NCG) derivative and its effect on the physichochemical properties of conjugated enzyme.

In this experimental study, nanochitosan was synthesized using reduction method with acetic acid and its physicochemical properties were evaluated using transmission electron microscopy and particle size analyzer. Activated NCG derivative was produced using 3% acetic acid. The conjugation of NCG derivative to L-asparaginase was performed with different molar ratios of enzyme/nanochitosan (1:2, 1:5, 1:10 and 1:20) in the presence of sodium cyano borohydrate; and the ratio with the highest residual activity was used for physicochemical evaluation. The activity of enzyme at different temperatures and pH, its half-life and stability after freezing and resistance to proteolysis were analyzed through repeated measure analysis of variance using SPSS 18 software.

The results of this study showed that the conjugation of L-asparaginase with NCG derivative resulted in maintaining the 70% enzyme activity. The activity of conjugated enzyme was higher than native enzyme after freezing and trypsin treatment. The optimum pH and temperature of conjugated enzyme did not change, while it had higher activity in wide range of pH and temperature compared with native enzyme.

Conjugation of L-asparaginase with NCG derivative improved physicochemical and stability of enzyme and this method can be used for production of improved L-asparaginase for clinical application.

Pectin is a complex mixture of polysaccharides that is widely used in the food industry as a gelling agent, stabilizer and emulsifier. The aim of this study was to investigate the efficiency and physicochemical properties of extracted pectin from quince fruit using ultrasound.

Pectin was extracted by ultrasound under the power of 320 W, two types of acids (HCL and citric acid), pH=2, time=30, 60 and 90 min, and temperature=60 °C. Then the physicochemical properties of pectin such as content of galactoronic acid, esterification degree, emulsifier properties, extraction efficiency, and rheological properties were investigated.

The results showed that pectin had an efficiency of 9.28% and a reasonable purity (with galacturonic acid content of 74.95%). The study of degree of extraction revealed that the pectin derived from quince fruit at 60 and 90 min of ultrasound and extraction with HCL was high methoxyl (HM) pectin. The pectin’s emulsifying activity was high. The viscosity results illustrated that the pectin solutions obtained from quince fruit by HCL at 30 min had a pseudo-plastic behavior, and at 60 and 90 min of ultra sonication and at higher shear rate, they had Newtonian behavior.

Good degree of purity and acceptable physicochemical properties of the obtained pectin show that this agricultural product can be used as a promising source for pectin production.

Today, the food consumption culture has changed in societies, and as a result, the need to produce a variety of new products such as enriched beverages has increased. Enrichment of beverages with functional components like probiotics and prebiotics is a recent progress in the field of beverage production.

In this study, suitable amount of inulin as a prebiotic compound was used, and the malt beverages produced by probiotic bacteria including Lactobacillus acidophilus, Lactobacillus casei and Lactobacillus plantarum were investigated.

In general, the viability of probiotic bacteria in synbiotic malt beverage decreased but remained in the standard range >107 during the refrigerated storage. After 28 days of storage, Lactobacillus acidophilus had the lowest count among the prebiotic bacteria. pH and acidity of the samples were decreased and increased, respectively due to the addition of probiotic strains. The results showed that the amount of sugar and Brix of the samples decreased with increasing of storage time. The amount of ethanol was lower than 0.1% in all samples. Moreover, the content of phenolic compounds was increased in all samples except the control counterpart during the storage time due to the hydrolysis of glycosylic phenolic compounds and production of free phenols. The results of antioxidant tests revealed that the antioxidant activity of samples also improved during fermentation.

The sample containing 2.25% inulin and 2.25% sucrose was selected as the optimum sample. After 28 days storing of the synbiotic malt beverages at a refrigerated temperature, the probiotic bacteria showed a standard viability. Moreover, samples containing probiotic bacteria had a higher antioxidant activity in comparison with the control sample. In general, the results of this research proposes that we can produce a synbiotic malt beverage with appropriate biochemical and nutritional properties by using proper probiotic strains

Gelatin is one of the most widely used colloidal proteins, which has unique characteristics and numerous applications, including the food industry, pharmaceutical, medical, and photography. On the other hand, significant amounts of fish-based factories that use fish as a raw material waste large amounts of residue materials. The aim of this study was to produce gelatin by microbial alkaline protease, from common scallops and fins of common carp wastes.
Different amounts of enzyme (5, 10, 15, 20, and 25 Unite/g fins and scales) were used to carry out the hydrolysis and extract gelatin. The physicochemical and functional properties of produced gelatin by the 20 unit enzyme, which was the most efficient level of enzyme, were compared with commercial gelatin. The yield of gelatin production was determined based on the wet weight of scales and fins, for each concentration of enzyme. Also SDS-PAGE was done to determine molecular weight of gelatin subunits.
The results showed that there is no significant difference between the protein and moisture content of both gelatins, but ash content was significantly different. Gelling temperature was equal approximately in both gelatins, but gelling time and melting temperature of gelatins were implicated different results. The results also showed that 20 unit enzyme per gram scale and fin powder was the optimum concentration. The SDS-PAGE pattern showed three bonds with 200, 120, and 100 kilo Dalton for beta, alpha 1, and alpha 2 chain respectively.
All of investigations indicated that this way has the potential to replace the commercial gelatin, especially for Muslims in all of the world, who have concern about their products with the Halal gelatin from safe resources.

Gums are polysaccharide components with high molecular weight that easily suspend in water and are dispersed under suitable conditions. They are used as stabilizer, texture modifier, gelling agent, thickener and emulsifier. The aim of this study was to determine the properties of the new Malva leaf’s gum.
The gum was isolated from the leaf of Malva neglecta plant by warm-water extraction. Purification was carried out by barium complexion. Purified gum was evaluated in terms of physicochemical properties. Furthermore, rheological properties of extracted gum were evaluated in shear rate at the range of 0.1–1000 s-1 with Brookfield viscometer and flow behavior and effect of temperature and gum concentration on the viscosity was evaluated.
The Purified gum contained 8.12±0.43% moisture, 77.04± 0.83% carbohydrate, 8.56± 0.62% protein, 2.49± 0.3% ash and 5.33± 0.29% uronic acid. Among the rheological models, power law model appropriately described the behavior of the gum. Arrhenius model was also properly applied to evaluate and describe the relation between gum viscosity and temperature. Three model's power, exponential and polynomial were used to evaluate the effect of gum concentration on the apparent viscosity in the shear rate of 10 s-1.
According to shear thinning behavior, Malva gum can be used in food industry. Extracted gum showed higher sensitivity to temperature at higher levels of gum concentration and power law model was selected as the best model to assess the effect of gum concentration on the viscosity.

In this study date concentrate was used as a sugar substitute in the blend fruit juice (grape-apple). The Effect of five factors including; sugar syrup (%Wt), date concentrate (%Wt), apple concentrate (%Wt), peach puree (%Wt) and storage time (day) on the physicochemical/color properties of juice samples were investigated.
An experimental design based on a D-Optimal Combine Design (DOCD) was used to study the different factors effecting (in 5 levels) the physicochemical properties of provided mixed fruit juices. Different quality indices, including acidity, vitamin C content, antioxidant capacity, none enzymatic browning index (NEBI), hydroxyl methyl furfural (HMF) and formalin index were measured and modeled.
Results showed that the sugar in grape-apple blend juice can be easily replaced by date concentrate, the blend of fruit juice containing date concentrate had higher HMF, vitamin C, antioxidant activity and NEBI indices than fruit juice blend containing sugar, which has significant health implications.
The date concentrate was used as a sugar substitute in fruit juice blend (grape-apple) and this substitution of sugar with date concentrate produced juices with higher HMF, vitamin C, antioxidant activity and NEBI indices.

Starch might be regarded as a polysaccharide consumed considerably. Starches as a food ingredient has important roles in the texture of food. Starch is used in food industry as thickening, stabilizing and gelling agent but some limitations such as low shear stress resistance, thermal decomposition, high tendency towards retrogradation and high syneresis might limit its application. The modification of starch can alter its physical and chemical properties and improves its functional characteristics.
In this work, starch isolated from barley grains, the variety Bahman was cultivated in Lordegan area of Chaharmahal and Bakhtiyari province and acetylated with acetic anhydride (%6 w/w) at two different times of 10 minutes and 5 hours followed by the evaluation of physicochemical properties concerned with syneresis, swelling power, thermal properties, viscosity and morphological characteristics.
The results showed that acetylated starches had higher swelling power. There was not a significant difference between the starch acetylated at 10 min and the control but this difference was considerable with the acetylated starch at 5 hours and the control (p˂5%). Decreases in syneresis and gelatinization temperature and increase in viscosity were significant as compared to the native barley starch. These modifications altered the size of the starch granules.
According to the results, modification of barley starch can improve some of its functional characteristics.

duction: Due to the increasing use of irradiation in food safety as an efficient and supplement method, it is needed to investigate effects of this new technology on the apparent and organoleptic characteristics of different products. Because primarily thing that attracts the attention of the customer to buy a food product is its appearance characteristics. The aim of this study was to determine the effect of electron beam irradiation on traditional ice cream.
Ice cream samples were shopped in the city and were moved to the laboratory in defined conditions into the cool box to keep sample frozen. In keeping with freezing conditions, samples were irradiated by electron beam in -18AWT IMAGEat doses of 0, 1, 2, 3 and 5 kGy. And after one week of storage at -18℃, physicochemical tests including moisture, fat, sugar, pH and sensory tests including color, odor, taste and overall acceptability, were done on it.
Results showed that there was no significant difference between irradiated and non-irradiated in the amount of sugar, fat and pH. However, it can be seen significant differences in the moisture content measured in the treated samples with electron beam and untreated one (p According to the result, it can be concluded that the maximum recommended dose is 2 kGy for irradiation traditional ice cream product and higher doses caused a decline in quality of product.

Salicornia is a genus of halophyte (salt tolerant). In this study, the structure and physicochemical properties of Salicornia Persica Akhani (sub sp. rudshurensis Akhani) oil were investigated.
Soxhlet method was used to extract Salicornia oil, and the obtained oil was evaluated by using gas chromatography. Then its fatty acids profile and physicochemical properties were evaluated. Finally, the oxidative stability of oil was determined based on rancimat test and peroxide value.
Maximum oil content extraction from plant Salicornia Persica Akhani was 9.3%. Gas chromatography analysis identified 10 types of fatty acids in the extracted oil. Palmitic acid among the saturated fatty acids and alpha-linolenic acid among the polyunsaturated fatty acids was predominant. Refractive index (°C), Iodine Value (IV), density, Saponification number and combustion heat (ΔHC) were 1.4704, 150.34 g I2/m gr oil, 0.927 gr/cm3, 196.8 mg KOH/g oil, 12.4 and 9428 Cal/g, respectively. Oxidative stability index (OSI) at 110°C was 8.5 hours, and the peroxide value after 8 days storage at 50°C was 5 meq active oxygen per kg of oil.
The analysis revealed that the oil extracted from Salicornia Persica Akhani contained about 70% unsaturated fatty acids, and its dominant fatty acid was alpha-linonenic acid. In addition, the extracted oil had proper oxidative stability compared to other edible oils used in the food industry.

Silver nanoparticles are of interest to be used as antimicrobial agents in medical care, wound dressings and cosmetics. Despite the fact that AgNPs are among the most commercialized nano materials owing to their specific antimicrobial properties, there is limited information about their risk assessment and possible hazards to human health and environment. Thus, this study was carried out to evaluate the cytotoxicity and morphological changes of different concentrations of two samples of commercialized silver nanoparticles (A and B) in CHO-K1 cells using MTT assay. The cytotoxicity effect of silver nanoparticles AgNP-A (19.6 nm in diameter) and AgNP-B (15 nm in diameter) on CHO-K1 was evaluated in the range of 0.005-500 µg/ml after 24 hours of treatment using MTT assay. The morphological changes of treated cells were examined by light microscopy. Based on the results of cytotoxicity by MTT assay, reduced viability of cells and cytotoxicity were observed. The 50% inhibitory concentration (IC50) of silver nanoparticles was recorded at 100 and 10 µg/ml for AgNP-A and AgNP-B, respectively. Moreover, microscopic observations indicated clear morphological changes of treated cells. Concentration and physicochemical properties of silver nanoparticles like size, shape, surface area, coating and zeta potential play a role in cytotoxicity and morphological changes of treated cells.

Replacing milk saturated fatty acids with vegetable oil can be a good way for reducing the risk of hypercholesterolemia and improving cardiovascular health. This study was carried out to determine the effects of using grapeseed oil on the sensory and physicochemical properties of ice cream. Milk fat was replaced with milk fat at 5 levels of grapeseed oil (0%, 20%, 40%, 60% and 80% (w/w)). The samples were subjected to physicochemical analysis (pH, titratable acidity, overrun, meltdown, texture and viscosity) and sensory evaluation (color, hardness, viscosity, meltdown, flavor and overall acceptability). The results showed that low levels of grapeseed oil had no significant effect on pH and acidity but at 80%, it significantly reduced the pH and increased the acidity of ice cream. Increasing in the concentration of grapeseed oil was accompanied by decreasing the overrun, meltdown, texture, viscosity, pseudoplasticity and consistency index, and increasing the flow index. The effect of grape seed oil on sensory properties such as smoothness, hardness and color was not significant, and only at 80% of oil, it decreased the acceptance level of viscosity, meltdown and overall acceptability (p<0.05). Grapeseed oil at lower level of 40% replacing had no significant effect on the flavor of ice cream (p>0.05). Incorporation of grapeseed oil in ice-cream to replace milk fat could affect the physicochemical properties of ice-cream. Considering that addition of grapeseed oil at 40% level did not have any adverse effect on the sensory qualities, consumers may enjoy the health benefits of essential fatty acids and antioxidants of grape seed oil in ice cream.

The aims of this study were formulating and experimental production of IEFSPs for emergencies and tough military circumstances while patrol، in cold weather or at heights. In the first place، 5 different formulation groups، each comprising 5 compounds made up of different percentages of ingredients were prepared; then from each group، the best one was picked out by test panels. Next، from the chosen IEFSPs، the optimum formulation was selected via taste panels. Shelf life and qualitative properties (organoleptic، chemical، and microbial) of the optimum formulation were evaluated at 38°C during the time of 0، 1. 5، and 3 months after production (equal to 0، 9، and 18 months at 27°C respectively). Although organoleptic properties and moisture content of the optimum formulation showed a little decrease after 3 months incubation at 38 °C، this reductions were not significant (p<0. 05). In addition، after 3. 0 month incubation at 38°C، microbial properties of the optimum formulation were within the standard range. Shelf-life and also qualitative properties of the IEFSPs، after 3 months incubation at 38°C، were acceptable and these IEFSPs can be easily used in emergencies and tough military circumstances.

Emu oil is a valuable source for the production of cosmetics or for food is used as edible oil. However, there is little information about the properties of this oil. In this study, using a fusion of wet fat ostrich oil is extracted and then some physicochemical properties (Yiddish value, saponification value, melting point, refractive index, specific gravity, and color) were studied. The results showed that the physicochemical characteristics of ostrich oil Yiddish value, saponification value, melting point (softening of oil), the refractive index and density, respectively, 70.64+ 0.2, 184+2.5 +, 31+1.5, 1.46+0.02, 0.9, color, yellow Lavyband cell size is 1 inch. In addition, the amount of free fatty acids and oil refining need not be separated and the separated oil can be used as a base in cosmetic products. separated ostrich oil can be used as a base in cosmetic products.

High in take of saturated fatty acids and animal fats, increases cardiovascular disease, cancer and obesity whereas ω-3 and ω-6 poly unsaturated fatty acids as necessary fatty acids have preventive effect on aforementioned disease. Necessity of ω-3 and ω-6 acids and limitation of their sources with increasing of population, make scientists to find other sources. For optimal usage of internal oil resources such as safflower, increasing of its cultivation and existence of Saffola as a mutative variety (high amount of oleic acid), this research for investigation the physicochemical characteristics of seed and oil of six variety/line of safflower farmed in Iran and the comparison of type and amount of oil and classification of them to oleic or linoleic acid group was done. Varieties/lines of Iranian safflower including Goldasht (as a spring variety), Mahali Esfehan, Esfehan 4, Esfehan 8 (as spring lines), Padide (as a fall variety) and Sina (as a day land farming variety) were provided)Provision Institute and Improvement of Plant and Seed located in Karaj), and characteristics of safflower seeds (oil, protein, ash, moisture and fiber contents) and its extracted oil (acid, iodine and saponification values, fatty acids profile and color) were investigated. Results indicated that the studied varieties/lines were only linoleic safflower (no any oleic safflower). Iranian safflower varieties/lines have the highest amount ofω -6 (7.6 - 75078) in comparison with other oil sources which are valuable and necessary fatty acids.