IRANIAN JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
Year:2017 | Volume:14 | Issue:68|Papers Count:40

The present work aimed to evaluate the impact of transglutaminase treatment (0-2 U g-1 milk protein) and whey proteins isolate (0-6 g/l milk) on physicochemical, textural and organoleptic properties of low-fat (0.4-1.4% milk fat) white-brined cheese. Data showed that fat reduction was concomitant with significant decrease in moisture to protein (M: P) ratio, resulting in increased hardness, cohesiveness, and springiness and decreased adhesiveness, cheese yield and consumer acceptance. Whey proteins, despite improving textural characteristic, did not significantly influence the total sensory scores of the low-fat white-brined cheese attributed to their adverse effect on the flavor acceptability of the final product. Increase in transglutaminase concentration up to a critical level, which was dependent on whey protein concentration, promoted the M: P ratio and hence caused increased cheese yield and deceased hardness, cohesiveness, and springiness; but further increase in enzyme concentration adversely affected the textural attributes.Response surface optimization revealed that treating the cheese milk (0.99% w/w fat) containing 5.05 g/l why protein isolate with an enzyme concentration of 0.91 U g-1 milk protein, makes it possible to produce a low-fat white-brined cheese with desired textural and organoleptic characteristics.

Ashi noodle is one of the local pasty products in Iran which is made of mixing flour, water and salt after going through various stages of production. Hence salt is one of the important components in the production of these products and the widespread use of salt in processed foods causes the concerns about the health of consumers in the recent years, the study aims at investigating the reduction of salt amount (with the amount of 2% and 3%) in comparison with with control sample (with 5% salt) in Ashi noodle by using guar and xanthan gums (with the amount of 0.5% and 1%). In addtion, the rheological properties of dough (dough consistency, softening the gluten and gelatinization of starch) using mixolab, chemical properties of final product (moisture and Ash) and sensory properties were evaluated. by increasing the density of gums and decreasing the amount of salt, the dough consistency and gelatinization are significantly increased while the amount of softening of gluten is significantly decreased and also the amount of moisture and ash in the final product is increased and decreased respectively. According to the results, treatment with xanthan 1% and 2% salt as the best treatment in terms of rheological properties, chemical and sensory was selected.Statistical analysis was performed in a completely randomized design.The results indicate the positive effect of decreasing the salt and adding hydrocolloids on the chemical and rheological properties of Ashi noodle produced.

Iran is the second main producer of Prunus armeniaca in the world and production of valuable product for using the post-harvest wastage of this fruit is necessary. In this study the production of new products from apricots (fruit pastille based on apricot puree) by different ratios of xanthan (0, 0.15 and 0.3%) and pectin (0.3, 0.4 and 0.5%) was investigated. the effects of these levels on water activity, textural feature, sensory evaluation and color parameters of apricot puree-based fruit pastille were studied. This product in term of sensory evaluation was in the accepted domain. According to the results, the effect of these variables on all parameters was significant. Also sample containing the highest percentage of pectin and xanthan has the highest overall acceptability. Moreover, this sample has desirable color parameters and textural properties, too. As a result, this novel product is consumer acceptable and has the potential to commercially produce.

Today due to known anti-radical activity in plants extracted compounds and its derives was regarded to adding those to food and biological systems. In present paper investigated radical scavenging activity of lignin (as a non-carbohydrate poly-phenol) was extracted from different plant resources.TAPPI standard, T222om-88h was used In order to determination of total lignin. The amount of lignin in abies species was much more than others. Lignin was prepared from three species of bagas (Herbaceous), abies (bornmuelleriana) (Needle-leaf) and poplar (populous euroamerica) (Broadleaved) by two process of Milled Wood Lignin (MWL) and Acidic Dioxan Lignin (DL).the extraction efficiency of the DL was higher than MWL method in all species. The radical scavenging activity and phenolic compound were determinate by stable DPPH free radical and Folin- ciocalteu reagent, Respectively. The results showed that lignin extracted from cane sugar bagasse in both MWL and DL methods has more radical scavenging activity in compare with other specimens. In all of samples DL has better anti-radical activity than MWL extraction method. The lowest and highest amount of IC50Were attributed to bagasse (278.7 ±1, 46) and poplar (682.2 ±0.71), respectively.

Microemulsions are optically transparent and thermodynamically stable systems showing selective and safe extraction capability of nutraceuticals from different plant matrices. Moreover, investigation of their nanostructure (normal micelle, reverse micelle, bicontinuous) provides noteworthy information with regard to application purposes. Therefore, in the present study the extraction of lycopene from the industrial waste of tomato paste plants was done using microemulsion technique (prepared with natural surfactant of saponin and cosurfactant of propylene glycol), and the divergent nanostructures of the single phase microemulsion were investigated by electrical conductivity and rheological measurements. These measurements along dilution lines in the pseudo-ternary phase diagram and water titration method showed good ability in simple and fast determination of different nanostructures and their boundaries in microemulsion region. Moreover, Herschel–Bulkley modelfitted best with upward mode (shear rate–shear stress) of all tested samples.

Incorporation of microalgae into cake would create functional characteristic. This is because they contain a wide range of nutrients and nutraceuticals and are considered as "functional food". For this purpose 25, 50, 75 and 100% of egg white in cake was substituted with this powder and the effects of such substitution on some physical and sensorial properties of batter and cakes were evaluated. The results showed that substitution of egg white withchlorella vulgaris had significant decrease in L*, a* and b* parameters of batter, crumb and crust of cake samples (P<0.05). Batter consistency, moisture and specific volume of cake samples were significantly decreased, too (P<0.05). However, these substitution levels increased significantly weight loss and hardness of samples (P<0.05).25% substitution level did not lead to a significant decrease in sensory properties of taste, color, odor, texture and total acceptance in cake in comparison with blank sample (P>0.05).

Nowadays, a new approach has emerged to the use of herbal medicines to treat infections, since herbal medicines are stronger antimicrobial activity and fewer side effects than chemical drugs. Aim of this study was assessing the antimicrobial effects of Leek extract on 5 Pathogenic Strains. In this study different concentrations of aqueous and ethanol extracts of Leek leaves were prepared and antibacterial effects of extracts were investigated by pour plate, agar well, broth microdilution, broth microdilution and triphenyltetrazolium chloride indicator methods. To analyze the data, one-way ANOVA was used and the Duncan test was performed to compare the means. Minimum Inhibitory Concentration (MIC) of the aqueous extract of Leek forSalmonella typhi, Escherichia coli, Bacillus cereus, Staphylococcus aureus, andStaphylococcus epidermidis were 256, 128, 64, 32 and 32mg/ml, respectively, and the MIC of the ethanolic extract were 128, 64, 64, 32, and 16mg/ml, respectively. Minimum Bactericidal Concentration (MBC) of the aqueous extract of Leek were 256, 128, 128, 64 and 32mg/ml, and the MBC of the ethanolic extract were 256, 256, 128, 32, and 32/ml, respectively. The results showed that the Leek extract had a significant antibacterial effect on all studied bacteria. That could especially prevent growth effectively in Gram-positive bacteria.

Lactic acid bacteria, a group of non-spore forming gram-positive microorganisms, in the form of cocci or bacilli which produce lactic acid as a major product of the carbohydrate fermentation. These bacteria produce several compounds such as bacteriocins that exhibit anti bacterial activity against pathogenic and spoilage bacteria which lead to increase the safety and shelf life of food. Lactic acid bacteria especially species of the genus Lactobacillus are an indispensable part of intestinal microbiota in human and animals and were found in most probiotic products. The aim of this study was to isolate and identify the lactobacillus strains from microbiota of six samples of traditional Motal cheese. In order to achieve this objective, out of 180 strains of lactic acid bacteria from Motal cheese, 19 isolates using biochemical confirmed tests were selected as the genus of Lactobacillus, using PCR amplification of 16s rRNA gene sequences methods. Finally, Lactobacillus brevis, Lactobacillus plantarum, Lactobacillus casei and lactobacillus buchneri were found to be 13, 4, 1 and 1 isolates respectively. Determination the potential technological and probiotic characteristics of all isolates in order to introduce their appropriate application are underway.

Natural preservatives that extracted from medicinal plants are the most important bioactive compounds that can be used in foods manufacturing. Generally, useing of these free oils as food preservatives are limited. One way to reduce these limitations is encapsulation of these oils in lipid carriers such as nanoliposomes. The aim of this study was to evaluate the antioxidant and antimicrobial activity of the Mentha piperitasessential oil and methanolic extract. The Extraction of essential oil of Mentha piperita species was performed by steam distillation and its chemical composition were identified using GC and GC-MS. Methanolic extracts were obtained by wet method. Nanoliposomes ofMentha piperita s essential oil was prepared by thin layer hydration and sonication methods. Nanoliposomes particle size was evaluated by using dynamic light scattering and zeta potential was evaluated by using zeta sizer. Also to evaluation the antimicrobial properties, the microdilution method was used. The most predominant constituents were menthol (40.46%), menthone (16.33%), mentho furan (13.37%) and menthyl acetate (7.11%) respectively. Particle size and zeta potential were 98.53 nm and -14 mV respectively and Nanoliposome was stable for 40 days. The minimum inhibitory concentration of essential oils in both free and inside overlap mode on gram-positive bacteria is more than gram-negative bacteria and fungi, while the methanolic extract was disable on gram-negative bacteria and fungi, also had poor inhibitory effect on the gram-positive bacteria. The antimicrobial effect of overlaped essential oil was more than free.

Now a day, one of the new methods, using ionized gasses generated by cold atmospheric plasma (CAP) for the purpose of sterilization of dairy products. In this research, the effects of CAP on to inoculated milk andCandida albicans were studied. Therefore, Sterilized milk with 3% fat, Candida albicans fungi and CAP produced by dielectric barrier discharge (DBD) were used.Candida albicans culturing was done in liquid Luria-Bertani (LB) medium and about 5.5× 105 colonies per milliliter of milk were inoculate. Then, the treatment of CAP on inoculated milk was done for 1, 3, 6, 9 and 12 minutes. In order to determine the CFU analysis, the treated samples were cultured on LB medium. Also, The variations of total content of free radicals and total antioxidant capacity (TAC) of milk after CAP treatment assayed by FRAP analysis, and Also lipid peroxidation of milk detected by evaluation malondialdehyde (MDA) using thiobarbituricacid. The results showed that by increasing the time of CAP treatment, the inactivity of fungi cells was enhanced. And, the minimum time required for sterilization of contaminated milk andCandida albicansgrowth ceasing is 9 minutes. Generally, after this period of treatment time no growth was seen in the solid LB medium. As well as, comparing assayed levels of MDA and TAC between treated and control samples showed no significant differences. These results proposed that the CAP treatment could be appropriate way for sterilization ofCandida albicans -contaminated cow milk.

The purpose of current study was to determine the effects of degree of hydrolysis (DH) on functional properties and antioxidants activity of hydrolysate from head and frame of common carp (Cyprinus carpio) fish. For this purpose, the head and frame of common carp was hydrolyzed by application of Neutrase Enzyme (0.8 L) during one, two and three hours. Accordingly, three types of hydrolysates with different degree of hydrolysis were obtained as 10.43 ± 2.32% (protein 1), 17.09 ± 1.71% (protein 2) and 21.45 ± 1.04% (protein 3). In this study, most of proteins properties were affected by the degree of hydrolysis, significantly. Apart from pH 2, as the DH was increased, the protein solubility was increased also, (p<0.05). The highest water holding capacity was recorded at protein 3 (4.29 ± 0.42 ml/g protein) (p<0.05), however no differences was observed between protein 1 and protein 2. Conversely, other functional properties such as emulsifying activity and emulsion stability index, oil absorption capacity were decreased as the DH was increased. In terms of antioxidants activity index, 1.2.2-Diphenyl-1-picryhydrazyl (DPPH) radical scavenging activity decreased with DH increased (p<0.05) and highest amount of this index recorded for protein 1 (87.96 ± 3.17%), whereas the degree of hydrolysis did not influenced the reducing power of three protein types, significantly (p>0.05). Chelating activity showed a direct relationship with the degree of hydrolysis and the highest one as 92.06 ± 2.92% was recorded for protein 3 (p<0.05).

In this study the antioxidant effects of kiwifruit peel extract (800 ppm) and synthetic antioxidant TBHQ (100ppm) on oxidation stability and fatty acids composition of sunflower oil were studied. First the kiwifruit peel extract was extracted. Then phenolic and tocopherolic compounds in extract were measured. Kiwifruit peel extract and TBHQ were added to oil in 800 and 100 ppm respectively and oil were heated in constant temperature of 180o C for 24 hours. Thermal oxidation factors such as acidy index, peroxide index, iodine index, conjugate index, carbonyl index, color index, oxidative stability, polar compounds, calculated oxidative stability of oil and fatty acid composition of oil were evaluated at intervals of 4 hours (0, 4, 8, 12, 16, 20 and 24). The results showed that change in fatty acids composition in oil containing kiwifruit peel extract was partly low, while samples containing TBHQ has more change in fatty acid profile at 180 o C. Stability of oil containing TBHQ in aspect of fatty acid change (based on COX value) was higher than oil containing kiwifruit peel extract. The results also showed that kiwifruit peel extract due to the presence of phenolic compounds created higher oil oxidative stability than oil containing TBHQ. The results of this study introduced kiwifruit peel extract as good source of natural antioxidant, which can prevent the oxidation of oils and reduce undesirable effects of synthetic antioxidant on human health.

The effect of two factors, packaging (with high density poly ethylene) and irradiation with gamma ray (with 0, 1, 3 and 5 KGr) was investigated on chemical and microbiological characteristics of industrial breads produced in Kermanshah city by Randomized Complete Block Design (RCBD) with 4 repetition. ANOVA showed packaging had no significant effect on above characteristics, while irradiation had significant effect (P<0.05) and (P<0.01). Mean comparison of data showed that gamma ray with 5 KGr had the most effect on reduction of total count, yeast and mold, but the moisture, ash and moisture content were unchanged. Correlation of bread characteristics showed that total count had significant correlation with yeast and mold at P<0.05 and with ash and protein content at P<0.01 and did not have a significant correlation with moisture. In addition, yeast and mold had significant correlation with chemical characteristics at P<0.01 and ash with protein had significant correlation at P<0.01. The obtained results confirm that gamma irradiation is effective in reducing the microbial load at industrial bread, without a significant change in chemical characteristics. The results of SEM analysis showed both bread with and without packaging under 5 KGy irradiation had the most pores and porosity, however the bread without packaging had a better texture.

The concept of functional foods includes foods or food ingredients that exert a beneficial effect on health and/or reduce the risk of chronic diseases, beyond basic nutritional functions. Appending functional foods can make an evolution in food industry. The objective of this research was to evaluate the effects of different amounts of inulin (3% and 8%) and green tea powder (2% and 4%) on chemical properties, including the amount of ash, moisture, fat, protein, fiber and other chemical peroperties, Product physical properties such as cooking quality, amount of crushed pasta, water absorption during cooking product, the glaze and other physical properties, The elasticity of the dough with Instron texture analyzer and also pasta organoleptic properties was performed by standard methods.A very small reduction in the amount of proteins and fat of samples were observed, but these changes were not statistically significant at the 95% level, as well as increasing the amounts of inulin and green tea powder resulted in a significant increase in the fiber. In physical and organoleptic properties increased inulin and green tea powder also resulted in an increase in cooking loss compared to the control treatment. In general, the results showed that increased green tea powder in combination with inulin and semolina to improve the baking properties, so in general, it seems that, in terms of product texture property, treatment 3 (T2 - 98% semolina+0% inulin+2% green tea powder) and in terms of organoleptic properties, treatment 5 (L3T2 - 95% semolina+3% inulin+2% green tea powder) compared with control treatment, were recognized as the superior treatments.

Nowadays, natural biopolymers such as proteins and polysaccharides in the preparation of biodegradable nanoparticles in food and pharmaceutical industries are of particular interest. The aim of this study was modeling and optimization of three component nanocomplex (protein, polysaccharide and small molecule emulsifier) production and study their stability using the Box-Behnken design. For each response, second order polynomial models were developed using multiple linear regression analysis. Analysis of variance confirmed that the models were highly significant (p<0.001) for all response variables and also showed that all of the predictive models had high RSquared and Adjust R-Squared, thus ensuring a satisfactory fitness of the regression models to the experimental data. Using desirability function, optimal processing conditions was achieved in the sodium caseinate concentration (0.15%), Arabic gum concentration (0.54%), Tween 20 concentration (0.09%) and pH (4.79). At this optimum zone, particle size (68.71), particle size distrubition (0.9), and turbidity (0.24), particle size growth (0.034), particle size distrubition growth (0.003) and turbidity growth (0.016). The multiobjective desirability was equal to 0.87 that, indicates the fulfillment of optimization goals. These nanodispersions may be useful as nutrients delivery systems for utilisation in functional food and drink products with low pH.

The aim of the research was to decrease of colorants, turbidity and impurities such as phenol, anthocyanin and protein along with increasing clarity of sugar beet final molasses for preparation liquid invert sugar.For this purpose, effect of pH at 3 levels (8.9, 7 and 4.5) and activated carbon at 4 levels (0.609, 0.783, 1.131 and 1.827 g), on characteristics of color, turbidity, clarity, total phenol, total anthocyanin and protein of sugar beet molasses solution were investigated. The first experiments showed that polymeric colorants of molasses solution are from types of caramels and melanoidins with high molecular weight of 2500 Dal. In the second stage of studies determined that decreasing molasses solution pH from 8.9 to 4.5 along with 0.011 g activated carbon, color 42.24%, turbidity 21.43% decrease and clarity 33.57% had increased. In the third stage, determined that with increasing activated carbon amount from 0.609 g to 1.827 g at pH 4.5, color 88.31%, turbidity 100%, total phenol 76.52%, total anthocyanin 86.39% and protein 98.51% decrease and clarity 75.83% had increased.

In the present study, tea shoots consist of an apical bud and two adjacent leaves, in two tea varieties (Hybrid and Colone 100), were collected from tea research center of country and after extraction, the content of total phenol, total flavonoids and antioxidant activity were evaluated by colorimetric method. Catechins and caffeine were analyzed by HPLC. Sensory properties evaluation was done by panel test using linear method. Results showed that total phenolic content in two types, Colone100 and Hybrid had not significant difference (p≤0.05). Flavonoid content and Antioxidant properties were different in two varieties and it was significantly (p≤0.05) higher in Colone 100 than Hybrid.HPLC result analysis showed higher levels of catechins and caffeine in Hybrid variety than Colone 100 variety. Considering colour and taste of the samples, Hybrid variety was stronger, vice versa Colone 100 had stronger aroma than Hybrid variety that expresses the superiority of Colone 100 in terms of its health properties to Hybrid variety.

Seafood contain protein and beneficial fats but they have little fiber that by adding of dietary fiber completed in the nutrition. Thus, in the present study, silver carp (Hypophthalmichthys molitrix) surimi was fortified with oat and wheat fibers (0, 2, 4, 6%) as a source of dietary fiber. chemical properties, physical and sensory properties for Production samples were investigated. Moisture, fat and protein contents decreased in surimi paste with oat and wheat fiber compared to the control (P<0.05). Addition of fibers resulted in an increase brightness and whiteness of surimi paste samples compared to the control. By adding wheat fiber in surimi gel significantly reduced hardness compared to the control. Add oat fiber and low level of fiber wheat (2 and 4%) had no significant effect on Gumminess and Chewniess gels But with increasing levels of oat fiber compared to wheat fiber increased Gumminess and Chewniess. whiteness and brightness surimi gel with oat and wheat fiber significantly reduced and amounts of yellow and red was not significant. Sensory evaluation results, showed no significant differences in the appearance, odour, flavour and generally acceptance and with increasing levels of wheat fiber color surimi gel was better. in general, higher levels of oat fiber (%6) resulted in provides access a better surimi gel.

Due to susceptibility of folic acid1 like many other vitamins to environmental and processing conditions, it is necessary to protect it by highly efficient methods such as micro/nano-encapsulation.Our main goal was to find the optimum conditions in pectin-WPC double emulsion preparations for nano-encapsulation of FA by spray drying. Five independent variables and their practical range including pectin and WPC content, dispersed phase content, pH, and surfactant type of Span and PGPR were considered along with encapsulation efficiency as the main response. The experiment design was performed by Taguchi approach and 16 treatments were determined. Final double emulsions were formulations containing an internal nano/micro-emulsion composed of a W/O system with FA present in the water phase, the whole dispersed within an aqueous phase of pectin-WPC complexes. The grand average of folic acid EE was approximately 88.3% in a range of 82.3 to 95.0%.The main effect analysis with Taguchi technique revealed that dispersed phase content of double emulsions was the most important factor affecting EE (36%) and surfactant had the minimum influence (5%). Also, it was revealed that the most important interaction between independent variables in terms of EE was between WPC and dispersed phase content while pectin-pH had the lowest interaction. Finally, optimum conditions were determined as 1.0% pectin, 4.0% WPC, 15% dispersed phase, pH=6, with a PGPR nano-emulsion which resulted in 99.0% EE of folic acid.

Date- milk drink is a flavored dairy drink which is prepared by blending the date palm syrup with milk and other ingredients. The present study was conducted to prepare a low sucrose dairy fruit juice blend based on date palm syrup by replacing the date liquid sugar instead of sugar in the formulation and evaluating the effects of this substitution on product properties. Finally, freshly made optimum formulation and its rehydrated powder were subjected to sensory evaluation. Therefore, at first 16 formulations with different proportion of date syrup, date liquid sugar and sugar were used to prepare date- milk drink. Then, 4 better formulations were selected based on the sensory analysis and their physicochemical properties were investigated. The results indicate in the 4 selected best formulae with 0, 2, 4 and 6% date liquid sugar, increasing date liquid sugar and reducing sugar in formulation resulted in decreasing lightness, pH, dry matter and total soluble solid (Brix) of product and increased acidity. Rheological behavior of the samples by the addition of date liquid sugar in the formulation has changed from a Newtonian fluid to a pseudo plastic. Based on the results acquired in this research the sucrose free sample with 4% date syrup and 6% date liquid sugar were designated to be optimum.Also no significant difference was observed in sensory evaluation of freshly made and rehydrated powder.

Food producer have to use natural materials to protect public health because of increasing the consumers awareness of the hazards of chemical additives. So this research was performed for improving sponge cake properties by chubak extract and balangu gum as natural additives. Effect of chubak extract in three levels of 0, 0.5 and 1% and balangu gum in levels of 0, 0.3 and 0.6% in in completely randomized design with factorial arrangement were used. Qualitative and quantitative properties of final product were evaluated. The moisture content and crust L* value were increased by increasing the amount of two natural additives. While the sample containing 0.5% chubak extract and 0.3% balangu gum had the highest amount of specific volume and porosity. Also the results indicated for making soft sponge cake texture and reducing the staling during storage, 0.5% chubak extract in lowest amount and 0.3% balangu gum was required. In addition the panelists introduced the samples containing 0.5% chubak extract and 0.3% balangu gum and 1% chubak extract and 0.3% balangu gum as the best in overall acceptance score. Chubak extract as natural emulsifier and native balangu gum were effective to improve qualitative and shelf life of sponge cake.

The color is the main appearance characteristic in acceptance of food materials. Because of side effect of artificial colors the uses of theirs have been minimized and there is more trend to use natural pigment. The purpose of this study was optimization of carotenoids extraction from from Persimmon fruit (Diospyros kaki L.) by using ethanol, n- hexane and their mixture in environmental temperature and boiling point in 2, 4, and 6 hours times. The results showed that, most absorption density is for ethanol solvent in boiling point after 6 hours. To selection the best ratio of sample to solvent, used the 50, 100, 200, 300, 400 ml of ethanol and got the most efficiency (p>0.5) is for 400ml of solvent and there was a meaning difference with other ratioes after 6 hour test in boiling point. After extraction, the sample solvents have been removed by rotary evaporator and residue has been powdered by freeze driers. The extraction efficiency of Persimmon color pigments powder was 10.85 percent to weight of whole amount of fruit.

Using indicator compounds is an adulteration assessment method in food materials. Tartaric acid, the dominant acid existing in grapes, can be used as an indicator for grape juice presence in other juices. This work aimed at fabricating a facile molecularly imprinted polymer for tartaric acid selective separation. Polymers syntheses were performed with acrylamide and methacrylic acid as functional monomers and ethylene glycol dimethacrylate as cross- linker in two levels (20 and 30 mmol). Applied polymerization method was precipitation type. Synthetized polymers binding capacity was investigated through HPLC. Polymers morphology was characterized with SEM, dynamic light scattering and Fourier transform infrared spectrometry analyses. Acrylamide based polymers with highest level of ethylene glycol dimethacrylate adsorbed highest amount of tartaric acid. Fabricated polymer had spherical shaped surface and was microsized. Tartaric acid complexation with acrylamide was affirmed by Fourier transform infrared spectrometry analysis.Based on the obtained results, molecularly imprinted polymer can be investigated and applied in detection and separation of tartaric acid from food medium.

In this study an experimental infrared system was designed and built to investigate the deactivation behavior of peroxidase in eggplant. Deactivation of peroxidase (90% reduction in enzyme activity) in eggplant slices was investigated during infrared irradiation at powers of 150, 250 and 375 watts and thickness of 5 and 10 mm in the range of 0 to 600 seconds. During the process, changes in cold spot temperature, moisture and peroxidase activity in slices of eggplant were measured. The results showed that using 150 W lamp at a thickness of 5 and 10 mm in, peroxidase was not inactivated after 600 seconds. The peroxidase enzyme was inactivated by using lamps with powers of 250 and 375 at a thickness of 5 mm after 500 and 150 seconds, respectively in which was associated with reduction of 50.06% and 31.62% of the initial moisture content at cold spot temperature of 73.76 o.C and 44.72 o C , respectively, using lamps with powers of 250 and 375 at a thickness of 10 mm after 600 and 200 seconds was associated with a reduction of 50.26% and 33.04% of the initial moisture content at cold spot temperature of 72.27o C and 73.86 degrees o C, respectively, In conclusion, increase in power and decrease in thickness, increased inactivation rate of enzyme peroxidase furthermore, because of the shortening of the processing time when using lamps with larger power the less moisture is removed from the sample.

Despite the presence of natural antioxidant the Halwa-Ardeh oxidative stability can be affected by storage condition. The use of thyme essential oils (0.05 and 0.1%) and BHT and their impact on the chemical (acidity, peroxide value and thiobarbituric acid number), sensory and microbiological characteristics of Halwa-Ardeh during the 2 months storage at 4 and 25oC compared to control samples were evaluated.Based on the results, the oxidative stability of Halwa-Ardeh samples containing BHT were higher than samples containing essential oil during storage at 4oC, but the peroxide and thiobarbituric values of samples containing essential oil at 25oC were lower than samples containing BHT. In both storage temperatures, the antifungal activity of essential oil was more than BHT. Also, the panelists were evaluated the sensory characteristics of samples in terms of aroma, taste, color, texture and overall acceptance. The results showed that except for the color, other sensory scores were decreased during storage at both temperatures. The sensory scores of the sample containing 1.0% thyme essential oil were significantly lower than others, and no significant differences were observed among other treatments. In general it can be stated that the addition of thyme essential oil up to 0.05% to Halwa-Ardeh improves antioxidant and antimicrobial properties of samples, and in order to creating diversify of the Halwa-Ardeh can be used in its formulations.

In this research, the effects of three variables, Konjac Glucomannan gum (KGM) (0-0.4% wt/wt), Xanthan gum (XG) (0-0.4% wt/wt) and Butter (3-9% wt/wt) on Textural properties (Hardness, Adhesiveness, Cohesiveness, Springiness, Gumminess, Chewiness) of Spreadable Processed Cheese with Texture profile analysis (TPA) were investigated. The central composite experimental design (CCD) was used and the data were analyzed using response surface methodology (RSM). Coefficients of determination, R2, of fitted regression models for all characteristics were above 0.85. The Result of analysis of variance (ANOVA) table showed that lack of fit was not significant for all response surface models at 95%. Therefore, the models for all response variables were highly adequate. The results showed that the optimum processing conditions for producing spreadable processed cheese with the best overall values for response variables were 0.37% (w/w) KGM, 0.045% (w/w) Xanthan gum and 5.23% (w/w) Butter. Finally, increasing the amount of butter and hydrocolloids was resulted in significant increase in hardness, gumminess, springiness but cohesiveness and chewiness of samples didn’t have any significant differences. Also, adhesiveness was decreased with different amount of hydrocolloids.

Owing to presence of large amounts of antioxidants, pomegranate (Punica granatum L.) reveals great nutritional properties. Study on rheological properties of fruit juice concentrates in order to appropriate design of manufacturing processes and to determine the nutritional values is of importance. The objectives of this study were investigating the effects of different total soluble solids (55, 60, and 65 °Brix) and temperatures (5, 15, and 25oC) on rheological properties of fresh pomegranate juice concentrate as well as on antioxidant and rheological properties during 20-week storage. The concentrated pomegranate juice samples were stored at different temperatures namely-80 (control), -20, 4, 20, and 35oC for measuring their rheological and antioxidant properties.Although, the viscosity of fresh pomegranate juice concentrate (particularly at 65 °Brix performed at 5 oC) decreased by increasing the shear rate and exhibited a typical non-Newtonian shear thinning behaviour (fitted to Herschel-Bulkley model), its storage led to shear thickening behaviour. After 20 weeks storage at different temperatures, FRAP value decreased and IC50 one increased; however, FIC and CUPRAC values remained constant. The samples stored at 4oC for 14 weeks revealed similar rheological (viscosity and shear stress) and antioxidant properties to those stored at -20oC. Taking into account the minimum cost, the best storage to yield high quality product was 4oC.

Bread is the basic food of the Iranian and the world people. Toast is one of volumetric bread. This bread is consumed in many parts of the world for breakfast. By using appropriate packaging food quality can be greatly saved. One method of food packaging is the use of modified atmosphere. This study aimed to evaluate the effect of modified atmosphere on quality and shelf life of toast bread during 14 days in modified atmosphere with 80% carbon dioxide+20% nitrogen, 60% carbon dioxide+40% nitrogen and normal air atmosphere that called H3, H2, H1, using two layers of PE film, PP, (F3) that used by factory, the three-layer film, aluminum foil, PE and PP on one side and two layers of transparent PE - PP film on the other side (F2) and three layers of aluminum foil, PE -PP as a complete package (all in aluminum foil) (F1). Using electron microscope scanning (SEM) imaging properties of useable toast bread samples during storage were investigated. The results showed that the slices of toast in modified atmosphere packaging H2F2 kept its quality during 14 days of storage with the exception of a very small percentage staling without any microbial contamination, moisture loss and no decrease on sensory properties and steel they were usable.

In this study survivability of probiotics, Lactobacilus acidophilus, Lactobacilus rhamnosus and Bifidobacterium bifidumwas assessed in simulated gastrointestinal tract. The count of probiotic bacteria was done in simulated gastric conditions (pH 1.5 and 2.5) at different incubation times (30, 60, 90 and 120 min) at 37oC. Initial number of live bacteria was 3 × 109 per ml. After incubation in the simulated gastric model (60 min), stomach contents were transferred to simulated intestinal model (pH 7.25) and incubated for mentioned times and the number of viable bacteria was enumerated.Statistical analysis revealed a highly significant difference between the probiotic bacteria, andB.bifidumshowed higher survivability compared to L. acidophilus and L. rhamnosus in simulated gastric and intestinal model. The count of probiotic bacteria was decreased during every half an hour of incubation times in simulated gastric media. No difference was noticed in declining rate of probiotics in simulated intestinal media except in the first 30 minute which number of bacteria was higher in this period.B. bifidum showed better survivability in both pH of simulated gastric environments. After incubation in simulated intestinal model (pH 7.25, 2hrs) number of survived cells were 2.33 log cfu mL-1 for B. bifidum, 1 log cfu mL-1 for L.acidophilus and 0.65 for L. rhamnosus respectively.