مجله علوم غذایی و تغذیه
سال هفدهم شماره 4 (پاییز 1399)

In recent years, the quality of Iranian bread has been drastically reduced. One of the reasons is the poor quality of gluten that has been produced from domestic wheat flour, which should be improved by special methods.

In this research, combination of three enzymes consisting of transglutaminase, glucose oxidase and phospholipase was used. In order to select the best combination of these three enzymes, Response Surface Methodology (RSM) optimal design was applied. The rheological properties of the dough were measured by Mixolab. The gluten index response was evaluated by centrifuging wet gluten for all the samples examined.

The results indicated that by increasing glucose oxidase and phospholipase enzymes simultaneously, the dough development time (C1) had a significant increase (p<0.01), which indicates the synergistic effect of these two enzymes on C1 of the samples. Also, by increasing the level of transglutaminase enzyme, the dough development time, required torque for breaking the protein network (C2) and water absorption had a significant increase (p<0.05( which indicates the positive effect of this enzyme on the improvement of rheological properties of the dough. Gluten index also had a significant increase with the increase of the(p<0.01) and glucose oxidase concentrations (p<0.05) that indicates the conversion of soft gluten with a high elasticity to tight gluten with desirable elasticity.

It is therefore concluded that the optimum concentrations of the enzymes were 30 ppm for transglutaminase, 15 ppm for glucose oxidase, and 13.16 ppm for phospholipase.

is the evaluation of the effect of gelatin/Hydroxypropyl-β-cyclodextrin coating containing nanoemulsion of nettle (Urtica dioica L. ( on chemical, microbial and sensory properties of turkey meat during storage.

Chemical compositions of nettle essential oil were detected using Gas Chromatography-Mass Spectrometry. Samples of turkey meat coated with 1.5% (V/V) nanoemulsion of nettle, coated with gelatin/hydroxypropyl-β-cyclodextrin (HPBC) containing nanoemulsion of nettle, packed in cellophane and without coating (Control) were stored at 4°C. Their physical and chemical (weight loss, total volatile basic nitrogen, and thiobarbituric acid reactive substances), microbial and sensory properties were evaluated at different intervals (0, 5, 10, 15, 20 days) of storage.

The results of Gas Chromatography-Mass Spectrometry showed the presence of effective compounds with antimicrobial and antioxidant activities especially Carvacrol (51.71%). According to the results, lower amounts of weight loss, total volatile basic nitrogen, mesophilic, psychrophilic bacteria, molds, and yeasts were observed in turkey meat samples treated with nanoemulsion of nettle essential oil in comparison to the control during storage (p˂0.05) and the highest sensory scores were gained.

Application of gelatin/HPBC coating containing nanoemulsion of nettle essential oil had a desirable effect on the control of chemical and microbial spoilage, therefore it can be used for increasing the shelf life of turkey meat in the food industry.

Increasing the fiber content (despite the therapeutic effects and functionalproperties) in food can compensate for fiber deficiency in the diet. However excessiveconsumption can have adverse effects on the product's acceptability.

The effect of potato fiber to replace with bread flour at threedifferent concentrations (10, 20 and 30%) were investigated in preparing the sponge cake andcompared to the control sample. The chemical, physical and sensory characteristics of thesamples were enaluatrd on the first day of the preparation and the best formula was selected.The prepared samples were kept in the storage at room tempreture and moisture content,physical and sensory properties were mesured every ten days interval. The results andstatistical analysis of the cake were evaluated using SPSS software and mean values werecompared with the Duncan test at 95% probability level.

The resultes indicated that an increase in fiber resulted in significant increases inash, crude fiber, dietary fiber, cavity density, moisture content and darkness of the crust andcrumb in the cake. The hardness of the cake increased significantly while the cohesivenesssignificantly decreased (P <0.05). The cakes containing up to 10% added fiber had acceptablesensory properties and did not have significant differences with the control sample (P >0.05).

The sample containing 10% potato fiber was the most accepted among thepanelist. According to the results of other tests, the addition of fiber up to 10% was acceptableand did not show significant differences with the control sample (P >0.05).

Shrimp among the sea food has the highest commercial demand universally. Due to biochemical, microbiological and physical spoilage after receiving from sea, it has a short shelf life. The object of this research is to improve the shelf life of shrimp caught from the sea. Active edible Carboxy Methyl Cellulose (CMC)-based coating containing Zinc Oxide nanoparticles (0.03%) and dill essential oil with 0, 1, 2, 3 and 4% levels as biopreservative were prepared to extend the shelf life of shrimp during 12 days of storage at 4 ºC. Using active edible CMC-based coating led to the reduction of pH changes in shrimp coated samples during storage time, therefore coating containing ZnO nanoparticles and 4% dill essential oil were most effective in increasing storage time significantly (p<0.05) and increased TVB-N content until the end of the 12 days but using ZnO nanoparticles and increasing the concentration of dill essential oil from 0 up to 4% resulted in a significant (p<0.05) decrease in TVB-N content. Although incorporation of the dill essential oil compared to control significantly (p<0.05) decreased the L* and increased the b values during storage time and the treated samples with a higher levels of the essential oil had less color changes. However, extending the storage time significantly (p<0.05) increases the b and reduces the L* values of shrimp samples. Increasing the storage time caused a significant decrease (p<0.05) in hardness of the shrimp samples but the use of nanoparticles and the essential oil reduces the process of softening. Total aerobic bacteria, E.coli and coagulase-positive Staphylococcus aureus counts showed that number of microorganisms was dependent on the presence of nanoparticles and the essential oil dosage used for treatment as well as storage time. Using high levels of the essential oil led to an increase (p<0.05) in sensory parameter scores significantly, therefore the treatment containing 3% dill essential oil had the highest acceptability score. The use of 3% dill essential oil as biopreservative along with ZnO nanoparticles in the structure of active edible CMC-based coating is recommended for the preservation of shrimp at 4 ºC.

The highconsumption of low nutritional value snacksand malnutrition of children and teenagers are one of the major problems in society. Usually, the small seeds that are in watermelon, although they are rich in nutrients including fatty acids, essential proteins, and many minerals are not used and have been thrown away.

This study was performed on the basis of a rotating central composite design. The effects of extrusion variables including screw speed (120-180 rpm), watermelon powder (10-20%) and feed moisture content (12-20%) on the physicochemical properties (expansion ratio, oil and water absorption index, porosity, and total acceptance) of expanded snack on the basis of corn-wheat flour grits were evaluated.

The results showedthat watermelon flour decreased the expansion coefficient and porosity, however, the interaction effect of screw speed and watermelon flour improved the physicochemical properties of the samples. The increasing screw speed led to a decrease in the viscosity and therefore the expansion coefficient and porosity increased.

The optimization of snack formulation was performed to find the optimum conditions of production. The watermelon flour of 11.31%, feed moisture content of 15.56% and a screw speed of 171.15 rpm were found to be to optimum conditions.

Camel milk has high antioxidant activity because of vitamins, protein anddifferent enzymes and it can play an important role in the reduction of oxidative stress.Furthermore, camel’s milk has a stronger inhibitory effect against bacteria. In this researchsurvey the protective effect of camel milk against oxidative stress infection caused bySalmonella typhimurium in vivo conditions has been investigated. Salmonella infectionactivated phagocytic inflammatory cells by producing pro- inflammatory cytokines causes therelease of nitrogen and oxygen free radicals which it results in its cellular damage throughlike membranes lipids peroxidation and DNA and protein oxidative.

Male Wistar rats (150±20g) divided into five groups (n=8). GroupA: contaminated with Salmonella typhimurium (ATCC14028). Group B: Contaminated withSalmonella typhimurium and treated by camel milk (33ml/kg). Group C: contaminated withSalmonella typhimurium (1.5×108) and treated by camel milk and antibiotic cefixime(400mg/kg). Group D: treatment with camel milk. Group E: Injection control. Aftercompletion of the course, animals became unconscious. The animals decreased and theirintestine, liver, and kidney were separated and the level of enzyme activity like SOD andCAT were checked in the tissues.

Statistical analysis showed that the level of activity of enzymes SOD and CATdecreased in the tissues of the infected group to Salmonella typhimurium, and by followingtreatment with camel milk and treatment with camel milk and antibiotics, this reductionincreased to a normal level.

Camel milk plays a useful role as antioxidant nutritional supplement againstSalmonella typhimurium in rats.

Cold plasma or non-thermal plasma technology is one of the methods of foodprocessing that is used to inactivate pathogen microorganisms and improve food safety. Coldplasma can affect the inactivation of a wide range of microorganisms, without harming thehost and healthy tissues.The aim of this study was to evaluate the effect of cold plasma directly on reducing thenumbers of Salmonella enteritidis on egg shell and also to determine the effect of plasmaexposure time and the composition of the injected gas.

In this study, the effect of cold atmospheric plasma radiation ofargon and argon containing 5% oxygen gas, at the rate of 3 liters / min, and at three differenttimes on inactivation of Salmonella enteritidis was investigated.

The effect of argon gas radiation for 1, 3 and 6 minutes on the reduction ofsalmonella enteritidis numbers being 4.490, 3.948, 0 cfu /ml respectively, was significant at1% probability level. Also, the radiation effect of argon containing 5% oxygen at 1, 3 and 6minutes,on reduction of Salmonella enteritidis numbers was 4.559, 4.226 and 0 cfu /ml,respectively. Both groups of the treatments caused a significant decreasing trend at thestatistical level of 1% as compared to the control sample.

The obtained data indicated that the effects of the gas type, as well as theirradiation time and their interaction on the tested bacterium were statistically significant atp>0/01 as compared to the control.

Today, different methods are being used to improve the properties of edible films; one of the most effective and commonly used ones is using nanometer-sized fillers and the production of polymer nanocomposites. The objective of the present study is to produce quince seed-based nanocomposite film reinforced with nanocrystalline cellulose and to study the properties of the resulting composite film.

In the first step, the quince seed mucilage was extracted and then, with different concentrations of nanocrystals cellulose (NCC) (3, 5, and 7%) and 35% (w/w) glycerol as plasticizer the nanocomposite film was produced by molding method. Then the physical, mechanical, barrier, thermal and structural properties of the films were examined.

Addition of nanocrystals increased the thickness of resulting films but decreased their moisture content, water solubility and water vapor permeability (WVP) to 7.2%, 29.3% and 5.6% when using 7% nanocrystal cellulose. Increasing of nanocrystals concentration in films resulted in an increase in a* and b* and a decrease in L*. Incorporation of nanocrystals also improved the mechanical properties of quince seed gum-based films including tensile strength and young module, whereas elongation at break was not significant. The glass transition temperature of films also was increased by the addition of nanocrystals which was determined by means of differential scanning calorimetry. FT-IR spectra of samples also approved the interaction between nanocrystals and quince seed gum.

The produced films exhibited good physical properties, reduced WVP, and enhanced mechanical properties, which are the main properties required for packaging applications.

Cadmium and arsenic have toxicity and can accumulate in food and causepoisoning and disease in the human body. In this research, the amount of contamination ofheavy metals, particularly arsenic and cadmium in lettuce and common cabbage and soil inthree cities of Hamidieh, Dezful and Ramhormoz in Khuzestan province were investigated.

In order to implement the research, 15 samples of lettuce andcabbage cultivars were cultured and 15 soil samples were collected from cities of Hamidieh,Dezful and Ramhormoz in Khuzestan province. The ecological risk of cadmium and arsenicwas studied using pollution indices.

The lowest amounts of contaminations in both cabbage and lettuce vegetablesconcerned with arsenic were found in Dezful at the concentrations of 1.39 and 0.85 ppmwhile the highest concentrations were observed in Ramhormoz at the levels of 2.44 and 1.49ppm respectively. Ramhormoz soil indicated the highest concentrations at arsenic (2.24 ppm)while Dezful soil showed the highest amount of cadmium (0.25 ppm). The results showed thatheavy metals of arsenic and cadmium in the studied cities had low ecological risk (Er<40) andlow risk (IR) risk index (RI<150). The highest risk index is in Hamidieh (32.4) and the lowestrisk index is Ramhormoz (11.66).

The results of Health Hazard Index (HI) in lettuce and cabbage were less than 1,indicating that the concentration of these elements in the soil would be hazardous and wouldhave adverse health effects for the consumer.

There is a relationship between the consumption of saturated, trans fatty acidsand coronary heart disease, however there are unresolved matters to be concerned about thecontent of saturated and trans fatty acids in Iranian confectionery sweets.

Four types of confectionary sweets popular and consumedfrequently consisted of dry, semi-dry, wet and frying types were selected and purchased fromthree famous confectionary shops with six replicate orders during six month periods. The oilsamples after extraction were subjected to methylation to prepare methyl ester of the fattyacids. The methyl ester samples were injected to a gas chromatography equipped with BPX70capillary column and Flame Ionisation Detector where the firm identification was made bycomparison with standards.

The results showed that the major saturated fatty acid in all the pastries was palmiticacid accounting for 25 to 35 % for different samples. The other major saturated fatty acid wasstearic acid ranging 5 to 10%. The unsaturated fatty acid; elaidic acid (C18:1t) accounted for7 to 13%, expect for Doughnut that was less than 1%. In total the amount of saturated fattyacids and trans fatty acid of the samples was much higher than the minimum standardtherefore total TFA content in Nan Brenji A, B and C brands were13.3, 8.03 and 11.45,respectively. The values of TFA in Danish type were 15.67, 15.25 and 16.78, respectivelyand in Napeloni type was11.82, 15.9 and 11.46, respectively.

It is necessary and advisable to replace the edible oils containing high trans fattyacids in the formulation of these sweets with healthier ones containing lower trans content.