مجله تحقیقات مهندسی صنایع غذایی
سال هفدهم شماره 1 (پیاپی 64، بهار و تابستان 1397)

The aim of present study is to investigate the effect of polysaccharide hydrocolloids including carboxy methyl cellulose and potato starch, as a fat replacer, to improve the quality of low fat chicken burger, similar sensory, physical, and chemical properties to a high-fat meat product, without increasing fat content, and matching to national standard.In this study, different low fat chicken burger formulations containing carboxy methyl cellulose (1.5%) and potato starch (1.5%) and each of them (3%) as polysaccharide hydrocolloids fat replacers produced, and comparedwith control sample, which matched to national standard regarding to chemical and texture characteristics.The results of chemical tests indicated thatsamples containing carboxy methyl cellulose and starch had higher moisture retention during baking, and as a result lost lower moisture. Also, the additives were not formed by fat, there was no increaseof the fat content. According to the results of texture profile analyzer, hardness, cohesivenessandchewiness,as well as other parameters including moisture retention,fat absorbtion retention, cooking yield, cooking loss,andjuiciness showed significant differences)p<0.05), comparingto control. The results of sensory evaluation showed that addition of hydrocolloids didn’t have recognizable effect on odor, taste and color of treatments but there was a significant effect on the overall acceptance and juicinesstreatment containing 1.5% carboxy methyl cellulose and 1.5% potato starch was recommended as the most favorite treatment.

Some physicochemical properties of rice in two different regionsofrice in Iran were evaluated.Tarom-Mahalli, Fajr and Shafagh cultivars were planted in Mazandaran and Fars provincesin 2012 with different climate conditions, and properties of milling, grain quality and viscosity were investigated. Significant differences have been observed for most of the quality parameters among the cultivars and locations, may be because of the differences in temperatureand number of rainy days in the two regions.Fars has lower temperatureand rainy days than Mazandaran. The percentage of broken rice, amylose content, alkali spreading value and aroma were higher in samples from Fars province.Rice samples of Mazandaran have higher hardness value.Pasting properties weremeasured by Rapid Visco Analyser were affected byclimate but not in the same algorithm. Peak viscosity and break down viscosity were decreased significantly in fars shafagh varity. This indicated better quality of shafaghricein fars province.

Mung bean is one of the most valuable legumes that is rich in phosphorus, potassium, protein and vitamins B1and B2and has health benefits. In this study, the effect of mung bean flour in three levels of 0, 5 and 10% of wheat flour and tragacanth gum in two levels of 0 and 0.5% of emulgel on the physicochemical and sensory properties of functional cake were evaluated. The characteristics of cake such as moisture, ash, protein, cooking loss, symmetry, volume, color indexes and sensory evaluation were determined. The results of statistical analysis of the data showed that by increasing the mung bean flour, the moisture content and the a* index decreased, but the ash content, protein, and cooking loss increased. Also, with increasing tragacanth gum, the moisture and ash content increased while cooking loss, the L* and b* indices decreased (p<0.05). The volume index of samples also increased with the increasing of tragacanth gum. Also the volume index of cake increased with increasing of mung bean flour to 5%, and then with the increasing of mung bean flour to 10%, decreased significantly (p<0.05). According to the results of sensory evaluation, color and texture score increased with increasing tragacanth gum in samples containing 5% of mung bean flour, but decreased in samples containing 10% of mung bean flour (p> 0.05). According to the results of this study, the use of 5% mung bean flour with 0.5% tragacanth gum for the production of functional sponge cake is recommended.

In this article physicochemical propertiesof fried doughnut during 7-days storage affected by green tea extract (0, 100, 150, and 200 ppm) and ascorbic acid (0, 50, 100, and 150 ppm) were studied using principal component analysis (PCA). The results illustrated the dependence of physicochemical properties to the ascorbic acid green tea extract concentrate as antioxidant substitutions in product. Both of them showed pro-oxidant andantioxidant activity in low and high concentration respectively. Ascorbic acid in concentrations 50 and 100 ppmas a pro-oxidant influenced the texture and appearance and had a weak antioxidant effect at150 ppm. Observed trend for green tea extract (regarding the more effectiveness of antioxidant properties at200 ppm) was the same as that of ascorbic acid.

The antimicrobial effects of infrared radiation as a novel food processing method have been approved. In present study, after determination of the maximum absorbents for Bacillus cereus(as a foodborne indicator) by FTIR, the effects of selective infrared wavelength (5.76, 6.01 and 6.26 μm), distance from radiation source (3, 5 and 7 cm), radiation time (15, 22.5 and 30 min) and sample thickness (2, 4 and 6 mm) on survival of B. cereusin broth medium were evaluated by response surface methodology. Based onthe results, the significant effect (p<0.01) of all variables (except thickness) on reduction of B. cereuswas clarified. Interaction of infrared wavelength with distance from radiation source and interaction of distance from radiation source with radiation time were also significant (p<0.01). Furthermore, the maximum reduction of B. cereus (equal to 4.34 log CFU/ml) was observed in treatment containing 5.76 μm infrared wavelength, 3 cm distance from radiation source, 30 min radiation time and 2 mm sample thickness. The results of present study can be used for optimization of industrial process for elimination of B. cereusby infrared radiation.

Determination of physical propertiesof agricultural products is essentialto analyzetheir behaviorduringprocessing operationssuch asmoving, peeling, cleaning, sorting,dryingand storage.Note that the design of the above-mentioned devices in addition to planting, growing and harvest implements without taking into account these properties will not lead to optimal results. In this research, the effects ofgrain moisture content(at levels of 10, 14and18percent)andkind of varietiesonthe physical propertiesof two varietiesofricepaddygrain, namely RezaJoo andDomSiyahwere investigated.In order to analyze the data, a factorial experimentwas used ina completely randomized designandmeans comparison were done byusing Duncan's multiple-range test (α = 1%).Based on the results, byincreasingthe moisturecontent, with the exception of the sphericity coefficient, otherphysical propertiessuch as length, width, thickness, geometrical diameter, arithmeticdiameter, surface,volumeandthe gravitypropertiessuch asbulkdensity, truedensity, porosity and1000 grainmassincreasedwhilethe kind of varietydid not have asignificant effect ontheseproperties.

Wheat bran is a rich source of valuable and nutrient compounds such as dietary fibers, amino acids, vitamins and minerals.Because of these valuable compounds, branis a suitable medium for growth and reproduction of beneficial microorganisms for human health. Several studies have confirmed the beneficial bacteria have different health benefits. These properties include the prevention and treatment of some infectious diseases, the beneficial impact on the intestinal flora, improve immune function and reduce allergy. Strong enzyme systems of these microorganisms can break down some of the components of the bran such as phytic acid and improve its nutritional properties. By fixing of these microorganisms on bran, prebiotic product containing beneficial microorganisms can be used in a wide range of food products including bakery products. In this study, Lactobacillus plantarumwhich hasbeneficial properties for human and also improve bread quality were used to ferment the wheat bran. Fermented bran by lactic acid bacteria was produced under optimal growth conditions. Then the effect three methods of storage including drying in ambient condition and storage at refrigerator and freezer temperatureat different temperature,23, 4 and -18 °C,respectively, on survival rate of microorganisms wereinvestigated. It was observed that the survival rate of microorganisms using refrigerator, drying in ambient condition and freezing, was 95, 8 and 2%, respectively.Results showed that storage at refrigerator keeps the balance condition for survival of microorganisms comparing to other studied methods.

In this paper, the effects of transglutaminase (MTG) enzyme dosage (0, 1, 3, 5 and 10 U/g pr), incubation time (1 and 2 hr) and milk solids concentration (9 and 25%) on some physical and functional properties of milk powder(particle size, true density, solubility, wettability, foaming and emulsifying properties and glass transition temperature)were investigated. Increasing milk solids concentration caused a significant increase in particle size(p<0.01), true density(p<0.05) andwettability(p<0.01) and a significant decrease in solubility(p<0.01). MTG treatment hadno significant effect on truedensity, solubility, wettability and foaming and emulsifying properties.Using3 and 5 units enzyme caused a significant increasing effect on glass transition temperature(p<0.05)and applying 10 units of enzyme increased particle sizesignificantly (p<0.01). Increasing incubation time caused a significant increase (p<0.01) in particle size and true density. The results showed thatthe effect of increasing the concentration of 10 units of enzyme and also 2 hrof incubation was more impressiveon particlesize and glass transition temperature. Moreover, the efficiency of MTG treatment was higher in lower milk concentration (9%) rather than the higher one (25%).