مجله علوم غذایی و تغذیه
سال هجدهم شماره 4 (پاییز 1400)

Fried food products are very popular due to their unique characteristics such as color, smell, taste and desirable texture. Controlling frying conditions and using edible hydrocolloid coatings (gums) is one of the best methods to reduce the oil uptake, moisture retention, and improving the appearance properties of fried foods. In this study, different concentrations of basil seed gum (0.0, 0.5, 1 and 1.5% w/w) were used to coat the eggplant slices during deep-frying at 150, 175 and 200°C and the relationship between process parameters and the quality of final product were modeled by genetic algorithm-artificial neural network method. The results of this study showed that coating with basil seed gum reduced the oil uptake of the final product. Coating pretreatment maintained the final product moisture and moisture content of the sample coated with 1.5% gum was higher than the other samples (64.05%). This process was modeled by genetic algorithm-artificial neural network method with 2 inputs that included basil seed gum concentration and frying temperature and 5 outputs that included oil percentage, moisture content, and three main color indexes (yellowness(b*), redness (a*), and lightness (L*)). The results of modeling showed that a network with 4 neurons in a hidden layer and using the hyperbolic tangent activation function can predict the physicochemical properties of fried eggplant slices. The coating containing 1.5% of basil seed gum retained moisture content and reduced oil absorption by the fried samples, and this coating is recommended as a suitable edible coating for coating of eggplant slices before the frying process. Sensitivity analysis results showed that the changes in the concentration of basil seed gum had the highest effect on the lightness index and then on the oil content of fried eggplant slices. The change of frying temperature also had the highest effect on the lightness index of fried samples.

Lactobacilli are a member of the Lactic Acid Bacteria (LAB) family that are used as starter culture in the production of industrial and traditional dairy products. Lactobacilli could potentially play an important role in the transition of antibiotic resistance to gastrointestinal bacteria or pathogenic bacteria. In this study, Lactobacilli were isolated from traditional yogurts, yogurt drinks and industrial yogurts and yogurt drinks and the antibiotic resistance to  13 antibiotic including: Penicillin, Ampicillin, Tetracycline, Erythromycin, Gentamicin, Streptomycin, Vancomycin, Nalidixic acid, Trimethoprim Sulfamethoxazole, Kanamycin, Rifampin, Ciprofloxacin, and Chloramphenicol have been investigated and the results were compared. According to the results, vancomycin resistance was the most prevalent phenotype in traditional yogurt (45.8%) and yogurt drink (40%) and in industrial yogurt (59%) and yogurt drink (50%) respectively. Except in the case of Penicillin and rifampin there was no significant difference between the resistances of Lactobacilli isolated from industrial yogurt to other studied antibiotics in this study are compared to the resistance of Lactobacillus isolated from traditional yogurt. Ciprofloxacin resistance in Lactobacilli isolated from industrial yogurt drink is significantly higher than the resistance of Lactobacilli isolated from traditional yogurt drink and there was no significant difference between the resistances to the other studied antibiotics inLactobacillus isolated from industrial and traditional yogurt drink.Antibiotic resistance was observed in Lactobacilli isolates of traditional and industrial samples. It seems that there is a need to pay attention to the antibiotic resistance in starter cultures used in the food industries in order to prevent the spread of antibiotic resistance.

Chocolate is one of the most consumed snacks in the world. In this study the quality of white chocolate namely browning process as well as physicochemical characteristics of this product are evaluated.

The effect of conventional emulsifiers such as lecithin with different intakes and emulsifier YN (ammonium phosphatides) at different concentrations were compared and evaluated in white chocolate. The samples were subjected to chemical analysis concerned with total fat content, acid insoluble ash, acidity iodine and saponification value, fatty acid composition, oxidative stability test (Rancimat) and sensory analysis according to the national standard.

The application of different concentrations of commercial lecithin did not have a significant effect on the qualitative characteristics of white chocolate, while the use of 0.4 and 0.5 % emulsifier YN at the time of production and 90 days after production improved the stability, quality of color and texture considerably. The yellow color index (b*) in white chocolate containing emulsifier YN was reduced significantly white the brightness index (L*) was increased favorably as compared to the control and the quality was maintained after production.

The application of emulsifier YN improved the qualitative characteristics of white Chocolate and exhibited synergistic effect with the natural antioxidant present in the substrate and increased the oxidative stability of the product.

Marination accompanied with the application of functional plant extracts is aconvenient method to preserve fish meat. The present study aims to extract Khandalcontaining antioxidant compounds by the use of microwave and applying it to marinatedfillets of Beluga in order to increase its shelflife at 4±1ºC. Microwave extraction optimization according to the solvent type,solvent ratio (5–15.5cc), time (10-30min) and power (90-270W) through RSM and applyingthe optimum extract in respect to the total phenolic compounds and the inhibitory potential ofDPPH free radicals for preparing marinates (i.e. control, treatments containing10 (T1),20 (T2),and 30% (T3) extract( and storage during 20days at 4±1ºC and monitoring the physical,chemical and sensory properties and comparing the results and data were carried out usingone-wayANOVA and chi-square methods. The results indicated that the optimal extract was obtained by the use of water for30min, at 90W and solvent ratio of 5. Moreover, it was revealed that TBA inT2wassignificantly controlled as compared to other groups and the amount of TVB-N, in T2 and T3were lower significantly (P<0.05) and being controlled. In terms of water activity, the highestamount was observed in T2 at days 0 and 10. The highest WHC was observed in the controlon day 0, which was decreased during storage time. The texture hardness, color, appearanceand odor didn’t show significant difference among the groups, but taste and oral sensationwere differed significantly over time. In terms of texture analysis, due to excessivemarinating, the samples became soft and watery and low score was obtained. Examination ofacid-salt taste showed that the marinated samples had acidic and salty taste. It is concluded that the sample containing 20% of extract was selected as thebest group in controlling chemical spoilage.

Different types of bread and in particular Lavash type produces a considerable amounts of waste generaly. In this study, integrated strategies to deal with the waste of this type of bread have been studied. By changing the formulation and adding functional additives to bread, industrially produced and the use of appropriate packaging to reduce the staling and microbial contamination are the objects of this research work.

Effect of natural anti-stagnation agents (including sprouted wheat powder, guar gum, kappa carrageenan) in concentrations of 0 to 0.3% and antimicrobial compounds (black cumin extract and propionic acid), maximum 0.5 ml with the package polypropylene packaging classification on the shelf life of industrial Lavash bread has been investigated. The physicochemical properties of flour (moisture, ash, pH, protein, wet gluten, Zeleny number, fall, and fat number) and rheological properties of dough produced in sixteen different formulations (such as water absorption, elasticity, maximum viscosity of the return factor) were tested. Using statistical optimization techniques, optimal treatments were determined. The treatments were produced, baked and packaged industrially, using black cumin extract and propionic acid. A control sample was also produced to compare the results. Series of microbial, textural and sensory evaluations according to the standards were carried out on the samples during storage at room temperature after production and ten and twenty days’ intervals.

The rate of fall in the initial flour sample was high and by adding 0.3% germinated wheat powder reached the appropriate level for the production of industrial Lavash bread. Two types of optimal formulations were obtained, of which with the shelf life of more than 10 days, that included 0.208% germinated wheat powder, 0.037% guar, and 0.055% kappa carrageenan with cumin extract and acid propionic was selected.

By using the industrial production line, proper packaging, and formulation of raw materials for Lavash bread, which is known as the most widely used bread in Iran, a positive step can be taken to reduce the amount of waste in this bread and improve its quality.

Coating with proteins and gums is a way to reduce the amount of oil absorbed in fried foods. The aim of this study was to evaluate the effect of temperature and time of frying and different concentrations of Persian gum and whey protein concentrate on physicochemical properties of fried turkey meat. Physicochemical properties of turkey meat coated with different concentrations of Persian gum (1 and 2%) and whey protein concentrate (5 and 10%) after frying for 5, 7 and 9 minutes at the temperature of 140 and 160 °C were investigated in 3 replicates according to the national standards. Increasing the frying temperature increased weight loss, fat, firmness, a* index and decreased moisture content and L* and b* indices (p<0.05). By increasing the concentration of Persian gum were increased the weight loss and was decreased the moisture content and firmness of the sample (p<0.05). Increasing the concentration of Persian gum did not have significant effect on the fat content and color parameters of the sample. Increasing whey protein concentrate decreased weight loss and fat in the sample and increased a* and b* indices (p<0.05) but did not have significant effect on moisture content, firmness and L* index. Coating with Persian gums and whey proteins has a significant effect on the physicochemical properties of the fried products.

Aloe vera gel has many applications in the pharmaceutical and food industries. Aloe vera leaf contains valuable materials such as pectin which its extraction can be beneficial from economic and environmental aspects.  The overall objective of this study was to evaluate the effect of three variable temperatures (35, 65 and 95), time (40, 120 and 200) and pH (1, 2 and 3) on the yield, the galacturonic acid content and esterification degree of aloe vera leaf pectin. In order to study the physicochemical properties of the pectin, emulsion stability tests and FT-IR were applied.  According to the results, high pectin extraction yield from aloe vera leaf was 6.9% which was obtained at temperature of 95℃, time of 120 min and pH of 1. The highest galacturonic acid content of the extracted pectin of aloe vera leaf was 78.48%, at temperature of 65ºC, time of 200 min and pH of 1, The highest esterification degree of extracted pectin of aloe vera leaf was 53.410%, which was observed at temperature of 35ºC, time of 120 min and pH of 3. The highest emulsion stability of aloe vera leaf pectin was at 4 °C on the first day of production. FT-IR results also showed that the strong absorption in the area 3200-3500 cm-1 in the extracted pectin samples was related to intra-and extracellular vibration of the hydrogen bond in the galacturonic acid polymer. The pectin extracted from aloe vera leaf with molecular weight of 127 kDa after 30 days storage at 4 and 23 °C had 75% and 63% emulsification stability respectively.  The results of this study showed that pectin extracted from leaf lesions of aloe vera could be introduced as a marketable pectin source.

Wild pistachio (pistacia atlantica), as a plant source is rich in phenolic and tocopherol content that has significant antioxidant, therapeutic and antimicrobial effects. Encapsulation can be used as an effective method to improve the stability and prevent undesirable taste of phenolic compounds. Therefore in this study, the effect of micro liposomes containing phenolic and tocopherol compounds of pistacia atlantica (Beneh) oil on oxidative stability of butter was investigated.

The particle size of liposome was in the range of 4-9μm. The addition of cholesterol had a significant effect on particle size. The addition of cholesterol increased the zeta potential of the samples. The total concentration of 40 to 20 mg lecithin to cholesterol was identified as an optimal concentration in the production of micro liposomes and it was used in determination of oxidative stability of butter. The results showed that N400 (sample containing 400 mg / 1000g of phenolic and tocopherol compounds of pistacia atlantica) had the highest stability.

The results of this study showed that use of phenolic and tocopherol compounds of Beneh kernel oil, in form of microcapsules might be used to prevent chemical spoilage and also increase the shelf life and beneficial properties of cream and butter derived it, and it has taken a positive step towards producing functional products and promoting consumer health.

The synthesis of zinc oxide nanoparticles is valuable due to its applications in the packaging and food industries as permitted additives to increase the shelf life.

 In this research, the synthesis of green nanoparticles of zinc oxide were performed by zinc acetate dihydrate. Calendula officinalis extract was used as reducing and stabilizing agent. The prepared ZnO NPs were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Energy dispersive X- ray (EDX) and X-ray diffraction (XRD) analysis.

The size of nanoparticles prepared by Calendula officinalis extract was obtained at 8 to 22nm In addition, the antioxidant properties of prepared nanoparticles were analyzed in the terms of total phenolic and flavonoid content. The antioxidant activity of zinc oxide nanoparticles was evaluated using 2,2- diphenyl picryl hydrazyl (DPPH) method. Gallic acid was used as standard to draw the calibration curve. The amount of total phenolic compounds in aqueous extract of the plant was 303 mg of gallic acid per gram.

Calendula officinalis extract showed high antioxidant activity and great potential for green synthesis of nanoparticles. The average diameter of nanoparticles synthesized without   plant extract as a stabilizer, was larger than the green synthesized one (more than 18 nm). There was also less agglomeration in nanoparticles synthesized by Calendula officinalis extract.

It is possible to increase the shelf life and maintain the quality of wheat germ during storage by using suitable packaging. One of the new technologies considered by researchers is the use of packaging based on nanoparticles. In this study, wheat germs were packaged in polyethylene packages containing silver nanoparticles, and the effect of the packaging on the quality characteristics and shelf life of wheat germ were determined. In this research work, at determining the most optimal conditions for the packaging of wheat germ, the effects of weight percent (wt%) of nanosilver (0, 3, and 5%), time of storage (0, 5, and 10 days), and three different temperatures (2, 4, and 6 0C) on the shelf life of wheat germ have been studied. The results showed that temperature, storage time, and concentration of nanosilver in polyethylene packaging had significant effects on moisture, pH, and enzyme activity of wheat germ. Experimental data indicated that the storage time of wheat germ increased by increasing the concentration of nanosilver from 3% to 5% and by decreasing temperature from 6 ° C to 2 ° C for ten days. Nanoparticle packages were significantly (P <0.05) able to reduce mold growth in wheat germ. Based on the results, it might be concluded that the application of films based on silver nanoparticles increases the shelf life of wheat germ. Wheat germ had the highest shelf life in packaging with 5% silver nanoparticles at 2 ° C and was selected as the selected sample.