مجله علوم و صنایع غذایی ایران
سال هفدهم شماره 4 (پیاپی 101، تیر 1399)

This study was aimed to fabricate a novel active edible coating with remarkable antioxidant and antimicrobial activity to ameliorate the beef shelf-life. For this purpose, the essential oil of Thymus vulgaris was firstly extracted by hydrodistillation method and its in-vitro antioxidant and antibacterial properties were then evaluated. The essential oil had a potentially high antioxidant activity and it was able to reduce the growth of bacteria Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, and Pseudomonas aeruginosa. The essential oil was then mixed with Plantago lanceolata seed mucilage to fabricate an active edible coating. The edible coating was used to coat beef and increase its shelf-life. The use of edible coating containing different concentration of essential oil significantly (p<0.05) inhibit the fat oxidation extent (primary and secondary products) and increase in total viable count, psychrotrophic bacteria, and coliforms in beef samples, and improved its shelf-life up to 6-day storage at refrigeration condition. In general, the T. vulgaris essential oil-loaded P. lanceolate seed mucilage-based edible coating could be used to control the lipid oxidation and microbial growth, as well as, to improve the shelf-life of meat products or other food products.

The use of milk fat substitutes in the manufacturing of dairy products is highly considerable in order to decrease in suffering chronic diseases and amount of calorie intake. However, semi-fat or non-fat dairy products have defects in their texture and sensory properties. The aim of this study was to investigate the effect of using whey protein isolate and locust bean gum as fat replacers on quality properties of non-fat yogurt. For this purpose, set-yogurt samples were manufactured using non-fat milk (lees than0/1%) and different concentrations of  locust bean gum and whey protein isolate. Control samples were also manufactured using whole milk (3% fat) and non-fat milk (less than 0/1%) without locust bean gum or whey protein isolate. The manufactured samples were stored in (4±1°C) for 15 days and their physicochemical, texture and sensory properties  were analyzed during storage. The results showed that the use of different concentrations of locust bean gum and whey protein isolate significantly influenced the  pH, acidity, water holding capacity, synersis, viscosity, hardness, springiness, cohesiveness, adhesiveness, appearance and color, ,texture and consistency , odor and flavor  and total sensory scores (p<0.05). While water holding capacity, acidity, hardness and viscosity were increased significantly during storage in all samples, synersis, pH and odor and flavor decreased significantly (p<0.05). In conclusion, the results of different analysis showed that use of the 10gr.L-1whey protein isolate, 5gr.L-1 whey protein isolate and 0.25gr.L-1 locust bean gum + 10gr.L-1 whey protein isolate instead of milk fat in formulation of non-fat set type yogurt led to manufacturing of final product with the most acceptable physicochemical, texture and sensory properties.

Nut's seeds can be a source of contamination with various types of microorganisms and so some of them are important for public health.  Therefore, with regard to household consumption of those type of seeds and their application in food industries, and also due to the fact that some of them are imported from other countries so they may have the possibility of microbial contamination from the source, therefore the purpose of this study was to evaluate the efficacy of UV irradiation in reducing the microbial load of some consumed seed nuts. Six types of beans including sunflower seeds, watermelon, pumpkin, walnut, pistachio, and hazelnut were randomly sampled in bulk from Tehran retail market. Testimonials were tested by methods in the Iranian national standard and food and drug organization standards. Subsequently, infected seeds were irradiated in 1, 2 and 3 layers of thickness and time at 5, 10 and 15 minutes in a UV cabinet with a wavelength of 254 nm and subjected to appropriate microbial tests. According to the results, the irradiation time and thickness were significantly affected by the total microbial count of pistachio, walnut and hazelnut (p<0.01). Also,  it has a significant effect on the coliform count  of pistachio, walnut, hazelnut seeds, pumpkin seeds, sunflower and watermelon, and the mould count of pistachio, walnuts and hazelnuts, sunflower seeds and a watermelon (p<0.01). It had less significant effect on the number of molds in pumpkin seeds (0.01<p).

Rice and corn flours are appropriate alternatives for developing gluten free products and modification of some of their properties such as water absorption index of flour due to extrusion process could be effective for improvement of gluten-free products quality. In this research, addition effect of extruded flour in 110 °C with 18% feed moisture, in four levels ( 0, 10, 20 and 30%) and hydrocolloids of xanthan and hydroxypropylmethylcellulose in two levels ( 0.5 and 1%) of each were studied in gluten-free bread formulation. The results were proved significant effect of extruded flour and hydrocolloids addition on evaluated characteristics so that specific volume and porosity were promoted with increasing level of extruded flour till 10%, but higher levels were caused reduction of these properties. Also, increasing of extruded flour  level was decreased crust L* and hydroxypropylmethylcellulose had more effect on crumb hardness reduction of gluten free bread in compared to xanthan. Finally with regard to features such as specific volume, porosity, softness, color and scores of sensorial test, gluten free bread formulation including 10% extruded flour and 1% HPMC was determined as appropriate formulation which had specific volume of 3.01 cm3/g, porosity of 65% and overall acceptance score of 4.1 in sensorial test.

The beneficial impact of coupling sonication with 400 W and 24 kHz (4, and 8 min) with LDPE antimicrobial nanocomposite packaging containing nano-ZnO (3:100 w/w)  (Pure packaging + US 4, Pure packaging + US 12, Nano packaging + US 4, Nano Packaging + US 12, and Pure packaging (Control)) on inactivation of inoculated saccharomyces cerevisiae (spoilage index) and E.coli (pathogen index) in strawberry juices during  4, 8, 12, 16., and 20 days (4 °C), was evaluated. Ultrasound technology (both 4 and 12 min) significantly (p < 0.05) reduced the population of saccharomyces cerevisiae and E.coli. Also, the D-value of S. cerevisiae was higher than E. coli in strawberry juice indicating its higher resistance to sonication. Application of Nano Packaging + US 12 showed the highest-ranked antimicrobial activity to the other sample and control on the population of the both S. cerevisiae and E. coli inoculated in strawberry juice during 20 days of storage. These achievements paved the way for hurdle technology applications involving combination of antimicrobial packaging containing nano-ZnO with short time sonication in retarding of microbial growth in strawberry juice during cold storage (4 °C).

In this investigation, the Cordia myxa fruit mucilage (CMFM) was extracted by water to seed ratio 1:6, extraction temperature 58 ᵒC, and pH 4. After sterilization of extracted mucilage, its antibacterial activity was assessed on pathogenic bacteria including Salmonella typhi, Escherichia coli, Pseudomonas aeruginosa, Listeria innocua, Staphylococcus aureus, Bacillus cereus, Bacillus subtilis and Staphylococcus epidermidis under laboratory conditions. Antimicrobial potential of mucilage, at the different CMFM levels: 37.5, 75, 150 and 300 mg/ml was evaluated using disk diffusion agar and well diffusion agar methods. Furthermore, the interaction of CMFM with gentamicin and chloramphenicol antibiotics was assessed. Results shown that by increasing the CMFM concentrations, the inhibition zone diameter around the discs were noticeably increased. In the disk diffusion agar method, the highest inhibition zone diameter was observed at the concentration of 300 mg/ml CMFM for Staphylococcus epidermidis with 11.10 mm. The minimum inhibitory concentration (MIC) for Salmonella typhi, Escherichia coli, Pseudomonas aeruginosa, Listeria innocua, Staphylococcus aureus, Bacillus cereus, Bacillus subtilis and Staphylococcus epidermidis was 64, 64, 16, 32, 128, 64, 256 and 64 mg/ml, respectively. Results shown that the minimum bactericidal concentration (MBC) of CMFM for the all tested bacterial strains was greater than their MIC.

Due to the growing demand for biocompatible natural ingredients, the use of hydrocolloids in the food industry is on the rise. Restructured foods are one of the most important aspects of the food industry, involving a complex mix of ingredients, as well as texturing and structuring processes. Achieving an optimal formula for gel formation with appropriate elastic texture can allow for the industrial application in various stuffed products such as olives and related products. Therefore, in this study, gelatin as a gelling agent at 3, 4 and 5 wt% and guar gum as a thickening agent at 0.5 and 1.5 wt% in 1 wt% citric or lactic acid were selected as restructured Ricotta cheese formulation and evaluated of textural properties and shelf-life. Tests included textural characteristics, gel stability, and shelf-life of the restructured cheese. Therefore, the appropriate formula of restructured cheese with appropriate textural properties was selected and evaluated for microbial properties. Due to the importance of sensorial properties of this restructured product, its sensory characteristics were also investigated. Process conditions during storage of samples were also investigated in citric and lactic acid. Finally, the formula containing 4% gelatin and 0.5% guar gum in the solution containing 1% citric acid was selected as the desired sample.

In this study, stevia and guar were used as alternatives for sucrose and fat in frozen yogurt formulation, respectively. For this purpose, a completely randomized block design with 0-100% replacement levels for stevia and 0, 0.25 and 0.5 % for guar gum was used. To investigate the effect of applied treatments, the physicochemical properties of frozen yogurt including acidity, viscosity, overrun, firmness, first drop time of melting and amount of melting were measured. The results showed that the viscosity decreased by increasing the level of stevia as a replacement for sucrose, while, overrun increased with increasing levels of sucrose substitution with stevia. All levels of stevia and guar replacement resulted in a significant increase in firmness. Also, with increasing the concentration of stevia and guar gum, the first drop time and stability of the sample increased. The results showed that stevia and guar gum are good alternatives to sucrose and fat, respectively, and samples containing 75-100% stevia and 0.5% guar were identified as the optimal treatment.

Frying and roasting are two common heat processes to improve sensory properties of nuts and subsequently change other properties including physicochemical, nutritional and antioxidant. According to the nutritional value of nuts, it seems necessary to investigate these changes. In this study some physicochemical, nutritional and antioxidant properties of raw and roasted cashew kernels including moisture and volatiles, total ash, total fat, protein, crude fiber, carbohydrate, peroxide value, energy, fatty acid profile, measurement of total antioxidant power and some mineral elements such as potassium, sodium, iron and calcium were investigated. Obtained results based on dry matter shows that raw samples contain higher amount of fat (43.89±0.04 g/100g), moisture and volatiles (1.64±0.01 g/100g) and fiber (3.22±0.08 g/100g), while roasted samples had higher amount of total ash (mineral elements) (2.76±0.07g/100g), carbohydrate (31.44±0.01 g/100g), peroxide (0.912±0.07 mEq. O2/kg of oil) and energy (597.29±0.009 Kcal/g). Antioxidant activity was investigated with DPPH and FRAP tests, both tests confirm each other and showed higher antioxidant activity of the roasted samples (IC50= 3388.6 mg L-1 and CFe2+= 0.15 mM). Based on the obtained results it can be said that, roasted cashew can be recommended as a snack with high nutritional value and low fat.

Maple syrup is a natural sweetener that it can replace sucrose. This compound contains polyphenols, antioxidants, repair compounds of nerve cell, calcium, iron and other compounds that it can promote nutritional health and the Possibility to produce low calorie products. The main role of sugars in enhancing the product's desirability is related to their sweetening role, improving the creamy properties and helping to highlight the fruity aroma. With all the benefits that sucrose has as a natural sweetener, it's high consumption is not recommended because of its undesirable side effects. The purpose of this study has been to investigate the possibility of sugar substitution with maple syrup and its effect on physicochemical, rheological, microbial and sensory characteristics of ice cream. In this study maple syrup was used and reviewed at 0, 25, 50 and 75% levels as sugar substitute for ice cream production. Then physicochemical, rheological, microbial and sensory tests were performed. The results of the tests were analyzed on the basis of completely randomized design at 5% probability level. With increasing replacement percentage, the viscosity and hardness of treatments increased significantly (p <0.05). The amount of dry matter, volume increase, specific gravity, melting speed were reduced significantly. The results of sensory tests showed that replacement at 50% and 75% had a significant effect on overall acceptance compared to control, and replacement at 50% was selected as the most appropriate replacement level. According to there is in the country, possibility to operation from maple tree, therefore, from maple syrup alone or in combination with other sweeteners can be used in various food products and dairy desserts to sweeten, increase flavor, production of low-calorie and dietary products suitable for all ages.

The objective of this study was to measure the amount of heavy metals cadmium, lead and arsenic between the amounts of metals and the risk assessment in wheat, extracted flax from imported wheat and indigenous cultivars. Considering the wheat cultivar and the number of flour mill factories in Golestan and Mazandaran provinces. Wheat samples were harvested. Samples after flint transfer to flour mills and process of flour process for evaluation and determination of heavy metals in laboratory. Research Institute of Science and Technology Research Institute. The results of this study showed that the highest concentration of cadmium in wheat flour samples in 2017 and 2018 was related to the R sample. The highest concentration of lead in wheat flour samples is related to the R sample. The highest concentration of arsenic in wheat flour samples is related to the N sample. According to the results obtained in wheat samples, the mean values ​​of cadmium in B sample were the highest. The mean of lead values ​​in the W sample was the highest. The concentration of arsenic in A sample is also the highest. The results showed that S, M, N, K, R, D, and E samples were unsafe for adult samples in flour samples. Also, R sample flour for adults was unsafe for cadmium. The F, H and M specimens were safe in adults in terms of heavy metals. In samples of wheat, S, N, and H samples were unsafe for adults in terms of lead levels.

Escherichia coli O157: H7 is one of the most important pathogens causing food poisoning in meat products. In this study, the antimicrobial effects of Lavandula angustifolia and NaCl on growth control of Escherichia coli O157: H7 inoculated into minced beef during storage were investigated. minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Lavender essential oil for Escherichia coli O157: H7 were determined 0.625% and 1.25% by micro broth dilution method, respectively. Lavender essential oil was added to the minced meat in three concentrations (0, 0.5 and 1%) and NaCl in three concentrations (0, 2 and 4%). Subsequently, Escherichia coli O157: H7 was inoculated into minced meat at 105 CFU/gr. Minced meat treatments with Escherichia coli O157: H7 were counted on days (0, 3, 6 and 9) kept at refrigerated temperature (4 °C). The results showed that growth control of Escherichia coli O157: H7 of all treatments was significant (P<0.05) and mean log CFU/gr of bacterial count in 9 days was lower in all groups than control. Comparatively, the effect of NaCl alone was greater than that of essential oil alone. The greatest inhibitory effect was related to the simultaneous use of essential oil and NaCl.

Essential oils (EOs) are highly aromatic and volatile compounds obtained from plant material, which are also known as secondary plant metabolites. The plant active ingredients are produced under the control of genetic processes; however, its production in the plant varies under the influence of some environmental factors. Therefore, in the present study, the chemical analysis and identifies dominant essential oils compositions from Sage) Salvia officinalis L.) are investigated in Ardabil province, Iran. Sage plant (Salvia officinalis L.) were collected and After drying at room temperature, samples extracted by method of water, essential oils yield 0.5% was obtained. Chemical analysis of the collected Salvia officinalis species was performed using a gas chromatograph (GC) coupled to a mass spectrometer (MS). Chemical analysis results showed that the plant contains 114 secondary chemical components, among which Camphor Bicyclo [2.2.1] heptan, compound was identified as the predominant essential oil (14.47%). Comparing the study results with other samples collected from different parts of Iran and world reveals some significant similarities and differences in chemical structure and dominant composition of the medicinal plant. In addition, the geographical features and environmental conditions influence the change of secondary metabolites in various plants, Therefore, the researchers need to pay attention to this issue while identifying the plant essential oils.

Lentil is one of the most important proteinous plant sources in the world. There is also some reports on the effect of germination on increasing of legume’s nutritional value. So the aim of this study is investigation on the effect of malting on γ- aminobutyric acid (GABA) content as a functional non proteinous  4 carbon amino acid with therapeutic properties and biological effects, the concentration of free and bound phenolic compounds, DPPH radical scavenging capacity and the Fe content in lentil. All of the measurments were performed on Kimia and Gachsaran Iranian lentil flour cultivars at ungerminated (control) and germinated (24 and 48 h) forms. According to the obtained results, generally malting caused significant (p<0.05) increase of GABA content at both cultivars, whereas decreased the Fe concentration. Measuring the free and bound phenolics content indicated the unsignificant effect of malting one free and bound phenolic compounds of Kimia cultivars (p≥0.05) while caused the significant decrease of these compounds in Gachsaran cultivar(p<0.05). Also in general, malting decreased DPPH radical scavenging capacity in both cultivars. Regarding to the  results, malting process can be introduced as a suitable and cost benefit approach for increasing of GABA concentration in lenil specially in kimia cultivar and using it on formulation of functional food products.

Drying due to the adverse physical and chemical changes is one of the most difficult processes in the food industry, especially to produce garlic powder. In this study, in order to avoid the Maillard reaction, garlics were pretreated by 0.5% sodium metabisulfite, 10% NaCl and citric acid (up to pH = 4) solutions. For this purpose, first, fresh garlic, after preparation according to the usual industrial method, was immersed in the pretreatment solution for 2 minutes at room temperature. The treated garlic was dried using cabinet method at 80 °C and 90 °C to achieve 5.2% water content, and then stored for 60 days at room temperature to evaluation of some quality characteristics including moisture content, vitamin C content, browning level, flavonoid content and pH. Based on the obtained results, moisture content did not change significantly in all treatments during storage. Control sample (without pretreatment) had had the highest off color and browning. Flavonoid and vitamin C contents were reduced in pretreated samples due to their solubility in water. Generally, based on the obtained results, garlic powder produced by pretreatments had lighter color than control sample which could increase their market acceptance and pretreatment with salt had highest effect in the production of garlic powder with a suitable color.