نشریه نوآوری در علوم و فناوری غذایی
پیاپی 48 (تابستان 1400)

Encapsulation of probiotics in food samples has been proven as a novel technique for enhancing the viability and stability of encapsulated probiotics in unfavorable environmental conditions. However, investigations on the optimized compositions of encapsulation to enhance the viability of the probiotic bacteria in food and simulated gastrointestinal environment are intending to increase. The aim of this study was to investigate the impact of alginate-chitosan encapsulation with herbal extracts including eucalyptus, ziziphora and thymus vulgaris l. on viability of probiotic bacteria suspended in fruit juices (orange, pomegranate, apple and raisin juices) during storage at 4°C.The strains of probiotics used in this work were Lactobacillus casei (PTCC 1608), Lactobacillus acidophilus (PTCC 1643) andBifidobacterium bifidum (PTCC 1644).Theresultsdisplayedthatthesurvivingpopulationof L. caseicellsentrapped with 0.05%(w/v) thymus extract were significantly higher than those encapsulated with eucalyptus and ziziphora extracts,after storage for 30 days.Accordingly,thislevelofthymus extract was selected to immobilize the cultures before inoculationin to fruit juices, in order to comparison with green tea extract. Upon storage, thymus and green tea extracts noticeably improved the stability of probiotic beads in all the products, as compared to the controls. Encapsulated L. casei and L. acidophilusshowed better survival than encapsulated B. bifidum.

The aim of this study was to evaluate and compare the different processing methods on the amount of nitrate and nitrite in potato. For this purpose, a variety of processing methods including blanching, boiling, steaming, boiling incorporated with ultrasound, microwave and frying were performed on potatoes, and the nitrate and nitrite levels was measured. The results showed that nitrate and nitrate levels were significantly reduced in all processing methods compared to the control sample (raw sample) (P<0.05). The highest nitrite and nitrate levels were observed in the control sample. Blanched, microwaved, steamed, boiled, ultrasonically boiled samples had the lowest nitrite and nitrate levels, respectively, since reducing 85% nitrite by frying and 57% nitrate by boiling plus ultrasound was obtained. Also, the differences observed in the method of boiling and its combination with ultrasound was not significant on nitrite and nitrate contents (P>0.05). Overall according to the results, it seems that the boiling method without any combined or alternative process is an effective way to reduce considerably the amount of these harmful substances in vegetables such as potatoes.

In recent years, researches have proven to be promising for specifying and confirming the potential benefits of using probiotic and prebiotics in dairy products and beverages. The combination of probiotics and prebiotics which have synergistic effect is called ymbiotic. The aim of this study was to produce ymbiotic carrot juice. To achieve this goal, carrot juice samples containing 2% inulin as a prebiotic substance was pasteurized at 90 °C for 4 minutes and fermented at 30 °C by adding two probiotic bacteria Lactobacillus casei and Lactobacillus plantarum, both individually and in combination. Probiotic bacterial count, pH, acidity, brix, viscosity tests during 45 days of storage and sensory evaluation on the seventh day were performed. The results showed the significant effect of bacterial type and time on the viability of probiotic bacteria, pH, acidity and brix of the samples (P <0.05). The samples containing the combination of two probiotic bacteria had a higher number of bacteria (14.49 ± 0.38 log cfu/ml) and the number of probiotic bacteria decreased over time. With increasing time, the pH of all samples decreased, which was more evident in Lactobacillus casei, but the acidity of them increased (P <0.05). The brix of combined bacteria samples was lower than others while the effect of the bacterial species on the viscosity of samples was not significant (P>0.05). Over time, brix and viscosity showed a decreasing trend. The effect of bacterial type and their application on sensory properties was not significant (P> 0.05). In general, ymbiotic carrot juice containing the combination of two mentioned probiotic bacteria with maximum survival of probiotic bacteria (≥107 ) and maintaining other chemical, physical and sensory properties was proposed as a functional product for use in consumer diets.

Gamma-amino butyric acid (GABA) as a non-protein amino acid has a widespread application in the body's various organs and inhibition of many physiologic diseases. Lactic acid bacteria are able to GABA synthesis in many foods. The purpose of this study was to ferment the soymilk by a new lactic acid bacterium called Lactobacillus sp. Makhdzir Naser-1 (GQ451633). At first, optimum conditions for maximum GABA production were obtained with regard to effective factors such as inoculation time, pH, soy milk concentration and ambient temperature. The optimum conditions are: fermentation time 48 hours, pH 5.3, 12% soy milk and warming temperature 37 ° C. At optimum point, with three repeats of treatment, the produced GABA was 4.17, which has not very significant difference with the predicted value (4.188). Therefore, the accuracy of the proposed equation for predicting GABA value was confirmed.

It appears necessary to produce drinks which are full of phenolic compounds and antioxidant,according tothe style of modern life and importance of confront with oxidative stress and changing the people's taste in using ready-made and carbonated drinks. The aim of this study was to investigate the effect of storage conditions on physicochemical, sensory and shelf-life characteristics of three samples of pomegranate juice, barberry and their mixture of in order to improve quality.In this study, indicators of antioxidant properties, color, vitamin C and sensory evaluation of three drinks, pomegranate, barberry and their mixture (50:50 v/v) in one month period in differenttemprature conditions (4, 17 and 30°C) and light was kept and measured for each indicator.Results indicate that treatment type, keeping time and mutual effects of these two factors have meaningfull effect on these three drinks (P≤0.05). This study showed that decreasing rate of antioxidant property in one month in carbonated and gas free type does not have a meaningful different and in some case carbonated type showed more capability in keeping its properties.Considering the public tendency for using carbonate drinks this is important.With regard to the obtained results and for keeping valuable trophic properties of drinks, they should be kept in low temperature after producing and consumed in a short period after producing.

Probiotics are normal flora of the mouth and digestive tract and have beneficial effects on the health of the consumer by regulating the microflora of the intestine, lowering blood cholesterol, stimulating immune system, improving lactose metabolism and the anti-cancer activities. They are also found in meat, vegetables, and dairy products. Most of probiotic bacteria belong to the Lactic acid bacteria group. Probiotics such as lactobacilli prevent the development of a wide range of human and animal's pathogens through producing antimicrobial compounds.In present study, 83 bacterial strains were isolated from 20 yoghurt samples which were collected from rural area of Kermanshah province, West of Iran. Samples were cultured on MRS agar and incubated at 30oC, in CO2 atmosphere. Gram-positive and catalase negative strains were considered as LAB. The antibacterial activities of these isolates were evaluated against Bacillus subtilis, Bacillus cereus and Escherichia coli, as food-born bacterial models using agar diffusion assay. To reduce antibacterial activity of produced lactic acid by the isolates, the supernatants of their fermentation broth were adjusted at pH 6.The results showed that maximum inhibition activity was belonged to strain 44, 61 and 72. These strains have antimicrobial activity against all tested g+ and g- bacteria. These investigated isolates showed no antibacterial activity on tested starter, including Lactobacillus casei and Lactococcuslactis. 16S rRNA gene analysis of strains 44, 61 and 72 revealed that all three potent LAB are belonged to Enterococcus genus. The results of current study showed that isolated LAB from traditional Kurdish cheeses are able to inhibit the growth of food-born spoilage and pathogenic bacteria. Metabolites of native can be considered as suitable alternatives chemicals with side-effects.

The button mushroom (Agaricus bisporus) is widely consumed with respect to good taste and high nutritional value. The nanocellulose composite packs were prepared by various percent of nanocellulose (zero percent as control sample, 1, 2, and 5 nanocellulose and CO2-emitter) in this study. The samples of button Mushroom were stored after packing in refrigerator at 3°C and all tests were conducted in three repeated treatments during storage periods (2, 6, 8, 10 and 12 days). ANOVA tables were utilized to compare data using SPSS software and the related diagrams and tables were drawn by Excel software at significance level (95%). The results showed that different percents of nanocellulose at 5% level and storage time and the interaction of different nanocellulose percents and storage time on the pH of the composite packs of the fungus nanocellulose had a significant effect on the level of 1% (p <0.01). Different percents of nanocellulose and storage time had a significant effect on 1% moisture content, electrical resistance, oxygen, carbon dioxide, ocular evaluation of decay mushroom (p<0.01). The treatment with 2% of nanocellulose content was introduced as the preferred treatment including the least rise of humidity, the smallest weight loss and carbon dioxide and maximum score in terms of cap color, stipe and inside cap by the 10th day of storage. Therefore, period of storage of button Mushrooms can be extended to 10 days by nanocellulose composite packing (2%).

Milk is the only known substance in nature that can provide the body with complete and balanced nutrition. Recombined milk is a milk replacement product. Recombined milk components are more easily adjustable than milk components. Using electrical conductivity, valuable information is available about the quality of different materials, including food. In addition, by this method, as a simple and practical tool, the quality of many foods can be controlled. In this study, Response Surface Methodology (RSM) was used for modeling and optimization of the electrical conductivity of recombined milk. The effects of protein (1, 2, 3, 4 and 5%), Lactose (4, 6, 8, 10 and 12%), fat (3 and 6%) and temperature (50, 55, 60, 65 and 70ºC) independent variables on electrical conductivity of recombined milk as dependent variables (response) were evaluated. Process variables were statistically significant (p<0.01) as quadratic regression model for this response. The R2 factor for the modeling of the electrical conductivity of Recombined milk was 0.92 by the response surface method. Optimum conditions for the electrical conductivity of the Recombined milk in the usual range (4 to 5.5 mS/cm) contained protein 3.4%, lactose 7.7%, fat 3% and temperature of 63.9 °C.

Food gums are a class of food additives playing various roles, such as thickening, gelling and stabilizing of the food aqueous solutions. The aim of this study was to investigation rheological properties of protein-free Balangu seed gum. For this purpose, balangu seed gum was prepared and after its enzymatic hydrolysis, protein-free Balangu was prepared and the rheological properties of balangu seed gum and protein-free balangu seed gum were evaluated in terms of different parameters such as intrinsic viscosity, steady shear flow properties (shear dependence and time dependence tests) and dynamic rehology properties (stress sweep and frequency sweep tests). The results showed that balangu and protein-free balangu seed gums at 1% w/w had shear-thinning and weak gel-like behavior, and indicated the random coil conformation in dilute region. Considering correlation coefficient (0.998), the Herschel–Bulkley model was selected to describe the rheological behavior of Balangu and protein-free balangu seed gum solutions. In the time-dependent test, the balangu and protein-free balangu seed gums showed same ability to create the structure and the amount of thixotropy. The results of dynamic rheological test showed the storage modulus curve was located higher than the loss modulus in the linear region, indicating semi-gel or semi-solid behavior in Balangu and protein-free balangu seed gum. Hydrolysis and decreasing protein content did not significantly affect viscoelastic behavior of balangu seed gum

Celiac disease is the most common disease that occurs because of consuming Gluten. The only method to treat this disease is to use gluten-free foodstuffs. The purpose of this research was to optimize the production of Gluten-free Brotchen bread based on corn that contains lentils flour and Mucilage to the seeds. For this reason, the lentils flour was added to the formulation in three levels of (25, 50, and 75 percent) as the replacement of wheat flour and mucilage to the quince seeds in three levels of (1, 2, and 3 percent), and finally the resulted and obtained optimized sample was compared to the sample that was without lentils flour and mucilage to the quince seeds. The statistical analysis and optimization of this process was performed in response surface method. The obtained results indicated that with adding lentils flour and mucilage to the seeds, the amount of viscosity, density and moisture of seeds were increased and the lightness and stiffness level of the sample tissues were decreased. The samples particular volume was decreased very slightly with adding lentils flour but it was decrease at first and then increased with more trend through adding the mucilage amount to the seeds. Also, the general reception of samples indicated that with increase in the amount of lentils flour the amount of general reception, from the viewpoint of evaluators, was decreased at first and increased then, while with increase in the amount of mucilage to quince seeds the amount of general reception was increased at first and decreased then. The results of formulation optimization indicated that to reach the above mentioned purposes it is necessary that density of lentils flour will be 25% and density of mucilage to quince seeds will be 3%. On the one side, the results of comparison between the control and optimized sample indicated that the optimised sample had more viscosity, moisture and general reception than control sample. According to the obtained results it can be said that mucilage to quince seeds can be used to simulate and imitate the properties of gluten and also the lentils flour can be used in producing the gluten-free bread.

Biochemical nano composites have attracted the attention of researchers in recent decades, because they are biocompatible, biodegradable and renewable, and they do not pose a risk to the health of humans and animals, while not contaminating the environment. The purpose of this study was to investigate the effect of using Nano-chitin on structural and anti-bacterial properties of zein film. In this study, zein Nano composite with Nano chitin was prepared in 0.2, 0.5 and 0.7% based on dry weight zein by solution casting method. Then the structural properties (image of electron microscope and infrared spectroscopy), films were investigated. The results showed that the addition of Nano chitin caused chitin adhesion to the polymeric substrate, increased roughness and uniform distribution of nanoparticles in the biopolymer matrix. Also, the results of antibacterial tests of Nano composite films by disc diffusion and non-zone growth with two bacteria of Escherichia coli and Staphylococcus aureus showed that the addition of Nano chitin to zein film increases the antibacterial properties of film compared to pure zein film.

The use of antioxidant properties and maintenance of plant and natural extracts in increasing the shelf life of meat products, especially fish products, are considered to be very important points and can be considered as a very good alternative to chemical preservatives. In this research, pomegranate extracts were extracted and purified in salmon fillet from 1.5 and 3% concentrations of pomegranate extract and control (without extract). After treatment and packing, the samples were kept at a refrigerated temperature (4 ° C) and at the intervals of zero phases, after 5, 10 and 15 days, qualitative evaluation (sensory and chemical tests was measuring . After collecting data and performing statistical analysis and using SPSS-17 software and comparing the means of the tests, the Tukey test and for sensory tests of the phase 0 to 15 days after the maintenance of Kruskal walis nonparametric statistical method It turned out. The final results showed that treatment with 3% of pomegranate extracts was considered as superior treatment and control treatments and 1.5% in the next priorities and its data was statistically significant with other treatments (P <0.05).

The amount of bread waste is mainly due to the non-principled and incorrect production. The researchers to improving the technological and sensory characteristics of bread types especially bulk and semi-bulk breads have proposed so different approaches. One of the most important way is application of sourdough in this strategic product. Therefore, the aim of this study was investigation of the possibility of using of wheat, rye and quinoa flour in sourdough preparing during different fermentation periods (4, 8 and 12h) and evaluation of sourdough addition on physicochemical, texture, visual and sensory properties of toast bread in the form of a completely randomized design with factorial arrangement (P≤0.05). Results showed that the lowest pHand the highest amount of moisture, acidity, organic acids (acetic acid and lactic acid), specific volume, porosity and softness of the texture was observed in the toast bread containing sourdough prepared by fermented rye flour for 12 hours. By evaluation of crumb color values the highest L* and a* values in samples containing wheat and quinoa flour, respectively were observed. While, by increasing the fermentation time the L* and a* values increased and decreased respectively. Finally, by evaluation of sensory characteristics, two samples prepared by wheat and rye flour that fermented for 12h had the most acceptability. Therefore, it can be said that in order to producing bulk and semi-bulk breads rye flour can be used while improving nutritional value, it also improves the physicochemical, texture and sensory properties of the final product.