Food Biotechnology
Elham Rouhi; Alireza Sadeghi; Seyed Mahdi Jafari; Mohammad Abdolhoseini; Elham Assadpour
Abstract
< p >Introduction: Evaluation of probiotic and antifungal properties of lactic acid bacteria (LAB) isolated from fermented substrates has great importance in order to provide microbial cultures for fermentation industries. Among the fermented foods, dairy products play the main role as carriers ...
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< p >Introduction: Evaluation of probiotic and antifungal properties of lactic acid bacteria (LAB) isolated from fermented substrates has great importance in order to provide microbial cultures for fermentation industries. Among the fermented foods, dairy products play the main role as carriers of probiotics. Meanwhile, non-dairy fermented foods have been rarely studied in order to isolation and characterization of their probiotic microorganisms. Sourdough as a mixture of flour and water is a proper fermented ecosystem to isolate probiotic and antifungal LAB. Besides their desired health, probiotics must become active in the consumer''s gastrointestinal tract without any adverse effect. These bacteria can be used as starter, adjunct or preservative cultures to produce different fermented foods. Furthermore, antimicrobial metabolites of the LAB have also numerous potential applications as bio-preservatives in food and/or medical technologies. < p > < p >Materials and methods: In the present study, after continuous back-slopping process, predominant LAB was isolated from fermented quinoa. Then the LAB isolate was identified using PCR amplification of its partial 16S rDNA gene. Subsequently, probiotic properties of the LAB including its resistance to low pH and bile salt, antibacterial effects, aggregation potentials, antibiotic susceptibility and haemolytic activity were investigated. Antifungal effect of the LAB on Aspergillus niger was also determined using overlay bioassay. Finally, the one way analysis of variance (ANOVA) with the least significant difference (LSD) post hock (at p < /em> < p >Results and discussion: Sequencing results of the PCR products led to the identification of Enterococcus hirae as predominant LAB isolated from quinoa sourdough. Sourdough fermentation depends on the several technological and environmental factors and therefore, different types of these complex stressful ecosystems have their specific microflora with unique properties. The LAB isolate had proper survival after continuous pH and bile treatments. Resistance to low pH and bile salt is not sufficient to predict the survival of the probiotics in the actual conditions of the gastrointestinal tract. However, these properties are necessary for assessment of viability and activity in this situation. Furthermore, the highest antibacterial activity of the LAB was observed against Bacillus cereus among the studied food borne indicator bacteria. The effect of crude cell free supernatant (CFS) obtained from LAB isolate on indicator bacteria was significantly (p < /em>
Sanaz Ghassemi; Seyed Mahdi Jafari; Morteza Khomeiri; Elham Assadpour
Abstract
Orange peel oil,a widely used industrial flavoring, is volatile and chemically unstable in the presence of air, light, moisture and high temperatures. Biopolymer Nano complexes, a bunch of Nano carriers, are produced between groups of charged polysaccharides and proteins with the use of electrostatic ...
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Orange peel oil,a widely used industrial flavoring, is volatile and chemically unstable in the presence of air, light, moisture and high temperatures. Biopolymer Nano complexes, a bunch of Nano carriers, are produced between groups of charged polysaccharides and proteins with the use of electrostatic interactions. The nanoparticles are able to carry, protect, and increase their bioavailability of food-drug materials. Hence, in this study, the Nano complexes of pectin- whey protein concentrate, as a carrier of orange peel oil, were produced and the features of prepared Nano complex solution with various concentrations of whey protein (4, 6 and 8%), pectin (0.5, 0.75 and 1%) and different values of pH (3, 6 and 9) were studied. The Viscosity, stability and color (index L *) of the treated designs, done in a response surface methodology, were examined. The results showed that whey protein 4% and pectin 1%( with a pH of 3 and 9) had the lowest and highest stability respectively. Also this treatment with a pH of 3 showed the highest viscosity as well as the highest L *. The lowest viscosity was achieved by whey protein 6% and pectin 0.75% with a pH of 3, and because of the unbalanced compound, the complex did not form and a phase separation occurred. The lowest L * was obtained by whey protein 4% and pectin 0.5% with a PH of 9. Ultimately, whey protein 4% and pectin 1% with a PH of 3 were selected as the optimum sample because of formation the strong and suitable complex. Particle size and zeta potential measurement of optimum sample, were 160 nm and -0.53 mV respectively.
Afshin Faridi Esfanjani; Seyed Mahdi Jafari; Elham Assadpour; Habibollah Mirzaee
Abstract
Introduction: Controlling and targeting release of bioactive compounds have a key role in improving their functional properties such as antioxidant and anti-disease activities. Encapsulation is one of the best methods for protection and controlling release of bioactive ingredients. Indeed, in this process, ...
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Introduction: Controlling and targeting release of bioactive compounds have a key role in improving their functional properties such as antioxidant and anti-disease activities. Encapsulation is one of the best methods for protection and controlling release of bioactive ingredients. Indeed, in this process, protection and controlling release of ingredients as core materials are performed by surrounding of them via variety of wall materials. Emulsions are most popular encapsulation systems that are classified in variety types such as single layer emulsion, multi-layer emulsion, doubleemulsion, and etc. Hydrophilic bioactive compounds can be loaded in inner aqueous phase of water in oil in water (W/O/W) double-emulsions. The stability of doubleemulsions is low due to presence of two interfaces in them.Applying a thermodynamically stable W/O emulsion (e.g., micro-emulsion) as a primary emulsion and using of complex biopolymers as emulsifier and stabilizer in outer phase of doubleemulsions can improve their stability (Dickinson, 2011; Boyer et al, 2012).Saffron bioactive compounds include crocin, picrocrocin, and saffranal are widely used for a variety of functional and healthy goals in food and pharmaceutical industries. These compounds have many different functions, including anti-carcinogenic, anti-oxidant, anti-depressant, anti-apoptotic, anti-tussive, anti-nociceptive, anti-inflammatory and anti-thrombotic properties (Moraga et al, 2004).In the present study, our main goal was kinetically evaluated release of crocin, picrocrocin and saffranal from inner phase to outer phase of doubleemulsion during 22 days storage by Zero order, Fist order, Higuchi, and Hixson-Crowell.Materials and method: Saffron was provided from Torbatheydariyeh farms, Khorasan-e-razavi, Iran. Sunflower oil and sodium azide were purchased from FRICO (Sirjan, Iran) and Sigma-Aldrich (St. Louis, USA), respectively. Whey protein concentrate (80% protein) and sorbitanmonooleate (span 80) were obtained from Sapoto cheese (USA) and Merck (Germany), respectively. Maltodextrin was obtained from Qinhuangdao starch Co. (DE 16-20, China) and citrus pectin with a degree of methyl esterification of 71.1% and galacturonic acid >65% was purchased from MP biomedical (Netherland). All other chemicals used in this study were of analytical grade.For extraction of crocin, picrocrocin and saffranal, a total of 10 grams of saffron sample was macerated in 150 mL of water in a glass bottle, covered with aluminum foil (to prevent direct exposure to light), and was placed in an incubator shaker (Kavooshmega, Iran) for 24 hours at 30oC. Then, this solution was homogenized (10000 rpm for 10 minutes, HeidolphSilentcrusher, Germany) for maximum extraction of saffron compounds. Finally, the extract was filtered under vacuum by using a Whatman No. 1 (11 mm) filter paper, and kept in the freezer at -18oC prior to any examination. ISO/TS 3632 procedure (2003) was used for the measurement of saffron compounds. The doubleemulsions were prepared in two-step:(a) Frist, primary W/O micro-emulsions were produced by two formulations: 60:30:10% and 62:33:5% of sunflower oil, span 80, and saffron extract, respectively. (b) Then, the W/O micro-emulsions was gradually added into the outer aqueous phase contains why protein concentrate (WPC)/maltodextrin or WPC/pectin/maltodextrin while blending by a homogenizer (12000 rpm for 5 minutes at 10oC, HeidolphSilentcrusher, Germany) and then these coarse emulsions were further emulsified using mentioned homogenizer (15000 rpm for 8 minutes at 10oC). All doubleemulsions were composed of 25% primary emulsion and 75% outer aqueous phaseDroplet size of doubleemulsions after one day and 22 days storage weremeasured using Zetasizer (Malvern Instruments, Worcestershire, UK).The released components in the outer aqueous phase were measured by evaluation of encapsulation efficiencyof the ratio of crocin, picrocrocin, and saffranalat a specific time:E (%) = 100- (C2×100/C1) (1)Where C2 is the percentage of crocin, picrocrocin and saffranal in outer aqueous phase and C1 equals to the percentage of compounds in inner aqueous phase.C2 is a released into outer aqueous phase relative to the total amount present in the outer aqueous phase if all compounds were released (M ∞).The viscosity of emulsions was measured using a programmable viscometer (model LVDV -II + Pro, Brookfield Engineering Laboratories, USA) and by a ULA spindle.The released are kinetly evaluated by Zero order, Fist order, Higuchi, and Hixson-Crowell.The experiments were all carried out in triplicate. The collected data were analyzed by one-way ANOVA; the means were compared by the Duncan's multiple range tests at the 5% level through SPSS version 21 (IBM, USA).Results and Discussion: As shown in fig. 1, the droplet size of produced W/O micro-emulsions were lower than 200 nm. In fact, these droplets are water droplets containing bioactive compounds of saffron dispersed within oil phase that surrounded with Span 80 (Fig. 2).Also, it was found that by increase of saffron extract (from 5% to 10%) as dispersed phase in W/O micro-emulsions, droplet size and poly-dispersityindex (PDI) weresignificantly (P< 0.05) affected (Table. 3).As shown in table. 4, crocin, picrocrocin, and saffranal had a same release trend, but the release rate of crocin was lower than saffranal and picrocrocin. As regard to R2, SSE, and RMSE from kinetic modeling in table. 5, the firstorder was a best model for release of crocin, and zero order was a best model for release of picrocrocin and saffranal. Also, kinetic date of release showed that the high release of crocin, saffranal, and picrocrocin was observed by increasing the dispersed phase content of primary W/O micro-emulsion and also it was found that WPC/pectindelayed the release of encapsulated ingredients more than single WPC (Table. 5). Indeed, the using of complex biopolymers as the external binary film of doubleemulsions causes a resistance to release for inner compounds (Dickinson, 2011).As shown in fig. 3, the viscosity of doubleemulsions stability with WPC/pectin complex was higher than doubleemulsions stabilized by only WPC. This can confirm the higher stability of stabilized doubleemulsions with complex biopolymers (Olivieri et al, 2003).
Elham Assadpour; Seyed Mahdi Jafari; Alireza Sadeghi Mahoonak; Mohammad Ghorbani
Abstract
In this study, functional properties of red bean, chickpea, lentil and canellini bean were evaluated. Our results revealed that beans had the highest emulsifying capacity. This property was minimum at the isoelectric point (about 4) among all samples which is in concistent with their solubility curves. ...
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In this study, functional properties of red bean, chickpea, lentil and canellini bean were evaluated. Our results revealed that beans had the highest emulsifying capacity. This property was minimum at the isoelectric point (about 4) among all samples which is in concistent with their solubility curves. Salt concentration of 0.5 M did not have a significant influence on emulsifying capacity but higher concentration (1.0 M) reduced this capacity significantly (P
Elham Assadpour; Seyed Mahdi Jafari; Alireza Sadeghi Mahoonak; Mohammad Ghorbani
Abstract
In this study, chemical composition and functional properties of red bean, chickpea, lentil and canellini bean were evaluated. Our results revealed that chickpea had the highest protein (43.4%) and fat (5.17%) content and lentil, red bean and canellini bean were the following ones. The isoelectric point ...
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In this study, chemical composition and functional properties of red bean, chickpea, lentil and canellini bean were evaluated. Our results revealed that chickpea had the highest protein (43.4%) and fat (5.17%) content and lentil, red bean and canellini bean were the following ones. The isoelectric point of all the samples were determined as about pH=4 but other than lentil, the remaining samples had a second isoelectric point. Red bean flour had the maximum water holding capacity (146.15%) and the influence of pH and ionic strength on the samples were similat in terms of water holding capacity. An increase in salt concentration led to a decrease in water holding capacity. Regarding oil absorption capacity, red bean flour had the highest capacity (92.1%) and lentil flour had the lowest one (80.45%).
Keywords: Legumes, Functional properties, Protein solubility, Chemical composition
