Food Biotechnology
Hadis Taghvatalab; Dornoush Jafarpour
Abstract
Introduction Scientific evidence is mounting that synthetic chemicals used as food additives may have harmful impacts on health and the biological system and cause many diseases and damages to the human body. Also, many consumers are concerned about the use of artificial ingredients to maintain ...
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Introduction Scientific evidence is mounting that synthetic chemicals used as food additives may have harmful impacts on health and the biological system and cause many diseases and damages to the human body. Also, many consumers are concerned about the use of artificial ingredients to maintain the quality and safety of foods. Therefore, the use of natural preservatives and food preservation methods based on natural compounds have attracted the attention of researchers. Edible films and coatings are useful materials, mainly produced from biodegradable polymers including polysaccharides (gums), proteins, and lipids, and are commonly used for the shelf life extension of foods. The primary edible films /coatings are promising alternative methods to preserve, and retard the adverse chemical reactions and microbial growth. They also can act as a carrier of antimicrobials, antioxidant substances, and other additives. Sage seed gum (SSG) is a water-soluble polysaccharide obtained from Sage (Salvia macrosiphon). It is an environmentally-friendly biodegradable material that can form high-viscosity aqueous solution and exhibit pseudoplastic behavior. Essential oils (EOs) are volatile and aromatic oily liquids extracted from various plants. Most of the EOs have antimicrobial and antioxidant activities due to their phenolic compounds, terpenes and terpenoids. A promising technique is incorporating EOs into coating solutions as active film/coating to extend the shelf life of food products. Bay leaf (Laurus nobilis) is an aromatic evergreen tree or large shrub with green, glabrous leaves. It is used as a flavoring agent and an essential ingredient in food preparation. Bay leaf has received much attention due to its antimicrobial, antioxidant, anti-inflammatory and immune system stimulating properties. Hence, the aim of the present study was to evaluate the antimicrobial and antioxidant properties of SSG coating incorporated with different concentrations of bay leaf EO (BLEO) and its nanoemulsion (BLNEO). Materials and Methods The active packaging was produced based on the gum of sage seed containing BLEO and BLNEO. After preparing the EO from bay leaves, their corresponding NEO was produced and the characterization of nanoparticles was evaluated in terms of droplet size, polydispersity index (PDI) and zeta potentials. Then, the antimicrobial and antioxidant properties of BLEO and BLNEO were compared. After that, SSG coatings were prepared with 1.5% and 3% BLEO and their corresponding NEO forms. Subsequently, the antioxidant (DPPH and ABTS) and antimicrobial (against Bacillus cereus, and Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli) properties of the produced films were investigated. Results and DiscussionGas chromatography-mass spectrometry (GC-MS) identified 1,8-Cineole and α- Terpinyl acetate as the major components of BLEO. The BLNEO exhibited a droplet size of approximately 92.4 nm and a zeta potential of -45.1 mV. In comparison to the control and SSG, it was found that the group comprising EO and NEO significantly (p<0.05) showed superior free radical scavenging capacity. SSG-3% BLNEO had the highest DPPH inhibition percentage (69.54%). According to the results, EO at the nanoscale can scavenge more free radicals than EO (p<0.05). Antimicrobial inhibition zone of different treatments against selected gram positive and gram negative bacteria showed that all bacteria were strongly inhibited after the addition of BLEO into the SSG. Moreover, data revealed that the growth of the studied pathogens was completely inhibited in a dose-dependent manner (p<0.05). SSG-BLNEO exhibited better antimicrobial activity than SSG-BLEO coating and its antimicrobial activity was significantly enhanced by increasing BLNEO concentration (p<0.05). This phenomenon is attributed to the protective role of encapsulation and the slow release of EO from the coating matrix, resulting in enhanced antimicrobial activity. Nanoemulsions, owing to their small droplet size and high surface area, offer superior efficacy compared to conventional emulsions. Consequently, the gradual release of essential oils from nanoemulsion-based edible coatings contributes to their enhanced antimicrobial performance. ConclusionThese findings suggest that the SSG-BLNEO edible active coating possesses promising applications as an antimicrobial and antioxidant agent for food packaging applications.
Food Biotechnology
Hossein Zanganeh; Fakhri Shahidi; Seyed Ali Mortazavi; Behrooz Alizadeh Behbahani
Abstract
IntroductionOxidation reactions and microorganisms’ activity are considered as the most important factors affecting the quality of food products. Recently, in the light of the inefficiency of some chemical preservatives against microorganisms and the presence of toxic residues in food products, ...
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IntroductionOxidation reactions and microorganisms’ activity are considered as the most important factors affecting the quality of food products. Recently, in the light of the inefficiency of some chemical preservatives against microorganisms and the presence of toxic residues in food products, the use of natural antimicrobials and antioxidants has been increased. Natural antimicrobial compounds have the potential to control microbial contamination and reduce the use of antibiotics. Plant essential oils are natural compounds with the potential to be used as active ingredients in the food, pharmaceutical, and cosmetic industries. Various studies have shown that essential oils have antifungal, antibacterial, antiviral, and antioxidant activity. The essential oils are considered as superb preservatives with various biological functions. Essential oils are generally recognized as safe product (GRAS) which can be used as an alternative to synthetic additives.Grapefruit (Citrus paradisi) peel and fruit contain active ingredients such as acids, flavonoids, vitamin C, and potassium, and its essential oil is composed of terpenic hydrocarbons, such as citral, limonene, citronelal, and geraniol. Although plant essential oils have antimicrobial and antioxidant properties, one of the main problems of these natural compounds is their high volatility and instability. In this context, nanoemulsion formulations are frequently used to increase the stability and efficiency of these biologically active compounds. This study is therefore aimed to nanoemulsifying the grapefruit essential oil and evaluate its antioxidant and antimicrobial properties. Materials and Methodsβ-carotene, linoleic acid, ABTS (2,2’-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), and DPPH (2,2-diphenly-1-picrylhydrazyl) were purchased from Sigma-Aldrich Co. (USA). Mueller Hinton Broth (MHB) and Mueller Hinton Agar (MHA) were supplied from Merck Co. (Darmstadt, Germany). Grapefruit peel was dried at ambient temperature and then powdered. The obtained powder was then transferred to a Clevenger device containing 750 ml of distilled water to perform the distillation extraction (3 h). The resulting grapefruit essential oil was stored at 4 °C until use. Grapefruit essential oil was prepared using the hydrodistillation method, and then nanoemulsified. The antioxidant activity of the nanoemulsified essential oil was investigated by DPPH and ABTS radical scavenging activity and beta-carotene/linoleic bleaching test. The nanoemulsified essential oil or methanolic (control) was mixed with DPPH solution and the mixture was then stored at ambient temperature for 30 min, in a dark place. The control sample was prepared by methanol. The absorbance of the samples was measured at 517 nm. To determine the ABTS-RS activity, the nanoemulsified essential oil was briefly charged with methanolic ABTS radical cation solution and the resulting mixture was left at room temperature for 30 min. Afterward, the absorbance was read at 734 nm. A spectrophotometric method was applied to monitor β-carotene/linoleate solution bleaching in the presence of the nanoemulsified essential oil. To do this, the absorbance of the solution was recorded at 490 nm after 120 min against the control sample at time zero and after 120 min. Antibacterial effect of the grapefruit essential oil nanoemulsion was also evaluated against Escherichia coli ATCC 25922, Salmonella typhi ATCC 6539, Pseudomonas aeruginosa ATCC 27853, Listeria innocua ATCC 33090, Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 14579, Bacillus subtilis ATCC 23857, Streptococcus pyogenes ATCC 19615, and Staphylococcus epidermidis ATCC 12228, based on disk diffusion agar, well diffusion agar, minimum inhibitory concentration, and minimum bactericidal concentration. Results and DiscussionsThe results showed that the nanoemulsion of grapefruit essential oil had a remarkable antioxidant effect of 42.27 mg/ml, 33.27 mg/ml and 54.54%, respectively, based on DPPH, ABTS, and beta-carotene-linoleic acid bleaching tests. According to disk diffusion agar and well diffusion agar results, the lowest inhibition zone was related to E. coli and the highest inhibition zone was observed in L. innocua. The minimum inhibitory concentration for L. innocua and S. aureus (the most sensitive bacteria) was 25 mg/ml, and E. coli, S. typhi, and P. aeruginosa had the highest inhibitory concentration. Also, the lowest bactericidal concentration was related to L. innocua and S. aureus bacteria and the highest concentration was observed for E. coli, S. typhi and P. aeruginosa. The nanoemulsified essential oil generally exhibited greater antibacterial activity against Gram-positive species. This could be mainly due to the difference in the cell wall composition of Gram-positive bacteria in comparison to Gram-negative; Gram-positive bacteria have a thicker mucopeptide layer in their cell wall, while Gram-negative bacteria have only a thin layer of mucopeptide and the wall structure is mainly composed of lipoprotein and lipopolysaccharide, thereby leading to a higher resistant to antibacterial agents According to the results, grapefruit essential oil nanoemulsion can be used as a natural antioxidant and antimicrobial agent to control oxidation reactions and the growth of spoilage and pathogenic microorganisms.
Food Chemistry
Masoumeh Heydari Gharehcheshmeh; Akram Arianfar; Elham Mahdian; Sara Naji-Tabasi
Abstract
[1]Introduction: Sesame oil and sweet almond oil are rich in unsaturated fatty acids and antioxidant components, providing nutritional and functional properties including improvement of the gastrointestinal system, decrease in blood cholesterol level, eventually leading to a decrease in the risk of cardiovascular ...
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[1]Introduction: Sesame oil and sweet almond oil are rich in unsaturated fatty acids and antioxidant components, providing nutritional and functional properties including improvement of the gastrointestinal system, decrease in blood cholesterol level, eventually leading to a decrease in the risk of cardiovascular disease. The present study examined the possibility of the production of emulsion based on sesame and sweet almond oils and the effect of preparation on its stability. Material and methods: Sesame oil and sweet almond oil with tween 80 and span 80 as emulsifiers were used in emulsion production. In order to prepare the nanoemulsions, the water and oil phases were prepared separately by the ultrasonic homogenizer. Ultrasonic waves were applied for homogenization and the effect of Ultrasonic time (5, and 10 min), oil content (2, and 4%), and emulsifier concentration (0.25, 0.5%) on particle size, particle distribution index (PDI), turbidity loss rate, emulsion stability and zeta potential of nanoemulsions were studied. Results and discussion: Ultrasonic time had a reverse effect on particle size, particle distribution index (PDI) and turbidity loss rate and a direct effect on emulsion stability. The particle size and turbidity loss rate of prepared emulsions had a direct relation with oil concentration and a negative effect on emulsion stability. Emulsifier concentration had a positive effect on emulsion stability, a negative effect on emulsion stability, and had no significant effect on turbidity loss rate. According to the results of the effect of type and concentration of oil on particle size distribution, turbidity reduction rate and stability of nanoemulsions in all cases, samples containing sesame oil with a concentration of 2% compared to sweet almond oil, had better results, the presence of this oil led to the formation of nanoemulsions with smaller particles and greater stability. The produced nanoemulsions had a particle size between 200-320 nm, a stability of 91-98/7% and a turbidity reduction rate of 0.0010-0.0027. Also, the highest stability and zeta potential were reported 98.7 % and -33mV respectively, which belonged to sample k4. Therefore, this sample was selected as the optimal sample.The results showed that the particle size, mean particle diameter, particle dispersion and turbidity reduction rate showed a significant difference between the samples, so that the lowest and highest were related to K4 sample (2% sesame oil, homogenization time 10 minutes and Emulsifier concentration ratio 0.5%) and sample B5 (almond oil 4%, homogenization time 5 minutes and emulsifier concentration ratio 0.5%) (p <0.05). The results also showed that the highest level of stability and zeta potential was related to K4 sample. Thus, the best nanoemulsion, K4 sample was introduced
Sara Forouzandeh; Mohammad Fazel
Abstract
[1]Introduction: Nowadays, various methods have been developed to transfer and improve the absorption of lipophilic compounds in food in the form of coating. Colloidal emulsion-based systems are widely used in commercial systems. Chia seed oil is an oil rich in unsaturated fatty acids, especially omega ...
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[1]Introduction: Nowadays, various methods have been developed to transfer and improve the absorption of lipophilic compounds in food in the form of coating. Colloidal emulsion-based systems are widely used in commercial systems. Chia seed oil is an oil rich in unsaturated fatty acids, especially omega 3 and omega 6, which can be used as the oily phase of nanoemulsions. The aim of this study was to investigate the fatty acid composition of chia seed oil and the effect of oil to water ratio and emulsifier on the properties of nanoemulsions of this oil. Materials and Methods: Clean chia seeds were purchased as a pack from Zistfa Company and all other chemicals were purchased from Marack, Pars Shimi and Dr. Majelli companies. By using the oil set machine, the seeds were treated by cold pressing method and oil extraction efficiency was calculated .Gas chromatography (GC) was used to identify and measure the fatty acid composition of chia seed oil. In this study, nanoemulsions were produced in three levels of oil to water (20%, 35% and 50%) and in three levels of oil emulsifier (5%, 10% and 15%).To produce nanoemulsions, the aforementioned ratios were first calculated and determined .Then, Weigh the tweens 20 and 80 with chia seed oil and water and mix the emulsifiers with the chia seed oil on the stirrer. Then a mixture of 20 and 80 tweens and oil was added dropwise to the weighed distilled water. The mixture was stirred gently by a magnet. After this step, the mixture is placed in the refrigerator to reduce its temperature. After this time, it was placed in an ice bucket and placed in an ultrasonic homogenizer for 9 minutes at a power of 300 watts to form nanoemulsions. Then, the properties of nanoemulsions including particle size and distribution, coating efficiency and antioxidant properties were evaluated. Vasco model DLS (Dynamic light scattering) was used for the particle size. The particle size of nanoemulsions was determined by this device using dynamic light diffraction method. DPPH method was used to measure the antioxidant activity of oils and nanoemulsions and the antioxidant activity was calculated by using the formula. To evaluate the efficiency of coating of nanoemulsions, the amount of surface oil and total oil was measured and the efficiency was calculated by using the formula. The release rate of nanoemulsions was evaluated for 7 weeks. The tests were performed in three replications. Experimental data were analyzed in a completely randomized design with factorial test and Duncan test was used to compare the mean data. Software (Excel, 2010) was used to draw the graphs Results and Discussion: According to the results obtained in this study, it can be said that chia seed oil contains a high percentage of unsaturated fatty acids and has a very high level of antioxidant properties (88.43%), which has antioxidant properties in the structure of nanoemulsions. Oil is better preserved in water. Other results showed that with increasing oil content of nanoemulsions, particle size, antioxidant properties and release increased and the coating efficiency decreased. Also, by increasing the ratio of emulsifier to oil in nanoemulsions, the coating efficiency and antioxidant properties increase and the particle size and release decreases. In the results obtained from these tests, the minimum particle size was 14.08 nm and the highest coating efficiency was 96.40%. The antioxidant activity of the samples was evaluated in the range of 5.61% to 21.43%. Also, the average release of samples at the end of 7 weeks of the study reached nearly 18%. During storage, the treatments were quite stable for five months, which could be due to the low particle size and low release of samples. Considering the mentioned advantages, using nanoemulsions of this oil is a suitable option for enriching beverages.
Nasrin Faraji; Mohammad Alizadeh khaled abad; Hadi Almasi; Sajad Pirsa; Soheila Faraji
Abstract
Introduction: Fish oil is an omega3 source, because it consists of a long chain polyunsaturated fatty acids (PUFAs), namely Eicosapentaenoic acid (EPA, 20:5 n-3) and Docosahexaenoic acid (DHA, 22:6 n-3) that are essential to all humans and provide multiple health benefits associated with brain development, ...
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Introduction: Fish oil is an omega3 source, because it consists of a long chain polyunsaturated fatty acids (PUFAs), namely Eicosapentaenoic acid (EPA, 20:5 n-3) and Docosahexaenoic acid (DHA, 22:6 n-3) that are essential to all humans and provide multiple health benefits associated with brain development, cardiovascular disease, circulatory disorders, immune dysfunction and inflammatory disorders. The human body cannot make omega3 fatty acids on its own, so they must obtained from daily diet or supplements. Low uptake of this nutrient can cause serious problems. Lipid oxidation of fish oil and other PUFA-rich foods is a serious problem that leads to loss of shelf-life, consumer acceptability, nutritional value and functionality. On the other hands, omega3 cannot be incorporated into many functional foods, due to their poor water-solubility, chemical instability and low bioavailability, so some ways should be used to protect PUFAs such as microencapsulation and Nanoemulsion. The performance of low-energy methods has become very popular due to the lack of expensive equipments and ease of production. In this research, nanoemulsion of omega-3 fatty acids was prepared by spontaneous emulsification method using Iranian mentha longifolia essential oils. Material and methods: Fish oil was purchased from zahravi company comprised of 101 mg of EPA/g of oil, 148 mg of DHA/g oil, and 312 mg of total omega-3 PUFA/g of oil. Nonionic surfactants Tween 80 and Tween20 (Sigma Aldrich, St. Louis, MO, USA) and Sodium caseinate (MP Biomedical LLC. (Solon, OH) were purchased from chemical suppliers. Distilled and deionized water obtained from a water purification system (Milli-Q, Millipore, Darmstadt, Germany) was used to prepare all emulsions. All other chemicals used in this study were either Sigma-Aldrich (St. Louis, MO) or Fisher Scientific (Pittsburgh, PA). Iranian Shallot oil (penny royal oil) was purchased from magnolia company (Iran). The supplier reported the chemical composition as determined by gas chromatography-mass spectroscopy instrument (GCMS-QP2010 SE, GAS, Shimadzu, Japan). Factor A contains the omega 3 percent (25 to 75 percent), factor B contains surfactant-to-oil ratio (SOR %), (10-300 percent), Factor c contains surfactant type (Tween20, Tween80, T80:T20 and caseinate sodium) and factor d contains storage time (1-60 days) to achieve optimal production formula were selected. Physicochemical characteristics of Nanoemulsion including pH, peroxide value, turbidity, creaming index, D43, span, antioxidant, brix, refractive index and TBA were studied and Optimization of formula was performed by Response Surface Method (D-optimal design) The results were analyzed using design expert software (ver11). Results and discussion: Preparation of Nanoemulsion based on Iranian mentha longifolia oil loaded with omega 3 fatty acids by a low energy emulsification technique to protect it was evaluated in this study. The initial size of the droplets depended on surfactant type, surfactant concentration, storage time and omega3 concentration. Emulsions made of the highest surfactant concentration produced the smallest droplet sizes and were physically stable. It was found that the most important parameter effecting final emulsion responses was surfactant concentration. Our results showed that oxidative stability could be improved by the increasing surfactant concentration, also Iranian mentha longifolia antioxidant compounds were effective in reducing peroxide index and delaying oxidation. In all surfactants, by increase omega3 content, antioxidant activity was decreased. Results showed that all four examined variables affected the provided emulsion characteristics and the following conditions were obtained as optimum; storage time of 40 days, SOR %: 100, T80:T20 and omega 3 (29.31%). These nanoemulsions and essential oils can be applied to prevent undesirable off flavor fish oil and can be applied to fortify food or beverage systems with omega3 fatty acids.
Maryam Nejadmansouri; Seyed Mohammad Hashem Hosseini; Mehrdad Niakosari; Gholam Hossein Yousefi; Mohammad Taghi Golmakani
Abstract
Adequate consumption of ω-3 essential fatty acids (EFAs) has a positive impact on human health. EFAs-enriched functional foods may be used for this purpose. Nanoemulsion is a promising delivery system for incorporating EFAs into a variety of foods and beverages. In this work, fish oil nanoemulsions ...
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Adequate consumption of ω-3 essential fatty acids (EFAs) has a positive impact on human health. EFAs-enriched functional foods may be used for this purpose. Nanoemulsion is a promising delivery system for incorporating EFAs into a variety of foods and beverages. In this work, fish oil nanoemulsions developed by sonication method were subjected to various analyses as a function of hydrophilic lipophilic balance (HLB) and surfactant to oil ratio (SOR). Analyses were performed upon production and during 1-month storage at two temperatures (4 and 25 ˚C) in the presence (100 ppm) or absence of α-tocopherol. Increasing in HLB and SOR decreased the particle size and surface tension; while, increased the refractive index and viscosity. During storage, the particle size of α-tocopherol-loaded nanoemulsions decreased; whereas, that of α-tocopherol-free nanoemulsions increased in a temperature-dependent manner. Irrespective of the storage temperature, surface tension values of antioxidant-loaded nanoemulsions remained constant. However, their viscosity values increased. Antioxidant incorporation fairly increased the nanoemulsions stability likely due to partitioning at the interface. TEM micrographs confirmed the results obtained by static light scattering. The results of this study may help the rational design of functional foods using nanoemulsion-based delivery systems.
