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 the ...
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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 (NEO).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 discussion: Gas chromatography-mass spectrometry (GC-MS) identified 1,8-Cineole and α - Terpinyl acetate as the major components of BLEO. The NEO 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 obtained, 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.Conclusion: These findings suggest that the SSG-BLNEO edible active coating possesses promising applications as an antimicrobial and antioxidant agent for food packaging applications.
Food Chemistry
Iysan Izanloo; Alireza Sadeghi Mahoonak
Abstract
Introduction Free radicals originate from oxidation reactions decrease food quality and also promote incidence of various diseases such as cancer. In this regard, the use of natural compounds with antioxidant properties, such as bioactive peptides, is of interest to many researchers. Food-derived ...
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Introduction Free radicals originate from oxidation reactions decrease food quality and also promote incidence of various diseases such as cancer. In this regard, the use of natural compounds with antioxidant properties, such as bioactive peptides, is of interest to many researchers. Food-derived bioactive peptides, can play an important role in the oxidative systems. Ultrasound, as a cheap and green technology, is widely used to extract proteins and antioxidant compounds. Ultrasound pretreatment before enzymatic hydrolysis can open the protein structure and increase the intensity of proteolysis by increasing the exposure of peptide bonds prone to enzymatic hydrolysis; which increases the production efficiency of bioactive peptides. Ultrasound treatment changes the three-dimensional structure of proteins. Therefore, a combination of pretreatment with ultrasound and sequential enzymatic hydrolysis can be a promising way to modify the function of proteins. Materials and Methods In this research the effect of hydrolysis time and ultrasonic pretreatment on enzymatic hydrolysis of edible mushroom protein by pancreatic enzyme to produce peptides with high antioxidant capacity was evaluated. First edible mushroom was turned into powder and then, in order to optimize the production of hydrolyzed proteins with maximum antioxidant activity, the hydrolysis was performed 30, 60, 90, 120, 150, 180 and 210 minutes with a ratio of enzyme to substrate of 1% (based on the result of previous research) and at 40°C in four conditions (1- without ultrasound pre-treatment, 2- with ultrasound pre-treatment with 40% power, 3- with ultrasound pre-treatment with 70% power and 4- with ultrasound pre-treatment with 100% power) by ultrasound probe in 5 minutes before adding the enzyme. In the next step, the antioxidant capacity of hydrolyzed proteins was measured at different times by DPPH free radical scavenging activity, iron ion reduction power, iron ion chelation and total antioxidant capacity. Results The results showed that the highest DPPH free radical scavenging activity in untreated and treated samples with 40, 70 and 100% ultrasound power were 69.1, 77.45, 79.07 and 80.27, respectively. In most of the hydrolysis times, DPPH free radical scavenging activity in ultrasound treatment with 100% power was higher than the samples treated with 40 and 70% power. The highest total antioxidant capacity in untreated and treated samples with 40, 70 and 100% ultrasound power were 0.871, 1.025, 1.05 and 1.2 (absorption at 695 nm), respectively. In most of the hydrolysis times, the total antioxidant capacity in the samples treated with ultrasound with 100% power was higher than the samples treated with 40 and 70% power. The results showed that the highest reducing power of Fe3+ in untreated and treated samples with 40, 70 and 100% ultrasound power were 2.03, 2.40, 2.44 and 2.51(absorption at 700 nm), respectively. The highest iron ion chelation power in untreated and treated samples with 40, 70 and 100% ultrasound power were 25.22, 30.40, 26.52 and 41.10%, respectively. By increasing the ultrasound power in most of the hydrolysis times, the chelating power of iron ions in the ultrasound treatment with 100% power was higher than the samples pretreated with 40 and 70% power. The results showed that samples pretreated with 100% power ultrasound have the highest antioxidant properties compared to samples without pretreatment and pretreated with 40% and 70% ultrasound power. Based on the results, using ultrasound treatment with 100% power and during hydrolysis time of 60 minutes, a product with high antioxidant capacity was obtained and selected as a suitable treatment. Conclusion The ultrasonic mechanism is attributed to its thermal effects, cavitation and mechanical efficiency, so that it can increase the mass transfer and increase the contact between the substrate and the enzyme or change the spatial structure of the substrate. The results showed that samples pretreated with ultrasound with 100% power have the highest antioxidant properties compared to samples without pretreatment and pretreated with 40 and 70% power. Therefore, the use of high-power ultrasonic pretreatment shortens the hydrolysis time to achieve peptides with higher antioxidant capacity and thus increases the efficiency of enzymatic hydrolysis.
Food Chemistry
Negin Jafarian; Afshin Akhondzadeh Basti; Hamideh Emtiazi
Abstract
Background and Objectives Natural preservatives extracted from herbs are important sources for bioactive compounds that can be used in protection of food products. Essential oils are aromatic oily liquids, obtained from plant material like flowers, buds, seeds, leaves, and roots. Unfortunately, ...
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Background and Objectives Natural preservatives extracted from herbs are important sources for bioactive compounds that can be used in protection of food products. Essential oils are aromatic oily liquids, obtained from plant material like flowers, buds, seeds, leaves, and roots. Unfortunately, most natural compounds are biologically instable, poorly soluble in water and they distribute poorly to target sites. Currently, some novel methods have been introduced in order to improve their stability and their bioavailability, among which is the use of liposomal encapsulation. Microencapsulation reduces reactivity with the environment (water, oxygen, light), decreases the evaporation or the transfer rate to the outside environment, promotes handling ability, masks taste and enhances dilution to achieve a uniform distribution in the final product when used in very small amounts. Essential oils, as natural extracted compounds extracted from plants, are unstable compounds with low water solubility and unable to achieve target cells. Essential oils encapsulation by nanoliposomes is a novel method for increasing their biological activity and protecting them from destructive factors. The aim of this study was production and optimization of nanoliposomes containing Z. teniur essential oil and investigating their antibacterial effects against pathogens (Staphylococcus aureus and Escherichia coli). Materials and Methods Lipid film hydration method was used to produce nanoliposomes containing Z. teniur essential oil. Soy phosphatidylcholine and cholesterol were the main wall materials and chloroform was used as the mixing solvent . The particle size of nanoliposomes and their zeta-potential were investigated using laser diffraction method. In order to determine the minimum inhibitory concentration and the minimum bactericidal concentration of Z. teniur essential oil against examined bacteria, serial dilution method was used. Also, antioxidant activity of free and nano-encapsulated essential oil of Z. teniur was determined by DPPH method. Results According to the results, highest encapsulation efficiency achieved by using 80:20 ratio of soy phosphatidylcholine to cholesterol in nanoliposomes’ wall structures. In general, by increasing the ratio of phosphatidylcholine to cholesterol, encapsulation efficiency was improved. Zeta-potential of nanoliposomes was equal to -5.3 mv and mean particle sizes were in the range of 94.7-119.9 nm. Results indicated that essential oil ejection from nanoliposomes has direct relation to the time of storage and after 30 hours, ejection rate will increase considerably. Ejection rate was higher in phosphate buffer pH=7.4 in comparison with phosphate buffer pH=5.4. Minimum inhibitory concentration and minimum bactericidal concentration of free essential oil against Escherichia coli was 100 and 175 (µl/ml) respectively. Although, Minimum inhibitory concentration and minimum bactericidal concentration of nanoliposomes containing Z. teniur essential oil were equal to 75 and 150 (µl/ml) respectively. Also, results shown that , minimum inhibitory concentration and minimum bactericidal concentration of encapsulated Z. teniur essential oil against Staphylococcus aureus were lower in comparison with free form of Z. teniur essential oil. Staphylococcus aureus (as Gram-positive bacteria) was more susceptible than Escherichia coli (as Gram-negative bacteria). Conclusion Encapsulation of Z. teniur essential oil by nanoliposomes led to improve antibacterial effects of essential oil against Staphylococcus aureus and Escherichia coli. Also, investigating of antioxidant activity showed that encapsulated Z. teniur essential oil in nanoliposomes was more effective than free form of Z. teniur essential oil in scavenging of DPPH free radicals. Using nanoliposome encapsulation technology can be an effective way for increasing the efficiency of natural antibacterial compounds and essential oils encapsulated in nanoliposomes are suitable alternatives for synthetic preservatives used in food industry nowadays. The use of liposomes containing Z. teniur essential oil can provide the necessary protection against growth of spoilage and pathogenic microorganisms such as Staphylococcus aureus and Escherichia coli in food products.
Food Technology
Shahab Naghdi; Masoud Rezaei; Mehdi Abdollahi; Mehdi Tabarsa
Abstract
[1]Introduction: Bioactive compounds are substances found in small amounts in food. In addition to their influence on human development, these compounds also play a crucial role in reducing diseases in human. Polysaccharides are a group of bioactive compounds that come from a variety of sources. Polysaccharides ...
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[1]Introduction: Bioactive compounds are substances found in small amounts in food. In addition to their influence on human development, these compounds also play a crucial role in reducing diseases in human. Polysaccharides are a group of bioactive compounds that come from a variety of sources. Polysaccharides are macromolecules that are usually composed of more than ten monosaccharides. The constituent monosaccharides are arranged linearly or branched together through glycoside bonds, depending on the length of the chain and the number of constituent monosaccharides. They also have different molecular weight. Polysaccharides, like other essential macromolecules such as proteins and poly-nucleotides in the body, are essential for the flaxseed body's daily activities and play an influential role in cell-cell communication, cell adhesion, and the identification of molecules in the immune system. A group of polysaccharides derived from marine sources are sulfated polysaccharides. These polysaccharides are a broad branch of the resulting polysaccharides. In industrial quantities, sulfated polysaccharides are produced from pig skin and pig bone, and there are some restrictions on the use of these products in some countries. The limitations on the use of these products made from pig waste are the risks of transmitting influenza, as well as the prohibition of pork in some Islāmic countries. In this regard, by-products from seafood processing, which account for about 20 to 50 percent of the initial weight of raw material, are one of the sources that researchers are considering to extract these compounds. Material and Method: After preparation of the by-product, it was covered with ice in a ratio of 1 to 3 and transferred to the laboratory of Tarbiat Modares University. The sample was then washed and then ground. Finally, it was packed in plastic bags and kept in the freezer at -18 ° C until the day of experiment. Then, the enzymatic hydrolysis method and precipitation by ethanol were used to get sulfated polysaccharides. Chemical analyses were performed to determine carbohydrates, sulfates, proteins, and uronic acid content. The FTIR spectrum of extracted sulfate polysaccharide was determined using an FTIR spectrophotometer in the range of 400-4000 cm-1. Evaluation of antioxidant properties of obtained sulfate polysaccharide was assessed by DPPH free radical scavenging activity, ABTS free radical scavenging activity, and ferrozine tests. Emulsifying and foaming properties were also evaluated as functional properties. Results and Discussion: In the present study, sulfated polysaccharide was extracted from Rainbow trout (Oncorhynchus mykiss) skin by pepsin enzyme and its FTIR spectrum, carbohydrate, sulfate, uronic acid and protein were analyzed. The results of the chemical analysis of the extracted polysaccharide showed that the extraction efficiency was 3.23± 0.02%, as well as the percentage of carbohydrate and protein of the obtained polysaccharide was 57.03± 2 2.56, 7.78± 0.43% respectively. Also, the amount of sulfate and uronic acid were 6.54± 0.77 and 3.86± 0.43, respectively. The results of infrared spectroscopy showed the presence of a broad peak in the range between 3350 and 3450 cm-1 for the –OH group and the S=O sulfate flexural band in the range of 1245 cm-1. An increasing and significant trend was observed in different concentrations used for the DPPH test (p <0.05) which had the highest neutralizing power (38.85%) at a concentration of 2 mg/ml. The highest percentage of ABTS radical chelating was observed at a concentration of 4 mg/mm of distilled water with 71.70% (p <0.05). The chelating results of the extracted polysaccharide against ferrous ions showed that the highest chelating percentage was 98.43% (p <0.05). The foaming capacity, stability properties of the foam, and the emulsifying ability of the studied sample showed a trend of increasing the concentration coefficient of the sample (p <0.05), and the concentration of 10% used sulfated polysaccharide had the highest foaming percentage (72/22%) and foam stability (62.22%) (p <0.05). The emulsifying property of extracted sulfate polysaccharide against soybean oil was higher in all concentrations used than sunflower oil (p <0.05), and the highest value of that was related to the concentration of 10% with 86.57% and 92.59% against sunflower oil and soybean oil (p <0.05). The obtained results demonstrated that the fish skin extracted polysaccharide can serve as a natural antioxidant and functional agent in the food industry
Food Biotechnology
Hediyeh Yousefipour; Mohammad Amin Mehrnia; Behrooz Alizadeh Behbahani; Hossein Jooyandeh; Mohammad Hojjati
Abstract
[1]Introduction: Herbs and spices, which are essential part of the human diet, have been used in traditional medicine to increase the flavor, color, and aroma of various foods and food products. Herbs and spices are also known as preservative, antioxidative, and antimicrobial agents. Plant extracts and ...
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[1]Introduction: Herbs and spices, which are essential part of the human diet, have been used in traditional medicine to increase the flavor, color, and aroma of various foods and food products. Herbs and spices are also known as preservative, antioxidative, and antimicrobial agents. Plant extracts and their components with pathogen-growth suppression effect and little toxicity to host cells could be considered as excellent candidates for developing new antimicrobial agents. Trigonella foenum- graceum is an annual herbaceous plant with bright yellow and sometimes purple-white flowers. Therapeutic effects of this plant include analgesia, anti-cancer, and treatment of diabetes by lowering blood sugar and lowering blood lipids. In ancient Egypt, this plant was used to embalm the dead and incense. The seeds of the plant are used to treat leprosy, hemorrhoids, and relieve bronchitis. The seeds of this plant contain various compounds such as vitamins, amino acids, saponins, fatty acids, and flavonoids. The antimicrobial and antioxidant effects of T. foenum have been detrmined byvarious studies. This study was therefore aimed to produce the T. foenum extract and evaluate its antioxidant and antimicrobial properties. Materials and methods: Fifty g of powdered plant was added to 250 mL of water and stirred for 72 h. The solution was passed through the Whatman filter paper and then centrifuged at 3000 rpm for 10 min to discard the suspended solids. Next, a vacuum evaporator was used to remove the excess water and the obtained extract was packed and kept away from light at 4 °C. Total phenol and flavonoid contents were measured by colorimetric methods. The antimicrobial effect of the extract on Escherichia coli, Enterobacter aerogenes, Staphylococcus aureus, Bacillus cereus and Candida albicans was evaluated using disc diffusion agar (DDA), well diffusion agar (WDA), minimum inhibitory concentration (MIC) and minimum bactericidal /fungicidal concentration (MBC/MFC) methods. Interaction of aqueous extract and Chloramphenicol and Amphotericin B was also evaluated. Antioxidant effect of the extract was determined by ABTS, DPPH, and β-carotene/linoleic acid bleaching assay. Fourier-transform infrared spectroscopy (FTIR) was also used to identify the functional groups. Results and discussion: Total phenol and flavonoid contents of the extract were 46.60 mg GAE/g and 37.57 mg QE/g, respectively. The aqueous extract also showed antioxidant effects of 60.55, 55.53 and 50.40%, based on DPPH, ABTS methods and β-carotene/linoleic acid assay, respectively. T. foenum aqueous extract had the inhibitory effect on all examined microorganisms, at all concentrations (20, 40, 60 and 80 mg/mL). The antibiotic effect of chloramphenicol for E. coli, E. aerogenes, S. aureus and B. cereus was 13.30, 14.50, 18 and 19.10 mm, respectively, and the effect of this antibiotic for C. albicans was not measured. Also, the antibiotic effect of amphotericin B for C. albicans was 15.10 mm. Furthermore, the interaction of T. foenum aqueous extract with the antibiotic chloramphenicol presented a synergistic effect on the examined bacteria and led to a significant increase in inhibition zone diameter. Additionally, the interaction of the extract with antibiotics showed a synergistic effect on C. albicans. In infrared spectrum, peaks at 3370, 2965, and 1613 cm-1 were related to stretching vibration of O-H, C-H, C=C bonds of aromatic ring and aromatic groups of T. foenum aqueous extract. In general, the extract of T. foenum could be used as a natural antioxidant and antimicrobial agent in food and pharmaceutical industries.
Soheyl Reyhani Poul; Seyed Ali Jafarpour
Abstract
Introduction: Following extensive research on antibacterial and antioxidant properties of chitosan and hydrolyzed proteins and their satisfactory results, the use of these compounds as natural preservatives and good alternative to antibacterials and synthetic antioxidants in various nutrients is essential. ...
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Introduction: Following extensive research on antibacterial and antioxidant properties of chitosan and hydrolyzed proteins and their satisfactory results, the use of these compounds as natural preservatives and good alternative to antibacterials and synthetic antioxidants in various nutrients is essential. The aim of the present study was to investigate the properties of chitosan coating containing FPH in the preservation of rainbow trout (Oncorhynchus mykiss) fillets at refrigerated temperatures. Materials and methods: The hydrolyzed protein powder (FPH) used in this study was produced by enzymatic hydrolysis of frame (skeleton with the meat attached to it) of common carp (Cyprinus carpio) with flavourzyme enzyme. Accordingly, this powder was added to the chitosan coating (2% w/v chitosan + 2% w/v FPH). In order to investigate antibacterial and antioxidant properties of chitosan coating containing FPH, rainbow trout fillets were coated with chitosan (treatment 2) and chitosan containing FPH (treatment 3). Then, these sample treatments and control (treatment 1) were subjected to chemical (PV, TVN-B, TBA, FFA and pH) and microbial (count of aerobic mesophilic and psychrophilic bacteria) tests on days 0, 4, 8, 12, 16 and 20 in refrigerated storage. This study was implemented in form of completely randomized design and data were analyzed by one-way ANOVA and significant differences between the means were tested by Duncan's test at 95 confidence level. Results and discussion: According to the chemical tests, TBA, TVN-B and FFA indices showed an increasing value during the refrigeration period significantly (P<0.05) while their trend was lower in treatment 3 compared to the treatments 1 and 2. TBA index for treatments 1, 2 and 3 in day 0 was 0.017, 0.015 and 0.014 mg MDA/kg fillet respectively that this amounts reached to 1.49, 0.99 and 0.52 mg MDA/kg in day 20. At the beginning of the preservation period, TVN-B index was calculated 13.36, 13.18 and 12.46 mgN/100gr fillet for treatments 1, 2 and 3, respectively. But these values changed to 43.36, 30.19 and 22.11 mgN/100gr fillet for mentioned treatments at the end of preservation period. FFA index was 0.16, 0.14 and 0.12 percentage of oleic acid for treatments 1, 2 and 3 in day 0 whereas after 20 days of storage, this index increased to 2.55, 1.76 and 0.98 percentage of oleic acid for mentioned treatments respectively. The PV index was significantly less in treatment 3 compared to the treatments 1 and 2 in days 12, 16 and 20 (2.72, 4.42 and 4.12 meq o2/kg lipid respectively) but continuous incremental trend was not recorded in this index with increasing preservation time, even the end of the experimental period (day 20), the index decreased in all of treatments compared to the 16th day. The results of pH changes showed the stability of this index in treatment 3 during the preservation period (pH~6.30). Meanwhile, in day 12, 16 and 20, the pH of treatment 3 was significantly less than treatments 1 and 2 (p<0.05). The bacterial load count of aerobic mesophilic and psychrophilic bacteria in treatments (while having an increasing trend during the preservation period) showed that in day 8, 12, 16 and 20, the bacterial levels of treatment 3 were significantly less than treatments 1 and 2 (p<0.05). In this study, adding FPH produced from common carp fish (with degree of hydrolysis 15.9%) to chitosan resulted in enhanced antioxidant and antibacterial properties of chitosan coating. So that, the film obtained from the combination of chitosan and FPH was much stronger barrier against lipids oxidation and bacterial proliferation in rainbow trout fillets (at refrigerated temperatures) than pure chitosan film.
Mohammad Amin Mehrnia; Hassan Barzegar; Leila Hagh jou
Abstract
Central composite design response surface methodology was used to optimize polysaccharide extraction from olive leaves. Effect of three independent variables [extraction time (3- 7 hours), extraction temperature (60- 100°C) and water-to-raw material ratio (5-25 mL/g)] on extraction yield were studied. ...
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Central composite design response surface methodology was used to optimize polysaccharide extraction from olive leaves. Effect of three independent variables [extraction time (3- 7 hours), extraction temperature (60- 100°C) and water-to-raw material ratio (5-25 mL/g)] on extraction yield were studied. Extracted polysaccharide was evaluated for antioxidant properties, total phenolic and flavonoid content and its structure and functional groups were studied using FTIR. Rheological properties and flow behavior of polysaccharide were determined by fitting to power law model. The most important parameter in experimental ranges was temperature and the lowest effect was seen in extraction time. Highest extraction yield was obtained at extraction time of 2 hours, extraction temperature of 80.96°C and water-to-raw material ratio of 17.94 mL/g. Antioxidant properties of extracted polysaccharide were measured using DPPH radical at 517 nm that showed notable antioxidant properties. Rheological property of extracted polysaccharide was studied at 1, 2.5 and 5% concentration. Results showed that at high concentration, polysaccharide shows shear thinning behavior. One of the most important obstacles in native polysaccharide applications is their extraction yield. Extract of olive leaf polysaccharide is highly affected by extraction temperature. Extracted polysaccharide showed good antioxidant properties comparing to BHT and phenolic extract of olive leaf. Moreover it could be used for increasing solution viscosity at higher concentrations.
Parvin Sharayei; Hossein Chaji
Abstract
Introduction: Saffron (Crocus sativus) is the most expensive kind of spice in the world while around 400 tons of saffron are estimated to be produced in the current Iranian year (March 2016-17) from 90,000 hectares of land under saffron cultivation across the country. But, high share of producing saffron ...
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Introduction: Saffron (Crocus sativus) is the most expensive kind of spice in the world while around 400 tons of saffron are estimated to be produced in the current Iranian year (March 2016-17) from 90,000 hectares of land under saffron cultivation across the country. But, high share of producing saffron is exclusively dedicated to produce and dry saffron stigma as whereas their violet color petals are mostly ignored and disposed. Saffron petal is one of the most economical sources of anthocyanin pigments. Attractive colour, functional properties and antioxidant properties of anthocyanins can make them a good substitute for synthetic pigments in the food industry. But, due to high moisture content of petals, 96.36% db, they must be dehydrated immediately to prevent the decay. In the meanwhile, the drying conditions are also too critical to petal sensitive compounds while the method of drying along with drying period and the amount of energy consumed, obviously play a significant role on price and quality of the final product.
Materials and methods: In this study, the optimization of the thin layer drying conditions of saffron petal was investigated using response surface methodology (RSM) and Face Centered Experimental Design (FCED) in order to designate the empirical expriments. Saffron petals were dried at different temperatures (40, 50 and 60◦C) and air velocities (0.7, 1.4 and 2.1 m.s-1) in a thin layer dryer and quantitative and qualitative characteristics of saffron petals (color )L: brightness; a: red – green; and b: blue-yellow, total phenolic compounds (TPC), total anthocyanin components (TAC), scavenging activity of DPPH (RSA), ferric reducing-antioxidant power (FRAP) and minimized 50% of radical-scavenging activity (IC50) contents) were invetigated.
Results & discussions: Maintaining the quality of final dried product as high as possible is a major concern while it is an important aspect to consider for use of phenolic compounds and anthocyanins as antioxidants and colorants in food industry. The results showed that the total phenolic compounds (TPC) and total anthocyanin content (TAC) had a remarkable increase with temperature rise from 40 to 50◦C while more temperature increase brought about sharp drops. But, an increasing trend of variations is observed in parallel with increases in velocity of drying air for each temperature. The rise in anthocyanin and phenolic content is more attributed to much significant reduction in drying duration from 40 to 50◦C in comparison with 50 to 60◦C. It was also observed that total antioxidant activity of dried saffron petals showed the same response as TPC and TAC to temperature rise from 40 to 50◦C. Such behaviour could be explained by the findings of other researchers in which the antioxidant activity has high correlation with anthocyanin content and total phenolic composition of food materials. As a complementary, it can be mentioned that polyphenols in an intermediate stage of oxidation have greater antioxidant power than initially even though this is temporary; furthermore high temperature stabilization procedures may lead to the formation of new compounds with higher antioxidant activity. This is essentially the case of the Maillard reaction, which creates various Maillard reaction products, with markedly higher antioxidant power.
Conclusion: Generally, according to Derringer’s desired function approach, the optimal conditions were 50◦C and 1.4 m.s-1.The experimental values agreed with those predicted values. At this optimum condition, the TPC, TAC, DPPH, FRAP, and a value of the dried saffron petal were found to be 46.39 mg/ g ,1205.58 mg/l, 52.97%, 1276.52 µmol Fe2+/l, and 11.13, respectively. The experimental values were in a good agreement with the predicted values.
Forough Gillani; Zeynab Raftani Amiri; Reza Esmailzadeh Kenari
Abstract
Introduction: Cornelian cherry (Cornus mas L.), which belongs to the family Cornaceae, grows in Iran, in areas such as Qazvin and Arasbaran. The fruit possesses anti-inflammatory and antioxidant properties and it is used as an herbal remedy in medicine. Separation of natural antioxidant compounds from ...
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Introduction: Cornelian cherry (Cornus mas L.), which belongs to the family Cornaceae, grows in Iran, in areas such as Qazvin and Arasbaran. The fruit possesses anti-inflammatory and antioxidant properties and it is used as an herbal remedy in medicine. Separation of natural antioxidant compounds from plant sources requires an appropriate method of extraction, which is effective factor to achieve the higher efficiency of these valuable compounds. In this study, the effect of extraction methods (immersion and ultrasound) and different solvents (ethanol 100%, ethanol – water (50:50 V/V) and water) on amount of phenolic compounds and antioxidant properties of cornelian cherry fruit extract were investigated.
Materials and Methods: Qazvin cornelian cherry was purchased from the local market of Amol city, Mazandaran province, Iran. All solvents and chemicals used in this study were of analytical reagent grade and were prepared from Merck (Darmstadt, Germany) and Sigma–Aldrich (St. Louis, MO). Cornelian cherry was washed, core separated, dried in front of the sun for 5 days and then powdered with kitchen miller. Powdered cornelian cherry fruit was extracted using immersion extraction techniques, ultrasound and different solvents (ethanol 100%, ethanol –water (50:50 V/V) and water). In the immersion method, powdered cornelian cherry fruit were mixed with each solvent in the ratio of 1:10, individually. Then, the mixtures were shaken overnight at room temperature. After 24 hrs, the extracts were filtered through Whatman No. 42 filter paper and the solvents were evaporated in an oven at 55°C. In the ultrasound technique, the mixture of powdered samples with any solvent (1:10) was sonicated in an ultrasonic bath for 45 min at 35°C. The extracts were then filtered and the solvents were evaporated using an oven at 55°C. Finally, the extracts obtained from extraction methods were kept in a freezer for furthere experiments. The total phenolic content of the extracts was determined with the Folin-ciocalteau method, briefly, 0.5 mL of cornelian cherry fruit extracts with concentration of 1mg/mL were mixed with 2.5 mL of Folin–Ciocalteu reagent (previously diluted 10-fold with distilled water) and 2 mL of 7.5% sodium carbonate solution, then the samples were kept for 30 min at room temperature in the dark and at the end the absorbance of the solutions was read at 760 nm. The ability of the extracts to scavenge 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH) was determined. 0.3 mL of each extract with a different concentration (500-3000μg/mL) was mixed with 2.7 mL of methanolic solution of DPPH (6 × 10 -5 mole/L), then the mixture was shaken vigorously and was placed in the dark for 60 min. Absorbance was recorded at 517 nm. The percentage of the DPPH radical scavenging was calculated according to the following equation:
% inhibition of DPPH radical= [(ADPPH – AS) / ADPPH] ×100
AS and ADPPH are the absorbance of the solution the absorbance of the DPPH solution, respectively. Reducing power of extracts on iron ion was measured. 1mL of each extract with a different concentration (500-3000μg/mL) was mixed with 2.5 ml of phosphate buffer (0.2 M, pH= 6.6) and 2.5 ml potassium ferricyanide [K3Fe(CN)6] (1%), then the mixture was incubated at 50° C for 30 min. After that, 2.5 ml of 10% trichloroacetic acid were added to the mixture, then, was centrifuged at 1000g for 10 min. Subsequently, 2.5 ml of the upper layer solution was mixed with 2.5 ml of distilled water and 0.5 ml of 0.1% FeCl3. Finally, the absorbance values of the solutions were read at 700 nm.
Results and discussion: The result of this study showed that the type of solvent and extraction method has been effective on amount of phenolic compounds of extracts, and also concentration dependent of phenolic compounds with antioxidant activity was observed in all extracts. The highest amount of phenolic compounds with 142.72 mg/g (based on Galic acid) was observed in sample extract obtained from solvent of water- ethanol (50:50 V/V) employing ultrasound method. Also, this extract with the lowest IC50 value with the amount of 0.955 mg/ml in the DPPH free radical scavenging method and the highest absorption with the amount of 0.601 in the reducing power of Iron III test, the highest antioxidant performance is shown. A negative correlation was observed between the total phenolic content and the IC50 value in the methods of measuring the antioxidant activity (DPPH and reducing power), which revealed the higher total phenolic content will give the lower IC50, that means the higher antioxidant activity. The results of present research showed that cornelian cherry fruit is a natural source of phenolic compounds and have considerable antioxidant activity.
Adeleh Mohammadi; Saeedeh Arabshahi- Delouee; Kyriaki Zinoviadou; Charis Galanakis
Abstract
Methanol, ethanol, acetone and water extracts of Indian Frankincense (Boswellia serrata) were evaluated for their total phenolic contents and antioxidant properties using various methods including 2,2-diphenyl-1-picrylhydrazyl, iron (III) reducing power, total antioxidant capacity and oxidative stability ...
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Methanol, ethanol, acetone and water extracts of Indian Frankincense (Boswellia serrata) were evaluated for their total phenolic contents and antioxidant properties using various methods including 2,2-diphenyl-1-picrylhydrazyl, iron (III) reducing power, total antioxidant capacity and oxidative stability index (Rancimat). The four extracts showed varying degrees of antioxidant activity in a dose - dependent manner in each assay. Methanol extract containing the highest amount of phenolic compounds exhibited the strongest antioxidant capacity in all the assays used. Moreover, all the extracts were able to improve the oxidative stability of soybean oil as evaluated by the Rancimat test. On the basis of the results obtained, B. serrata oleo-gum resin was found to serve as a potential source of natural antioxidants due to their considerable antioxidant activity.
Sodeif Azadmard Damirchi; Razagh Mahmodi; Mahood Sowti Khiabani; Majid Shirmohammadi
Abstract
Introduction: Pistacia is a genus of the family Anacardiaceae. Among the 15 known species of pistachios, only 3 species grow in Iran, including Pistacia vera, Pistacia Khinjuk and Pistacia atlantica. P. Khinjuk is a native plant in Iran. The plant is known as Khenjuk or Kelkhong in Persian. Resin of ...
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Introduction: Pistacia is a genus of the family Anacardiaceae. Among the 15 known species of pistachios, only 3 species grow in Iran, including Pistacia vera, Pistacia Khinjuk and Pistacia atlantica. P. Khinjuk is a native plant in Iran. The plant is known as Khenjuk or Kelkhong in Persian. Resin of this plant has been used as an indigestion, tonic, toothache and astringent. In addition, fruits of P. Khinjukare used as edible wild fruits in form of roasted or salted nuts. There are reports on extract obtained from wild pistachio. It has been shown that the extract is rich source of phenolic compounds and other antioxidant compounds. Oil obtained from wild pistachio also has high content of essential fatty acids which can reduce and prevent from different diseases. Extracts obtained from the wild pistachio tree has also been used in pharmaceutical and cosmetic industries. However, there is no scientific report on qualitative properties of wild pistacia species khinjuk. Therefore, the aim of this research was to study the chemical and nutritional composition hull and core of wild pistacia species khinjuk.Materials and Methods: The Pistacia Khinjuk was collected during flowering stage from Southwest of Iran (KouhgiloyeBoyerahmad province) and identified by the Herbarium. Separate tests were performed on the hull and core of wild pistachio. First, the fruit hull was isolated from its core and then they were crashed and their core was separated. Moisture, oil, protein and ash content and pH of the hull and core of the fruit were determined. The hull and core of fruit were used for oil extraction. The hull and core were powdered and their oil was extracted by hexane. For fatty acids profile, extracted oil samples were methylated and obtained fatty acid methyl esters were analyzed by gas chromatography. Also, the extracted oil stored for three month at room temperature, and every thirty day peroxide value (PV), acid value (AV) and chlorophyll content were determined. PV and AV were determined by titration methods. Chlorophyll content was determined by spectrophotometer. Extract of the dried hull and core of fruit were obtained with percolation in ethanol and its total phenol content and DPPH free radical scavenging activity were determined. Phenolic content was determined using folinciocalteu method. Also, the extracts were added at percentages of 1, 2 and 3% to the rapeseed oil and extracts antioxidant properties were evaluated by rancimat.Result and discussion: Analysis showed that hull has more oil and ash content and lower protein content than core. Hull oil content (84%) was two times more compared to the core of the fruit (47%), but core protein content (7%) was almost twice compared to hull protein content (3%). The results showed that the percentage of major fatty acids in hull and core of fruit was oleic acid 33% and 41.2%, linoleic acid 10.6% and 21.5%, alpha-linolenic acid 6% and 3.1%, palmitic acid 17.2% and 11% and palmitoleic acid 13.1% and 3.1%, respectively. Results showed that oil extracted from hull and corehave high content ofmonounsaturatedand polyunsaturated fatty acids with relatively high amount of essential fatty acids. Total phenolic content of hull and core of the fruit were 25.6 and 6.3 mg gallic acid per 1 gram of dried sample, respectively. This results show that hull is a rich source of phenolic compound which can be important from nutritional point of view. Peroxide value and acid value increased during 4 month storage significantly. Increase in PV was higher in oil obtained from hull than core oil. Increase in PV can be result of fatty acid oxidation which is affected by several factors such as fatty acid composition, antioxidant content, peroxidant content and storage condition. AV of oil extracted from hull was higher than oil obtained from core. AV was increased in oils obtained from core and hull, but increases in hull were higher. Increase of AV can be result of hydrolyses of triacylglycerols which produce free fatty acids.Chlorophyll content was higher (7 times) in oil obtained from core compared with oil obtained from hull. Oil obtained from core had green color because of high chlorophyll content. Chlorophyll content reduced significantly (P≤0.01) during storage. It should be mentioned that chlorophyll content is an important factor in oil oxidative stability because chlorophyll act. as a sensitizer and enhance oil photoxidation.Evaluation of oil stability by rancimat showed that highest rapeseed oiloxidative stability was obtained by addition 3% of hull extract. Hullextract was more effective onfree radicalscavenging(88%) than core(75%).Hull of wild pistachio in comparison to its core has more phenolic content, therefore more antioxidant activity is also is expected. Phenolic compounds can act as antioxidant and make oils more stable against oxidation. Conclusion: According to suitable fatty acid composition and total phenol content, wild pistachio need more attention in people’s diets as a cheap and useful nut.
