Full Research Paper
Zabihalh Bahmani; Parastoo Abolfathi
Abstract
[1]Introduction: With increasing demand for chicken meat, the chemical composition of meat carcasses has become more important. Despite advances in medical care and food technology in recent years, foodborne infections and food poisoning, as well as food spoilage in developed and developing countries ...
Read More
[1]Introduction: With increasing demand for chicken meat, the chemical composition of meat carcasses has become more important. Despite advances in medical care and food technology in recent years, foodborne infections and food poisoning, as well as food spoilage in developed and developing countries are still a major problem for human health and the economy. During the storage period, the quality characteristics of meat is shortened due to bacterial and oxidative spoilage. Oxidative spoilage causes unpleasant odors, unpleasant changes in taste, and changes in the structure of nutrients and reduces the nutritional value of the product. While spoilage and microbial contamination lead to product wastage and poses serious health risk to consumers. Increasing interest in using less synthetic preservatives has led to use of natural derivatives with antimicrobial properties. Biodegradable coatings are a good alternative to plastic packaging, given the problems they have with recycling and environmental pollution. Chitosan coating containing Zataria multiflora essential oil is known to possess good antioxidant and antibacterial properties due to the presence of thymol and carvacrol compounds and their ability to establish hydrogen bonds with other monoterpenes such as γ-tropenes. Materials and methods: Zataria multiflora was purchased in the spring from Sari Medicinal Plants Store. It’s essential oil was prepared by distillation method using Clevenger and then dehydrated with sodium sulfate and passed through 0.45 μm syringe filters and stored in dark containers at 4°C (Rezaie et al., 2015).In this study, the use of biodegradable and edible coating of chitosan with thyme essential oil to increase the shelf life of chicken fillets during refrigeration was investigated. Treatments included control, 2% chitosan, 1.5% essential oil and treatment containing 2% chitosan with 1.5% essential oil, which were stored at 4 ° C for 24 days. The antioxidant and antimicrobial properties of chitosan and thyme essential oil were evaluated by measuring the total amount of phenolic compounds, free radical scavenging (DPPH), and FRAP. Quality assessment with chemical tests; pH, TBA, TVB-N, and microbial count (mesophilic bacteria and Pseudomonas) were measured at 4-day intervals. Results and discussion: The results of quality assessment during the refrigeration period for all treatments showed an increasing trend in pH. TBA (mg MDA/kg fat), TVB-N (mg N/100g), TMC and Pseudomonas (CFU/g) in coated treatments with 2% chitosan and 1.5% essential oil on day 24 of storage were 6.6, 1.78, 26.8, 6.7 and 6.42, respectively, and showed the highest shelf-life. Since, thyme essential oil and chitosan have increased the shelf-life of chicken fillets due to their antioxidant and antimicrobial activity.The use of biopolymers such as chitosan, gelatin, etc., which have a good ability to maintain and release antioxidant and antimicrobial compounds, is increasing in food packaging. In this study, the preservation effects of chitosan coating containing Zataria multiflora essential oil on increasing the shelf life of chicken fillets were investigated and it was found that chitosan coating and Zataria multiflora essential oil alone and in combination had good preservation effects. According to the results, 2% chitosan coating containing Zataria multiflora essential oil can increase the shelf life of chicken fillets, which is due to the very good performance of chitosan coating containing Zataria multiflora essential oil due to its synergistic effect on antimicrobial and antioxidant properties. Between chitosan coating and thyme essential oil in preventing microbial growth and chemical spoilage and shelf life for control treatments, chitosan 2%, thyme essential oil 1.5%, and chitosan 2% containing thyme essential oil 1.5% respectively 8, 16, 16 and 24 days. Therefore, they can be used to store chicken fillets and meat products.
Full Research Paper
Marjan Teimorimanesh; Hajar Abbasi
Abstract
[1][2]Introduction: Vinegar is an ancient fermented food consumed by human since Babylons period. It is a condiment that produced from various carbohydrate sources by alcoholic and subsequently acetic acid fermentation. Alcoholic fermentation is carried out by Saccharomyces cerevisiae, while the acetic ...
Read More
[1][2]Introduction: Vinegar is an ancient fermented food consumed by human since Babylons period. It is a condiment that produced from various carbohydrate sources by alcoholic and subsequently acetic acid fermentation. Alcoholic fermentation is carried out by Saccharomyces cerevisiae, while the acetic acid fermentation is performed by acetic acid bacteria. Most of the acetic acid bacterial strains are classified in the Acetobacter genus and derived from vinegar factories that are able to oxidize ethanol to acetic acid and some strains over oxidize acetic acid into CO2 and H2O (over-oxidation). In acetic acid fermentation, important physical parameters that affect the growth of A.aceti are temperature, aeration and pH. Other most important factors for enhancing production efficiency of acetic acid are the nutrients of substrate for increases microbial activity. Considering the significant role of carbon sources and micronutrients in the fermentation culture to increase the production of acetic acid, in the present study, the effect of adding ammonium phosphate (0- 0.75 g), potassium sulfate (0- 0.75 g) and Saccharomyces cerevisiae (0- 1.5 g), were investigated to increase the production of acetic acid using Acetobacter spp. Materials and methods: Yeast (Saccharomyces cerevisae) was obtained from the Iranian Research Organization for Science and Technology, Department of Biotechnology in Tehran, Iran with code number 5052. All chemicals were from Merck Co. Acetic acid production was performed by Acetobacter spp in a fermenter (Biostat B B.Brun) with a capacity of 10 L which contained 5000 ml of fermentation culture in 9.9 acidity. Mash with a capacity of 3000 ml containing 450 ml of vinegar with 9.9 acidity, 350 ml of ethanol 97%, 2.1 g of dextrose and the rest up to 3000 ml of water was produced and 300 ml of it was injected into the fermenter every 4 hours (in 10 steps). After complete injection, the fermentation operation continued for 9 hours. Agitation speed, aeration rate and temperature in the fermenter were 900 rpm, 50 L/min and 32°C, respectively. Determination of the best conditions for producing acetic acid was performed by Response Surface Methodology (RSM) in the form of central composite design. Independent variables were yeast concentration (0- 1.5 g), concentration of the ammonium phosphate (0- 0.75 g), and the potassium sulfate concentration (0- 0.75 g). RSM models were developed and optimization was done for the highest acidity, activity and oxidation value and the lowest residual alcohol content in the product. Optimal and control samples were examined in terms of qualitative characteristics such as acidity, activity, residual alcohol content, oxidation value, total dissolved solids, reducing sugar, total phenol, ascorbic acid, sulfur dioxide and heavy metals. Comparison of the optimal and control samples was done in a completely randomized design using SAS ver: 9.1 software. Results and discussion: The results showed that increasing the concentration of yeast and ammonium phosphate led to increase the initial and final acidity, activity and oxidation value and decrease the amount of residual alcohol. The effect of increasing potassium sulfate was negative and reduced the initial and final acidity, activity and oxidation value. However, interaction effects of potassium sulfate concentration with other variables at its intermediate levels on reducing the amount of residual alcohol in the product was positive. The optimal levels of the studied variables were determined as 1.5 g of Saccharomyces cerevisiae, 0.75 g of ammonium phosphate and 0.38 g of potassium sulfate. In control sample (without the independent variables), initial and final acidity, activity and oxidation index were lower and the residual alcohol content was higher than the standard level. Therefore, the optimal sample was compared with the control and using industrial activator (Astasome). The optimal sample in terms of initial and final acidity, activity, residual alcohol content and oxidation value had not a significant difference (p> 0.05) with the control sample (containing Astasome). Moreover, the optimal and control samples were not significantly difference in ascorbic acid and reducing sugar (p> 0.05), while the optimal sample in terms of total phenol content, sulfur dioxide and heavy metals like lead, zinc and copper was superior compared to the control sample (p <0.05). Overall, the results of this study indicated the positive effect of yeast, ammonium phosphate, and the potassium sulfate at suitable concentration on qualitative characteristics of acetic acid.The results revealed that using of appropriate amounts of Saccharomyces cerevisiae, ammonium phosphate and potassium sulfate in substrate as a source of micronutrients improve quality of acetic acid production by Acetobacter spp.
Full Research Paper
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 ...
Read More
[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.
Full Research Paper
Food Biotechnology
Rezvan Shaddel; Safoura Akbari-Alavijeh
Abstract
[1]Introduction: Today, the incidence of non-communicable and emerging diseases is increasing due to lifestyle changes, reduced mobility and changing dietary patterns. Some clinical evidences in simulated samples and real cases show that some compounds and plant extracts have a significant effect on ...
Read More
[1]Introduction: Today, the incidence of non-communicable and emerging diseases is increasing due to lifestyle changes, reduced mobility and changing dietary patterns. Some clinical evidences in simulated samples and real cases show that some compounds and plant extracts have a significant effect on the prevention and even treatment of these diseases. On the other hand, due to the structural and functional diversity of plant polysaccharides, there is a great tendency among researchers to find new polysaccharides in different sources with new functional and bioactive properties. Despite extensive studies in this field, no study has been done on the extraction of polysaccharide compounds with prebiotic properties from green almond hull as one of the agricultural wastes. Therefore, the purpose of this study was to introduce a new type of synbiotic compound to balance clone microbiota and promote consumer health. Materials and methods: In this study, after extraction of water-soluble almond hull polysaccharides (AHP) by hot water extraction and precipitation with alcohol, the chemical analysis was done. To investigate the chemical composition of AHP, phenol sulfuric acid test was used to measure total sugar and Bradford test was used to measure protein. The amount of fat and ash in the sample was measured using standard methods (AOAC, 2005) and (AOAC, 2000), respectively. The amount of uronic acid of AHP was measured by calorimetry using metahydroxyphenyl at a wavelength of 520 nm. The content of AHP phenolic compounds was investigated by Folin Siocalcu calorimetric method. Fourier transform infrared (FT-IR) was also used to identify the functional groups and the anomeric status of AHP components. The prebiotic effect of this compound was also tested by digestion resistance and also by growth stimulation of the probiotic strain of Lactobacillus casei ATCC 393 in vitro for the first time. Results and discussion: Chemical analysis showed that AHP is a heteropolysaccharide consisting of 86.30% w/w of total sugar, 5.10% w/w protein and 3.21% w/w uronic acid. FT-IR analysis also confirmed the chemical structure of AHP as a heteropolysaccharide. The results of digestion resistance showed that 91.24% of AHP can remain stable and undecomposed after the stages of gastrointestinal digestion, while this rate was 74.94% for inulin as a commercial prebiotic. The second prebiotic property of AHP investigated in this study was the stimulation the growth of Lactobacillus casei ATCC 393 as probiotic in sugar-free MRS-based culture media and the results showed that AHP compared to inulin significantly increased the survival of Lactobacillus casei ATCC 393 (p <0.01). The proliferation index in media containing AHP and inulin showed a significant difference and AHP stimulated the growth of Lactobacillus casei ATCC393 significantly more than inulin (p <0.01). Therefore, to design a synbiotic product, if AHP is used as a prebiotic, the probiotic strain of Lactobacillus casei ATCC 393 would be a good choice.Considering the annual production of thousands of tons of almond green hull waste in Iran and the concerns related to environmental problems caused by its accumulation, the introduction of industrially feasible and economically justified methods to produce value-added products from this agricultural waste seems essential. In the present study, polysaccharides extracted from almond green hull by hot water extraction and alcohol precipitation, which is an economically feasible method and can be implemented on an industrial scale, were introduced as a useful compound. In vitro studies also used culture medium containing AHP as a commercial prebiotic in comparison with culture medium containing inulin. The results showed that this compound has a good resistance to digestive conditions in the gastrointestinal tract compared to inulin. The compound was also able to stimulate the growth of the probiotic Lactobacillus casei ATCC 393 in culture medium. In general, in this study, a new synbiotic compound including Lactobacillus casei ATCC 393 and AHP was introduced as a health beneficial food additive.
Full Research Paper
Food Chemistry
Reza Safari; Seyed Vali Hosseini; Sharareh Firouzkandian; Soheyl Reyhani Poul; Mona Zamani
Abstract
[1]Introduction: One way to turn chicken waste into high value-added product is to produce fermented silage (biosilage). This product is superior to fish powder due to its characteristics such as high quality protein, probiotic bacteria and low price and can be considered as a suitable alternative for ...
Read More
[1]Introduction: One way to turn chicken waste into high value-added product is to produce fermented silage (biosilage). This product is superior to fish powder due to its characteristics such as high quality protein, probiotic bacteria and low price and can be considered as a suitable alternative for feed industry. Silage can be produced from protein wastes by both acidic and biological methods. The acidic method of producing silage (acidic silage) uses a variety of organic and inorganic acids such as formic acid and sulfuric acid. In the production of biological silage, two methods of autolysis (using internal enzymes) and fermentation (using microbial starters) are used. Starters used for inoculation are mainly from the group of lactic acid bacteria. To produce silage, protein wastes are used, especially fish wastes. Since poultry waste has not been used for biosilage production in the country so far, the aim of the present study is to produce biological silage from chicken waste and evaluate the profile of amino acids and fatty acids in the biosilage. Materials and methods: Chicken intestine was prepared from meat production complex in Golestan province, Kordkoy city and also Simin Naz poultry industrial slaughterhouse in Sari and was transferred to the processing pilot of Caspian Sea Ecology Research Institute in the shortest time in cold container. During the biosilage production process, protein-degrading bacteria (containing protease enzymes such as gram-positive sporulated bacteria) and acid-producing bacteria (to reduce the pH of the suspension and accelerate the fermentation process, such as lactic acid bacteria) were used as initiator bacteria or microbial starters for intestinal digestion. The product was analyzed for protein, fat, moisture and ash according to standard methods. In this study, high performance liquid chromatography (HPLC) of Cecil model (Seri 200) was used for amino acids analysis. Samples were prepared for assaying amino acids profile in two stages including hydrolysis and derivatization and the results were expressed in grams per 100 grams of substrate. To determine the fatty acids composition of the biosilage sample, the fat was first extracted. In order to evaluate the profile of fatty acids, a Shimadzu model gas chromatography device was used and the results were expressed as a percentage. Results and discussion: The product produced contained about 60% protein and 21% fat. According to the results, the total of essential amino acids in the produced biosilage was 24.416, the total of non-essential amino acids was 30.959 and the total of essential and non-essential amino acids was 55.375 g per 100 g of substrate. Among essentialamino acids, the highest amount belonged to the amino acids leucine (7.334±0.45 g/100g) and valine (4.71±0.27 g/100g) and among non-essential amino acids, the highest amount belonged to glutamic acid (10.6±0.73 g/100g) and alanine (5.864±0.81 g/100g). It was also found that all essential amino acids except tryptophan are present in biosilage. Evaluation of biosilage fatty acids profile revealed that the total amount of saturated fatty acids (SFA) was 33.57%, monounsaturated fatty acids (MUFA) was 41.17% and polyunsaturated fatty acids (PUFA) was 24.36%. It was further found that in biosilage the total omega 3 was 2.07%, the total omega 6 was 22.91% and the sum of EPA and DHA was 2.06%.The profile of amino acids and fatty acids in the biosilage produced from chicken waste is almost the same as that of other products made from protein waste (such as fish meal, fish waste biosilage and hydrolyzed protein powder). This property, along with cheap production and high nutritional value, allows the use of biosilage obtained from chicken waste in the livestock, poultry and aquatics feed industry.
Full Research Paper
Food Technology
Narges Akafian; Hajar Shekarchizadeh
Abstract
[1]Introduction: In the last decade, nanotechnology approaches have been used to improve the functional properties of packaging materials. The main focus is on creating new packaging materials that extend the shelf life of food, which in turn improves food safety performance. The use of nanostructures ...
Read More
[1]Introduction: In the last decade, nanotechnology approaches have been used to improve the functional properties of packaging materials. The main focus is on creating new packaging materials that extend the shelf life of food, which in turn improves food safety performance. The use of nanostructures can also improve the mechanical properties of the packaging. Many traditional packages are made from non-degradable materials that double the environmental pollution in addition to using fossil fuels to produce them. Resin is a natural or synthetic compound that is very viscous and hardens under certain conditions. It is usually soluble in alcohol r. Natural resin is obtained from plants. This material is very sticky but hardens over time. Due to environmental concerns and the possibility of depletion of oil reserves, the construction of composites based on natural resins from renewable sources has become important. In previous studies, Javashir gum has been used to prepare an edible film with high water vapor permeability and solubility, as well as poor physical properties. Since Javashir gum is a natural, native and inexpensive gum, so in this research, the improvement of the properties of the film prepared from Javoshir gum is considered using.a combination of nanoparticles and resin obtained from Javoshir gum Materials and methods: Javshir nanoparticles were sprayed on Javashir film (4% gum and 2.5% glycerol) at two different times of 30 and 60 minutes. In order to increase the hydrophobicity of the films, Javashir resin was covered as a layer on the surface of the films. Then different physical and mechanical properties of the film such as thickness, water solubility, and water vapor permeability, elongation at break, tensile strength, contact angle and morphology were determined. Results and discussion: The results of thickness measurement showed that adding large amounts of nanoparticles as well as coating the film surface with resin increased the film thickness. Solubility results showed that all films have a very high solubility due to the hydrophilic nature of Javashir. However, the addition of nanoparticles and coating with resin reduced the water solubility of the film. The water vapor permeability of nano-60 film was increased compared to the control film which can be attributed to the increase in film surface due to the addition of nanoparticles. However, coating the surface with resin significantly reduced the water vapor permeability of the film. The tissue test showed that nano-30 resin film had 6.54 ± 2.72% elongation to tear point and 302.9 ± 47.1% tensile strength. Nano 30 resin film had the highest tensile strength and the lowest tensile percentage. The results of the contact angle showed that the lowest contact angle, which indicates high hydrophilicity, was related to the control sample, and the contact angle increased by adding nanoparticles and coating with resin, resulting in increased hydrophobicity. SEM images also showed that the addition of nanoparticles and resin coating reduced the film roughness.Finally, it can be said that the addition of Javoshir nanoparticles could well increase the tensile strength of Javashir film, and coating the surface of the film with resin was very effective in reducing the hydrophilicity and water vapor permeability of Javashir film.
Full Research Paper
Mohsen Ebrahimi Hemmati Kaykha; Hossein Jooyandeh; Behrooz Alizadeh Behbahani; Mohammad Noshad
Abstract
[1]Introduction: Oxidative reactions are needed for human survival, but these reactions can sometimes be destructive. There is a lot of evidence that shows many disorders (neurological, renal, hepatic) and diseases such as cancer and vascular diseases, and even food spoilage are caused by oxidative reactions ...
Read More
[1]Introduction: Oxidative reactions are needed for human survival, but these reactions can sometimes be destructive. There is a lot of evidence that shows many disorders (neurological, renal, hepatic) and diseases such as cancer and vascular diseases, and even food spoilage are caused by oxidative reactions of free radicals. Some types of reactive oxygen species, such as oxygenated water, and free radicals such as hydroxyl and superoxide, can react with certain fats, nucleic acids, and proteins in the body to kill them. In general, any substance that delays or prevents the oxidation process is called an antioxidant. In various studies that have been done so far, the antioxidant and protective properties of the novel plants have been reported. Among other species of medicinal plants, the rosemary plant with the scientific name (Rosmarinus officinalis L.) belongs to the mint family, the leaves of which are used as an additive in many foods. This plant is cultivated in many parts of the world, including Iran, but the main habitat of this plant has been attributed to the shores of the Mediterranean Sea. The purpose of this study was to identify chemical compounds, antioxidant effects, total phenolic and flavonoids contents, and cytotoxicity effect of Rosmarinus officinalis essential oil (ROEO) on colorectal cancer cell line (HT29) and identification of functional groups of ROEO using Fourier transform infrared spectroscopy (FTIR). Materials and methods: In the present study, the analysis of chemical compounds in ROEO was determined by gas chromatography-mass spectrometer (GC-MS). The total phenolic and flavonoid content of ROEO was evaluated using Folin-Ciocalteu and colorimetry using aluminum chloride, respectively. Antioxidant properties of ROEO were evaluated by DPPH and ABTS methods. The cytotoxic effect of ROEO on colorectal cancer cell lines (HT29) was evaluated by MTT method. The compositions of the functional groups present in the essential oil were investigated using Fourier transform infrared spectroscopy. Results and discussion: The chemical analysis of ROEO comprised of 29 compounds, which composed 94.22% of total essential oil. The main compound identified in the essential oil used in this study was eucalyptol with 40.13%. Total phenolic content was 72.55 mg gallic acid per gram of essential oil and its flavonoid content was 36 mg QE/g. The ROEO antioxidant activity for both DPPH and ABTS tests were 78.74% and 81.97%, respectively. The results of cytotoxic effect of ROEO showed that the cytotoxic effect of ROEO was highly dependent on its concentration. The higher the concentration of essential oil, the higher the level of cytotoxicity. Fourier transform infrared spectroscopy analysis confirmed the presence of aldehyde compounds, ketones, carboxylic acids, esters and alkenes. The results of all ROEO tests showed that this essential oil can be used as a potential source in the pharmaceutical, food, cosmetic and health industries.
Full Research Paper
Fatemeh Karegar; Rezvan Pourahmad; Peyman Rajaei
Abstract
[1]Introduction: Nowadays, with the development of probiotic products on the world market, the need for developing new products containing probiotic bacteria becomes more apparent. Probiotics are defined as living microorganisms that, if consumed in sufficient quantities, will have beneficial effects ...
Read More
[1]Introduction: Nowadays, with the development of probiotic products on the world market, the need for developing new products containing probiotic bacteria becomes more apparent. Probiotics are defined as living microorganisms that, if consumed in sufficient quantities, will have beneficial effects on the health of the host. Probiotics are now widely used in the production of food products and account for approximately 65% of functional foods. Probiotics often belong to either the genus Lactobacillus or Bifidobacterium. Lactobacillus rhamnosus is one of the known probiotic bacteria with beneficial properties. Prebiotics are defined as indigestible compounds, mainly carbohydrates that can be used as carbon source for probiotic bacteria and stimulate their growth and viability. Oligofructose is a type of short chain inulin and is one of the most well- known prebiotics. Moreover, microencapsulation of probiotic bacteria can improve the survival of these bacteria. In this approach, living probiotic cells are covered or trapped by various compounds. Hydrocolloids such as alginate and carbohydrates such as starch can be suitable compounds for microencapsulation. The purpose of this study was to investigate the effect of oligofructose and microencapsulation on the viability of Lactobacillus rhamnosus, textural, physicochemical and sensory characteristics of functional jelly. Materials and methods: In this study, different concentrations (0, 1.5 and 3 percent) of oligofructose as prebiotic were used to produce jelly samples, and 107 CFU/mL of probiotic bacteria (free and microencapsulated Lactobacillus rhamnosus) was inoculated. Microencapsulation of probiotic bacteria was performed by emulsion method using sodium alginate and corn resistant starch. The jelly samples were stored at 4˚C for two weeks. pH, acidity, dry matter, firmness, probiotic bacterial count and sensory properties (taste, odor, texture, color and overall acceptance) of the samples were evaluated on the first, 7th and 14th days of jelly production. Seven samples including 6 treatments and 1 control sample (without probiotic bacteria and prebiotic compound) with three replications were studied. The data were subjected to analysis of variance (ANOVA), followed by the Duncan’s multiple range test to determine the significant difference between samples at 95% confidence level (p<0.05) using the SAS 9.4 M4 Software. The charts were drawn by Excel 2013. Results and discussion: The results of sensory evaluation showed that the effect of different percentages of oligofructose on the sensory parameters, except for the taste, was not significant (p>0.05). Using 1.5% oligofructose and probiotic bacteria (free or microencapsulated) did not change the score of taste but the use of 3% oligofructose and free probiotic bacteria decreased the score of this parameter. The effect of storage time on sensory properties (taste, odor, texture, color and overall acceptance) was significant (p<0.05) so that with increasing storage time, the score of sensory parameters decreased. The results of physicochemical tests indicated that with increasing oligofructose, dry matter increased and acidity decreased (p<0.05). The results of texture analysis showed that the microencapsulation of probiotic bacteria and addition of oligofructose significantly (p<0.05) increased the firmness of jelly texture. During storage period, pH and dry matter significantly (p<0.05) decreased but acidity and firmness of jelly texture increased. The results of probiotic bacterial count indicated that the use of microencapsulated probiotic bacteria and oligofructose significantly (p<0.05) increased the survival of Lactobacillus rhamnosus. The viability of probiotic bacterai decreased during storage period, t however, the number of probiotic bacteria in the samples was in the range of 106- 107 CFU/g. On the first and 7th days, no mold and yeast contamination was observed in the samples and on the 14th day, the number of molds and yeasts was less than 10 CFU/g. The sample containing microencapsulated probiotic bacteria and 3% oligofructose (sample 4) was selected as the best sample in terms of probiotic bacterial count and textural, physicochemical and sensory quality. Therefore, it is possible to produce synbiotic jelly with the desired quality
Full Research Paper
Food Technology
Faezeh Ghorch Beigi; Alireza Rahman; Fatemeh Hosseinmardi
Abstract
[1]Introduction: With the increasing the global population and the scarcity of food resources, using agricultural waste has become a recent challenge for food scientists. Materials and methods: In this study, to optimize the amount of crop residues and the preparation and formulation of dietary ...
Read More
[1]Introduction: With the increasing the global population and the scarcity of food resources, using agricultural waste has become a recent challenge for food scientists. Materials and methods: In this study, to optimize the amount of crop residues and the preparation and formulation of dietary and beneficial sauce, two crop residues, pistachio peel, and melon seed, were used as flour. In this study, treatments of mayonnaise sauce were formulated using pistachio peel powder with 0, 0.1, 0.5, 0.75, and melon seed flour with 6, 12, 18, 24, 30, and 36%. Mayonnaise treatments were evaluated at time intervals of the production day, 30th day, 60th day, 90th day for pH, moisture content, ash (%), fat (%), carbohydrate (%), protein (%), colorimetric indices (Lightness, redness, yellowness), viscosity, total microbial population, stability test, and particle size. For the sensory evaluation, the 5-point hedonic test was performed by ten trained panelists scoring these components (color, taste, texture, fluctuation, consistency, general acceptance). Statistical analysis was performed using Minitab 17 software at the statistical level of 0.05. Results and discussions: The results showed that moisture content, carbohydrate, ash, protein, pH, viscosity, and particle size were increased by increasing pistachio peel powder and melon seed flour. Total microbial population and the stability of mayonnaise treatments were significantly decreased (p≤0.05). Also, by increasing storage time, moisture content and the stability of mayonnaise and particle size were increased. Rheological indices such as cohesion decreased, and firmness and adhesion indices were increased (p≤0.05). All sensory scores of mayonnaise treatments decreased during storage time, and finally, treatment coded T1(0.1% replacement of pistachio green peel powder and 6% melon seed flour) was selected as optimal, and T6 with 0.75% replacement of pistachio green peel powder and 36% melon seed flour) as worst sample. The use of pistachio peel powder and melon seed flour significantly reduced the microbial population of mayonnaise treatments. Higher values than the optimum treatment cannot be used due to decrease in the stability and increase in the microbial population, as well as reduction of sensory scores.
Full Research Paper
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 ...
Read More
[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
Full Research Paper
Amir Rezaei; Masoud Rezaei; Mahdi Alboofetileh
Abstract
[1]Introduction: Nowadays, pH indicator has engrossed wide attention because of its eligibility to monitoring shelf life. Intelligent packaging is authoritative of detecting, sensing, tracing, recording and communicating properties to provide information is communicated directly through color changes. ...
Read More
[1]Introduction: Nowadays, pH indicator has engrossed wide attention because of its eligibility to monitoring shelf life. Intelligent packaging is authoritative of detecting, sensing, tracing, recording and communicating properties to provide information is communicated directly through color changes. In the meantime, natural anthocyanins are non-toxic, water- soluble and safe dye that are indicator to pH change. Anthocyanins are a large group of natural dyes. Some natural anthocyanin, such as anthocyanin extracted from mulberry, black bean, blueberry and violet basil (Ocimum basilicum) are used to spoilage monitoring. In present study, an intelligent pH-indicator film based on Arabic gum- Carboxymethyl cellulose incorporated with Violet basil (Ocimum basilicum. L) Anthocyanin was prepared and its properties including structural, physical, mechanical, thermal, antioxidant activity and color sensitivity to changing pH and ammonia gas were evaluated. Materials and methods: For this purpose, at first anthocyanin of Violet basil was extracted and its color reactions were investigated. In next step, the extracted anthocyanin was added to Arabic gum- Carboxymethyl cellulose at different concentrations (40, 60 and 80 mg/100 g film formation solution) and their properties were evaluated. Results and discussion: The results of FTIR and XRD tests showed that the extracted anthocyanin was successfully dissolved in the composite film. Addition of anthocyanin to film matrix led to increasing the WVP and antioxidant activity and decreasing the water contact angle, elongation at break (EB) and thermal properties. The tensile strength value of the prepared films increased from 19 to 23.64 MPa with increasing anthocyanin content from 0 to 60 mg/100 g film solution; but, it decreased with further increase of the anthocyanin content. Exposing the indicator films to ammonia gas and different pHs led to changing the color changes from red to yellow. These color variations of films were consistent with the color changes of the anthocyanin solution. This result indicates that the films prepared sensitive to pH change, and observed different color in films as the solution is changed from acidic to alkaline because causes its structural changes. The structure of anthocyanin is yellow salt ions in acidic solutions, is converted to quinoidal in weak alkaline solutions, and becomes unstructured in high pH solutions.In this study, pH indicator films were prepared based of Carboxymethyl cellulose and Arabic gum containing violet basil anthocyanin. The developed films are non-toxic and biodegradable and provide visible color response. Based on these results can be concluded that the indicator film prepared in present study could be used as intelligent food packaging for visual evolution of freshness/spoilage in food products
Full Research Paper
Paniz Khaloo Kermani; Marzieh Moeenfard; Reza Farhoosh; Arminda Alves
Abstract
[1]Introduction: Date seed are considered as a valuable by-product from Phoenix dactylifera L. which played an important role in the economy and social life of the people of the Middle East and North Africa region. They consist mostly of carbohydrates, fatty acids and proteins as well as phenolic compounds. ...
Read More
[1]Introduction: Date seed are considered as a valuable by-product from Phoenix dactylifera L. which played an important role in the economy and social life of the people of the Middle East and North Africa region. They consist mostly of carbohydrates, fatty acids and proteins as well as phenolic compounds. Despite the presence of various beneficial bioactive compounds, they are usually discarded or are utilized as animal fodder. Therefore, explore the effective methods to incorporate date seeds in the human diet is a great of interest. Roasting provides a low cost and easy approach to add value to these wastes as roasted date seed powder is being used in the Arabian region to make “date seed coffee”. However, along with color and aroma changes, carcinogenic substance such as acrylamide may also formed during the roasting process. To date, no data have been published on the analysis of acrylamide in the roasted date seeds and respective brews. Therefore, the objective of the present study was development of an analytical method for determination of acrylamide in various date seeds varieties and their respective moka brews for the first time. Besides, other parameters related to the roasting process such as the color parameters and melanoidins content were also determined and compared with values obtained from Arabica coffee. Materials and methods: For this purpose 5 different varieties of roasted date seeds including Shahani, Zahedi, Kabkab, Mazafati and Estamaran as well as Arabica coffee were used for coffee brewing. For acrylamide determination in solid samples, they were firstly extracted using hot deionized water. Afterwards, 5 mL of sample (extract or coffee brew) was placed in a 15 mL falcon and extraction solvents including acetonitrile (10 mL), hexane (5 mL) along with 1 g of NaCl and 4 g of MgSO4 were added. After mixing on vortex for 1 min and centrifugation (5 min, 5000 rpm), 2 mL of the supernatant was cleaned using appropriate combination of sorbents (100 mg PSA, 50 mg C18 and 50 mg SAX) along with 0.30 g of MgSO4.The cleaned supernatant was filtered and analyzed using high-performance liquid chromatography coupled with a photodiode array detector (HPLC-PDA) at 202 nm. The injection volume was 20 μL. The chromatographic separations were performed on a Eurospher 100-5 C18 column (250× 4.6 mm). Optimization was performed according to the type of organic solvent (acetonitrile and methanol), the percentage of organic solvent in the mobile phase (10, 5, 3% v/v) and the flow rate (0.1, 0.7, 0.5 mL/min). The color parameters (using photography and help of ImageJ software) and melanoidin content (spectrophotometrically at 420 nm) were also determined. Results and discussion: The results indicated that the water/acetonitrile with a ratio of 97:3 and a flow rate of 0.7 mL/min permitted the acceptable separation of the acrylamide peak from the interfering compounds. The LOD and LOQ of optimized analytical method were 9.1 and 30.62 µg/kg, respectively. The suggested HPLC/PDA method is promising for analysis in order to guarantee the quality control of acrylamide. The presence of acrylamide in all roasted date seeds was observed. Accordingly, acrylamide content in Arabica coffee (1825.23± 17.44 µg/kg) was significantly higher than those obtained from date seeds varieties. The amount of acrylamide in different types of date seeds varied from 360.99± 4.15 to 129.43± 2.37 µg/kg, being Kabkab and Mazafati as the highest and lowest values, respectively. Moka brews prepared from roasted date seeds demonstrated the presence of acrylamide in the range of 25-68 µg/L. The highest level of melanoidin were observed in Arabica coffee followed by Shahani, Zahedi, Kabkab, Mazafati and Estamaran, respectively. In the most cases, an inverse relationship was observed between the acrylamide and melanoidin content in roasted date seeds. For example, Shahani had low acrylamide and high melanoidin content. The study of color parameters revealed that the parameters a* and b* largely follow the pattern of melanoidin, so with increasing the amount of a* and b*, the amount of melanoidin also increased in the samples.
Short Article
Soheyl Reyhani Poul; Sakineh Yeganeh; Reza Safari
Abstract
[1]Introduction: Nisin is one of the antimicrobial substances that is used today as a preservative in various foodstuffs. It is a bacteriocin comprised of 34 amino acids and a molecular weight of 3.5 Da. With all the benefits of nisin, there are barriers to its use in dairy and protein rich products. ...
Read More
[1]Introduction: Nisin is one of the antimicrobial substances that is used today as a preservative in various foodstuffs. It is a bacteriocin comprised of 34 amino acids and a molecular weight of 3.5 Da. With all the benefits of nisin, there are barriers to its use in dairy and protein rich products. One of these barriers is the combination of nisin with fats, proteins and sugars and the consequent reduction of its antibacterial activity. In the food science and industry, the use of the technique of encapsulation and production of liposome is the best possible solution in such cases. Also, by adding an antimicrobial agent such as chitosan to the coating of nanoliposomes, the antibacterial activity of the product may be increased. The aim of the present research was to produce nanoliposomes carrying nisin with (and without) chitosan coating and to evaluate the physical and antibacterial properties against two gram-positive bacteria, Bacillus cereus and Staphylococcus aureus. Materials and Methods: In this study, four treatments of nanoliposomes carrying nisin (NN), nanoliposomes carrying nisin coated with chitosan 0.05% ((NN-CH (0.05)), nanoliposomes carrying nisin coated with chitosan 0.1% (NN-CH (0.1)) and nanoliposomes carrying nisin coated with chitosan 0.5% (NN-CH (0.5)) were prepared and examined in terms of physical properties (average particle size, particle dispersity index, zeta potential and encapsulation efficiency) and antibacterial activity (against two gram-positive bacteria, Bacillus cereus and Staphylococcus aureus with two diffusion methods in agar medium and microdilution test). This research was conducted in a completely randomized design and SPSS and EXCEL softwares were used for statistical analysis and drawing of diagram, respectively. Data were analyzed by one-way analysis of variance and the difference between the means was evaluated by Duncan's test at 95% confidence level. Results and Discussion: The results showed that the average particle sizein different treatments with each other are significantly different (P<0.05) and vary from about 110 to 327nm; Also as the amount of chitosan in the coating increased, the particle size increased (P<0.05). This indicates the successful binding of chitosan to the surface of the nanoliposome, which results in the formation of a layer around the nanoliposome and an increase in particle size. Particle dispersity index was recorded less than 0.3 in all treatments and was not related to the amount of chitosan in the coating. With increasing the amount of chitosan in the coating of nanoliposomes, zeta potential increased significantly (P<0.05). This index changed from -55.34 in NN treatment to 53.14 mV in NN-CH (0.5) treatment. In fact, chitosan as a cationic polysaccharide changes the potential to positive values. As the amount of chitosan in coating of nanoliposomes increased, the encapsulation efficiency increased significantly in the treatments (P<0.05); this index increased from 32.19% in NN treatment to 75.14% in NN-CH (0.5) treatment. The results of the antibacterial activity of nisin in two methods of diffusion in agar medium and microdilution test showed that its antibacterial activity increased with nanoencapsulation of nisin with (and without) chitosan coating (p<0.05). Also, with the increase in chitosan concentration, the antibacterial activity of carrier nanoliposomes increased and the highest antibacterial activity was recorded in NN-CH (0.5) treatment (p<0.05). The diameter of the non-growth halo of Bacillus cereus against the research treatments (with five concentrations of 2.5 to 25 μg/ml) varied from about 4.5 to 17.5 mm. This amount for Staphylococcus aureus was recorded from 2.1 to 26.5 mm. By increasing the concentration of nisin and carrier nanoliposomes, the diameter of the halo of non-growth of both bacteria increased significantly (p<0.05). But an exception was recorded in this case; The diameter of the non-growth halo for Staphylococcus aureus in two concentrations of 2.5 and 5 μg/ml of treatments was the same and had no significant difference (p>0.05). The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the examined treatments for Bacillus cereus were in the range of 100 to 400 and 200 to 500 μg/ml, respectively. These two concentrations for Staphylococcus aureus were recorded as 50 to 200 and 100 to 400 μg/ml respectively. Based on the values of diameter of non-growth halo, MIC and MBC it can be claimed that Bacillus cereus is more resistant to the examined treatments than Staphylococcus aureus.Nanoencapsulation of nisin in the form of carrier nanoliposomes with chitosan coating is a suitable solution to improve its physical and antibacterial properties. In such a way that by increasing the concentration of chitosan in the coating, both of the aforementioned properties improved significantly. Nanoliposomes carrying nisin with (and without) chitosan coating have the ability to inhibit the growth and killing Bacillus cereus and Staphylococcus aureus bacteria. The antibacterial activity increases with the increase in nisin and carrier nanoliposomes concentrations. The value of non-growth halo, minimum inhibitory concentration and minimum bactericidal concentration confirm that Bacillus cereus is more resistant to nisin and its carrier nanoliposomes than Staphylococcus aureus.
