Research Article
Food Technology
Mahtab Moradnia; Akram Arianfar; Ali Mohamadi Sani; Zahra Sheikholeslami
Abstract
IntroductionDonut is a type of sweet fried snack which is usually produced from leavened and deep fried dough. The deliciousness and high energy of donut has made it very popular among sweet products made from wheat flour. The sensitivity of wheat flour to weather conditions as well as bad economic conditions ...
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IntroductionDonut is a type of sweet fried snack which is usually produced from leavened and deep fried dough. The deliciousness and high energy of donut has made it very popular among sweet products made from wheat flour. The sensitivity of wheat flour to weather conditions as well as bad economic conditions in recent years led to perfomingt research to replacewheat flour with other grains. Quinoa is a rich source of protein (the essential amino acids lysine, methionine, cysteine, and threonine), magnesium, fiber, vitamin B, potassium, and other minerals such as iron. Quinoa seeds have less starch than other grains (wheat, barley, corn, and rice). The value of dietary fiber in quinoa is much more in comparison to other grains, it had about 31% insoluble fiber. Also, as a source of phytoestrogens, it prevents cancer, cardiovascular diseases, and osteoporosis. The main problem with quinoa to be used for human diet is the presence of saponin in the outer shell of the seed. Saponins are considered anti-nutritional agents due to their hemolytic activity on red blood cells, bitterness, foaming ability, and inhibition of enzymes. Therefore, the most important step for using quinoa in food products is to remove saponin. The other problem with using saponin its too bitterness hence causing bloating and heartburn. This study aimed to choose the best saponinization method from quinoa and the possibility of using the saponinization quinoa instead of wheat in donut formulation and investigation the quality, texture, and sensory properties of the donuts. Materials of Methods The methods for saponin removal include (maceration, microwave, ultrasound, wet method, and a combination of wet and dry methods) were compared. Donuts were produced with quinoa flour at two levels of 20 and 40% substitution. The Fiber, ash, and protein values of wheat flour, saponinized quinoa flour, and donuts with different levels of saponinized quinoa flour were measured. The effect of replacement wheat flour with saponinized quinoa flour on oil absorption, texture, SEM, and sensory properties of donuts was evaluated. Results and Discussion A comparison between different methods of saponinization indicated that the ultrasound method had the minimum efficiency in saponin removal and the highest amount of saponin removal was in the combined wet and dry methods, followed by the maceration method. The difference between the combined method and maceration was not significant and had the most influence in extracting saponin from quinoa flour. Of course, the maceration method is economically important due to the long time of the process and production of a lot of waste water leading to loss of nutrients from quinoa. The highest amount of protein, fiber, and ash was obtained in saponinized quinoa flour and a donut containing 40% quinoa flour. The amount of firmness, elasticity, SEM, and sensory properties in the sample with 20% quinoa flour had similar characteristics to the control sample, but increasing the amount of quinoa flour reduced these factors. The oil absorption percentage in donuts containing 40% quinoa flour was higher than in other samples. The results of using saponinized quinoa flour on the sensory characteristics (color crust and crumbs, taste, smell, texture and overall acceptance) of donuts showed that donut with 20% quinoa was similar to the control sample and was acceptable for panelists but increased the concentration up to 40% wasn’t pleasant. Conclusion In this study, the saponinized quinoa flour used in donut formulation to increase the nutritional value and reduced the calories of donuts also overcame the challenges of wheat shortage. The saponinization methods were compared to choose the method with the highest saponin removal. Then donut with saponinized quinoa flour was prepared. The use of saponinized quinoa flour as a replacement of wheat flour increased the nutritional value of donuts. Adding saponinized quinoa flour to the donuts formulation significantly declined the oil absorptions. Generally, the donuts containing saponinized quinoa flour had relatively similar sensory properties to the donuts with wheat flour (commercial donuts). Therefore, it seems that saponinized quinoa flour could be used successfully to improve the nutritional value of donuts and also consumers' acceptance.
Research Article
Food Technology
Hoda Ghorbanzadeh; Jafar Mohammadzadeh Milani; Ali Motamedzadegan
Abstract
IntroductionWith the growth of the population and increasing demand for obtaining food and supplying the required food, the interest in the cultivation and consumption of edible mushrooms has increased. Since 1990, the world has focused on the mushroom production industry. In recent years, mushrooms ...
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IntroductionWith the growth of the population and increasing demand for obtaining food and supplying the required food, the interest in the cultivation and consumption of edible mushrooms has increased. Since 1990, the world has focused on the mushroom production industry. In recent years, mushrooms have become one of the most important food and medicinal sources. One of the largest species of edible mushroom is button mushroom (Agaricus bisporus), which has high nutritional value due to the presence of fiber, carbohydrates, protein, amino acids, minerals, vitamins, etc., and also its antioxidant, anti-cancer, and anti-diabetic properties. This commodity has shown good health benefit for humans. The quality of button mushrooms is determined by their color, texture, and taste. Color is the first characteristic that is perceived by consumers. Browning is one of the main reasons for the loss of mushroom quality, which reduces the commercial value of mushrooms. Edible coating is considered as the best method for maintaining quality of perishable foods, these coatings almost prevent the penetration of oxygen, depending on the type of coating used, and reduce the loss of moisture during storage. Chitosan has functional characteristics such as antimicrobial and antioxidant properties. The purpose of this research was to find a suitable chitosan coating for button mushrooms that can maintain its characteristics such as color, texture hardness, and moisture during the storage period and increase the shelf life of mushroom. Materials and MethodsTo make chitosan solutions, first, each type of chitosan (70% deacetylated, 80% deacetylated, 90% deacetylated, and 100% deacetylated) was weighed in amounts of 0.5g, 1g, and 2g., then it was dissolved in 100 ml of 0.5% acetic acid and stirred for 12 hours at a speed of 1000 rpm at room temperature to dissolve uniformly. After 12 hours, each sample was centrifuged for 15 minutes at 6000 rpm at 25°C to separate undissolved materials. Mushrooms were prepared freshly harvested, washed with water, and then excess water was removed. After sorting and screening in terms of size and approximate weight, the mushrooms were added to 0.5%, 1%, and 2% chitosan solutions without being sliced and were immersed in the solution for one minute. The control sample was immersed in 0.5% acetic acid solution for one minute. After that, the mushrooms were air-dried at room temperature for one hour, and at the end, their excess water was removed with a tissue. The mushrooms were placed in 18*14 size polyethylene zip lock bags and stored in a refrigerator at 4°C. The effects of chitosan coating on weight loss, color and browning index, enzyme activity, texture, and total phenolic compounds of mushroom were studied. Results and DiscussionThe spoilage of edible mushrooms happens in a short time, and the storage of mushrooms has become one of the most important challenges in mushroom marketing. Coating edible mushrooms is one of the suitable methods to increase the shelf life of edible mushrooms. In this research, chitosan with four degrees of deacetylation and three different concentrations was used as a coating for button mushroom. The results indicated that coating the mushroom with chitosan could delay the occurrence of spoilage and change its color or texture. Due to the very strong antimicrobial properties of chitosan, it is suggested to investigate the microbial load of edible button mushrooms ans other tissue factors of the mushroom, such as gumminess, adhesive properties and cohesieveness. ConclusionThe spoilage of edible mushrooms happens in a short time, and the storage of mushrooms has become one of the most important things in mushroom production. Coating edible mushrooms is one of the suitable methods to increase the shelf life of edible mushrooms. In this research, chitosan with four degrees of deacetylation and three different concentrations was used as a coating for button mushroom. The results indicated that coating the mushroom with chitosan could delay the occurrence of spoilage and change its color or texture. Due to the very strong antimicrobial properties of chitosan, it is suggested to investigate the microbial load of edible button mushrooms, also other tissue factors of the mushroom, such as gumminess, adhesive properties and cohesieveness can be studied.
Research Article
Food Technology
Zohre Ganjeh-Soltanabadi; Rezvan Shaddel; Younes Zahedi
Abstract
IntroductionNowadays, the attention and desire of consumers to the role of food in health and nutrition has led the manufacturers to produce functional food and researchers to study this field. Polyphenols are secondary metabolites produced by many plants. They have anti-obesity, anti-inflammatory, anti-cancer ...
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IntroductionNowadays, the attention and desire of consumers to the role of food in health and nutrition has led the manufacturers to produce functional food and researchers to study this field. Polyphenols are secondary metabolites produced by many plants. They have anti-obesity, anti-inflammatory, anti-cancer and antioxidants activities. Despite all the mentioned benefits, due to the vulnerability of phenolic compounds to the environmental conditions and their low bioavailability in the digestive system, efforts have been made to encapsulate them with nanoniosomes. Encapsulation of polyphenolic compounds with nanoniosomes is an effective way to increase their stability and bioavailability as well ashinder their undesirable taste and smell. Niosomes are class of bi-layered structure formed by hydration of non-ionic surfactant, cholesterol or other amphiphilic molecules. This structure has two hydrophilic and hydrophobic properties, so it has the ability to be encapsulated with different solubility. Fortification food with polyphenols promotes community health. Therefore, the aim of this research was to produce nanoniosomes containing polyphenolic compounds, and to determine their important physical and chemical properties.Materials and MethodsIn this research, four polyphenol-loaded nanoniosomes were prepared using Span 60 and Tween 80 surfactants with a ratio of 3:1, and cholesterol with the concentration of 0, 10, 20 and 30 (mg/140 mg surfactant) as F1, F2, F3 and F4 treatments respectively. Physicochemical properties of the polyphenol-loaded niosomes (particle size, polydispersity index (PDI), zeta potential, encapsulation efficiency (EE)) were analyzed, and the formulation with the best characteristics was selected based on having the smallest size, less PDI and the highest EE. The selected formula was analyzed for morphology (scanning electron microscope (SEM)) and probably interactions (Fourier transforms infrared spectrometry (FTIR)). Additionally, the ability to preserve polyphenolic compounds as free or inside the nanonisomes during the storage period of 60 days was investigated. Further, the in vitro release of polyphenol from niosomes (gastric and intestinal simulated fluid) was also evaluated. The experiment was performed as completely randomized design (CRD) and the obtained data were analyzed with one-way analysis of variance (ANOVA).Results and DiscussionResults indicated that the effect of using different amounts of cholesterol on the average particle size (Z-average) of nanonisomes was significant (p<0.05). With increasing cholesterol up to 20 mg (F1 to F3), the Z-average decreased, but with further increase to 30 mg (F4), the Z-average increased. Different concentrations of cholesterol showed significant influence on the PDI of nanonisomes. The minimum value was observed for F3 (20 mg cholesterol) and the maximum for F4. The incorporation of cholesterol in the nanonisomes decreased the zeta potential (p<0.05), dedicated an increased electrostatical stability of the particle, and the values were in the range of -50.35 to -65.36 mV. The value of EE was in the range of 88-95%, and F3 treatment had the maximum EE. Based on particle size, PDI, zeta potential and EE, F3 was selected as the best nanoparticle for other assays. According to the FTIR results, there was no change in the spectrum of nanonisome (F3) containing polyphenol peaks, and the polyphenols were properly enclosed in the nanonisomal vesicles without changing its nature. SEM results also showed vesicles with a uniform and appropriate structure. Nanonisome (F3) containing polyphenol was more stable than the control sample (polyphenol) during 60 days of storage at ambient temperature, which indicated the higher potential of nanonisomes to preserve the polyphenolic compounds during storage. The release behavior in the simulated digestive system (gastric and small intestine media) indicated a diffusion-based release system, and the Kopcha model was the best model to describe the release behavior of polyphenol from the fabricated niosomes in the simulated digestive environment.ConclusionAccording to the results of this research, it is concluded that nanoencapsulation of polyphenols as a rich source of antioxidant properties inside the nanonisomes can be an effective strategy to maintain their nutritional value. These nanonisomes can be utilized to produce functional foods, and the effects of their addition on the physico-chemical properties of a model food can be investigated.
Research Article
Food Biotechnology
Marjan Nouri
Abstract
IntroductionFish supplies a type of nutrients containing protein and long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs) and micronutrients such as selenium, iodine, potassium, D and B-vitamins. Groupers are one of the best fishes in the south of Iran that are extensively distributed in tropical ...
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IntroductionFish supplies a type of nutrients containing protein and long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs) and micronutrients such as selenium, iodine, potassium, D and B-vitamins. Groupers are one of the best fishes in the south of Iran that are extensively distributed in tropical and warm waters all over the world. The perishability is considered as one of the main problems for fish with high nutritional value in food supply chains during the shelf life. The use of edible coatings indicates a novel method to extend the shelf life. The aim of present research was to apply biodegradable chitosan/ chia mucilage coating containing Rubia tinctorum L. plant extract (0, 0.5, 1 and 2 % as T1, T2, T3 and also T4) on the surface of grouper fillet fish to maintain qualitative and microbial attributes during the shelf life (1, 15, 30 and 45 days).Materials and MethodsThe qualitative and qualitative assays (peroxide index (meq O2/kg sample), thiobarbituric acid (mg MA/kg), total volatile nitrogen (mg /100 g) and trimethylamine (mg /100 g)), microbial counts (aerobic mesophilic and lactic acid bacteria, total coliforms, mold and also yeast), texture (hardness, adhesion, flexibility, cohesiveness and gumminess), sensory attributes (taste, smell, color, texture and overall evaluation) and measurement of identified biogenic amines were carried out during the shelf life.Results and DiscussionThe results illustrated that oxidation parameters of treatments such as peroxide index, trimethylamine, total volatile nitrogen components and thiobarbituric acid were declined by increasing the extract concentration in a fixed time period (p ≥ 0.05). The highest and lowest microbial loads were obtained in T1 and T4 during the storage, respectively. The microbial counts increased significantly (p < 0.05) by extending the storage time of treatments and on the other hand, this decreased significantly (p < 0.05) by increasing the concentration of Rubia tinctorum L. extract in a fixed period of time. The utilization of Rubia tinctorum L. extract and chia mucilage in a coating of chitosan created a synergistic effect and led to a lower microbial load in treatments. On the other hand, a reduction was occurred in textural attributes particularly cohesiveness and hardness through moisture loss and drying of coating surface in fillets during storage (p < 0.05). The softening tissue could be related to the higher microbial activities during storage, although intensity of these changes was lower in T3 and T4 treatments due to the lower microbial load, which indicated the positive effect of Rubia tinctorum L. extract on maintaining tissue quality. All examined factors changed and most of the mentioned parameters in T1 and T2 exceeded the permissible limit during storage, but T3 and T4 had better conditions during storage. Finally, fish fillet coated with 1 % Rubia tinctorum L. extract (T3) compared to others demonstrated better sensory evaluation at the end of shelf life, which was selected as the superior treatment. The type and amount of biogenic amines in control and T3 (superior sample) illustrated that the highest amine compound was recorded for histamine at 79.87 (mg/kg) on the 15th day and the lowest level in tyramine at 0.79 (mg/kg) on the 1st day of storage. The concentration of amines increased significantly during storage time (p < 0.05).ConclusionThe results shown that applying chitosan/ chia mucilage coating including Rubia tinctorum L. extract has significant effect on extending the shelf life of fish fillets.
Research Article
Food Technology
Maryam Akbari govarchin galeh; Mohammad Javad Varidi; Mehdi Varidi; Hanieh Yarabbi
Abstract
Introduction Mayonnaise is one of the world’s most popular sauces. It is a semi-solid oil-in-water emulsion made by mixing vegetable oil, egg yolk, water, vinegar, and other ingredients. Due to the high calorie and cholesterol content of egg yolks, excessive consumption of mayonnaise can lead ...
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Introduction Mayonnaise is one of the world’s most popular sauces. It is a semi-solid oil-in-water emulsion made by mixing vegetable oil, egg yolk, water, vinegar, and other ingredients. Due to the high calorie and cholesterol content of egg yolks, excessive consumption of mayonnaise can lead to health-related problems. Major issues faced by mayonnaise producers include fat oxidation during storage, which leads to off-flavor and taste, as well as reduction in nutritional value and food safety. These factors may negatively affect on the consumer acceptance of mayonnaise. With increasing consumer demand for low-fat and low-cholesterol foods, low-fat mayonnaise has significant consumption potential. One of the consumer demands is to reduce the fat content in mayonnaise and salad dressing. Fats play many functional roles in food emulsions, contributing to the taste, appearance, texture, and shelf life of the product in specific ways. Therefore, it is challenging to maintain the quality of traditional products when preparing low-fat foods. It is possible to select specific fat substitutes in particular amounts to create a product with a texture similar to traditional mayonnaise. Light mayonnaise often contains certain fats added to help stabilize the emulsion and thicken its consistency. This research studied the possibility of using aloe vera gel as partial fat substitute in mayonnaise.Materials and MethodsAll the powdered ingredients were mixed together with eggs, water, and half of the required amount of vinegar in a blender for 3 minutes. To form an emulsion, oil was added in two stages while stirring together with starch and gums for 5 minutes. Mixing oil and the aqueous phase simultaneously leads to the formation of a water-in-oil emulsion. Finally, the remaining vinegar was added and mixed for 3 minutes until the fat particles were evenly dispersed in the sauce. Aloe Vera gel was also added in proportion to the reduction of oil according to the formulation of the samples. The optimal mixture design was used for three independent variables: oil A 15-60%, gel B 0-55%, and water C 0-10%. The multiple combinations of these variables led to an experimental design with 16 samples that were determined using Design Expert software, and the physicochemical, rheological, and textural characteristics of the samples were investigated. Additionally, suitable regression equations and mixed contour diagrams were obtained by this software for each response.Results and DiscussionThe results showed that increasing the replacement percentage of aloe vera gel and decreasing the percentage of oil led to an increase in pH and a decrease in acidity, stability, textural properties, and transparency of the samples. To describe the rheological properties, Bingham's model was used, and the viscosity parameters and Bingham's yield stress were investigated with an increasing the percentage of aloe vera gel replacement. Additionally, the apparent viscosity of the samples exhibited a decreasing trend and thinning behavior with shear. These changes in characteristics are attributed to the effect of adding fat to the mayonnaise formulation. The optimal values of independent variables in the production of low-fat mayonnaise were oil (40%), aloe vera gel (30%) and water (0%), respectively.ConclusionThis research showed that aloe vera gel can be used in the formulation of mayonnaise as apartial substitute to oil. Due to the strong demand from consumers for this product, reformulating this high-fat emulsion is a fundamental need in the food industry. The use of aloe vera gel offers many benefits, including reducing cholesterol and fat levels overall, increasing microbiological stability, and, in some cases, lowering manufacturing costs.AcknowledgementThanks to the staff and research and educational officials of Ferdowsi University of Mashhad (Project Code: 2663532).
Research Article
Food Technology
Fateme Eini Tari; Abdollah Ehtesham Nia; Hasan Mumivand; Mohamadreza Raji
Abstract
IntroductionThe rapid increase in population has raised concerns about food security in the world. On the other hand, to produce more food, in line with population growth, it is necessary to consider sustainable development goals so that the increase in production does not lead to excessive use of resources ...
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IntroductionThe rapid increase in population has raised concerns about food security in the world. On the other hand, to produce more food, in line with population growth, it is necessary to consider sustainable development goals so that the increase in production does not lead to excessive use of resources and environmental damage. Therefore, one of the effective ways to develop food security in line with sustainable development is to reduce the waste of agricultural products, especially garden products.Materials and MethodsThis study aims to investigate the effect of chitosan and essential oil foliar spraying pre- and calcium chloride immersion post- harvesting on Golden delicious apple fruits grafted on MM 111 (Malling Merton 111) in an 18-year-old apple orchard. A factorial experiment in the form of a completely randomized design and in four replications (each replication containing at least 30 fruits) was carried out in 2 hectares orchard located in the Abistan region of Khorram Abad city in 2021. The first factor of pre-harvest and post-harvest foliar treatments including control treatments (spraying solution with distilled water), foliar spraying of chitosan (100 mg/l) and essential oil (2500 mg/l), and immersion of harvested fruits with Calcium chloride solution (2 %) in the post-harvest stage, and the second factor is the storage period (in days 0, 60, 90 and 120 days after storage (which according to the high storage life of the apple fruit and performing the pre-test and until the end of life) Fruit storage was achieved. Results and DiscussionThe results of the analysis of variance showed that the effect of treatments and storage time on all desired characteristics was significant at the 1% level. Treated fruits had higher total phenolic and flavonoid content, antioxidant activity, vitamin C, and titratable acids and lower taste index, acidity, soluble solids, malondialdehyde, PPO activity and weight loss than the control. The highest amount of total phenol and flavonoid content, antioxidant activity, vitamin C, and titratable acids in all four measurement times belonged to chitosan + essential oil + calcium chloride treatment and the lowest amount was related to the control treatment. Also, in the control treatment, the amount of malondialdehyde, soluble solids, taste index and acidity increased during the storage period. In the fruits treated with chitosan + essential oil, the lowest acidity and soluble solids were observed, and in the chitosan treatment alone, higher titratable acids and the lowest taste index were observed. In general, based on the obtained results, it was observed that the application of chitosan and essential oil before harvesting and calcium chloride after harvesting improved the quality characteristics of Golden Delicious apple fruit. Weight loss is mainly caused not only by sweating but also by breathing. By forming a membrane on the surface of fruits, chitosan biopolymer acts as a mechanical and physical barrier to reduce gas exchange, and as a result, fruit maturation and aging are affected. Composite coatings reduce weight loss by maintaining hydration and reducing gas exchange and water vapor emission. Edible coatings can act on the phenylpropanoid pathway and increase the level of phenolic compounds in plants, and the phenylpropanoid pathway includes the synthesis of various plant secondary metabolites such as lignin, flavonoids, phenolic volatiles, and tannins. The semi-permeable barrier of the chitosan coating limited the rate of respiration, reduced water loss, and delayed ripening and aging, which resulted in higher total phenolic content during storage. Composite coatings delay the oxidation of phenolic compounds, eliminate metals and free radicals and create a quasi-bonded structure that prevents the passage of infiltrating materials such as O2, CO2, and water vapor.ConclusionIn this research, applying a combination of chitosan + essential oil + calcium chloride as a coating on apple led to increase the vitamin C, antioxidant activity, total phenol and flavonoid content, and reduction the weight loss. In addition, the application of this treatment led to the improvement of other characteristics such as the reduction of malondialdehyde, acidity, soluble solids, taste index, and increase of titratable acids. Therefore, it can be stated that in addition to the fact that these compounds alone improved the quality of apple fruit, their combined use is also recommended as a biodegradable and natural coating to increase the storage life of Golden Delicious apple fruit.
Research Article
Food Technology
Elham Ahmadi; Sara Panahi; Amirhossein Karimzadeh; Hamed Hassanzadeh; Mohammadyar Hosseini
Abstract
IntroductionIn recent years, with increasing concerns about food safety and environmental issues related to waste generated by non-degradable plastic packaging, study on novel biodegradable packaging materials has attracted the attention of researchers. Active packaging based on biopolymers, which offers ...
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IntroductionIn recent years, with increasing concerns about food safety and environmental issues related to waste generated by non-degradable plastic packaging, study on novel biodegradable packaging materials has attracted the attention of researchers. Active packaging based on biopolymers, which offers a sustainable and environmentally friendly way to improve food shelf life, considered one of such packaging technologies. Edible coatings and films, are a thin layer of edible compounds and biopolymers applied on the surface of foodproducts that play important role to control physicochemical, microbial and physiological changes in food. Gelatin is obtained from partial degradation of collagen. Due to its availability, relatively cheap price, biodegradability and good properties such as its excellent ability to form a film and reduce the transfer of oxygen, oil and moisture, it is highly regarded as an edible film and has antimicrobial and antioxidant activity. In general, the gelatin film showed high water absorption due to the presence of several hydrophilic groups, which may weaken the mechanical properties and water vapor transport of the film. For this reason, the combination of gelatin with other biopolymers such as chitosan, starch and gum is a suitable method to eliminate the drawbacks of gelatin-based films.Materials and MethodsTo prepare the composite film of the four formulations studied in this research, gelatin powder (3% by weight/volume of water) and glycerol (30% by weight/volume of gelatin powder) were added to deionized water and magnetically stirred for 10 minutes at 2400 RPM. To prepare an aqueous suspension of carboxymethyl cellulose, powder (CMC 2% by weight/volume of water) and glycerol (30% by weight/weight of carboxymethyl cellulose powder) were mixed with deionized water. This suspension was heated to boiling temperature and kept at this temperature for 15 minutes and then kept for 30 minutes at 90°C water bath and stirred. The G/CMC coating was also prepared by dissolving 40 grams of gelatin, 10 grams of carboxymethyl cellulose and glycerol (30% by weight/weight of polymer materials) in one liter of water. The mixture was stirred for 1 hour at 60 degrees Celsius. The mixture was then dried at 25-35 degrees Celsius. Different concentrations of the extract (0, 0.5, 0.75, 1.5 and 3.25%) were added to the mixture and stirred for 2 minutes. In the next step, the mixture was added to a plastic Petri dish with a diameter of 15 cm and placed under a vacuum hood for 1 hour. Then it was transferred to a fan oven and kept for 20 hours. In the final stage, the dried films were placed in a desiccator at room temperature for testing. The effect of different concentrations of Dorema aucheri extract for the production of edible films on the physicochemical, mechanical, antioxidant and antimicrobial properties was analyzed with one-way analysis of variance (ANOVA) and comparing the average data was performed based on Duncan's multi-range test using SPSS26 software at probability level of 0.05.Results and DiscussionThe highest tensile strength and elongation at break point and Young's modulus in the treatment was 1.5%. In all concentrations, solubility and permeability were significant (p<0.05). The lowest solubility was observed in the control. The highest permeability and turbidity were observed in the treatment of 1.5% Dorema aucheri extract. In all edible film treatments, the antioxidant property using DPPH radicals was significant (p<0.05). The results of the evaluation of the antimicrobial activity of the film with the help of diffusion discs showed that the maximum diameter of the inhibition halo in the concentration of 3.25% was related to Escherichia coli with an average halo diameter of 5.33 mm. Average halo diameter for Pseudomonas aeruginosaand Staphylococcus aureus was reported as 4 mm and 3.99 mm, respectively. The overall results showed that the addition of Dorema aucheri extract at a concentration of 1.5% produced films that, in addition to inhibiting the growth and proliferation of bacteria, have strength and can be used for perishable food.
Research Article
Food Technology
Karim Mandahakki; Hamid Hassanpour
Abstract
IntroductionDue to the high rate of respiration, strawberry is prone to water loss, mechanical damage and fungal decay post-harvesting, which may reduce its shelf life (Yan et al., 2019). Food waste is an important global challenge that estimated about 30% of the world's agricultural land. Every year, ...
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IntroductionDue to the high rate of respiration, strawberry is prone to water loss, mechanical damage and fungal decay post-harvesting, which may reduce its shelf life (Yan et al., 2019). Food waste is an important global challenge that estimated about 30% of the world's agricultural land. Every year, about 9.5 million tons of food is lost in the post-harvest phase of agriculture crops (Bishop et al., 2021). Post-harvest storage of strawberry at low temperature without using other combined treatments may reduce its shelf life due to its highly perishable nature. Therefore, in addition to low temperature storage, other post-harvest techniques have also been reported to increase the shelf life of strawberry fruits after harvest. One of these techniques is using chemicals (Kahramanoglu et al., 2019).Glutathione is present in various plant tissues in concentrations of 2 to 3 mM and plays an important role in many cellular processes such as cell differentiation, enzyme regulation, cell signaling and cell death and acts as an antioxidant. (Diaz-Vivancos et al., 2015). During the experiment, spraying GSH on strawberry plants increased the amount of total flavonoids and ascorbic acid in the harvested fruits, and the results showed that the application of GSH can increase the shelf life of strawberries. (Ge et al., 2019). It has been reported that application of glutathione after harvesting okra has reduced browning and prevented its weight loss, which has created a suitable market for it, also GSH has increased the level of total phenol and the activity of ascorbate peroxidase enzyme and reduced the level of ROS and malondialdehyde, which can increase the shelf life of okra in cold storage after harvesting (Li et al., 2023).Materials and MethodsSabrina strawberry fruit was obtained from a commercial greenhouse located in Urmia in the full maturity stage. The fruits were transported to the laboratory of Horticultural Sciences Department of Urmia University, observing the necessary precautions to prevent mechanical damage. The fruits were separated in terms of size and uniformity, so that the fruits were divided into 5 groups of 15, one group as a control group and 4 groups treated with different concentrations of L-glutathione (4, 16, 32 and 64 mM respectively). After drying, the treated fruits were placed in zipped nylon bags and stored for 15 days in a cold room at ± 0.5 °C and a relative humidity of 90-95%. Also, three biological replicates at each time interval were included in the analysis. Samples obtained at each of specified time were placed to evaluate skin color, titratable acidity, soluble solids, taste index, pH, weight loss, total antioxidant capacity, total phenol content, and polyphenol oxidase enzyme activity.Results and DiscussionThe results of variance analysis showed that the effect of GSH treatment after harvesting, the effect of storage and the interaction between them differently affect each of the studied indicators. In terms of color, no significant effect was found. The effect of storage (p≤0.01) and post-harvest treatment (p≤0.05) were significant on TA trait and its highest value was observed in 10 days of storage with 32 mM. In terms of antioxidant capacity (p≤0.05) and PPO activity (p≤0.01), the effect of GSH treatment after harvest was significant, and the highest amount was observed in 16 and 64 mM treatment, respectively. Also, the effect of storage time (p≤0.05) and the effect of GSH treatment after harvesting (p≤0.01) were significant in the trait of total phenol content, and the highest amount was observed in 15 days of storage and 64 mM treatment. However, both the storage (p≤0.01) and the post-harvest GSH treatment (p≤0.05) effects on fruit weight reduction were significant and the lowest weight loss was observed in 5 days of storage and 64 mM treatment. There were no significant changes in indices such as TSS, taste index and pH.ConclusionAccording to the obtained results, the treatment of 64 mM GSH is the best concentration of GSH to increase the shelf life of harvested strawberry fruits in cold storage.Author ContributionsManda-Hakki: conceptualization, data management, financing, research and review, resources, validation, visualization, writing-main draft, Hassanpour: formal analysis, methodology, project management, software, supervision, Writing - review and editingFunding SourcesPart of this project was financially supported by Urmia University.AcknowledgementWe appreciate and thank all those who were with us in this project, especially the officials of Horticulture Laboratory, Faculty of Agriculture, Urmia University.
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