Research Article
Food Technology
Mohammad Fazli Rad; Jafar Milani; Sepide Haghighat
Abstract
IntroductionWheat plays a major role in global nutrition but it cannot be used without processing. The nutritional importance of wheat flour is due to the presence of gluten proteins that create viscoelastic properties. Gluten as a protein inhibits the staleness of bread. Physical modification of flour ...
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IntroductionWheat plays a major role in global nutrition but it cannot be used without processing. The nutritional importance of wheat flour is due to the presence of gluten proteins that create viscoelastic properties. Gluten as a protein inhibits the staleness of bread. Physical modification of flour is a safe method without using any kind of chemicals. Physical modification of flour includes heat treatment and particle size classification. Particle size distribution is the most widely used technique for classifying solid particles, which is effective in improving rheological properties by affecting the physicochemical properties of flour during hydration, such as water absorption, solvent retention, sedimentation, and adhesion properties. Heat treatments, depending on the intensity of temperature and process time, by modifying starch granules, denaturing proteins, and deactivating enzymes, reducing microbial load, and even modifying flavor and aroma are suggested as a suitable way to improve the quality of bread, especially for weak flour. Considering that the interaction of particle size with wet and dry heating of wheat flour on the rheological properties of dough and staleness of bread has not been studied so far. In this research, by dividing wheat flour with different particle sizes and using wet and dry heat treatments for modification the functional characteristics of wheat flour and the improvement of the rheological characteristics of dough and staleness of bread were investigated.Materials and MethodsThe content of moisture, pH, ash, protein, and Zeleny number of wheat flour was measured using the AACC standard method (2000), and wet and dry gluten with the standard number (9639-1, 3) was measured. To classify the size of the particles, wheat flour was divided by a shaker sieve with different sizes of 180, 150, and 125 microns, then under the influence of dry heat treatment for 10 minutes at 100 degrees Celsius and moist heat treatment with 16% humidity for 5 minutes at a temperature of 96 degrees Celsius was placed. Materials for bread formulation for 100 g of wheat flour included 58 ml of water, 2.5 g of sugar, 1 g of salt, 1 g of vegetable oil, and 2 g of yeast. The rheological parameters of the dough were measured by an alveography device. To check the staleness of bread during the storage period, moisture tests of core and shell, blue activity of core to shell, analysis of bread texture, and DSC were performed. Finally, the factorial test was used to investigate the effects of particle size and heat treatment on wheat flour, and Duncan's multiple range test was used to compare the means at the 5% probability level. Results and DiscussionThe results showed that the effect of particle size and dry heat treatment on dough rheology and water activity of bread core and crust was significant, while moist heat treatment had significantly more bread core moisture (p<0.05). According to the results, dry heat treatment did not affect the texture of bread (p>0.05), while the use of flour obtained from moist heat treatment with a particle size of 180 microns led to the improvement of bread texture by reducing the hardness and chewability (p<0.05). The results of thermal analysis showed that the moist heat treatment sample with a particle size of 180 microns had the lowest enthalpy and was the best sample (p<0.05).ConclusionIn general, the use of flour with a particle size of 180 microns and moist heat treatment to improve the rheological and staling properties of bread were the best examples.
Research Article
Food Chemistry
Atfeh Ghorchi; Akram Arianfar; Vahid Hakimzadeh; Sara Naji-Tabasi
Abstract
IntroductionRed beet has nutritional and health-promoting properties due to containing bioactive compounds such as phenolic compounds and betanin. Co-encapsulation of more than one core material in a single encapsulation system may increase the bioactivity of individual components. Customer attitudes ...
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IntroductionRed beet has nutritional and health-promoting properties due to containing bioactive compounds such as phenolic compounds and betanin. Co-encapsulation of more than one core material in a single encapsulation system may increase the bioactivity of individual components. Customer attitudes and behaviors have moved towards health foods because they have more concerns on increasing environmental stresses such as pollution and toxic substances in the environment. Confectionery products are not exactly foods, but they are widely consumed by children and adults. Traditional gummy confection consists of high amounts of synthetic colorings or flavorings in a gelling agent, commonly known as gelatin, along with acids and sweeteners. Natural color in the form of pigments is synthesized and accumulated in living biological cells of algae, vertebrates, invertebrates, fungi, lichens, or bacteria. The red color in food industry comes mainly from two pigments: anthocyanin and betalains. Among the major groups of natural pigments, betalains can be considered as the least studied, due to its limited sources. The main commercially produced crop containing betalain is red beet root, however many researchers are exploring red dragon fruit or pitaya as a viable alternative. Betalains, derived from beetroot are water-soluble nitrogenous pigments that stop or delay the oxidation process and exhibit anti-tumor and antiatherosclerotic effects. The application of red color from beetroot (mainly betalains) is permitted widely in ice cream, sherbet, yogurt, powdered soft drink mix along with confectionaries, soups, and bacon products. The stability of betalains varies with different levels of water activity, temperatures, exposure to oxygen, and light. Complex coacervation is one of the oldest and simplest techniques of encapsulating bioactive compounds for delivery in controlled manner. The technique associates simple preparation conditions, such as non-toxic solvent and low agitation, the techniques has also been employed in the encapsulation of protein and human cells. Microcapsules prepared by complex coacervation are water-insoluble, possessing excellent controlled-release characteristics. Complex coacervation is a technique by which phase separation occurs when oppositely charged polyelectrolytes are electrically balanced in aqueous media. This depends on relatively a set of conditions such as pH, charge density on the polymers, colloid concentration, ionic strength of the medium, temperature, etc. However, all polyelectrolytes do not exhibit this phenomenon.Materials and MethodsThe features of water activity, moisture, acidity, Brix, antioxidant activity, texture characteristics, colorimetry and sensory evaluation of pastilles were investigated. All analyzes were performed with three replications in a completely randomized design. Means were compared using Duncan's multi-range test at a significant level of 5% with SPSS version 22 software.Results and DiscussionThe results showed that water activity of samples containing nanomicrocoating of red beet extract was significantly lower than the control sample (p<0.05), but the moisture, acidity and brix of the sample containing nanomicrocoating of red beet extract were significantly higher from the control (p<0.05). During the storage period of 28 days, it showed that the sample containing 1.5% red beetroot extract's nano-coating had a significantly higher stability of the antioxidant property than other samples (p<0.05). The results of the histological test showed that the sample containing the red beet extract nano-coating had a significant decrease in hardness, stickiness and chewability compared to the control (p<0.05), but the degree of cohesion showed a significant increase (p<0.05). Examining the color parameters of the samples containing red beetroot extract nano-coating compared to the control sample also showed that it caused a decrease in brightness (L*) and yellowness (b*) and an increase in (a*).ConclusionThe results of the sensory evaluation showed that the sample containing 1% red beetroot extract nano-coating was awarded the highest score compared to the control.
Research Article
Food Engineering
Fakhreddin Salehi; Maryam Tashakori; Kimia Samary
Abstract
IntroductionBalangu seed gum (BSG) is a hydrocolloid extracted from the seeds of Lallemantia royleana L.. This gum works as thickener and stablilizer in food products. This gum had high performance compared to some commercially available food grade gums. When this gum is mixed with water, it becomes ...
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IntroductionBalangu seed gum (BSG) is a hydrocolloid extracted from the seeds of Lallemantia royleana L.. This gum works as thickener and stablilizer in food products. This gum had high performance compared to some commercially available food grade gums. When this gum is mixed with water, it becomes thick (viscous fluid) and this gel-like substance becomes thin when stirred or shaken (pseudoplastic behavior) (Salehi & Inanloodoghouz, 2023). The term organic acid refers to organic compounds with acidic properties. The acidity of organic acids is associated with their carboxyl group and therefore they are called carboxylic acids. Organic acids can be classified according to the type of carbon chain (aliphatic, alicyclic, aromatic, and heterocyclic), their extent of saturation and substitution, and the number of carboxyl groups (mono-, di-, tri-carboxylic). Monocarboxylic acids like acetic acid are highly volatile liquids with a pungent taste. Malic and tartaric acids are also dicarboxylic acids that contain one and two hydroxyl groups, respectively. Citric acid is the best-known tricarboxylic acid with one hydroxyl group that is found in foods (Yildiz, 2010). The most abundant organic acid in citrus juice is citric acid. Also, citrus juices such as lemons, oranges, and grapefruits are a good source of ascorbic acid (Nour et al., 2010). pH is an important parameter that affects the rheological properties of hydrocolloid solutions. Addition of acid to an aqueous gum solution leads to changes in pH which affect the viscosity of this solution (Hayta et al., 2020). In this study the effect of four edible organic acids (ascorbic, citric, malic, and tartaric) at two concentrations (0.5, and 1 %) on the viscosity and rheological behavior of Balangu seed gum solution (0.2%, w/v) was investigated.Material and MethodsIn this research, organic acids including ascorbic, citric, malic, and tartaric were purchased in powder form (China) and dissolved in distilled water. Two concentrations of each acid, 0.5% and 1%, were prepared, and the distilled water was considered as the control (0% acid). The Balangu seed gum solutions were prepared by disolving the gum powder (0.20%, w/v) in distilled water containing different concentrations of ascorbic, citric, malic, and tartaric acids using a magnetic stirrer. The rheological parameters of Balangu seed gum dispersions were measured using a viscometer (Brookfield, DV2T, RV, USA) at 20°C. Power law, Bingham, Herschel-Bulkley, and Casson models are common ways of representing the behavior of several gum dispersions. In this research, these models were used to match the shear stress and shear rate results of the gum solutions containing edible organic acids. Differences between means were established using Duncan’s multiple range using SPSS (version 21).Results and DiscussionThe findings of this study showed that the apparent viscosity of Balangu seed gum solution reduced when the shear rate increased. Additionally, the apparent viscosity of the Balangu seed gum solution reduced as the organic acids concentration increased. The highest decrease in viscosity was related to solution containing 1% citric acid and the lowest was related to tartaric acid with a concentration of 0.5%. The rheological behavior of solutions was successfully modeled using Power law, Bingham, Herschel-Bulkley, and Casson models, and the Power law model was the best one for describing the behavior of Balangu seed gum solutions containing organic acids. The Power law model had a good performance with the highest correlation coefficient (>0.9406) and least sum of squared error (<0.0090) and root mean square error (<0.0275) for all samples. The consistency coefficient of the samples reduced as the acid percent was increased. Sample containing 1% citric acid had the lowest consistency coefficient and sample containing 0.5% malic acid had the highest consistency coefficient. The Power law model shows that a fluid with shear-thinning behavior has a value of flow behavior index less than 1 (Kumar et al., 2021). By adding acid to Balangu seed gum solution, the flow behavior index of most samples increased. The Bingham yield stress of all samples reduced when acids percent was increased. The dispersion containing 1% citric acid had the lowest Bingham yield stress and the sample containing 0.5% tartaric acid had the highest yield stress. The Bingham plastic viscosity of the samples reduced when acids percent was increased. The solution containing 0.5% ascorbic acid had the highest Bingham plastic viscosities (0.0038 Pa.s) and the sample containing 0.5% malic acid had the lowest plastic viscosities (0.0014 Pa.s). The results showed that when the ascorbic acid concentration was increased from 0.5% to 1%, the Casson plastic viscosities of the Balangu seed gum solution was decreased significantly from 0.054 Pa.s to 0.042 Pa.s (p<0.05). ConclusionThe results of this study indicated that it is a mistake to use Balangu seed gum in food products containing high concentrations of citric acid, and this acid reduces the viscosity and consistency of the products containing this gum.
Research Article
Food Technology
Maryam Davtalab; Sara Naji-Tabasi; Mostafa Shahidi
Abstract
IntroductionRice is a strategic product and considered as staple food of over half of the world's population particularly in Iran. Considering the high levels of rice waste, including broken grains or those of lower quality, it can be utilized for producing value-added foods and reducing waste. Extrusion ...
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IntroductionRice is a strategic product and considered as staple food of over half of the world's population particularly in Iran. Considering the high levels of rice waste, including broken grains or those of lower quality, it can be utilized for producing value-added foods and reducing waste. Extrusion is a process widely used to improve food products and develop fortified foods. Quinoa flour is rich in phenols, and can be utilized to produce fortified extruded rice. The extrusion of gluten free flours like rice and quinoa has different challenges. In this study, sodium alginate was used to prepare emulsion filled gel to enhance the stability of Pickering emulsions containing β-carotene and also structuring rice during extrusion process. Pickering emulsion is one of the encapsulation methods suitable for encapsulating lipophilic compounds like β-carotene. Emulsion-filled gels, developed using hydrocolloid mixtures, significantly enhance emulsion stability and make them suitable for aqueous food environments. Finally, extruded rice based on a mixture of rice- quinoa flours and fortified with beta-carotene was prepared, and its physico-mechanical properties were evaluated.Materials and MethodsPickering emulsions were stabilized using whey protein- cress gum soluble complex nanoparticles. Beta-carotene was dissolved in the oil phase at a concentration of 0.1%. Subsequently, 4% (w/v) sodium alginate was used to develop emulsions filled-gel.The Pickering emulsion was dispersed in the sodium alginate gel at a ratio of 15:85. Extruded rice was then prepared using an equal ratio (50:50) of broken rice flour and quinoa flour via a cold extruder. To evaluate the impact of the gel-filled emulsion on improving the characteristics of rice grains, different concentrations (30%, 35%, and 40% w/w) of the gel-filled emulsion (based on flour weight) were added to the mixture. The physico-mechanical tests (moisture content, ash content, optimum cooking time, water absorption ratio, cooking loss, lateral expansion, textural characteristics of rice, color properties, sensory analysis, structural morphology, Beta-carotene stability) were conducted. Duncan test was utilized to identify statistically significant differences (p<0.05) among the means, while one-way analysis of variance (ANOVA) was employed to investigate the impact of various factors. Results and DiscussionThe incorporation of emulsions filled-gel into quinoa-rice blend significantly influenced the physico-mechanical properties of extruded rice. As the concentration of emulsions filled-gel increased from 30% to 40% (w/w), there was a significant increase in moisture content, ash content, expansion ratio, and cooking time. Extruded rice samples with emulsion-filled gel exhibited significantly greater β-carotene stability than those without, both after cooking and during storage. Conversely, adhesiveness decreased while hardness increased with increasing emulsion filled-gel concentrations. The control sample exhibiting the highest adhesiveness and lowest hardness. The lightness of the extrudates was also improved with increasing emulsion filled-gel levels, reaching a maximum at 40% (w/w). Sensory evaluation revealed that the 40% emulsion filled-gel level was the most preferred sample by panelists. The optimized extruded rice closely resembled natural Hashemi rice in terms of sensory and textural properties.ConclusionThe findings of this study demonstrate that the addition of emulsions filled-gel enriched with beta-carotene can effectively enhance the physico-mechanical properties of extruded quinoa-rice blends. Specifically, increasing the emulsion concentration resulted in improving expansion, textural, and appearance properties of the rice. 40% emulsion filled-gel was found to be optimal, resulting in a product with desirable sensory attributes. This research proposes that extruded rice based on mixed rice-quinoa flours enriched with beta-carotene-loaded emulsion-filled gel can provide a nutritious and appealing alternative to broken rice products, leveraging the nutritional benefits of quinoa. Sensory and textural evaluation revealed that the extruded rice exhibited sensory properties highly similar to natural Hashemi rice, coupled with favorable cooking characteristics. Consequently, it can be introduced as a suitable substitute for natural rice.
Research Article
Food Engineering
Fatemeh Sabzmeidani; Masoud Taghizadeh; Mohammad Saleh Hemati Hasan Poor
Abstract
IntroductionIce cream is a frozen product, which is obtained from milk by adding compounds such as sweeteners, emulsifiers, stabilizers and flavoring agents. The structure of ice cream is a complex physicochemical system composed of three phases: liquid, solid and gas. Scientific results have shown that ...
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IntroductionIce cream is a frozen product, which is obtained from milk by adding compounds such as sweeteners, emulsifiers, stabilizers and flavoring agents. The structure of ice cream is a complex physicochemical system composed of three phases: liquid, solid and gas. Scientific results have shown that there is a connection between high fat consumption and cardiovascular diseases. Considering that ice cream is an almost fatty product and is particularly popular among people in the society, there is a greater demand for consuming low-fat varieties of this product. The food industry is also looking for new alternatives to minimize the negative effects of fat reduction on quality of ice cream. Hydrocolloids, are carbohydrate-based fat substitutes, which can mimic the mouthfeel and flow characteristics of fat cells due to their emulsifying and water binding capabilities. Eremurus luteus is one of the rhizome plants belonging to the Asphodelaceae family, cultivated around the world, including Iran. Cerise root gum is a new source of hydrocolloid with a glucose to mannose ratio of 1:1 to 1 from the family of glucomannans. The intrinsic viscosity of this gum was measured as 6.32 and 6.35 dl/g according to Huggins and Kramer equations, respectively, and it has the highest foam stability in concentrations of 0.2 to 0.5%. The rheological properties of cerise root gum have proven its important role as a new thickener, stabilizer and foaming agent.Materials and MethodsIn this research, sterilized and homogenized milk (1.5% fat) from Mihan Dairy Industries Company, sterilized and homogenized cream (25% fat) from Pegah Khorasan Dairy Industries Company, emulsifier 471 E from Beldom Belgium Company, powdered skim milk from Pegah company.Sugar and vanilla from confectionery store. Serish root gum was prepared according to the method of Salahi et al. (2020).The amount of ingredients required for the normal sample (high-fat control) was determined based on primary sources, including 10% fat, 11% fat-free milk solids, 12% sugar, 0.25% stabilizer, 0.15% emulsifier and 0.1% vanilla. According to the definitions for reduced-fat ice cream, 75% fat reduction was made from the normal sample (10% fat). In this regard, the investigated treatments were as follow: the amount of fat (2.5% fat: L), the type of gum (SRG) and the concentration of gum (at four levels: 0.2, 0.3, 0.4, 0.5%) compared to the control sample as high fat (10% fat: F).First, the liquid ingredients, including milk and cream, were continuously stirred while heating up to a maximum of 5 °C. After that, the mixture of solid materials (sugar, milk powder, gum, etc.) was added to the liquid part and mixed with a stirrer for three minutes after dissolving thes solids. The resulting mixture was pasteurized at 80°C for 25 seconds and homogenized with a homogenizer at 22,000 rpm for 1 minute and transferred to a water, salt, and ice bath and cooled to 50°C. Then, it was kept in the refrigerator at a temperature of 5°C for 24 hours. Finally, the mixture was transferred to a non-continuous ice cream machine for 15 minutes for the freezing stage, and the samples were poured into special containers with lids and coded, and placed in a freezer at -18 °C for at least 24 hours.Results and DiscussionBy adding gum and increasing its concentration, the amount of apparent viscosity, consistency coefficient, yield stress, plastic viscosity, textural characteristics (hardness, adhesion, continuity and apparent modulus of elasticity) increased. In the sensory evaluation section, the characteristics of creaminess, sweetness, viscosity, roughness, coldness and hardness were evaluated by transient dominant sensation test and these changes were significant in most cases. Sample containing 0.3% gum had the highest overall acceptance after the control sample compared to other samples. The results showed that these variables have the ability to simulate rheological properties (apparent viscosity, consistency coefficient, yield stress and plastic viscosity), melting speed and sensory characteristics such as creaminess, roughness, cryogenicity, viscosity, hardness and overall acceptance of the control sample with high fat as effective factors on the texture production process and the mouthfeel of the product in low-fat ice creams. On the other hand, due to the absence of significant differences between the data obtained from the pH and dry matter measurement tests, the applicability of Serish gum can be confirmed as a fat substitute.ConclusionThe examined samples all showed the loosening behavior with cutting. In the sample containing 0.2% gum, the melting speed increased (from 0.32 to 0.39), also with the increase in the amount of gum in the samples, the freezing temperature decreased by one degree Celsius (from39.4 to 39.5). Overall acceptance, pH and dry matter did not change significantly, which indicates the usefulness and applicability of this method. Also, regarding the rheological characteristics, the highest consistency coefficient in the 0.5% gum sample was 2.2605, similarly, the highest yield stress was in 0.5% gum sample and was 6.7076 pa. Similarly, the highest amount of Plastic viscosity and apparent viscosity belonged to the sample containing 0.5% gum. It was also shown that in the rheological characteristics, with the increase in the amount of gum in the samples, the amount of the relevant parameter increased significantly, and in all these parameters, sample containing 0.2% showed a lower amount than the control sample.
Research Article
Food Engineering
Parisa Mardani; Ghadir Rajabzadeh; Bijan Malaekeh-Nikouei; Aram Bostan
Abstract
IntroductionThe majority of pharmaceuticals and nutraceuticals are encapsulated in various delivery vehicles in order to avoid some restrictions. This is mainly due to the molecules' physicochemical instability in physiological structure and/or their low bioavailability. Food ingredients or bioactive ...
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IntroductionThe majority of pharmaceuticals and nutraceuticals are encapsulated in various delivery vehicles in order to avoid some restrictions. This is mainly due to the molecules' physicochemical instability in physiological structure and/or their low bioavailability. Food ingredients or bioactive components can be encapsulated inside delivery systems for protection and controlled release. Encapsulated ingredients are protected from unfavorable reactions, such as lipid oxidation and volatile loss during production, storage, and handling.Materials and MethodsFlaxseed oil was purchased from Barij Essence Pharmaceutical Co., Tehran, Iran. Saffron was bought from Novin Saffron Co., Mashhad, Iran. Cholesterol, span 60 and tween 60 were from Sigma-Aldrich. Phosphate buffered saline, sodium azide, hydrochloric acid, and other chemicals were procured from Merck (Darmstadt, Germany). All other solvents and reagents were provided from Merck Pharmaceutical Co. (Germany) as analyticall grade.Crocin ExtractionThe extraction of crocin from saffron was done based on crystallization method which has been explained by Mohajeri et.al.Flaxseed Oil ExtractionFlaxseed is one of the richest plant sources of ω-3 fatty acids, alpha-linolenic acid (ALA, C18:3 ω-3). A Soxhlet extraction was carried out on flaxseed powder (20g) using n-hexane for 14 hours at 70°C. After extraction, the sample was concentrated in a rotary evaporator at 40°C .Niosome PreparationA surfactant with a HLB number between 3 - 8 is suitable for the co-encapsulation of hydrophobic and hydrophilic substances (Korani et al. 2019. Hence, span 60: tween 60 variable ratios were selected to achieve HLB in this range. Additionally, the ratio of surfactants to Chol was considered variable. The DCP was applied at a constant concentration to enhance noisome stability.Results and DiscussionCharacterization of niosomesThe influence of experimental variables on the particle size, PDI and zeta potential of niosomes prepared by heating and bubble methods was investigated. In order to choose the appropriate ratios of surfactant, the physicochemical characteristics of niosomal particles, including particle size, zeta potential, PdI, and EE have been considered.Tween 60 is a nonionic surfactant with a large hydrophilic head group and high HLB (14.9). In turn, span 60 has a large hydrophobic moiety (HLB 4.7) and low water solubility. The smaller head groups and longer alkyl chains in surfactant structure have led to larger vesicles. This might be the reason for the larger particle size of H1-H3 and B1-B3, containing higher amount of span 60 compared to other samples. The PDI of the prepared samples was found in the range of 0.29 to 0.49. This value was considered to be within the range of sufficient for attaining stable and aggregation resistant systems. However, higher span 60 content showed comparatively a lesser degree of PDI. Zeta potential is a respectable index of the quantity of the interaction between colloidal particles. In this work, the prepared niosomes had a zeta potential range of -31 to -48 mV, which was sufficient to maintain niosome stability without aggregation between vesicles. Negative zeta-potential in nonionic surfactant vesicles has been reported. Based on the results, B12 and H12 samples with the span: tween ratio of 4:1 and surfactant: Chol ratio of 1:1 formed better niosomes based on particle size, PDI, EE, and zeta potential.In the optimum conditions, the EE of crocin and ω-3 in heating method were 76% and 32%, and in bubble method they were 73% and 28%, respectively.Stability of niosomesThe stability of the optimum niosomes prepared by bubble and heating methods were evaluated at 4°±2°C, 25±2°C, and 37°±2°C for 90 days, by means of stability in size, PDI, and EE. Conclusion In conclusion, this study revealed that co-encapsulation of omega3 and crocin with niosome led to better stability, slower and more controlled release profile, suggesting a promising drug delivery system.
Research Article
Food Biotechnology
Zahra Ziaei Ghahnavieh; Mohammad Reza Raji; Abdollah Ehteshamnia; Seyed Sajad Sohrabi
Abstract
IntroductionExcessive human exposure to chemicals in agricultural practices contribute to the production of unhealthy and environmentally destructive products. For this reason, natural coatings are used to prevent adverse changes in the quality of various products. Natural coatings can be ...
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IntroductionExcessive human exposure to chemicals in agricultural practices contribute to the production of unhealthy and environmentally destructive products. For this reason, natural coatings are used to prevent adverse changes in the quality of various products. Natural coatings can be a barrier on the outer surface of food to prevent the loss of aromatic compounds, and moisture content and provide the possibility of selective natural exchange of some gases and increase shelf life post harvest. Considering the economic importance of button mushrooms and the need to provide optimal solutions to increase shelf life post harvest, the present study was conducted to investigate the effect of natural coatings based on chitosan nanoparticles and nanohydroxyapatite on increasing the shelf life of button mushrooms.Materials and MethodsFor this purpose, the effect of these coatings was evaluated in a factorial experiment in the form of a completely randomized design with three repetitions to prevent adverse changes in button mushroom quality. Button mushrooms were covered with different concentrations of chitosan nanoparticles (zero, 1% and 2%) and nanohydroxyapatite (0, 40, 80 mg) for 28 days. The mushrooms that were prepared for coating were divided into 9 groups. One sample without coating and 8 samples were coated with different percentages of chitosan nanoparticles and nanohydroxyapatite and coded. All mushroom sampless were immersed in each of the coating solutions for five minutes. The mushrooms were then taken out of the solutions and placed on the mesh basket (at room temperature) for 15 to 30 minutes so that the additional amount of coating material drips. Then the mushrooms were weighed individually and six numbers were transferred in three replicates in single-use plastic containers with perforated lids. Then they were transferred to the refrigerator. The control sample was immersed in distilled water for 5 minutes instead. The data was measured on days 0, 7, 14, 21 and 28. After coating, the characteristics of total phenol, flavonoid, antioxidant capacity, total protein, ascorbic acid content, and electrolyte leakage of mushrooms were recorded and analyzed during 28 days of storage.Results and DiscussionBased on the results, the highest amount of total phenol, flavonoid, antioxidant capacity, ascorbic acid content, total protein, and the lowest amount of electrolyte leakage were obtained in 1% nano chitosan coating containing 40 mg of nanohydroxyapatite during 28 days of storage. In the control treatment (without coating), the lowest amount of total phenol, flavonoid, antioxidant capacity, ascorbic acid content, total protein, and the highest amount of electrolyte leakage were obtained during 28 days of storage.ConclusionDue to the high perishability of button mushroom, its maintenance is very important. Coating is considered as one of the methods of keeping quality of button mushrooms. The purpose of this study was to evaluate the effect of natural coating based on chitosan nanoparticles and nanohydroxyapatite on the total phenolic, flavonoid, antioxidant capacity, ascorbic acid content, electrolyte leakage, and total protein of mushrooms on zero, 7, 14, 21, and 28 day, in order to maintain quality and increase the shelf life of button mushroom. For this purpose, the coating of chitosan nanoparticles (zero, 1%, 2%), nanohydroxyapatite (zero, 40, 80 mg), and the combination of chitosan nanoparticles with nanohydroxyapatite in the mentioned concentrations were used. Finally, according to the findings of this study, it can be stated that coating with 1% nano chitosan containing 40 mg of nanohydroxyapatite can increase the shelf life of button mushroom up to 14 days post harvest, with increased marketability.
Short Article
Food Technology
Zeinab Rahmani; Pasha Ahmadi; Reza Sharafati Chaleshtori
Abstract
IntroductionRose water, as one of the distillation products prepared from the rose, is widely used in the food industry and traditional medicine in Iran. Therefore, maintaining the microbial and chemical quality of this product is important. Non-thermal processing technologies have attracted wide attention ...
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IntroductionRose water, as one of the distillation products prepared from the rose, is widely used in the food industry and traditional medicine in Iran. Therefore, maintaining the microbial and chemical quality of this product is important. Non-thermal processing technologies have attracted wide attention from the food industry. These alternative technologies can increase shelf life and reduce the negative impact on nutrients and natural flavor of foods. Cold plasma technology has been used as a replacement for new generation methods and as a non-thermal technology in the food processing. This research was designed to investigate the effect of atmospheric pressure cold plasma on the physicochemical properties and microbial load of rose water. Materials and MethodsIn this experimental research, a dielectric barrier discharge system was designed. This system was used by producing plasma microbubbles to have an effect on rose water samples with an essential oil content of 28 mg/100 ml. Rose water samples were plasma-treated at 12 and 15 kV for 4, 6 and 8 minutes. Tthe essential oil amount, acid value, iodine number, pH, density, oxidation number, ester number and the total bacterial count were then performed on the samples.Results and DiscussionPlasma showed no significant change in the density of rose water in all treatments. Changes in acidity, pH, ester number and iodide number were observed with increasing time and plasma voltage. These changes were significant between the treatment groups and the control group (P<0.05), but not significant within the treatment groups (P<0.05). The greatest decrease in the amount of essential oil was 10.81 and 8.49 mg per 100 ml of rose water, respectively, related to the treatment with voltage of 15 kV at 6 and 8 minutes. Generation/destruction paths of the radicals and their reactions demonstrate the complicated interplay between the plasma induced species (electrons, photons, radicals, etc.) and the dissolved compounds in the liquid species, which ultimately affect the ion concentration (pH and σ) and the oxidizer concentration (redox) in the liquid. However, a decrease in pH is accompanied by an increase in Eh and σ, with a parallel increase in ROS. In addition, plasma in 8 minutes at voltages of 12 and 15 kV caused a decrease of about 3 log in the total number of mesophilic bacteria compared to the control group. Plasma significantly reduced the total number of mesophilic bacteria in rose water. The bactericidal activity of plasma might occur through several mechanisms. Impact on permeabilisation of the cell membrane or wall, leading to leakage of cellular components, containing potassium, nucleic acid, and proteins. In addition, it causes critical damage of intracellular proteins from oxidative or nitrosative species and direct chemical DNA damage. Plasma-generated reactive species and specially H2O2 were found to be the causative agent of cell death. H2O2 is a well-known antibacterial agent that damages iron–sulphur and mononuclear iron enzymes in bacterial cells.ConclusionThe application of plasma at high voltage and longtime caused a sharp decrease in the amount of essential oil, increased acidity and decreased pH of rose water. It is suggested that future studies be conducted on the type of gas used to produce plasma, the size of the reactor used, and the identification of changes in essential oil compounds using gas chromatography with mass spectrometry.Funding Sources This research did not receive any specific funding from funding organizations in the public, commercial or non-profit sectors. Acknowledgement The present research is derived from the master's thesis in physics, and therefore the support of the research deputy of Kashan University and Kashan University of Medical Sciences is acknowledged and thanked.
