Food Biotechnology
Nasim Najafi; Hajar Abbasi
Abstract
Due to its health benefits, fresh sprouted cereals are considered popular food source. They are very sensitive and highly susceptible to microbial spoilage during transportation, processing, and storage. This phenomenon makes them potentially high-risk fresh products. This study aimed to assess the effect ...
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Due to its health benefits, fresh sprouted cereals are considered popular food source. They are very sensitive and highly susceptible to microbial spoilage during transportation, processing, and storage. This phenomenon makes them potentially high-risk fresh products. This study aimed to assess the effect of emulsion coating consisting of Dracocephalum kotschyi essential oil (0, 50, 150, 250, 300 ppm)-chitosan solution (0, 0.3, 0.38, 0.63, 0.75%) during the immersion time (10, 25, 55, 85, 100 s) on the microbial properties of fresh sprouted wheat stored at 4°C. The Response Surface Methodology (RSM) was adopted in modeling the independent variables’ effects. The results shown that increase in the essential oil and chitosan solution concentration reduced the microbial spoilage. High concentration of Dracocephalum kotschyi oil decreased the fungus population after 12 days. Coating of sprouted wheat at optimized level of independent variables (0.62% chitosan, 57 ppm Dracocephalum kotschyi oil and 29.49 s immersion time) reduced the microbial and fungal populations. This treatment can reduce weight loss, and maintain tissue firmness, total phenolic, and ascorbic acid content of the sprouted wheat during cold storage, with no effect on its sensory properties. Our findings indicate that nanoemulsion coating based on chitosan and Dracocephalum kotschyi oil at appropriate levels could be beneficial in maintaining sprouted wheat quality and increasing its shelf-life.
Food Technology
Samira Farizad; Hajar Abbasi
Abstract
Introduction
Hydrocolloid is a term refers to all polysaccharides extracted from plants, seeds, and microbial sources that regardless of their biological and nutritional role has various functional properties in food products such as concentration and gel production of aqueous solutions, stabilization ...
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Introduction
Hydrocolloid is a term refers to all polysaccharides extracted from plants, seeds, and microbial sources that regardless of their biological and nutritional role has various functional properties in food products such as concentration and gel production of aqueous solutions, stabilization of foam, emulsions and dispersed systems, prevention of ice and sugar crystals, control of the release of flavor compounds and consequently control and improve food quality. Ultrasound has been widely used in the food industry due to its numerous physical and chemical effects. The effect of ultrasound is due to cavitation, heating, dynamic mobility and shear stresses to the sample. Today, ultrasound is used as a green new technology with unique effects on food storage and processing. One of the newest applications of ultrasound is altering the structure of polymers such as polysaccharides. Changes in the structure of hydrocolloids lead to modification in their functional properties.
Materials and Methods
In this study, effect of ultrasonic waves, time (0-90 min) and processing temperature (25-75 °C) on physicochemical, rheological and functional properties of locust bean gum was investigated. In this regards, different parameters including changes in pH, solubility, minimum gelatinization concentration, viscosity and emulsifying properties (Emulsifying capacity, emulsion stability and particle dimensions) of treated locust bean gum were determined. Response surface methodology in central composite design was used to evaluate the effect of independent variables on qualitative properties of locust bean gum and model their changes. The best treatment condition was determined and the optimum treated samples were evaluated and compared in microstructure using scanning electron microscopy, rheological properties (rotational and oscillatory test) and Fourier transform infra-red.
Results and Discussion
The results showed that with increasing the time of ultrasound treatment, pH, and viscosity of the hydrocolloid decreased and its solubility and minimum gel concentration increased. However, with increasing temperature, pH, minimum gelatinization concentration and hydrocolloid viscosity increased and its solubility decreased. Optimization of treatment conditions was performed by considering the achievement of the best hydrocolloid performance characteristics. Two different temperature and time conditions were proposed for the desirable treatment of the hydrocolloid using ultrasound. In the first case, the selection criteria were to achieve the best solubility and emulsifying properties of the hydrocolloid, and in the second case, the selection criteria were solubility and emulsifying properties improvement while maintaining the gelatinization properties of the hydrocolloid. Based on the desired quality factors, optimization was performed and the results showed that in the first optimal sample (treated at 40 ° C and 48.9 minutes), solubility and emulsifying properties and in the second optimal sample (treated at 66.67 ° C and 15 Min) by maintaining the gelation properties of hydrocolloid, the solubility of the hydrocolloid increased significantly. The performance of treated samples validated developed models. SEM results showed that the ultrasound increased three-dimensional structure of gum. The smaller microscopic structure was observed in untreated sample and the larger one was in treated with ultrasonic waves for 40.9 minutes at 40 ° C. Therefore, ultrasound caused agglomeration of treated freeze dried gum. It is noteworthy that several holes observed in the structure of treated gum with ultrasonic, which can increase solubility of the gum. The flow behavior of the sonicated and control samples showed that the viscosity of all samples decreased with increasing shear rate, which indicates their pseudoplastic behavior. At low shear rates (about 0.01 per second), the viscosity of the control sample was higher than that of the sonicated samples. However, at high shear rates (about 40 per second), viscosity of the three samples were almost the same. Therefore, the control sample was more affective to shear rate compared to the treated samples. The modulus of elasticity (G ') and viscosity (G' ') of the treated specimens were lower compared to the control. Also, the frequency sweep of samples shown that in the frequency range under study, G 'and G'' were frequency dependent and with increasing frequency, the amount of these two parameters increased. This observation indicates the influence of rheological properties of the samples on the frequency changes that are commonly observed in suspensions. At low frequencies, the predominance of viscous behavior over elastic was observed in all three control and ultrasonic samples (G ''> G ') and this feature was higher in the treated samples than the control. The modulus of elasticity and viscosity of the treated sample for 49 minutes was lower than other treated samples for 15 minutes, which shows the effect of ultrasound on the rheological properties of the hydrocolloid.
Conclusion
The results of this study showed that ultrasonic waves provide a good opportunity to change the physical and functional properties of carob seed gum. It is possible to significantly improve the solubility and emulsifying activity of this hydrocolloid using ultrasound. It is necessary to determine the treatment conditions of the sample according to the intended application.
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 ...
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[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.
Food Technology
Nasim Najafi; Hajar Abbasi
Abstract
Introduction highly sensitive to fungal and biochemical changes such as respiration and enzymatic activity, as a result, it has a short shelf life: wheat is an important cereal crop used as staple food in many parts of the world and provides 20% of the energy and 78-93% of the protein in the human diet. ...
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Introduction highly sensitive to fungal and biochemical changes such as respiration and enzymatic activity, as a result, it has a short shelf life: wheat is an important cereal crop used as staple food in many parts of the world and provides 20% of the energy and 78-93% of the protein in the human diet. Seed germination is a process which begins with activating proteinase due to uptake of water. Metabolic activity occurs during the germination process, leading to the hydrolysis of proteins and carbohydrates, and the synthesis of metabolites that have health-promoting properties for human. Sprouted wheat is a rich source of protein, dietary fiber, minerals, vitamins and phytosterols. Using chemical preservatives to extend the shelf life of food has a great health concern for many years. Therefore, developing safe methods to control perishability and maintain quality of perishable foods during storage is crucial. Chitosan is a linear polysaccharide composed of randomly distributed β-(1-4)-D-glucosamine and N-acetyl-D-glucosamine. Chitosan coating is beneficial to maintaining the storage quality and prolonging the shelf life of postharvest fruits and vegetables. Dracocephalum kotschyi is one of the medicinal herbs with special constituents including caryophyllene, limonene, α-pinene, geranial, and flavonoids. The essential oil of this plant has significant biological activities, including antiviral, antibacterial and anti-corruption. Considering the successful application of chitosan and essential oils in edible coating formulae and its proven antifungal properties due to its nano-particles prompted us to initiate this study aiming at assessing the efficiency of an edible coating for maintaining quality and increasing the shelf life of wheat sprout. Therefore, in the present study, nano-emulsion of Dracocephalum Kotschyi essential oil in chitosan was considered for coating sprouted wheat in order to delay its perishability. Materials and Methods: Materials used in this study consisted of wheat (Pakanbazr Co.), chitosan (Shayan Chemical Co.) and Dracocephalum kotschyi were supplied from Isfahan's medicinal plants market. All chemicals were from Merck Co. In order to prepare wheat germ, wheat grains were immersed in water containing 0.07 % sodium hypochlorite for 10 min. Then, the disinfected samples were soaked in water at 25 °C for 12 h. After soaking, the samples were placed in a germination chamber at 30 °C and 98% relative humidity for 48 h. Quality properties of sprouted wheat such as moisture, ash, fat, protein, mineral, fiber and ascorbic acid concentration were measured. Sprouted wheat was coated by immersion in nano-emulsion and then was packed at modified atmosphere (30% oxygen, 70% nitrogen), for 12 days at 4° C. The pH, weight loss, total phenol content, antioxidant activity and hardness of the samples were determined. Optimal and control samples were examined in terms of qualitative characteristics such as pH, weight loss, total phenol content, antioxidant activity and hardness during 0, 4, 8, 12, 16 and 20 days after production. In the present study, effects of independent variables such as essential oil concentration (A), chitosan concentration (B) and immersion time (C) on total phenolic content, antioxidant activity, ascorbic acid content, and hardness were investigated by Response Surface Method in the form of a central composite design with 6 central point (α=1.5). Comparison of the optimal and control samples was done in a completely randomized design using SAS ver: 9.1 software. Results and Discussion: An increase in chitosan and immersion time resulted in better preservation of total phenolic. The interaction effect of essential oil concentration and immersion time also resulted in better retention of total phenolic compounds. An increase in essential oil and chitosan concentration up to intermediate level increased the antioxidant activity. Chitosan and Dracocephalum Kotschyi essential oil play a key role in maintaining the total phenolic content and antioxidant capacity of sprouted wheat by reducing gas exchange, respiration rate and the activity of polyphenol oxidase and peroxidase enzymes. Interaction effects of variables up to intermediate level resulted in higher level of preservation of ascorbic acid. The interaction effect of essential oil and chitosan at high levels led to better preserved of hardness. Coating treatment contains 25% chitosan with 84.18 ppm Dracocephalum Kotschyi essential oil and 25s immersion time can be introduced as a safe and effective method to maintain the quality characteristics and increase wheat sprout shelf life. Coating of wheat sprout reduced the changes in pH, weight loss, total phenol content, ascorbic acid, antioxidant activity and hardness in coated samples during storage compared to the control sample. Furthermore, sensory properties did not change significantly after storage time. The results revealed that the use of chitosan- Dracocephalum Kotschyi oil coating delay bacterial and fungal decay and improved the quality characteristics and shelf life of sprouted wheat during storage. The results of this study indicated the positive effect of chitosan-Dracocephalum Kotschyi oil nano-emulsion coating on preserving the quality of sprouted wheat
Fatemeh Khodaian; Hajar Abbasi
Abstract
Introduction: Honey is a bee product with appropriate organoleptic characteristics and high nutritional value. Vegetative source, climate conditions, time of nectar collecting, bee specious, and also storage condition of product are effective factors on its quality. During the process and storage stages, ...
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Introduction: Honey is a bee product with appropriate organoleptic characteristics and high nutritional value. Vegetative source, climate conditions, time of nectar collecting, bee specious, and also storage condition of product are effective factors on its quality. During the process and storage stages, chemical reactions such as maillard change the quality and nutritional characteristics of the product. The effectiveness of these reactions depends on various parameters such as primary component’s nature, water activity and pH of product as well as the product storage conditions. Different factors such as, carbohydrate content, enzyme activity, hydroxymethylfurfural (HMF) are introduced as criteria in evaluating qualitative characteristics of honey. HMF is one of the most important factors in this group. It is a consequence of thermal process on foods containing high quantity of fructose and glucose. Therefore, it is considered as an important index on heating and shelf life of this product. In the first step of the present research, qualitative characteristics of four usual Iranian honeys were evaluated. Then, in order to study the effect of storage condition, the quality changes of products at different temperatures and times of storage were investigated. Materials and methods: In the first stage of the present research, qualitative characteristic (fructose/glucose ratio, sucrose, polyphenol content, hydroxymethylfurfuran, moisture, free acidity, lactic acid, total acidity, pH, color, diastase and electrical conductivity) of four Iranian honey (astragalus, ziziphus, citrus and thyme) collected in random sampling were measured. Then, effect of storage temperature (4, 23, 30 and 37°C) on changes of important qualitative characteristic of product (hydroxymethylfurfural content, polyphenol content, pH, color characteristic) were evaluated monthly for six months. Results and discussion: According to results, qualitative characteristics of samples were significantly different since the beginning of storage (p≤0.05). Moisture content of samples varied from 14.5 to 16.5%. PH was found to be 4.38 to 4.94, and total acid content ranged from 6.92 to 16.32%. The highest sucrose content was observed in ziziphus honey and the highest fructose-glucose ratio and pH were observed in astragalus honey. Thyme honey contains the highest diastase activity, acidic compounds, and the lowest amount of moisture and pH and ziziphus honey had the highest amount of acid lactic and electrical conductivity (142/0 mmol/cm). The amount of HMF in ziziphus honey was higher than other kind of samples (28.29 mg/ kg), and the content of these component were lower than 5 mg/kg in astragalus and citrus honey. All of the four samples were in permissible range according to maximum acceptable HMF content based on both Iranian national standard and honey international commission (40 mg/kg). In appearance characteristic, L* (brightness) of thyme and citrus honey were more than others and the highest greenness was observed in thyme honey and the highest yellowness were observed in astragalus and ziziphus samples. In the present study, the polyphenol content of samples was 23.33-39.33 (mg gallic acid in 100 g of sample) and thyme honey contained the highest polyphenol content. Diversity in floral is one of the main reason for differences in the qualitative characteristic of samples. Changes in mineral content, phenolic components, and floral origin were considered as the main effective factors in color changes of honey types. Storage condition and honey type had significant effects on qualitative characteristics of product. Increasing time and storage temperature reduced brightness and hue angle, and increased chroma index in all kind of honey. By increasing the temperature and storage time, undesirable HMF content of samples were increased. Among the studied conditions, the best storage temperature in control of HMF content of product was 4 °C. Increasing storage temperature and time decreased the phenolic compounds of samples until the third month, and after that it was increased. In this regard, the effect of higher temperature on increasing polyphenol contents of product was more obvious. This observation is a consequence of secondary compounds formations from browning process in the product. Evaluating correlation among different parameters showed that, there were a positive significant correlation between HMF content with polyphenol compounds (r= 0.738), a* (r= 0.8868) and chroma index (r= 0.373) (p<0.05), and there were a negative significant correlation with brightness of appearance (r= -0.853) and hue angle (r= -0.858) of product at a level of 0.05. Also there were observed positive and significant correlation among polyphenol content of product with a* (r= 0.65) and chroma index (r= 0.298) and also negative and significant correlation with brightness (r= -0.655), hue angle (r= -0.651) and ph (r= -0.258). Therefore, honeyes with more redness and less brightness usually contain higher polyohenol which their participation in Millard reaction is the main reason for higher content of HMF in these samples. Therfore, determining suitable condition and storage time of honey according to their different primary characteristic should be considered in order to protect qualitative characteristic of product.
Sepideh Etezazian; Mohammad Fazel; Hajar Abbasi
Abstract
Introduction: Sponge cake is one of the most demanded and consuming grain products, but due to its gluten content, it is not usable for patients with celiac disease. In recent years, gluten-free products have gained a great attraction. However, producing gluten-free products has several difficulties ...
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Introduction: Sponge cake is one of the most demanded and consuming grain products, but due to its gluten content, it is not usable for patients with celiac disease. In recent years, gluten-free products have gained a great attraction. However, producing gluten-free products has several difficulties such as lack of gluten viscoelastic network protein constituents, lower technological quality and advent of some quality problems in production including low volume and weak texture. Some compounds such as certain enzymes and gums with the aim of improving the texture, mouth feeling and general acceptance, as well as imitating viscoelastic properties of gluten could be employed in the formulation of gluten-free products to make them acceptable for the celiac patients. For this purpose, guar gum is used widely as a thickener and stabilizer for producing gluten-free products. Also, addition of enzymes to grains produce could help in increasing the holding water capacity, improving softness and dough flexibility, enhancing texture and final product’s volume. Furthermore, notwithstanding widely researches on the cake, comparing to other production, this production has low nutrition values yet. So, enriched cakes with dietary fiber and natural antioxidants, is one of the goals of the industry. The researches has shown that dried, powdered and extracted pomegranate peel has rich fiber, bioactive materials and high antioxidative characteristics. Therefore, the main purpose of the present research is to study the effect of replacing the pomegranate peel (0-12 %), Guar gum (0-1.5 %) and Hemicellulase enzyme (0-90 ppm), respectively on the physiochemical properties.
Material &Methods: Moisture content measurement of moisture by oven, density by using rapeseed seeds displacement method, hardness (STM 200 device), color index of crumb and crust by using CIE Lab colorimetric system that measure L* (brightness), a* (redness) and b* (yellowish), antioxidant activity with spectrophotometery method in 517 nm wavelength, and sensory properties of gluten-free sponge cake based on wheat starch. In association with sensory test,30 panelists was used for checking desirability of mouth texture, appearance texture, smell and taste, color, after-taste and general acceptance with six point hedonic test that they rated samples from most agreeability to most un agreeability. For this aim, the statistical plan of response surface method (RSM) of central composite design (CCD) with three variables and four central points were used and the texture test was applied four times and the other tests were applied three times. For this purpose the Design-Expert 7.0.0 software was utilized for determining of optimum point (a point in which the minimum density and hardness that this parameters considered as a blank in the cake limits), Duncan examination was used for comparing the average of data and analyze of data was implemented with SPSS 16 software.
Results & Discussion: The results have shown that increasing the percentage of pomegranate peel in the formulation, density and bright and yellowish cakes were decreased and moisture, a* index, DPPH and hardness were increased. From the other hand, increasing the amount of replacing the gum caused to increase density, moisture and hardness. Adding the enzyme had effect in decreasing the light of crust and increasing density and color index in the crust of the cake. Totally was determined pomegranate peel had more effect on the antioxidant activity, density, hardness and colorful properties. Guar gum had fewer effect on this parameters and played most important roll on moisture of cakes. About enzyme can say it didn’t have significant effect on properties of cakes. Then, the optimum points has been defined via the software that the amounts of pomegranate peel and the guar gum were estimated at 9.1 and 0.56 %respectively, and the amount for hemicellulase enzyme calculated as 0 ppm. After that, the properties of the optimum cake were compared with blank cake and in addition to previous tests, sensory test was also performed. Moreover moisture and hardness of optimum cake was investigated in during of 14 days storage (days of 1, 7 and 14).The results have shown the physical, chemical and texture properties of optimum cake were largely similar to the blank samples and the main difference was in taste sensory properties of pomegranate peel that will corrected with the use of flavor agents. Over time, also, moisture was decreased and hardness was increased primarily and decreased later in both of blank and optimum sample. Therefore, gluten-free cake based on wheat starch with 9.1 percent pomegranate peel and 0.56 percent guar gum can be used, that only doesn’t have adverse effect on its properties, but also is acceptable for celiac patient.
Fatemeh Bahrami Maghsudbeki; Hajar Abbasi; Mohammad Goli
Abstract
Introduction: Legumes are suitable sources in nutraceutical properties due to existence of anticancer, antioxidant and also significant antimicrobial substances. Different processing such as soaking, peeling and germinating improves nutritional value and bioavailability of minerals such as calcium, iron ...
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Introduction: Legumes are suitable sources in nutraceutical properties due to existence of anticancer, antioxidant and also significant antimicrobial substances. Different processing such as soaking, peeling and germinating improves nutritional value and bioavailability of minerals such as calcium, iron and phosphorus content of legumes and based on the literature review, germination is the best method among the others. The results of previous researches demonstrated significant improvement of nutraceutical and farmoceutical properties of products due to germination. In legumes, sprouted lentil has higher nutritional value such as minerals and essential amino acids than others. Cereal based products, especially products of wheat flour such as bread, pastries, biscuits and etc are used generally as a staple food around the world. Cake is one of the widely used confectionary cereal based product that its nutritional quality is important in public health. According to deficiency of wheat flour from many essential amino acids and important minerals such as iron, the aim of present study was to employ natural enrichment of cake with sprouted lentile and improving the qualitative characteristics of products using active gluten and hemicellulase enzyme. Due to the existence of problems in enrichment of wheat flour with iron due to difficulties in uniform distribution of particles and creation of unsuitable organoleptic properties in the products, currently, iron enrichment is limited to whole flour in Iran. Therefore, the results of the present research could an alternative way for flour enrichment with iron and other nutrients.
Materials and method: In order to prepare sprouted lentil flour, the “official” lentil variety was prepared and treated at ambient temperature (24°C) and suitable humidity (90%) in dark place in order to germinate and increase the shoot height to 1.5 cm. The sprouted lentils were dried at room temperature in shadow. Then, they were milled and sieved in order to achieve suitable particle size. At the beginning step, sprouted lentil flour and wheat flour were evaluated in terms of protein, moisture, ash, fat and minerals such as iron, calcium, potassium and phosphorus. After numerous pre-tests by experts in cereal technology, the usable quantities of sprouted lentil flour according to organoleptic characteristics of the product, was considered 25% of batter’s flour. Improving the textural characteristics of products due the negative effects of germinated lentils flour was considered using independent variables of present study (hemi-cellulase enzymes at 0, 25 and 50 ppm levels and active gluten powder at %0, %1/5 and %3). Sprouted lentil flour was treated for 30 minutes with enzyme before using in batter formulation. Prepared samples with 25% replaced sprouted lentil with wheat flour and hemicellulase (0, 25, 50 ppm) and active gluten (%0, %1.5, %3) were investigated in terms of volume, bulk density, color properties of crust and crumb, moisture content, textural properties (hardness, cohesiveness and springiness) and also sensorial properties. Prepared product based on optimized formulation according to the results of chemical, physical and sensorial analysis was evaluated in staling rate, the quantities of fat, protein, ash, fiber and minerals such as iron, calcium, phosphorus, potassium and its results were compared to control. Data was analyzed according to the factorial experiments based on completely randomized design by SAS software (version 9.2), and the means were compared by LSD test at 5 significance percent level. Statistical evaluation of sensorial properties was also done based on qualitative method of Kruskal-Wallis.
Results and Discussion: In chemical composition of wheat and sprouted lentil flour, there were significant differences between two samples in terms of protein, ash, and minerals content such as iron, calcium, phosphorus and potassium. But, there was no significant difference in fat content. The quantity of iron in lentil flour was five times more than that of wheat flour, calcium was double, potassium was seven times and phosphorus was six times more than that of wheat flour. Also, sprouted lentil flour showed higher protein content than wheat flour. Addition of sprouted lentils to batter formulation increased moisture content of the sample than the same one prepared only with wheat flour. Gluten and hemicellulase had significant effects on reducing the apparent density of samples and improving the physical, sensorial and textural characteristics of the product. In this regard, the hardness of sample’s crumb were decreased and theirs cohesiveness and springiness were increased significantly. According to the results of the present study, the addition of gluten and hemicellulase enzyme was improved color properties, especially in crust position. Therefore, independent variables were effective in improvement of qualitative properties of products. Finally, the optimal sample based on physical, textural and sensorial evaluation was introduced a sample with 25% sprouted lentil flour, 3% active gluten and 50 ppm hemicellulase enzymes. The optimum sample was closed to wheat control sample in the case of the qualitative characteristics. Comparison of textural characteristics of optimum and control samples during storage was indicated the similar characteristics of them. Sprouted lentil flour was a rich material in fiber with high water binding capacity in technological point. Therefore, it improved moisture retention and softness of texture. As well as, comparison the textural qualitative characteristics of the selected and control samples (prepared with wheat flour completely without additives) was shown a very high affinity in them. The products made with sprouted lentil had significantly higher nutritional value in protein, ash, crude fiber and minerals such as iron, calcium, potassium and phosphorus content than control. The iron content of optimum sample was more than twice of the control. Therefore, the results of the present research are effective in production of the functional product with improved nutritional characteristics. Due to the unique nutritional value of grain, more sprouted bean is recommended to use in food product formulation, and at the same time suitable additives are used for reducing their impact on the textural and sensorial properties of product.
