Food Technology
Behdad Shokrollahi; Mohammad Ali Hesarinejad; Zahra Zamani; Negin Yousofi; Anna Abdolshahi; Ashkan Jebelli
Abstract
Introduction: Due to increasing the demand for new sources of protein and the lack of animal protein sources, using and replacing of plant proteins is widely considered. The purpose of this study was to identify the potential of Vicia villosa flour as a native and novel source of protein. In this research, ...
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Introduction: Due to increasing the demand for new sources of protein and the lack of animal protein sources, using and replacing of plant proteins is widely considered. The purpose of this study was to identify the potential of Vicia villosa flour as a native and novel source of protein. In this research, the physical properties of vicia villosa seed and chemical composition (protein, fat, ash, and carbohydrate and moisture contents) and color parameters of its full fat flour were determined and compared with defatted flour as well as the effect of defatting and pH on the functional properties of full fat and defatted vicia villosa flour were investigated. Materials and methods: Vicia Villosa seed was obtained from the local market in Chaharmahal and Bakhtiari province and was cleaned, skinned and, milled. Half of the full fat flour was defatted. The obtained flours were then refrigerated at 4°C for further analysis. Physical properties of the seed including size, dimension, mass, true and bulk density as well as porosity were measured using standard methods and calibrated equipments. Chemical composition of both the seed and skinned seed’s flour (moisture content, fat, protein and ash) were determined using standard methods (AACC, 2003). The carbohydrate content of the samples was determined by subtraction of the sum of other compositional substances from 100. Color properties, protein solubility, water soluble index, water and oil absorption capacity, least gelation concentration, foaming capacity and emulsifying capacity and emulsion stability and foaming stability were also measured for the full fat and defatted Vicia Villosa flours. Results and discussion: The results obtained from the measurement of physical properties for the Vicia Villosa seed showed that length, width, and thickness of the seeds were 5.4 mm, 5.37 mm, and 5.38 mm respectively. The surface area of seeds was found to be 90.98 mm2. True density, bulk density, and porosity of samples were found to be 1286.3 mm3, 788.8 mm3, and 38.67%, respectively. The amount of protein for full fat and defatted Vicia Villosa flour was 28.3% and 31.02%, respectively. L* was measured for the obtained flours and the highest L* was belonged to defatted Vicia Villosa flour, probably due to the removal of the seed shells in the solvent removal stage. Defatting of flour would result in brighter and increase in protein content of flour. The test on protein solubility showed the high dependency of this parameter to pH of the flour proving the U form dependency in the pH range of 2-12. At an isoelectric point of 4.5, the minimum solubility of existing proteins was shown. Water and oil absorption capacity of Full fat were 1.33± 0.4 and 0.85± 0.07 and Defatted Vicia Villosa flour,were 1.94± 0.2 and 1.19± 0.1 respectively (grams of water or oil per grams of the sample). Furthermore, at pH= 4.5, the emulsion and foaming capacity decrease due to its proximity to the isoelectric point. It is noteworthy that in isoelectric pH, the highest foaming stability and the lowest emulsion stability were observed. In addition, the results showed that pH and defatting conditions have a significant effect on functional properties that can be created by changing these parameters, flours, and products with various characteristics. The results showed that changes in pH and defatting process affected the solubility, water and fat absorption, least gelation concentration, foaming capacity and emulsion capacity of flour, so that by defatting and changing pH, functional properties improved significantly.
Masoud Taghizadeh; Hesam Akhoondzadeh; Zahra Zamani
Abstract
Introduction: Grains are important food sources for human diet because of high protein content. There are different kinds of grains used as food worldwide. Today herbal proteins play an important role as food sources in societies. Herbal protein sources are actually strategic points for improving national ...
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Introduction: Grains are important food sources for human diet because of high protein content. There are different kinds of grains used as food worldwide. Today herbal proteins play an important role as food sources in societies. Herbal protein sources are actually strategic points for improving national dietary all over the world. (Mashayekh et al, 2008). Food experts are becoming more open to Quinoa, because of high protein content, (Dallagnol et al., 2013). FAO compares Quinoa grain with concentered milk powder considering high nutritional facts, and called grains as multi vitamin (FAO, quinoa, 2011). According to scientific reports quinoa grain can be replaced with rice in national dietary (Ferreira et al, 2015. Oelk et al., 1992). Quinoa originally cultivated in South America (barazil, Chile, Peru etc.) and known as semi-cereals (Schoenlechner&Berghofe2010).Furthermore, Quinoa flour is a highly nutritional alternative to feed animals as well as in the production of foods which are suitable for patients with celiac disease and gluten-sensitive patient worldwide. (Dallagnol et al, 2013). From the technological point of view, functional properties hold an important position, Water and oil absorption capacity, protein solubility, gelatinization capacity, foam ability and foam stability are the most important functional properties. (Kaur and Singh, 2007. Ameri shahrabi, 1390). Functional properties are affected by different parameters such as protein network structure, lipid, carbohydrate, temperature and pH, respectively. (Alukoand Yada, 1995). This study proposed to investigate the physicochemical properties of Quinoa flour of three different varieties and monitor the effect of pH on their functional characteristics Materials and methods: three different variety of Quinoa grain, originated and cultivated in Peru, were used for experiments, varieties were black (BLACK COLLANA), white (SALCEDO INIA) and red (PASANKALLA), respectively. Grains were grind by 75 degree in mesh and refrigerated during storage. Carbohydrate, fat, ash, moisture content and protein were measured by AACC, (2003) methods. Functional properties were also measured using scientific methods, Owusu-Apenten, (2002), Kaur and Singh (2007) and customized Adebowale et al, (2005) method which used to measure protein solubility, Water and oil absorption capacity, foam ability and foam stability, respectively. Emulsion capacity and emulsion stability were measured using majzoobi et al, (2012) method. Results and discussion: chemical properties are important in both technological and nutritional aspects, chemical characteristics were observed and reported for three studied varieties. Protein solubility known as the first criteria in protein functional properties (Asadpour et al., 2010), this parameter is influenced by pH and the least value were observed in pH=4.5 (protein isoelectric point). Water and oil absorption capacity is one of the most important characteristics in flours (Kinsella, 1979), this parameter is a physical phenomenon which is known as oil or water confined in non-polar protein chains that is dependent on protein spatial shape. (Kinsella, 1979؛ Kaur and Singh, 2007؛ Trayunham et al., 2007) responses led to 1.285, 1.475 and 1.295 for white, red and black varieties, respectively. Foam ability and foamstability, actually known as volume increase caused by fast stirring and usually results in convenient rheological properties in products texture like ice cream and bread.this parameter refers to the ability of protein to make stable foam aginst mechanical and Gravitational stresses and measured in a 90 min. period of time (Oladela & Aina,2007) (Kinsella,1979). Least responses in this case were observed in pH=4.5 which is an isoelectric range of pH for protein chains. Results were corresponded by responses of El Nasri and El Tinay (2007), Lawal) 2004(, Taghizadeh et al, (2017) and Asadpour et al (2010) about other semi-cereal grains. Last metered parameter was emulsifying ability and emulsion stability, emulsifying in protein structure is an equilibrium between hydrophilic and hydrophobic parts of protein and affected by alkaline range of pH (Ragab et al., 2003( this parameter is influenced by protein solubility which is in the least measures in isoelectric point (Feizi et al., 2013). Results had shown that foam stability would decrease during time passes. This may be due to the coupling of dispersed phase particles (oil droplets) over time. Concerning the effect of pH on emulsion stability, the results showed that the stability values at alkaline pH were higher than that of acidic pH, so that this stability at pH = 9 was significantly different from other pHs. Among the three varieties of quinoa, the amount of protein in the black variety (16.81%) was higher than the other varieties, which could be further investigated as a potential protein source. In addition, results indicate functional properties are influenced by pH, which means out of iso electric point, protein solubility increase and other fictional properties were improve followed.
Nilofar Esmailikhani; Shadi Mehdikhani; Ali Mohammadi
Abstract
Introduction: Meat quality is always very important for consumers. Tenderize meat one way to improve the quality of Meat and its products. In the study effect of three levels (0.0025, 0.005 and 0.01 percent) of protease produced by Aspergillus niger on meat tenderness during the 28 days of storage at ...
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Introduction: Meat quality is always very important for consumers. Tenderize meat one way to improve the quality of Meat and its products. In the study effect of three levels (0.0025, 0.005 and 0.01 percent) of protease produced by Aspergillus niger on meat tenderness during the 28 days of storage at 4 ° C were studied. Then treatments to control the physicochemical and sensory characteristics were evaluated. In this study tests the total soluble protein, moisture content, pH, colorimetric, texture analysis, water holding capacity and sensory evaluation of meat quality parameters were used. The results of the tests carried out showed that soluble proteins, pH and moisture content levels generated by increasing the enzyme from 0.0025 to 0.01 percent was significantly increased (P<0.05), But on the rigidity by increasing the enzyme decreased firmness. Results also showed that water holding capacity has decreased, but all treatments during storage period 0/01 enzyme treatment showed the highest capacity at the end. Brightness index (L *) and yellowness index (b *) during maintenance treatments reduce the redness index (a *) increased. The sensory characteristics of diet supplemented with 0.0025% of fungal enzymes and control the admission showed more acceptable. So this study using Aspergillus niger enzyme for use in to tenderize meat it considers appropriate.
Materials and methods: For this purpose, 4 samples of 500 grams of Rhomboideus muscle from the 1.5-year-old Holstein male calf from the Rock Company slaughterhouse were immediately prepared for killing. Samples were stored in a refrigerator at 4 ° C for 48 to 72 hours. Each muscle was maintained as a non-injectable control unit (control sample). Then injected into three other parts of the enzyme solution. Protein solution of Aspergillus Niger was obtained from the Iranian Institute of Science and Technology. Then injection of the extracts of the enzyme into the sequences by the injector with 0.01% (AN 0/01), 0.005% (AN 0/005) and 0.0025% (AN 0/0025) (Mg / 100 grams of meat) of fungal protease separately into meat pieces. The pieces of meat were treated using an injector with 4 needles in each row with 10 needles with a spacing of 2.8 cm and a pressure of 35 injections. After injection, the muscle samples were packed under vacuum and immediately stored at 4 ° C for 28 days. On the days 1, 7, 14, 21 and 28, the relevant tests were performed on the treatments. To measure the pH, 10 g of the milled meat was mixed in 90 g of deionised water. The prepared mixture was then plated with a rough filter paper (average watten-diameter of 150 mm). Finally, pH was measured using a digital pH meter. The homogeneous moisture content of the meat samples was measured using the oven method and according to AOAC standard No. 46/950. The basis of the test is based on the measurement of total nitrogen in foods, assuming that all N is a protein type and is based on the coefficients of N-to-protein conversion. To determine the protein values, use the method outlined in AOAC (1996). Used. To measure the protein, the Kjeldahl method was used by the Kjeldahl machine constructed in Japan. The color of the meat was measured by a color spectrometer (CR-300, Minolta, Co. Ltd., Japan) every seven days. White tile with b *: 1.72; a *: -0.02; L *: 97.46 is considered as reference.This test was performed to examine the tissue texture strength of the specimens by using Feismann et al. (1999) by Brookfield Engineering Laboratories, USA at 4 ± 2 ° C. In this test, a cylindrical probe with a smooth cross-section with a diameter of 12.7 mm and a speed of 1 ml / sec was used. In order to measure the water holding capacity, the amount of water extracted from the cutting surface of meat samples under 500 psi pressure and 1 minute time to the filter cassette was accurately weighed to 0.001 g and was expressed as extractable moisture content. The evaluation of sensory features in terms of five factors including hardship, substrate, texture, color and general acceptance was performed using 10 evaluated trainees by Hedonic method by completing an evaluation questionnaire. To each of the mentioned factors, the privilege was allocated from 1 to 5. The way to score was based on the fact that the number 5 represents the highest score and the number 1 represents the lowest score all experiments were performed in a completely randomized design with three replications. Means were compared using SPSS 21 and based on Duncan's tests at 5% level. The resulting charts in the 2013 excel software were drafted and compared.
Results & Discussion: There are several ways to improve the quality of meat and its better use in the production of meat products. One of these methods is to increase the solubility of the meat proteins and, consequently, to crumble and increase the properties of the emulsion and other functional properties such as increasing water holding capacity. Today the effects of the enzymes in plants, bacteria and fungi have been investigated. In this study, the Aspergillus Niger fungal enzyme was used to crust meat. One of the results of this study is that the fungal enzymes have been able to greatly increase the water content of the water, pH and soluble proteins in the flesh, due to increasing the duration of the enzyme's effect and the concentration of the enzyme on Insoluble proteins such as collagen and elastin are completely digestible and their nature has changed (Englund et al., 1968). Also, the results show that the enzyme breaks down some of the protein proteins and forms them in smaller molecular weight units. As you can see, increasing the amount of enzyme concentration on meat proteins has increased the amount of crust and solubility of meat proteins.
Samira Feyzi; Mehdi Varidi; Fatemeh Zare; Mohammad Javad Varidi
Abstract
Introduction: Plant proteins play a significant role in the human diet, and among which legumes are excellent foods with several nutritional and functional advantages and low price. Among legumes, fenugreek (Trigonella foenum graecum) seed, belonging to the Fabaceae family, is a great source of plant ...
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Introduction: Plant proteins play a significant role in the human diet, and among which legumes are excellent foods with several nutritional and functional advantages and low price. Among legumes, fenugreek (Trigonella foenum graecum) seed, belonging to the Fabaceae family, is a great source of plant proteins, with a total protein content of about 25.00 – 38.60%. Functional properties are defined as physical and chemical properties, which could be altered due to the protein source and procedures used for flour preparation, protein concentrate and isolate extraction. Physiochemical parameters such as pH, temperature, salt and ionic strength can also highly affect proteins, functional properties.Therefore, in this study color parameters and functional properties of fenugreek protein isolate (FPI) were investigated. Also, the effect of pH changes on protein solubility, foaming capacity (FC) and stability (FS), emulsifying capacity (EC) and stability (ES) was studied. Materials and methods: Fenugreek seeds were obtained from a retail market in Isfahan, Iran. All chemicals were of analytical grade, and were purchased from Sigma Chemical Co. (St Louis, MO, USA), and Merck KGaA (Darmstadt, Germany). Protein Isolation: Protein from 10g defatted fenugreek flour (DFF) was extracted with 0.33M sodium chloride solution; the ratio of DFF to NaCl solution was set at 1:20 (w/v) and pH was adjusted to 9.25. The stirring period was 2 h, during which pH was also adjusted. Aliquots were then centrifuged and supernatants were adjusted to pH 4.5 (isoelectric pH of fenugreek protein). Again, the protein solution was centrifuged in order to precipitate the protein. Protein precipitate was washed twice with deionized water, followed by centrifugation and resolubiliztion by adjusting the pH to 7.2. The extraction process was carried out at room temperature (25°C). Color parameters: A digital colorimeter was used to measure the color of full fat and defatted fenugreek flours, and FPI samples. Color parameters were recorded in L*a*b* space. Protein solubility: Protein solubility of FPI at pH 2-10 was determined. A 1.5% (w/v) solution of sample was made in deionized water for each pH. The solutions were treated with either 0.5M HCl or 0.5M NaOH to obtain certain pH (2-10), while stirring. The slurry was centrifuged to separate the supernatant. Protein content was determined by the Biuret method using spectrophotometer at 540nm wavelength. Calibration was done using bovine serum albumin (BSA) as external standard. Viscosity: A suspension of 5% (w/v) FPI in distilled water was prepared. Viscosity of sample was determined using a programmable Brookfeildrheometer, using spindle ULA at room temperature. Coagulated protein: Percent of coagulated protein was measured by preparing 0.2g of FPI in 10mL of 0.025M citrate-phosphate buffer (pH 7.0). The solution was stirred, followed by centrifugation. The remaining supernatant was heated for 15min in a 100°C water bath, after cooling the same procedure was repeated. The absorbance of both samples, before heating (A1) and after heating (A2), was measured at 540nm according to Biuret method. The percent of coagulated protein was calculated by the following equation: Coagulated protein = (A1 – A2 / A1) × 100 (1) Foaming capacity and stability: FC and FS were determined using 2% (w/v) FPI solution in distilled water. For each sample solution, the pH was adjusted to desired level (2, 3, 4.5, 6, 8, and 10). The solution was stirred slightly for 5min and then was whipped vigorously by a disperser. The volume of solution before whipping, also the total volume of solution and foam after whipping were recorded as V0 and V1, respectively. The foam capacity percentage was calculated as: FC (%) = (V1- V0/V0) × 100 (2) Foam stability was determined as the total volume of solution and foam at 30, 60, 90 and 120 min at room temperature and it was recorded as V2. Foam stability (FS) was calculated as: FS (%) = (V2 - V0) × 100/ (V1 - V0) (3) Emulsifying capacity and stability:For EC and ES, a 1% (w/v) FPI solution in distilled water was prepared. The pH was adjusted to desirable level (2, 3, 4.5, 6, 8, and 10) followed by stirring for 5min, then sunflower oil was added. The mixture was homogenized to make emulsion, followed by centrifugation. Then the height of both emulsified layer after centrifugation (H1) and the total height of content before centrifugation (H0) were measured. Emulsion capacity was calculated as: EC (%) = (H1/H0) × 100 (4) The ES (%) was calculated at 0, 30, 60, 90 and 120 min by measuring height changes (H2). ES (%) = (H2/ H1) × 100 (5) Results and Discussion: FPI with 89.1% protein content had significantly (p < 0.05) lower L* than DFF, while its L* was higher than the full fat fenugreek flour. Also, FPI showed shear thinning behavior with viscosity equal to 1150, 922.5 and 787.5 cP at 15, 30 and 50 (1/s) shear rates, respectively. pH changes had noticeable effect (p
Mir-Hassan Moosavy; Nassim Shavisi
Abstract
Nisin, belonged to type-A lantibiotcs, is a well-known bacteriocin that applied as natural preservative in food productions such as milk and cheese. This peptide has an inhibitory effect on many of Gram-positive bacteria. Using of nisin alone and in combination with other hurdles may serves as an effective ...
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Nisin, belonged to type-A lantibiotcs, is a well-known bacteriocin that applied as natural preservative in food productions such as milk and cheese. This peptide has an inhibitory effect on many of Gram-positive bacteria. Using of nisin alone and in combination with other hurdles may serves as an effective method to eliminate Listeria monocytogenes and other pathogens in food industries. This study was undertaken to evaluate the effect of nisin against listeria monocytogenes in different temperatures (4, 9 and 14°C), pH (5, 6 and 7) and NaCl concentrations (0, 1, 2 and 4).The minimum inhibitory concentration (MIC) of nisin was assessed using a broth micro-dilution method. Furthermore, differences in population (DP) assay was used in order to analyze the effects of (storage) temperature, pH and sodium chloride concentration on Listeria monocytogenes survival in presence of nisin. The MIC value of nisin was 320IU/ml. The effectiveness of nisin was increased at 14°C better than at 9 and 4°C (P<0.016).Nisin activity increased in the presence of 2 and 4 g/100 ml of NaCl concentration (P<0.001). Also higher inactivation was observed after to pH 5 compared to pH 6 and 7 (P<0.001). Our results demonstrated that among different NaCl, pH, temperature and nisin values, the effect of NaCl was confounded than the effect of other factors at all prepared combinations (P<0.001).Our findings suggest the application of hurdle technology for achieving effective control in most in food industries.
