Food Technology
Aliakbar Gholamhosseinpour; Saeed Zare
Abstract
Introduction Cheese is a term that encompasses a diverse group of fermented dairy products produced globally, available in a variety of flavors, textures, and shapes. It is rich in proteins, minerals, and vitamins, all contributing to its high nutritional value. Among these, brined ultrafiltered ...
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Introduction Cheese is a term that encompasses a diverse group of fermented dairy products produced globally, available in a variety of flavors, textures, and shapes. It is rich in proteins, minerals, and vitamins, all contributing to its high nutritional value. Among these, brined ultrafiltered cheeses are soft cheeses that undergo their ripening process in brine. In recent times, this type of cheese has gained popularity, securing a significant consumer market in our country. Food hydrocolloids, comprising polysaccharides and proteins, are extensively utilized in the food, and biomedical industries. They function as thickening agents, forming gels with controlled functionality and specific physical properties. Additionally, they act as stabilizers in various dispersions and serve as carriers for bioactive compounds. Many hydrocolloids, such as whey proteins or dietary fibers, also possess health-promoting properties and can provide essential nutrients necessary for maintaining human biological activity. Beyond their nutritional benefits, food hydrocolloids find applications in advanced materials like food packaging, biomedical materials, biopolymers, polymer electrolytes, mineral nanoparticle synthesis, and organic pollutant removal. Natural hydrocolloids are typically non-toxic and environmentally friendly. They are made naturally from plants, animals, algae, or microorganisms. They are employed to enhance the physicochemical, structural, rheological, and sensory properties of dairy products. Persian gum, derived from the almond tree (Amygdalus scoparia Spach), is one such natural hydrocolloid commonly used as an herbal remedy in Iran. It is commercially available in various colors, shapes, and sizes. Its low cost, availability, biodegradability, and capability to substitute stabilizers and emulsifiers have increased its utilization in the food and pharmaceutical industries. Materials and MethodsAfter being received and initially cooled, raw cow milk underwent pasteurization and was stored for the ultrafiltration process. Persian gum (PG) was incrementally incorporated into a specific quantity of warm retentate and thoroughly blended. This mixture was then combined with the remaining retentate to produce retentates with PG concentrations of 0.03%, 0.05%, and 0.1%. These mixtures were then subjected to homogenization and pasteurization. Following these processes, the retentate was cooled to a temperature range of 35-40°C. It was then poured into containers for coagulation, to which microbial rennet and a starter culture comprising Lactobacillus lactis subsp. lactis, Lactococcus lactis subsp. cremoris, and Streptococcus thermophilus were added. After roughly 6 hours, once the curd pH dropped to 5.1, a 12% brine solution was introduced into the container. Finally, the containers were sealed and placed in a 4°C cold storage for microbial, physicochemical, and sensory evaluations over a 90-day storage period. Statistical analysis was conducted using the Minitab software (version 16.2.0.0 for Windows, Minitab Inc., Coventry, United Kingdom) at a 95% confidence level. Results and Discussion Based on the obtained results, during the storage period, no microbial spoilage (including coliforms, molds, and yeasts) was observed in the control and gum-containing samples. The ash content (%), gumminess (N), chewiness (Nmm), adhesiveness (Ns), and fracturability (N) of the samples increased initially up to day 45 and then decreased. The acidity (% lactic acid) of the samples continuously increased during the storage period, while the amount of fat (%) of samples showed a decreasing trend. An increase in gum concentration led to a significant decrease (p≤0.05) in the acidity (167.22 to 123.11 %), gumminess (8.35 to 1.30 N) and chewiness (216.19 to 38.83 Nmm) of the samples, while the ash content (3.69 to 3.92 %) and cheese adhesiveness (0.66 to 0.80 Ns) increased significantly (p≤0.05). Regarding sensory properties, color and appearance, and aroma scores of the cheeses were not significantly affected by the storage time. The interaction effect of time and gum concentration did not create a significant difference in texture and flavor scores, while their single effects were significant (p≤0.05). Overall acceptance of the samples was only significantly affected by the gum concentration (p≤0.05), and the interaction effect of time and concentration did not significantly affect the overall acceptance score. Finally, the cheese containing 0.5% gum received the highest sensory score compared to other samples, while the cheese containing 0.1% gum received the lowest sensory score. Considering the positive effect of Persian gum on various cheese properties, especially texture improvement, its utilization in industrial cheese production, as well as investigating its combined effects with other hydrocolloids, is recommended.
Food Technology
Mohammad Sadegh Arab; Hannan Lashkari; Mehrdad Niakosari; Mohammad Hadi Eskandari
Abstract
This study aimed to evaluate the effects of intelligent pH-sensitive composite film based on gelatin and Persian gum incorporated with purple carrot extract (PCE) on the freshness of wrapped mozzarella cheese. In this regard, the color, pH, yeast and mold count of control and treatments wrapped with ...
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This study aimed to evaluate the effects of intelligent pH-sensitive composite film based on gelatin and Persian gum incorporated with purple carrot extract (PCE) on the freshness of wrapped mozzarella cheese. In this regard, the color, pH, yeast and mold count of control and treatments wrapped with intelligent pH-sensitive composite film during 60 days were evaluated. The results showed that the pH significantly reduced in wrapped cheese with and without PCE (control) samples during storage. However, this reduction was more pronounced in the control sample (P<0.05). Additionally, the application of composite film on cheese affected the color during storage. It was observed that L* and a* values of the composite film-wrapped cheese were significantly higher than the control sample, but the b* values were significantly lower than the control sample. Moreover, poor microbial growth (yeasts and mold) was observed in cheese samples wrapped by composite film with purple carrot compared to the control. Also, the pH of the composite film with extract significantly decreased from 6.33 to 4.85 during storage (P < 0.05), which showed the changes of color from purple to pink. After 40 days, the color changed to pink, indicating the end of the cheese storage. Therefore, it was concluded that the pH-sensitive film, while being an effective method to improve the shelf life of mozzarella cheese, can also use as an indicator for freshness.
Reyhaneh Dakhteh; Mohammadreza Khani; Shahriar Dabiriyan
Abstract
Introduction: Because of the relationship between fat intake and obesity and the incidence of cardiovascular diseases, the demand for low-fat products has been increased. There are several methods to produce low fat products, which one of these methods is the use of fat replacer. The present study was ...
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Introduction: Because of the relationship between fat intake and obesity and the incidence of cardiovascular diseases, the demand for low-fat products has been increased. There are several methods to produce low fat products, which one of these methods is the use of fat replacer. The present study was aimed to partial substitution of fat in table cream by Qodume shirazi (Alyssum homolocarpum) and Persian (Amygdalus scoparia) gums. Materials & Methods: The fat content of cream was decreased from 25% (in control sample) to 18% and 15%, and each of these gums were added to the low-fat cream formulation in 0.2%, 0.3%, and 0.4% (w/w), separately to make 12 treatments. All samples were examined for physicochemical (including pH, acidity, dry matter, moisture, synersis, and viscosity) and organoleptic (including color, aroma, taste, texture and overall acceptability) properties. Results and Discussion: The results showed that the effect of type and amount of gums was significant for the pH, acidity, dry matter, moisture, syneresis, and viscosity of produced samples (P<0.05). In both types of cream (with 15 and 18 percent fat), pH of treatment containing 0.4% Qodume gum (6.81) was significantly higher than control (6.69) and other treatments (P<0.05). Moisture content of the control sample (68.7%) was lower than other treatments (73-78.7%) but dry matter of the control sample (31.3%) was higher than other treatments (21.2-26.9%) and in both creams containing 18% and 15% fat, the higher dry matter was devoted to sample containing 0.4% of Persian gum. The viscosity of cream with 18% fat containing 0.4% Qodume shirazi gum (21915 cP) and Persian gum (21919 cP) was significantly higher than the control sample (21507 cP) and other treatments. Moreover, syneresis of treatments with 18% fat containing 0.4% Qodume and Persian gums (0 ml), and also cream sample with 15% fat containing 0.4% Qodume gum (0 ml) was not observed as in the control sample (P>0.05). Evaluation of sensory properties revealed that the type of gums only had significant effect on color and the effects of cream type and amount of gums were mostly significant on texture and overall acceptance. In general, low-fat cream with 18% fat containing 0.4% Qodume and Persian gums had showed the best physicochemical and sensory results comparing to other treatments.
Maryam Mohammad Khani; Mohammad Fazel
Abstract
Introduction: Increasing society's desire to consume healthy and low-calorie foods has led to the production of low-fat and healthy foods. In this study, the effect of oil replacement with tofu cheese and Persian gum on physicochemical, textural, rheological and sensory properties of Mayonnaise sauce ...
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Introduction: Increasing society's desire to consume healthy and low-calorie foods has led to the production of low-fat and healthy foods. In this study, the effect of oil replacement with tofu cheese and Persian gum on physicochemical, textural, rheological and sensory properties of Mayonnaise sauce as well as its particle size, were investigated. Tofu was replaced with fat at three concentration levels of 20, 35 and 50% and Persian gum was added to the sauce at three concentrations of 2.5, 3, and 3.5%. The control sample contained 60% fat and guzanthan gum. With increasing tofu, pH and acidity increased and with increasing Persian gum acidity decreased. With increasing tofu, histological test (hardness, adhesiveness, adhesive force, work done to hardness, apparent modulus) decreased and with increasing Persian gum, their increased. With increasing tofu, decreased particle size. With increasing gum until 3%, average of particle size decreased and with more increase of gum, average of particle size increased. The rheological behavior of all samples at a shear rate of 0.01 to 1000 (on second) showed that the viscosity decreased with increasing tofu decreased and with increasing gum, increased. In all samples, with increasing shear rate, the viscosity was decreased, and the behavior of the samples was pyseudoplastic and the parameters followed the power law model. Sample with 20% tofu cheese and 3.5% Persian gum as top samples, whose properties are closer to fatty mayonnaise and can be called Mayonnaise with reduced fat. Materials and methods: Physical and thermal stability tests of the emulsion were performed with a centrifuge machine. PH test was performed using pH meter and acidity test in terms of acetic acid percentages. The fat percentage was performed with a Soxhlet. The texture properties were performed by back extrusion test and the parameters of hardness, adhesiveness, adhesiveness force, apparent modulus and force required to squeeze were calculated. The particle size was measured using a dynamic light dispersion apparatus, and the average particle size, mod, and D50 of the emulsion particles of oil were investigated. The rheological behavior was performed by the rheometer and sensory evaluation was conducted by the hedonic method. Statistical analysis was performed by using SPSS software and the mean comparison test at 5% probability level and in the form of factorial test. Results & Discussion: In the physical and thermal stability test of the emulsion, no two phases were observed in the samples. This could be due to the strong structure of the emulsion and the high viscosity of the continuous phase. By increasing the tofu value, the pH increased, which can be attributed to the decrease in the concentration of hydrogen ion or the increase of the aqueous phase. With increasing amount of gum, there is no change in pH, because the Persian gum has a neutral nature. Increasing the amount of gum did not affect acidity. As the tofu increased, acidity increased, and this increase was very slight, which can be attributed to buffering mode of tofu due to high amounts of high amino acids. By increasing the tofu percentage, the percentage of fat decreases because the percentage of fat in tofu cheese is law and its protein content is much. The increase in gum did not affect the amount of fat, because Persian gum structure was made up of saccharides. The tofu increase up to 35% reduced the texture properties, because the aqueous phase increased, with increasing gum percentage, texture properties increased because it produced a strong gel structure.With the increase in tofu content, the particle size of the oil decreased, because with increasing the amount of fat, the particle size increased. By adding gum the particle size decreased to 3% and then increased, because in the Persian gum structure, there are insoluble branches and the solubility of these branches is low. In the evaluation of rheological behavior, flow behavior test was investigated; viscosity of all samples was reported at shear rates of 0.1, 1, 10, 100/ sec. In all samples, the viscosity decreases with increasing frequency. By increasing the gum at a constant shear rate, the viscosity increased, which can be explained by the fact that the formation of a stronger structure in the presence of higher concentrations of gum. By increasing the shear rate at a constant concentration of gum, the viscosity decreased, and the increase in gum with increasing shear rate also reduced the viscosity and sauce had profit and plastic behavior that could be due to the opening of the bonds. As the tofu percentage increased in all shear rates, viscosity decreased and by increasing the tofu value at a constant shear rate, the viscosity decreased, and the increasing tofu with increasing shear rate reduced viscosity due to high moisture content of the cheese. The rheological parameters of mayonnaise sauce were checked in accordance with the power law. As the gum increased, the consistency coefficient increased , because the number of molecules with high molecular weight in the liquid phase increased, with increasing the percentage of tofu cheese, the coefficient of consistency decreased. The flow behavior coefficient does not have a clear trend, and since it is less than 1, the samples are non-Newtonian. In the strain scan test in lower strains, mayonnaise always has linear viscoelastic behavior. By increasing the gum concentration, both the elastic and viscous components are transported to higher values, which can be due to more interaction between the Persian gum and the components of the emulsion. In the sensory evaluation of the samples, the addition of gum and tofu percentage was not effective.With regarding the data of the tests, mayonnaise sample was identified with the replacement of 20% tofu cheese and 3.5% Persian gum as a superior sample, which its properties are closer to fatty mayonnaise and can be classified as Mayonnaise with law Fat. An extensive medicinal property of Persian gum with tofu cheese in mayonnaise sauce makes it a rich and very good source.
Fatemeh Azarikia; Soleiman Abbasi
Abstract
Introduction: Maillard reaction is a well-known technique for covalent coupling of protein–polysaccharide which is usually used to improve the functional properties of proteins. Conjugation by the dry heating method is occurred during Amadori rearrangement step in the Maillard reaction where amine ...
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Introduction: Maillard reaction is a well-known technique for covalent coupling of protein–polysaccharide which is usually used to improve the functional properties of proteins. Conjugation by the dry heating method is occurred during Amadori rearrangement step in the Maillard reaction where amine groups of the proteins are linked to the reducing end of the polysaccharides. This glycation process leads to the improvement of solubility, foaming and emulsifying properties of proteins (Liu et al., 2012). Protein-based emulsions are sensitive to pH and ionic strength alterations as well as heating and freezing–thawing processes. While, joining proteins to high molecular weight polysaccharides protects them against environmental stresses. A wide range of carbohydrates were already utilized to enhance the emulsifying properties of proteins–polysaccharides namely whey protein isolate–dextran (Akhtar et al., 2003), β-lactoglobulin–dextran (Wooster et al., 2006), sodium caseinate–maltodextrin (O’Regan et al., 2009), deamidated wheat protein–maltodextrin or glucose (Wong et al., 2011), whey protein isolate–pectin (Xu et al., 2012), yolk phosvitin–dextran (Chen et al., 2014), β-lactoglobulin–six-carbon monosaccharides (Cheetangdee et al., 2014), soy protein isolate–soy soluble polysaccharides (Yang et al., 2015), lysozyme–tragacanth (Koshani et al., 2015), and β-lactoglobulin–Persian gum (Golkar et al., 2015). However, based on the existing literature, it seems that conjugation of Iranian native gums and proteins needs to be more attended to show their potential applications. Therefore, in this study, conjugate formation between milk proteins (sodium caseinate and whey protein isolate) and soluble fraction of Iranian native gums (gum tragacanth and Persian gum) was optimized using response surface methodology (RSM) and the resulting conjugates were used in emulsion formulation in order to compare protein capability before and after being attached to the gums.
Materials and methods: Iranian native gums were pulverized and sieved (mesh size < 60) after being prepared from local herbal stores. To obtain protein–polysaccharide conjugates, dry heat treatment was accomplished at 60oC and 79% relative humidity at different protein:polysaccharide ratios and heating times. Free amino group content was determined by the ninhydrin method described by Doi et al. (1981). To measure color changes before and after Maillard reaction, Hunter Lab was used. Besides, possibility of stabilizing oil-in-water emulsions using the conjugates was studied. Emulsions were formed by addition of oil phase (4% w/w) into protein–polysaccharide conjugates solution (0.4% w/w) following by ultrasound treatment (amplitude of 100%, for 4 min). Samples were kept at 4 oC for 30 days after adjusting the pH at 3, 5 and 7 to compare the effect of protein–polysaccharide conjugates on their stability at different protein charges. For optimization of Maillard reaction using RSM (central composite design), protein:polysaccharide ratio and heating time were selected as independent variable and were studied at 5 levels. The dependent variables were the substitution degree of free amino groups and color change.
Results & Discussion: Based on our findings, the decrease of free amino group indicated that NH2 group of amino acids in milk proteins was covalently linked to carbonyl group of the gums. Comparing free amino group reduction of the samples containing soluble fraction of gum tragacanth and Persian gum also showed that Persian gum was more capable of forming covalent linkage with milk proteins than gum tragacanth; probably, due to the lower side branches of Persian, its molecular weight as well as its structural flexibility. Moreover, we believe the higher side branches of attached-tragacanthin molecules might prevent further attachment of protein to the other polysaccharide molecules via steric repulsion. According to the results of color measurement before and after dry Maillard reaction, conjugation led to reduction of L* and increase of a* and b*. In addition, higher heating time and protein:polysaccharide ratio caused progress of Maillard reaction (especially in the case of milk proteins–soluble fraction of Persian gum). Based on our findings, in dry Maillard reaction, the optimum heating time and protein:polysaccharide ratio were 8 days and 1:1.59 for whey protein isolate–soluble fraction of Persian gum, 7 h and 1:2 for sodium caseinate–soluble fraction of Persian gum, 13.64 days and 1:3 for whey protein isolate–soluble fraction of gum tragacanth, and 7.82 h and 1:3 for sodium caseinate–soluble fraction of gum tragacanth, respectively. Besides, the obtained Maillard reaction products did not cause complete stability of emulsions at pHs 3, 5 and 7. Our findings also declared that attachment of polysaccharides to proteins might negatively affect the proteins functionality, as emulsifier, possibly by hindering adsorption of hydrophobic groups of proteins to oil droplets. Furthermore, homogenization process during emulsion preparation using ultrasound could break the formed covalent bonds and polysaccharide structure leading to lower steric repulsion and viscosity.
