Food Chemistry
Masoumeh Heydari Gharehcheshmeh; Akram Arianfar; Elham Mahdian; Sara Naji-Tabasi
Abstract
[1]Introduction: Sesame oil and sweet almond oil are rich in unsaturated fatty acids and antioxidant components, providing nutritional and functional properties including improvement of the gastrointestinal system, decrease in blood cholesterol level, eventually leading to a decrease in the risk of cardiovascular ...
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[1]Introduction: Sesame oil and sweet almond oil are rich in unsaturated fatty acids and antioxidant components, providing nutritional and functional properties including improvement of the gastrointestinal system, decrease in blood cholesterol level, eventually leading to a decrease in the risk of cardiovascular disease. The present study examined the possibility of the production of emulsion based on sesame and sweet almond oils and the effect of preparation on its stability. Material and methods: Sesame oil and sweet almond oil with tween 80 and span 80 as emulsifiers were used in emulsion production. In order to prepare the nanoemulsions, the water and oil phases were prepared separately by the ultrasonic homogenizer. Ultrasonic waves were applied for homogenization and the effect of Ultrasonic time (5, and 10 min), oil content (2, and 4%), and emulsifier concentration (0.25, 0.5%) on particle size, particle distribution index (PDI), turbidity loss rate, emulsion stability and zeta potential of nanoemulsions were studied. Results and discussion: Ultrasonic time had a reverse effect on particle size, particle distribution index (PDI) and turbidity loss rate and a direct effect on emulsion stability. The particle size and turbidity loss rate of prepared emulsions had a direct relation with oil concentration and a negative effect on emulsion stability. Emulsifier concentration had a positive effect on emulsion stability, a negative effect on emulsion stability, and had no significant effect on turbidity loss rate. According to the results of the effect of type and concentration of oil on particle size distribution, turbidity reduction rate and stability of nanoemulsions in all cases, samples containing sesame oil with a concentration of 2% compared to sweet almond oil, had better results, the presence of this oil led to the formation of nanoemulsions with smaller particles and greater stability. The produced nanoemulsions had a particle size between 200-320 nm, a stability of 91-98/7% and a turbidity reduction rate of 0.0010-0.0027. Also, the highest stability and zeta potential were reported 98.7 % and -33mV respectively, which belonged to sample k4. Therefore, this sample was selected as the optimal sample.The results showed that the particle size, mean particle diameter, particle dispersion and turbidity reduction rate showed a significant difference between the samples, so that the lowest and highest were related to K4 sample (2% sesame oil, homogenization time 10 minutes and Emulsifier concentration ratio 0.5%) and sample B5 (almond oil 4%, homogenization time 5 minutes and emulsifier concentration ratio 0.5%) (p <0.05). The results also showed that the highest level of stability and zeta potential was related to K4 sample. Thus, the best nanoemulsion, K4 sample was introduced
Food Technology
Sima Naji-Tabasi; Elham Mahdian; Akram Arianfar; Sara Naji-Tabasi
Abstract
Introduction: Fats have a special place in human nutrition and their main role is supplying energy for the body. But scientific findings approve an association between high fat intake and an increment risk of some diseases, such as atherosclerosis, heart disease, and …. Demand for low-fat foods ...
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Introduction: Fats have a special place in human nutrition and their main role is supplying energy for the body. But scientific findings approve an association between high fat intake and an increment risk of some diseases, such as atherosclerosis, heart disease, and …. Demand for low-fat foods has increased dramatically as people become more aware of fat consumption side effects. However, due to the multiple role of fats in food products, eliminating or decreasing fat lead to poor quality of products. Therefore, it is necessary to use a combination of fat substitutes to maintain the rheological, texture and sensory properties of the low fat food products. The use of emulsion gel structures are new methods for the production of low-fat product that has been studied in this investigation. The Pickering emulsion was used to produce the emulsion. In this method, instead of using surface-active agents, solid particles are used to stabilize the emulsion. The aim of this study was to prepare Pickering Emulsion from Isolated Soybean protein (ISP) and Basil Seed Gum (ISP-BSG) Complex. Finally, emulsion gel systems were applied as fat substitutes in cream. Materials and Methods: Basil seeds were purchased from Mashhad market. Isolated soy protein was purchased from Shandong Yuxin Bio-Tech Co. (China). Sodium azide was purchased from Applichem Inc. (Dramstadt, Germany). Sodium dodecyl sulphate (SDS) was obtained from Merck, Germany. Pickering (solid particles) of soy protein isolate (SPI) and SPI-basil seed gum (ISP-BSG) complex used as emulsifier for stabilization of cold emulsion. ISP-BSG particles were prepared with different mass ratios of ISP: BSG, 1: 0, 1: 1, 2: 1 and 3: 1 and named 1S: 0B, 1S: 1B, 2S: 1B and 3S: 1B, respectively. These solid particles were used as Pickering for emulsion preparation. Cold Emulsion was prepared by adding calcium chloride. The oil leakage, oil leakage after thermal treatments, microscopic structure, textural properties and viscoelastic properties of emulsion gel were studied. Then, the best structures used as a fat substitute in cream (5, 10 and 15%). Results & Discussion: Investigation of emulsion gel properties showed that coating the surface of emulsion droplets with solid nanoparticles formed a rigid shell that acted as a barrier against the deformation and transfer of materials from the interfacial surface. The use of ISP-BSG nanoparticles as picking particles caused more homogeneity and stiffness in emulsion gel structure. The rate of water loss in reduced fat cream was in the range of 1-2% by using the emulsion-gel system, which indicates the effectiveness of these systems in reducing dehydration in cream. The increasing replacement percentages led to increase water loss (p <0.05). However, emulsion type had no significant effect on water loss content (p> 0.05). According to the results, ISP-BSG nanoparticles impart high potential to stabilize emulsion with small oil droplets. Based on the results of the sensory test, it was found that the characteristics of the cream samples depended more on the replacement rate than the type of system used as an alternative. The presence of a fat replacement system maintained the desired quality in low-fat cream samples. Most of the samples scored higher than 3, which indicate the high acceptance of low-fat samples.
Elham Mahdian; Reza Karazhyan
Abstract
A nutraceutical food may provide expanded utility beyond its nutritional benefit. These benefits are commonly attributed to the active components of the food. Fruit by-products are rich source of dietary fibers that have beneficial effects on human health. Also they can improve the growth and viability ...
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A nutraceutical food may provide expanded utility beyond its nutritional benefit. These benefits are commonly attributed to the active components of the food. Fruit by-products are rich source of dietary fibers that have beneficial effects on human health. Also they can improve the growth and viability of probiotics in food matrix and therefore suitable to produce synbiotic food products. In this study, the effect of adding fiber obtained from apple, banana and mango peels at levels of 0.5, 1 and 1.5% on physicochemical and sensory features and the viability of Lactobacillus casei LC-01 in ice cream during 60 days storage at -18°C was investigated. Based on the results, all ice cream mixes were pseudoplastic fluids. The values of flow behavior index decreased and consistency coefficients increased by increasing the level of all mentioned fibers. The pH and specific gravity of samples containing banana and mango fibers were lower than control and sample with apple fiber. Using fibers had no significant effects on overrun values, whereas viscosity and melting resistance of ice cream samples increased with increasing fiber amounts. The most reduction in Lactobacillus casei LC-01 count after freezing and during storage period was associated to control sample and adding all types of examined fibers improved probiotic viability. Minimum cell reduction after freezing and during storage period occurred in sample containing 1.5% mango fiber with 0.03 and 0.48 log cycle respectively. Sensory properties of samples containing apple fiber were good and comparable with control sample.
Mohebbat Mohebbi; Elham Mahdian
Abstract
Foaming conditions of the red beet (Beta vulgaris L) puree were optimized using response surface methodology (RSM) with respect to Arabic gum concentrations (0.01 – 0.4% w/w), red beet puree (40 _ 60% w/w),egg white concentration( 5 _ 15% w/w) and whipping time (3 – 9 min) for minimum foam ...
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Foaming conditions of the red beet (Beta vulgaris L) puree were optimized using response surface methodology (RSM) with respect to Arabic gum concentrations (0.01 – 0.4% w/w), red beet puree (40 _ 60% w/w),egg white concentration( 5 _ 15% w/w) and whipping time (3 – 9 min) for minimum foam density and foam drainage volume as response variables. Foams were prepared from various pulp concentrations by adding various concentrations of egg white as foaming agent and Arabic gum as stabilizer at different whipping time. The optimized conditions after the numerical and graphical optimization for maximum stability and minimum foam density were found at Arabic gum (0.29% w/w), egg white (15% w/w), red beet Puree (60% w/w), and whipping time (9 min).The results showed that the stability of foams increased with increasing Arabic gum concentration( p
