Ayda Saleh; Mahmoud Rezazadehbari; Mohammad Alizadeh khaled abad; Najmeh Sabahi Mohammadi
Abstract
Introduction : Yoghurt is one of the most popular dairy products in all over the world.Nowadays due to the tendency of consumers to use the products with healthy effects, probiotic and synbiotic products are considered. Yoghurt by itself is a healthy food; because of its high levels of protein and calciumcontents.Consumption ...
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Introduction : Yoghurt is one of the most popular dairy products in all over the world.Nowadays due to the tendency of consumers to use the products with healthy effects, probiotic and synbiotic products are considered. Yoghurt by itself is a healthy food; because of its high levels of protein and calciumcontents.Consumption ofprobiotic bacteria via food products is a way to reestablishthe intestinal microflora balance. Several studies have been done to improve the growth and viability of probiotic bacteria by adding supplements to milk.The objective of this study was to investigate the effect of three component mixture (Arabic gum, whey protein concentrate and milk protein concentrate) on quality indices of synbiotic yoghurt containing transglutaminaseenzyme. The content of theseprotein component, the amount of enzyme, enzyme addition time to the yoghurt samples and storage time were variableMaterials and methods:Yoghurt samples were prepared with milk which contained 2.5 percent fat.Milk was heated around 40 ̊C. WPC, MPC and Arabic gum were added to samples according to the research design and increasing the solid none-fat content of the milk up to 1.5%. Samples were pasteurized at 90 ̊C for 10 minutes in a water bath and were cooled rapidly to 43 ̊C for inoculation starter culture and probiotic bacteria. Also enzyme was added to samples before or after pasteurization (according to the research design).In this study microbial test was done to investigateviability of probiotics (BB-12) by differential culture medium (MRS-LP Agar). The titratable acidity was determined using 0.1 N NaOH until accessing the constant pink colour for 30secondes. Water holding capacity (WHC) was determined due to measure the protein quality of keeping water inside. Syneresis is expressed as the weight percentage of serum released by centrifugation. Viscosity was measured using a Brookfield viscometer.Viscosity measurementswere made using 250 mL ofyoghurt samples at 10 _CDiscussion & Results: The effect of WPC, MPC, Arabic gum, enzyme concentration and theaddition time of enzyme on viability of B. lactis (BB-12) for 21 days of cold storage at 4 ̊C were monitored. The results indicatedthat the effect of Arabic gum, WPC and MPC on viability of probiotic was significant (p
Hoda Khalesi; Mohammad Alizadeh khaled abad; Mahmoud Rezazadehbari
Abstract
Zedo gum is a polysaccharide that exudates from Amygdalus scoparia Spach tree. In this study the apparent viscosity under the influence of the gum concentration (0.5%, 0.75%, 1%, 2%, 3%, 4% and 5% w/v), temperature (20, 45, and 70 ˚C), pH (2, 5 and 8) and salt concentration (0-0.5 M) has been investigated. ...
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Zedo gum is a polysaccharide that exudates from Amygdalus scoparia Spach tree. In this study the apparent viscosity under the influence of the gum concentration (0.5%, 0.75%, 1%, 2%, 3%, 4% and 5% w/v), temperature (20, 45, and 70 ˚C), pH (2, 5 and 8) and salt concentration (0-0.5 M) has been investigated. Zedo gum is composed of soluble and insoluble components that respectively have the properties of solubility and swelling in water. The apparent viscosity changed due to temperature and pH. The highest viscosity was obtained at pH of 7.2 and 24 ˚C. Viscosity was changed by addition of certain strong electrolytes. The emulsion capacity and stability of oil in water emulsion increased by increasing gum concentration. Thermal behavior of Zedo gum with different moisture content was studied by differential scanning calorimetry (DSC). Thermal profiles showed an endothermic event. Considering the results obtained, Zedo gum is a potential natural and domestic additive for industry as a thickening agent, emulsifier and stabilizer.
