عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Background and objectives: Lycopene is a carotenoid pigment with positive effects on human health. It has been proved that lycopene can prevent some severe diseases such as cancer but because of multi unsaturated bonds, it is very sensitive to environmental conditions. Its fast deterioration during processing, always was a reason for not being used commonly in food industry. A method for controlling its deterioration is encapsulation and covering it by biopolymers in capsules. Due to lycopene is not a polar agent, the first step is producing emulsions with high stability.
Material and Methods: In this investigation, Arabic gum and Maltodexterin were used as water soluble solid materials in lycopene emulsions. In order to prepare emulsions, lycopene was solved in edible oil to make a 5% oily lycopene, then Arabic gum and Maltodextrin were solved in distilled water separately and stayed over a night to be sure of complete solvation, then prepared materials were used for emulsion production step. During emulsion processing, speed of homogenizer rotation (rpm), percentage of solid materials (w/w) and lycopene (w/w) were considered as independent variables and results were optimized by using Response Surface Methodology (RSM) method and Central Composite Design (CCD). Alpha was “1” because face center option was chosen. The software which was used to optimize the process was “design expert version 6.0.2. According to RSM worksheet, effect of three independent variable including speed of homogenizer (14000-18000 rpm), percentage of solid materials (Arabic gum+ Maltodexterin, 30-40% w/w) and percentage of lycopene (10-20% w/w)on three dependent variable including droplet size, creaming index and viscosity as response was investigated.
Results and Discussions: Results showed that, homogenizer speed and percentage of solid materials and lycopene, had significant effect (p< 0.05) on all dependent variables. Higher speeds of homogenizer resulted to smaller droplet size and less creaming index but viscosity raised dramatically. Inversely, Increasing of solid materials in system, resulted to lowering droplet size and creaming index but increased viscosity. On the other hand, with increasing lycopene content, droplet size, creaming index and viscosity were increased. Finally, by optimizing the process by RSM, best conditions for producing a stable emulsion could be achieved by using 37.025 w/w solid materials, 19.52% w/w lycopene and at speed of 18000 rpm.
Conclusion: Results showed that in order to produce a proper and stable emulsion, it is necessary to increase speed of homogenizer and amount of solid materials but this should not cause very high viscosity and re-coalescence of droplets due to over processing which can effect emulsion stability.