بررسي تأثير پيش فرآيند اسمز بر روي خصوصيات ارگانولپتيكي هويج خشك شده با هواي گرم

Investigation Efect of Omotic Dhydration Petreatment on Oganoleptic Poperties of Hot-air Dried Carrot

Osmotic dehydration, the process for partial water elimination from food stuffs, is called partial drying; it involves immersion of product in a hypertonic aqueous solution. The process has been used mostly as a pretreatment before different drying methods such as: hot air drying, vacuum drying, freeze drying and microwave drying. Therefore, in this research osmotic dehydration process was used as a pretreatment before air drying of carrot. For identification of optimum operating conditions, several factors like solution concentration, its temperature, and contact time were investigated. Temperature treatments included: 25, 40, 55°C and time treatments durations were 15, 30, 60,120,240 and 360 minutes. Three levels of glucose syrup concentration (30, 40 and 50%) and three levels of sodium chloride concentrations (5, 10 and 15%) were used to provide nine different solutions. The optimum operating conditions in view of water loss, solid gain and organoleptic properties were chosen to be 40°C for 240 minute. The results showed that 50% glucose + 5% salt solutions were the best concentrations gave a smaller solid gain(SG), maximum large water loss(WL) and desired organoleptic properties.