Study of Ice Cream Freezing Process after Treatment with Ultrasound

Application of power ultrasound to Food freezing is a relatively new subject, cavitations is the most significant power which can not only lead to the production of gas bubbles in ice ream but also the occurrence of micro streaming, also it can promote ice nucleation to accelerate the heat and mass transfer process accompanying the freeze process. In this work ice cream freezing process time after treatment with ultrasound (20 KHZ) was studied. Results were shown that ultrasound is beneficial power to ice cream freezing process and it can be shorten the Freezing process time. Also be lead to product of better quality of ice cream e.g. reducing crystal size and preventing incrustation of freezing surface. Key word: Ice cream freezing process ultrasound INTRODUCTION is used to initiate nucleation in ice cream, it is suggested Ice cream can be considered as an aerated and the preferred frequency be 20 KHz. Further more, the suspension of crystallized fat and water in highly duration should be as short as possible and preferably no concentrated sugar solution containing hydrocolloids, more than 5 second [5]. In this study we have utilized from casein micelles and proteins. The control of the ultrasound power (20 KHz) for promoting of ice nucleation crystallization process is one of the major factors affecting and accelerate the heat and mass transfer process and the stability and sensory characteristics of these reduction time in freezing process. Also it be use to products. Power ultrasound is a relatively new technology provement of sensory characteristics such as flavor, which can be used to promote the nucleation of ice [1]. In texture and mouth feel in ice cream. the presence of an acoustic wave, ice can be initiated at a higher nucleation temperature, than under control MATERIALS AND METHODS conditions. The results from theoretical studies have indicated that the cavitations bubbles produced by the The first for the purpose of determining the effect of ultrasonic wave are responsible for the nucleation process power ultrasound during ice cream freezing process. One [2]. Cavitations bubbles also benefit the freezing process horn ultrasonic with frequency 20KHz and 5 levels of time by reducing both the heat and mass transfer resistance at (1, 5, 20, 40, 60 min) model Dr Hielscher, was used. also for the ice/liquid interface and thus increasing freezing rate ice cream manufacture a pasteurized, homogenized and [3, 4]. Ice crystal is another major component of the ripened standard ice cream mix were used and ice cream freezing system, of ice cream than will fracture when they consisted of 8% milk fat, 10% milk solids nonfat, 18% are subjected to sound wave. Fragmentation of ice sugar and 2.5% guar mixed were batch pasteurized at 75oC crystals leads to crystal size reduction [4]. Factors that for 15 min and homogenized at 17.2 mpa first stage, affect the efficiency of power ultrasound can be classified 3.4 mpa second stage. Cooled to 4°C and aged for 24h. in two categories. Product factors and sound factors, Then mix place into, Ice cream maker and, Ice cream frozen product factors involve, parameters such as product time investigate by determining of the nucleation forming structure, moisture content and viscosity, initial gas of ice crystals, Then determining of over run and content and bubble size, etc., Sound factors include characteristics properties in mix of ice cream. The power and duration or pulse time of ultrasound, statically analysis system was used an ANOVA to find ultrasound frequency, ultrasonic mode. Power ultrasound out effects of different levels pulse ultrasonic on the that the power should be greater than 2 w cm of liquid 2