Concentrated fruit juice as an osmotic solution in production of candied apple
Application of concentrated fruit juice (CFJ) in production of candied apple was investigated. Different ratios of sugar syrup to CFJ and levels of CaCl2 were studied as processing variables and their effects on physicochemical properties of candied apples were monitored during storage. The highest sugar content was obtained in the ratios of syrup to CFJ 2.5:1.5 and 1.75:2.25 for concentrated orange and sour cherry juice, respectively. Besides, apples candied in concentrated orange juice had higher levels of ascorbic acid. Furthermore, osmotic dehydration improved the colour attributes of the product. Sensory scores revealed that by increasing CFJ the desirability of the product was improved. Regarding measured quality indices, obtained data can be used to develop a natural candied apple with high nutritional value.
Nowadays, the interest in fruits and vegetables is increasing since their significance in human diet has been proven. They contain a wide range of nutrients including vitamins which have protective effects against human diseases. Along with having desirable components, fruits and vegetables are perishable products. Therefore, many preservation methods such as drying have been established to enhance their shelf life. On the other hand, as a result of chemical and nutritional modifications, a drying process can either enhance or diminish quality attributes (1). One of the methods which can improve the sensory and nutritional properties of fresh products is osmotic dehydration (2).
Osmotic dehydration is a preservation method in which food material is immersed in a solution with high osmotic pressure and low water activity. This process leads to removal of water through the food material and diffuse of solutes from the osmotic solution in to the food. Additives such as calcium chloride or some acids including lactic or citric acid may be used for different purposes during osmotic dehydration (3). For instance, incorporation of calcium ...