Preparation of Khoa by Traditional and Mechanical Methods

摘要

Khoa is a rich source of calcium which helps in strengthening of bones and teeth. It is helpful in osteoporosis and abundance of riboflavin in khoa helps to maintain healthy immune system. . The traditional method of khoa making has a number of drawbacks: It has a limited capacity due to batch operation which results in non-uniform product quality and thus not suitable for large volume production, inefficient use of energy and low heat transfer coefficient results in bulky equipment, large spillage losses, it requires more manual labor and sometimes burning of the product occurs which lowers its quality. In the present study a comparison between preparation of khoa by traditional method as well as mechanical method using steam jacketed khoa pan was carried out. Khoa was prepared by traditional method by stirring the raw milk continuously in a pan over a flame until the raw milk was converted into semi solid stage. The drawbacks such as vary in temperature during the experiment because of non-uniform distribution of flame and burn out of milk solids were identified in this method. This leads to burnt flavour and discolouration of khoa. To overcome these drawbacks of traditional method, khoa was made in a steam jacketed khoa pan installed at Dairy and Food Processing Pilot Plant, College of Agricultural Engineeering, Madakasira at a uniform pressure of about 1.5 kg/cm~(2). In this mechanical method, the khoa was prepared in less time as well as it has good appearance, flavour, texture etc. compared to khoa prepared by traditional method. In traditional method, about 0.242 kg of of khoa was obtained from 0.94 kg of raw milk with addition of 0.0925 kg of sugar while 11.50 kg of khoa was obtained from 40 litres of raw milk with addition of about 4 kg of sugar when khoa was made in steam jacketed khoa pan. In this mechanical method, the khoa was prepared in less time as well as it has good appearance, flavour, texture etc. compared to khoa prepared by traditional method.