Development of Batch Type Multiplier Onion Peeler Ravindra Naik 1 , SJK Annamali 2 and Dawn CP Ambrose 3 1& 3 Scientist (Senior Scale), Post harvest processing, Central Institute of Agricultural Engineering, Industrial Extension Project, TNAU, Coimbatore, Tamil Nadu 641 003, India. ABSTRACT Multiplier onion (Onion aggregatum) is consumed in large quantity in southern province of India. These onions are used in large quantity in the catering and pickling industries creating a need for peeling equipment. Onion peeling is an essential step in producing many of the onion products such as dehydrated onions, onion powder, onion flavoring, onion salt, onion rings, and pickled and canned onions. Several methods have been used for peeling onions. The common methods used in modern onion processing industry are lye treatment, flame peeling are not suitable for peeling of multiplier onion. A batch type peeling machine suitable for farm-level operation was designed and tested for multiplier onion. The equipment consists of an aluminum drum seated over a rotating disc. Inner surface of the aluminum drum and top surface of the disc was covered with corrugated rubber sheet which aids in peeling process. The multiplier onion needs to have the ends cut with a knife sharp knife and soaked in clean water for a period of 10 min to assist the loosening of peel followed by air dried for 1-2 minute to remove the surface water. Interaction studies were carried out in-between the speed of rotation v/s peeling efficiency percentage damage and unpeeled sample and operational parameters were optimized. The capacity of the peeler was found 50-60 kg/h. The peeling efficiency found about 92 per cent with unpeeled and damaged percentage being 6 and 2 per cent, respectively. The cost economics study revealed that the equipment can be adopted by small and medium multiplier onion processing industries. Keywords: Multiplier onion, peeling, peeling efficiency, cost economics 1. INTRODUCTION Multiplier onion (Onion aggregatum) is consumed in large quantity in the southern provinces of India. Peeling is a time consuming process, as a result of which the working women avoid this particular type of onion even though it is much preferred and reported to have many medicinal advantages. These onions are used in large quantity in the catering and pickling industries creating a need for peeling equipment Multiplier onion peeling is an essential step in producing many of the products such as dehydrated, powder, pickled and canned products. Several methods can be used for peeling multiplier onions. The common methods used in modern processing industry are lye treatment and flame peeling. Lye peeling and flame peeling methods are harsh and are not suitable for many multiplier onion products. In lye peeling or flame peeling, onions are abraded and then treated in a hot solution of caustic soda or burnt by passing through a furnace. Burnt skins are removed by scrubbing them with brushes. These methods suffer from a number of disadvantages. First, they produce incompletely peeled multiplier onions, that is, the core of the root remains with the onion bulb and require further processing. Chemical and flame treatment tend to damage the onions and their flavor compounds which affects the quality of some products. Furthermore, the peels are destroyed and cannot be used for extraction of flavoring compounds which tend to concentrate in the peels. These