The amount of oil added to the standard No. 5 tuna can for solid 

 pack is Ig ounces. Some packers vary this amount a little for flake 

 or chunk pack. The oil is generally added hot at temperatures between 

 160° and 225° F., each plant adjusting the temperature to what they 

 consider to be optimum. Most plants use temperatures in the range of 

 180° to 200° F, and a few plants do not heat the oil at oil. Heating 

 of the oil decreases its viscosity and increases the rate of penetration 

 of oil into the tuna. In hand packs more uniform penetration is achieved 

 by putting part of the oil in the bottom of the empty can and part on 

 top after the can has been filled with fish. Such a system is infeasible 

 when such packing equipment as the Carrufchers Pak-Shaper is used owing 

 to feeding of the empty cans to the machine on edge. Heating of the oil 

 also helps to create vacuum in the cans where a vacumm sealer is not 

 employed. 



Oil is added to the cans of tuna along a conveyor belt leading 

 from the packer on the packing line. Oilers are usually either of the 

 perforated pipe or piston pump type. Quite frequently oil is added 

 not only by separate pumps but also at different points along the line. 

 Thus three piston pumps might add half the oil within a space of a foot 

 or so and then the cans might travel along the conveyor for 10 feet, 

 allowing the oil to penetrate the fish before adding the remaining oil 

 from three additional piston pumps.. When hot oil is employed, it is 

 heated in a thermostatically controlled tank usually employing steam 

 pipes. The oil may flow by gravity from such an overhead tank or it may 

 be pumped to the oilers. Excess oil which may not fall into a can is 

 generally collected in a sump beneath the can conveyor belt, screened, 

 and returned to the heating tank. Nozzles on piston pump oilers are 

 sometimes provided with fine screens which prevaits dripping and loss 

 of oil between shots. 



From 1/16 to I/8 ounces of salt are added to the 307 x 113 size 

 cans; l/lO to l/l2 ounces of salt is an average range. Several dif- 

 ferent types of salters are employed, with two makes being most fre- 

 quently employed, A few plants have improvised salters and some of 

 these seem to work as well or better than standard manufactured salters. 

 It was observed that a few salters spread the salt fairly uniformly 

 over the entire top of the can. Usually, however, most of the salt 

 was dropped in a spot about the size of a quarter in the middle of the 

 can. Whether different degrees of uniformity of sprinkling of the salt 

 on the can make any appreciable difference in uniformity of salt pene- 

 tration into the fish is not known, 



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