Method of packaging lettuce for storing and shipping

Abstract

A container system which is environmentally controlled for the packaging and shipment of vegetables, and particularly of lettuce, such as iceberg lettuce. The packaging relies upon a reusable paperboard container which is of a polygonal shape, such as an octagonal shape, providing a large number of corner margins which afford strength in stacking of like containers on pallets. A plastic liner is disposed within the paperboard container and receives the vegetables such as the heads of lettuce. This liner is evacuated through a small incision made in the liner and the liner is sealed, or the former air atmosphere is replaced with a modified atmosphere, such as a high carbon monoxide concentration or nitrogen atmosphere, and thereafter, the opening is sealed. The modified atmosphere precludes the oxidation and deterioration of the lettuce or other vegetable product. In a more preferred embodiment, a pair of plastic liners, comprising inner and outer liners, are employed. When the inner liner is filled, the pair of liners are then rolled over and sealed. A small incision is made in the inner liner in order to evacuate the air from the environment in which the lettuce is held. Thereafter, the small opening used for evacuating the air is sealed. The same procedure takes place with the second or outer liner in that it is evacuated and charged with a modified carbon monoxide or nitrogen atmosphere and the opening thereof sealed. In this way, if there is a leak in the inner liner, the lettuce or other vegetable will only be exposed to the modified carbon monoxide or nitrogen atmosphere and not oxygen which causes a very rapid deterioration of the vegetables. Leakage through the outer liner will not injure the vegetables as long as the inner liner remains secure and intact.