Early Postharvest Time Period Affects Quality of Butterhead Lettuce Packed in Crates

AGÜERO MARÍA VICTORIA; VIACAVA GABRIELA ELENA; PONCE ALEJANDRA G; ROURA SARA INES

International Journal of Vegetable Science

Taylor & Francis

Año: 2013 vol. 19 p. 384 - 402

1931-5260

The period between when butterhead lettuce (Lactuca sativa var. L) heads are harvested and stored in cold rooms can be up to 4 hrs. During this period, environmental conditions are uncontrolled, and heads could undergo deterioration that has not been previously quantified. Quality changes of lettuce heads packed in crates, and exposed to optimal or sub-optimal conditions, during the 24 hrs after harvest were evaluated. Effects of placement within crates (lower, middle and upper layer) was assessed. Proximity of heads within crates created a barrier to transfer of heat and humidity. This resulted in negative responses for plants under optimal conditions because there was a delay in temperature reduction and a deterioration in quality. At sub-optimal conditions the response was positive because respiration and transpiration allowed development of a saturated environment around heads delaying loss of quality. This effect was most obvious in heads from middle and lower layers which present the highest overall visual quality and water content. Use of crates caused extensive mechanical damage on heads, making it necessary to discard outer leaves leading to 10 and 35% weight losses under optimal and sub-optimal conditions, respectively. Initial quality rapidly decreases in the first day after harvest. It is necessary that technologies be upgraded to reduce quality and economic losses.