Influence of Temperature on Shelf Life of Butterhead Lettuce Leaves Under Passive Modified Atmosphere Packaging

Abstract

The aim of the present work was to study the influence of temperature on sensory and microbiological qualities, and on shelf life of butterhead lettuce leaves in passive modified atmosphere packages. Butterhead lettuce was washed and placed under ambient air in 30 ¥ 40 cm polypropylene bags, and stored at 5, 10 and 15C. A first-order equation was obtained for the development of the evaluated appearance sensory attributes as a function of storage time. For all the evaluated storage temperatures, microbiological shelf lives (14, 17 and 42 days at 5, 10 and 15C) were higher than estimated sensory shelf lives (8, 14 and 26 days at 5, 10 and 15C), showing that shelf life of lettuce in passive modified atmosphere packages was limited by sensory properties and not by microbial growth. PRACTICAL APPLICATIONSSensory shelf life of lettuce in passive modified atmosphere packages was estimated using consumer data, which are an improvement of a more arbitrary 4 Corresponding criteria presented in most studies. Moreover, if failure criteria used in other studies were applied, consumer rejection at the end of shelf life would be higher, suggesting that more conservative criteria are necessary to assure the product's quality at the end of its shelf life. SHELF LIFE OF BUTTERHEAD LETTUCE 242C. LAREO ET AL.

Phytochemical and microbiological changes of honey pomelo (Citrus grandis L.) slices stored under super atmospheric oxygen, low‐oxygen and passive modified atmospheres

“…, 2002). The microbiological growth under HOA and LOA was reduced to <4.71 log 10 cfu g −1 , comprising the tolerance criteria for fresh‐cut produce on the production day (10 5 –10 6 cfu g −1 ) (Lareo et al. , 2009).…”

Methodology for Sensory Shelf‐life Estimation: A Review

“…Based on an arbitrary COP of 5 on a 1-9 hedonic scale they estimated SSLs for the different water activities and also estimated how SSL was affected by a change in 0.1 in water activity. Lareo et al (2009) used the accelerated survival model published by Hough et al (2006a) to estimate SSLs of lettuce stored at different temperatures. They determined that shelf life of lettuce in passive modified atmosphere packages was limited by sensory properties and not by microbial growth, thus showing the importance of SSL for fresh vegetable products such as lettuce.…”

Number of consumers necessary for survival analysis estimations based on each consumer evaluating a single sample

“…Thus, a Weibull distribution was chosen for the present simulation calculations. The failure function of a Weibull distribution is given by: considered (Ares et al, 2006;Giménez, Ares, & Gámbaro, 2008b;Lareo et al, 2009;Sosa et al, 2008;Torrieri, Di Mónaco, Cavella, & Masi, 2008). The average of the total 25 r values was 0.41, with minimum and maximum values of 0.17 and 0.77, respectively.…”