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Efficacy of light emitting diode (LED) irradiation treatments for post-harvest quality
preservation and microbiological safety of fresh lettuce

1
1 Mas Liza Aiza Maskor, Wan Zawiah Wan Abdullah*

1 Faculty of Fisheries and Food Science, Universiti Malaysia Terengganu, 21030 Kuala Nerus,
Terengganu, Malaysia.

* Corresponding author: wzawiah@umt.edu.my

Abstract:

Light emitting diode or LED is an energy efficient device that doesn’t contain hazardous material, have
longer life expectancy and low emission of radiant heat. LED properties in retain the colour, texture,
weight and total solid content of fresh fruit and vegetable have delay the senescence process and natural
degradation and has been proved as non-thermal decontaminating tools to eliminate the microbes rather
than being a lighting source only that make it suitable alternative to replace chemical-based treatment
on post-harvest vegetables such as lettuce. As the highly consumed vegetable around the world, lettuce
(Lactuta sativa L.) have short storage life limited by the texture and colour changing gradually because
of a few factors such as dehydration and enzymatic browning. Leaves of harvested lettuce are prominent
to yellowing, wilting, and decaying during storage at ambient temperatures, which results in a
detrimental texture changes and decreasing its sensory quality. Lettuce also had be identified as common
food related vehicle for virus transmission that can cause acute gastroenteritis and bacteria such as
Bacillus, Pseudomonas and Panteo are frequently be found in the lettuce which has led to many
outbreaks since lettuce is generally eaten raw and popularly consumed in salad mix. In this research, the
fresh lettuce will be irradiated under four LED treatments which are white light (448nm), red light
(630nm), blue light (470nm) and green light (530nm) and without LED treatment as control to evaluate
the effects on post-harvest products quality, microbiological safety and occurrence of biofilm formation
of the isolated bacteria on lettuce for every 2 days interval in 16 days with the total daily light exposure
will be 8 hours as cycle (8 cycles of 1 hour per day).

Keywords: Light emitting diode, Post-harvest quality, Food safety, Fresh lettuce, Biofilm formation