Extension of Shelf Life and Control of Human Pathogens in Produce by Antimicrobial Edible Films and Coatings - Microbial Safety of Fresh Produce - page 231

Use of Edible Films and Coatings on Fresh Fruits and Vegetables
The most important quality attributes contributing to the marketability of fresh produce
include appearance, color, texture, fl avor, nutritional value, and microbial safety.
These quality attributes are determined by plant variety, stage of maturity or ripening,
and the pre- and postharvest conditions (Lin and Zhao 2007). Fresh fruits undergo
vigorous biological reactions after harvest because their respiration accelerates the
natural loss of fruit tissue. Therefore, fruits tend to lose water at room temperature;
change appearance, texture, and quality; and decrease in commercial value. For use
on fresh fruits and vegetables, an edible fi lm would include good barrier properties
and be odorless, tasteless, and transparent. Edible polymer fi lms may be formed as
either food coatings or stand-alone fi lm wraps and pouches. They have the potential
use with food as moisture, gas, and/or aroma barriers. A list of applications of edible
fi lms on fresh fruits and vegetables is shown in Table 12.2.
Table 12.3 shows some examples of successful applications of antimicrobial edible
coatings on fresh fruits and vegetables. Antimicrobial edible coatings are more promis-
ing to be used on fresh-cut fruits and vegetables than on fresh produce, except when
the produce is commonly consumed without peeling like the fresh produce listed in
Table 12.3. Surprisingly, little research has been done on applications of antimicrobial
coatings to melons or tomatoes, both of which have been reported in several major
foodborne pathogen outbreaks.
The potential benefi ts of using edible fi lms and coatings in the fresh produce indus-
try include providing a moisture barrier on the surface of produce to decrease moisture
loss; providing a suffi cient gas barrier to control gas exchange between the fresh
produce and its surrounding atmosphere to slow respiration, delay deterioration, and
protect the fresh produce from brown discoloration and texture softening during
storage; restricting the loss of natural volatile fl avor and color compounds from the
fresh produce or the acquisition of foreign odors by providing gas barriers; protecting
produce from physical damage caused by mechanical impact, abrasions, pressure,

Table 12.2. Application of edible fi lms on fresh fruits and vegetables
Product

Application Film Materials Functions References

Strawberry Wrap, pouch Wheat

gluten - based
fi lms

Retention of fi rmness,
reduced weight loss,
and maintained visual
quality during storage

Tanada - Palmu and
Grosso 2005

Apple Wrap Apple - based

edible fi lms

Reduced moisture loss
and browning in
fresh - cut apples

McHugh and
Senesi 2000

Lettuce Wrap Biodegradable

protein fi lm

Did not show any
benefi cial effects on
pectic substances and
pigments

Schreiner and
others 2003

Green pepper Wrap Polylactic

acid - based
biodegradable
fi lm

Can be used to maintain
quality and sanitary
conditions in modifi ed
atmosphere packaging

Koide and Shi 2007