Biomedical Engineering Reference
In-Depth Information
1.8.3
Factors Affecting the Washing of Fresh-Cut
Fruits and Vegetables
Washing is an important step for minimally processed fruits and vegetables and the
following factors need to be considered:
1. Washing: Proper washing of fresh cut fruits and vegetables is the utmost desired
immediately after cutting. This step removes the dirt and some microbes present
on the surface of products. Usually chlorinated water is used for rinsing the
peeled fruits and vegetables. Therefore, the contact time during washing, pH and
temperature of the rinsing water play a key role for assuring the quality of prod-
ucts (Sapers
2003
).
2. Contact time: The contact period needs to be consider for an effective operation.
Generally, chilled water is required for rinsing the peels and fresh-cut fruits and
vegetables. Thus it is one way to cool the products before further processing and
their packaging.
3. Temperature: Temperature needs to be controlled for avoiding the spoilage at
preliminary step. It should be maintained at around 0 °C.
4. Chlorination: Optimum concentration of chlorine needs to be used. The concen-
tration of chlorine should be kept between 50 and 100 ppm. However, higher
concentration of chlorine can affect the quality of the peeled fruits and vegeta-
bles. Proper kits for chlorine testing should be used for controlling chlorine level
in water.
5. pH: Optimum controlled pH is required for maintain the bactericidal activity of
chlorinated water. If the pH rise above 7.5, the antibacterial effect would be van-
ished and spoilage of the products can occur due to microbial growth.
1.9
Packaging Technologies for Minimally Processed Foods
Tremendous progress has been made in the modifi ed atmosphere packaging of
fresh fruits and vegetables (Marsh and Bugusu
2007
; Alzamora et al.
2000
;
Devlieghere et al.
2004
; Al-Ati and Hotchkiss
2003
). As oxygen is a prerequisite
for the aerobic microorganisms' growth and replacing it with gases, such as carbon
dioxide can hinder the growth of organisms. However, optimum gas compositions
need to be used for each product. The use of antimicrobial packaging is a new trend
( Ayala
Aguilar
2010
). These antimicrobial substances in
packaging are released to the food product during storage, which prevent the unde-
sirable growth of micro-organisms on the surface of food (Vermeiren et al.
2002
).
There are different ways of adding these antimicrobials to the food product. Either
they can be incorporated as a sachet inside the packaged or surface of the packaged
can be coated with the antimicrobial compounds (Ayala-Zavala et al.
2008
).
In addition, silver nanoparticles are coated in non-edible fi lms and could be used.
‐
Zavala and González
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