Agriculture Reference
In-Depth Information
Research on how to maintain quality and safety of fresh-
cut fruits increased greatly during the past 20 years in
response to commercial development of value-added,
ready-to-eat products. Strategies for delaying browning and
softening of wounded plant tissues and for maintaining
their safety by minimizing microbial growth have been de-
veloped (Lamikanra, 2002; Sapers et al., 2006; Fan et al.,
2009; Martin-Belloso and Soliva-Fortuny, 2010), but more
research is needed to enable extension of postcutting life
based on flavor and nutritional quality. Minimal process-
ing technologies (such as treatments with high pressure,
UV radiation, and/or mild heat) and use of nanotechnology
in food preservation and packaging are active R&D areas
(Barrett et al., 2004).
processors need to implement the following action plan
(Kader, 2008):
1. Replace poor flavor cultivars with good flavor cultivars
from among those that already exist and/or by select-
ing new cultivars with superior flavor and good textural
quality.
2. Identify optimal cultural practices that maximize flavor
quality, such as optimizing crop load and avoiding ex-
cess nitrogen and water, which along with low calcium
shorten the postharvest life of fruits due to increased sus-
ceptibility to physical damage, physiological disorders,
and decay.
3. Encourage producers to harvest fruits at partially ripe to
fully ripe stages by developing handling methods that
protect the fruits from physical damage.
4. Identify optimal postharvest handling conditions (time,
temperature, relative humidity, atmospheric composi-
tion) that maintain flavor quality of fruits and their value
added products.
5. Develop ready-to-eat, value-added products with good
flavor.
6. Optimize the maturity/ripeness stage in relation to fla-
vor quality at the time of processing and select process-
ing methods to retain good flavor of the processed fruit
products.
Nutritional and flavor quality of fruits
Fresh fruits play a very significant role in human nutri-
tion, especially as sources of vitamins (vitamin C, vita-
minA,vitaminB 6 , thiamine, niacin), minerals, and di-
etary fiber (Vicente et al., 2009). Other constituents that
may lower risk of cancer and other diseases include fla-
vornoids, carotenoids, polyphenols, and other phytonutri-
ents (Tomas-Barberan and Gil, 2008). Postharvest losses in
nutritional quality, particularly vitamin C content, can be
substantial and are enhanced by physical damage, extended
storage duration, high temperatures, low relative humidity,
and chilling injury of chilling-sensitive fruits. The effects
of processing methods on nutritional quality of fruits are
presented in reviews by Rickman et al. (2007a, 2007b).
Further research by human nutrition and health researchers
in collaboration with postharvest horticulturists and food
scientists is needed to better understand the bioavailability
and value of phytochemicals in fruits to human health.
Much greater efforts are needed to inform consumers,
especially children, about the health benefits of eating
fruits.
Flavor attributes and associated constituents include
sweetness (sugars), sourness or acidity (acids), astringency
(tannins), aroma (odor-active volatile compounds), off fla-
vors (acetaldehyde, ethanol, and/or ethyl acetate above cer-
tain concentrations that depend on the fruit's sugar content),
and off odors (sulfurous compounds above certain concen-
trations).
Providing better flavored fruits is likely to increase their
consumption, which would be good for the producers and
handlers (making more money or at least staying in busi-
ness) as well as for the consumers (increased consump-
tion of healthy foods). To achieve this goal, producers and
Management of temperature and
relative humidity
Providing the optimal ranges of temperature and relative
humidity (RH) is the most important tool for maintaining
quality and safety of intact and fresh-cut fruits (Gross et al.,
2004; Kader, 2002). There is a continuing trend toward in-
creased precision in temperature and RH management to
provide the optimum environment for fresh produce dur-
ing cooling, storage, and transport. Precision temperature
management tools, including radio-frequency identification
(RFID) tags and time-temperature monitors, are becoming
more common in produce handling. Several manufacturers
have developed self-contained temperature and RH moni-
tors and recorders, which are small and can be packed in a
box with the product. Data are read by connecting these
units to a personal computer with the appropriate soft-
ware provided by the manufacturer. Infrared thermome-
ters are used to measure surface temperature of products
from a distance in various locations within storage facilities.
Electronic thermometers (with very thin, strong probes for
fast response) are used for measuring product temperature
during cooling, storage, and transport operations. Recent
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