Agriculture Reference
In-Depth Information
2006) and increase nonenzymatic browning reaction of
hydroxymethylfurfural (Rattanathanalerk et al., 2005) and
solubilisation/degradation of pectic polysaccharides, with
a notable decrease in the degree of pectin esterification
(Femenia et al., 2007). During osmodehydration, some hy-
drosoluble components may escape into the osmotic so-
lution (Peiro-Mena et al., 2007). Bioactive compounds of
fresh-cut products (vitamin C, phenolics, carotenoids, etc.)
also decrease during storage (Gonzalez-Aguilar et al., 2005;
Gil et al., 2006).
New processing technologies have been developed in
order to reduce losses in nutritional and sensorial quality
and to meet the consumer demand for healthy, nutritious,
and “natural” products (Deliza et al., 2005).
UV-C
This can be used to reduce microbial load in juices in-
stead of thermal or antimicrobial treatments (Keyser et al.,
2008). Fresh-cut pineapple treated with UV-C has more an-
tioxidant capacity and flavonoids but less vitamin C than
untreated fruit (Alothman et al., 2009).
Pulsed electric field
This inactivates micro-organisms in pineapple juice (Jaya
et al., 2004).
Thermal processing
This helps to maintain puree color, which is an important
quality attribute. This retention is made possible by the
increase in our knowledge of the kinetics of color change
(Chutintrasri and Noomhorm, 2006).
Ultrasound
Ultrasound as a pretreatment for drying pineapples in-
creased the effective diffusivity of water in the fruit, reduc-
ing air-drying time (Fernandes et al., 2008). A reduction in
drying time is better for nutrients retention.
Vacuum frying
This is a dehydration process that produces healthy fruit
snacks (pineapple chips) that partially preserves the fruit's
original color and nutritional compounds and high hy-
drophilic antioxidant capacity (Perez-Tinoco et al., 2008).
Osmotic dehydration
This can be used as a pretreatment with the final aim of
obtaining high-quality dried fruit products. Yield can be
improved applying vacuum pulse (Singh et al., 2008).
Radiation processing
Radiation processing of fresh-cut pineapple (2 kGy) does
not affect significantly the nutritional value and the sensory
quality and increase the product's shelf life (Hajare et al.,
2006).
Solar drying
The dried pineapple quality using a solar energy-assisted
photocatalytic closed-type dryer is better than conventional
hot-air drying, while the total mold and bacterial counts for
the drying cabinet and dried pineapple slices are signifi-
cantly lower (Chen et al., 2008). Drying in an ethanolic
atmosphere promotes more rapid water evaporation and
better retention of the volatile compounds (Braga et al.,
2009).
Dehydrofreezing technique
This involves partial dehydration before freezing. The par-
tial dehydration removes part of water from plant tissue
prior to freezing and reduces freezing-related tissue dam-
age. Ramallo and Mascheroni (2010) evaluate the effect
of osmotic dehydration and hot-air drying applied prior
to slice freezing and found that ascorbic acid losses were
somewhat greater during the osmotic dehydration than with
air dehydration.
High-pressure processing
This is used in food processing where food-borne micro-
organisms and enzymes are inactivated at low temperature,
without the need for chemical preservation. This is done
for fruit juice to preserve most of the nutritional qualities
fairly close to that of fresh fruit (Deliza et al., 2005; Buzrul
et al., 2008). The product still has a cooked flavor.
Health significance
Pineapple is a dietetic and healthy fruit. Pineapple contains
bromelain (EC 3.4.22.32), a major cysteine proteinase that
has several therapeutic properties as it is effective in the
treatment of albuminuria. Pineapple reduces appetite and
is used for weight control (Coveca, 2002). It also aids in
digestion by facilitating protein breakdown (Coveca, 2002;
Roxas, 2009). Owing to the fiber content of the pulp,
pineapple prevents and corrects constipation, regularizes
the intestinal flora, and is also used in the control of diarrhea
Osmotic evaporation
This is a process whereby pineapple juice is concentrated
at moderate temperatures and pressures and retains good
nutritional and sensory qualities. This process causes minor
changes in the concentrated juices, which makes it more
preferable (Shaw et al., 2002; Hongvaleerat et al., 2008).
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