Agriculture Reference
In-Depth Information
Compositional changes during ripening
During ripening of acerola, water, sugars, and soluble solids
increase, while vitamin C and protein decrease (Carvalho
and Manica, 1994; Vendramini and Trugo, 2000; Nogueira
et al., 2002). Acidity was found to increase by Vendramini
and Trugo (2000) and to decrease by Carvalho and Manica
(1994).
In 12 genotypes, considerable variations were observed
in fruits of the same stage of maturity, the total phenolic
varying from 841 to 1,888 mg/100 g catechin equivalents
and the total carotenoid from 9.4 to 40.6
μ
g/g
β
-carotene
equivalents in the ripe fruit (Lima et al., 2005). Pheno-
lic degradation and carotenoid biosynthesis were noted
during ripening. The
Harvesting
Transport to packing-house
Sorting
Washing
Freezing
-carotene increased two to three
times from the partially ripe to the ripe fruits in com-
mon and 'Olivier' acerolas (Porcu and Rodriguez-Amaya,
2006);
β
Packaging
-cryptoxanthin and violaxanthin also increased
significantly.
β
Storage
Possible health benefits
With the presence of vitamin C, carotenoids, and pheno-
lic compounds, bioactive substances associated with the
reduction of the risk of degenerative diseases (e.g., can-
cer and cardiovascular diseases), acerola may contribute to
the prevention of these diseases. This fruit was shown to
have tumor specific cytotoxic activity and multidrug resis-
tance reversal activity, suggesting possible application for
cancer therapy (Motohashi et al., 2004). Acerola extract
enhanced the antioxidant activity of soy and alfalfa phy-
toestrogen extracts in a variety of low-density lipoprotein
(LDL) systems (Hwang et al., 2001). Polyphenols isolated
from acerola (cyanidin-3-
α
-
O
-rhmanoside, pelargonidin-
3-
α
-
O
-rhmanoside, and quercetin-3-
α
-
O
-rhmanoside) pos-
sessed O
2
-scavenging activity and an inhibitory effect on
both
Marketing
Figure 29.2.
Flow diagram of the preparation of
frozen acerola fruits.
aged, spoiled, or fermented. Fruits with physical defects
cannot be used as raw material for frozen fruit but can be
utilized for frozen pulp or juice.
The fruits are washed by immersion in tanks with chlo-
rinated, cold water, which is constantly renewed. At the
tank's exit, water-jet washes remove excess chlorine.
The fruits are taken to freezing rooms or tunnels in con-
tainers that permit uniform passage of the cold air. Among
the different types of freezers available, the tunnel with
forced-air circulation has been shown to be very efficient
for the freezing of acerola (Bleinroth et al., 1996).
A flow diagram for the processing of frozen pulp and
juice is shown in Figure 29.3 (Tocchini et al., 1995; Manica,
2003). After washing and a second sorting to remove those
unfit for processing, the fruits are subjected to pulping to
separate the pulp from fibrous material, seeds, and skin, at
the same time reducing the particle size thus turning the
product more homogenous. A brush-type pulper is used
with a 1-mm dia mesh sieve. Any air incorporated during
pulping is removed by vacuum to minimize oxidation. The
pulp is cooled to approximately 5
◦
C, filled into drums lined
with double polyethylene bags, and sealed. Freezing is done
in a tunnel operated at -20
◦
C. The frozen pulp is stored at
thesametemperature.
α
-glucosidase and advanced glycation end product
formation in vitro (Hanamura et al., 2005). With its very
high vitamin C content, acerola can be utilized in pharma-
ceutical formulations or for the enrichment of foods.
Processing and processed products
In Brazil, acerola is now widely marketed as fresh fruit,
fresh and thermally processed juice, frozen fruit, frozen
pulp, or juices in combination with other fruits. It is also
used in ice creams, jams, jellies, desserts, and liquors. The
various steps involved in the preparation of the frozen fruit
are shown in Figure 29.2 (Alves et al., 1995; Bleinroth
et al., 1996; Manica, 2003).
In the packinghouse, the fruits on conveyor belts are in-
spected to remove those that are immature, overripe, dam-
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