Guava - Tropical and Subtropical Fruits: Postharvest Physiology, Processing and Packaging - page 206

times lead to oxidation of this compound (Imungi et al.,
1980; Askar et al., 1992).
The treatment of guava juice with 600 ppm of pectic
enzyme at 45 ◦ C for 120 min, in association with fining
agents (silica sol and gelatin), allowed for the production
of juices with good stability, maintaining the same ascorbic
acid content as the puree before enzyme addition (Brasil
et al., 1995). Similar conditions (700 ppm of pectic en-
zyme, 50 ◦ C for 90 min) were suggested for obtaining prod-
ucts with higher yields, ascorbic acid contents, and soluble
solids contents, without a significant loss in guava flavor
(Chopda and Barrett, 2001).
However, to enhance the shelf life and assure microbial
safety, a heat treatment before packaging is often required,
although it may considerably reduce the amounts of bioac-
tive compounds, as observed in guava nectar. A loss of 30%
of the ascorbic acid after the pasteurization of clear guava
juice has been reported in the literature (Askar et al., 1992).
Thus, besides removing the cloud particles from the guava
juice, the use of ultrafiltration may also cold-sterilize the
juice, instead of the heat treatment, allowing for a reduc-
tion in the losses of thermolabile compounds (Chopda and
Barrett, 2001).

can also be prepared from the pulp remaining after the
jelly manufactuirng process or from the outer peel and seed
core discarded during canning and OD treatments. The hot
product is set on trays and, after cooling, is cut into smaller
pieces and wrapped in plastic films such as cellophane or
polyethylene (Martin and Kato, 1988). Industrial goiabadas
are usually canned.
The presence of pieces/fragments of guava in the final
product is widely accepted by Brazilian consumers, result-
ing in the so-called goiabada casc ao. The final product
usually has a firm cutting texture and is thus also known as
guava cheese in some English-speaking countries.

Guatchup ('guava ketchup')
In substitution of the traditional ketchup, guatchup made
of guava has been developed in Brazil and has already
been exported to other countries such as the United States
and Switzerland (Valor Econ omico, 2004). Owing to its
similarities with the product made from tomatoes, this
product is called guatchup and is produced by cooking
the pulp of red guava with seasonings and spices, before
homogenizing.

Guava wine
Guava wine may be produced either from the clarified
guava juice or from the guava pulp, added yields can be
attained by enzyme treatment. Sugar and citric acid may
be added prior to fermentation. Wine yeasts are used in
fermentation, which occurs in two stages. First, the yeast
ferments the juice/pulp aerobically for 48 hours at room
temperature ( ∼ 25 ◦ C), and then the product is poured into
containers where anaerobic fermentation occurs for sev-
eral days/months. Ngwira (1996) observed that the white
guava resulted in a dry wine, while the red guava produced
a sweet product. The authors attributed this difference to
some of the sugars present in the red guava, which were not
fermented by the yeast.

Jellies and jams
Both jellies and jams are obtained by cooking the guava
puree with sugar and other additives such as pectin and
acids, to improve the consistency and acidity of the final
product. Commonly, 45 parts of fruit or juice/puree and
55 parts of sugar are used for processing jellies and jams.
The mixture may be concentrated either in open vessels
or under vacuum, to a final soluble solids content of about
65 ◦ Brix (Martin and Kato, 1988; Ricardo Lopez et al.,
2000).
Despite having similar processes, jellies and jams differ
from one another according to the guava puree used in the
process. Jellies are produced from the clear juice, since
no insoluble solids should be present in the final product.
Jams, on the other hand, are produced directly from the
cloudy puree. Chopped or crashed guava may also be used,
resulting in a product containing seeds and fibers. Menezes
et al. (2009) observed that higher yields and firmer guava
jams were obtained with the increasing addition of ascorbic
acid addition and reduction in the fruit/sugar ratio.

By-products from guava
The various steps of guavas processing generate a large
amount of waste (pulp, peel, seeds, and inedible fruits).
In Malaysia, for instance, nearly 25% of the pink guava
(cv. 'Sungkai Beaumont') used for puree production are
discarded as waste (Kong et al., 2010). However, this waste
can be used as a potential source of antioxidant components,
natural additives, and functional food ingredients (Schieber
et al., 2001; Amin and Mukhrizah, 2006).
Solvent extraction of the by-products from the process-
ing of 'Sungkai Beaumont' guava puree results in a product
with a high lycopene content (49.82 mg/g extract) and a

Guava paste or goiabada
Guava paste or goiabada is a typical Brazilian dessert made
from red guava. It consists of concentrated guava pulp (50%
to 60% in total mass) with an elevated amount of sucrose,
resulting in a thick paste with an SSC of 70 ◦ Brix. It >