Annona Species Monograph.pdf - Crops for the Future

Chapter 7. Uses
7.2 Industrial food uses
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Cherimoya is widely consumed in a processed form. Industrial processing
depends on development of freezing techniques for pulp preservation. In a
simple freezer, frozen cherimoya can be successfully preserved for 120 days.
For freezing, the fruits should be peeled, preferably with stainless steel
knives or by chemical peeling with caustic soda (20%). The pulp or fruit
slices should be bagged in polyethylene prior to freezing and sugar can be
added if desired (Lizana and Reginato, 1990). Additives, such as EDTA,
ascorbic acid and citric acid, preserve against oxidation.
Soursop is the other annona of which the pulp or nectar can be frozen,
processed and used industrially (Beneto et al., 1971). It is perhaps the best
annona for industrial processing and commercialisation because of its exotic
taste and agreeable aroma. The processed pulp can be preserved by
pasteurisation or freezing (Zayas, 1966) and conditions for these processes
and storage have been developed. The quality of the processed product
depends on total sugars and ascorbic acid retention, low acidity, viscosity and
presence of pectinesterase activity. The final product should have an
agreeable flavour and a good consistency. Temperatures of 93°C and 107°C
decrease the quality in unsweetened and sweetened frozen soursop puree,
respectively (Bueso, 1980). The high temperatures and exposure also
influence pectinesterase activity and ascorbic acid retention. Moreover,
soursop fruit composition differs among varieties (Pinto and Silva, 1994) and
cultural treatments. Hence, it is necessary to work out the best conditions for
each variety in each production environment.
Several authors have reported on soursop pulp or nectar processing, freezing
and canning (e.g., Sánchez-Nieva, 1953; Payumo et al., 1965). Bueso (1980)
reported that fruits should be picked by hand, washed with chlorinated water
and peeled by hand. The edible pulp should be extracted from the fruit using
a blender, a pulper or dispersed in a sugar syrup. At this stage, care should be
taken not to mix peel with pulp or to break the seeds, as these are dangerous
because of the presence of bioactive compounds (see Chapter 6). After
extraction, the pulp is strained through a screen. Sánchez-Nieva (1953, in
Bueso, 1980) commented that extraction of the pulp should be done quickly
so as to avoid aeration and oxidation.
Holanda et al. (1980) reported that the fruit should be processed after
selection and further maturation (3-5 days depending on temperature) in an
acetylene acid maturation chamber at 12.5-16°C and 80% relative humidity