Guyabano or soursop is one of the minor crops that is gaining popularity because of its economic uses. It is a nutritious fruit, rich in ascorbic acid, potash, phosphorous and calcium. The edible portion is 70% with food energy of 63 calories and the sugar content ranges from 4 to 14%.
The nature green fruits of guyabano are used as a vegetable and for making sweet meats, while the ripe one is eaten off hand or as dessert. Its juice is used for flavoring ice cream, sherbets, canning and for preparation of refreshing drinks. It may also be processed intro preserve, candies, jam and jelly.
Preservation/utilization of fruits has been getting widespread attention not only on its increasing acceptability in the food market but also because of its potential as a means of generating an export. The various preservation of guayabano was briefly described in the following procedures.
After washing sound ripe fruits, they are blanched for 3-4 minutes in boiling water. They are cooled in water, peeled and their inner core removed. They are cut into 5 cm square pieces. One cup water is added to 1 cup fruit heated at 80 degree C for 3 minutes or until the fruit is soft enough to squeeze of the juice. The juice is pressed through a muslin bag while hot. The juice from the residue is extracted for the second time with the same amount of water. The two extracts are mixed and sugar is added to taste. The juice is poured into jars and exhausted before sealing to 82 degree C (approximately 15 minutes from boiling time). The jar is sealed immediately, sterilized in boiling water for 10 minutes, cooled and stored.
Mature but firm fruit is peeled sliced about 1 cm thick using stainless steel knife, and soaked in water. It is blanched in boiling water for 5 minutes cooked in syrup (2 parts sugar and 1 part water), and soaked in syrup overnight. It is again boiled for 30 minutes until thick, drained and packed in preserving jar. The jar is filled up with syrup, half-sealed, sterilized for 25 minutes in boiling water and sealed completely.
Mature but firm fruits peeled sliced to about 1 cm thick with a stainless steel knife, and soaked at once in water to avoid discoloration. It is cooked in syrup (2 parts sugar to 1 part water) for 10 minutes and soaked in syrup for 1 week, boiling it daily for 5 minutes. It is cooked over a slow fire until syrup becomes sugary. It is removed from fire, separated from sugar, cooled and wrapped individually in cellophane.
The fully ripe, sound fruit is peeled and its seeds are removed. To every cup of fruit, an equal amount of sugar is added and the mixture is cooked to jam consistency. It is poured while hot in a preserving jar. After removing the bubbles, the jar is half-sealed, sterilized for 25 minutes in boiling water and sealed completely.
Frozen Guyabano Pulp
The sound ripe fruit is peeled and its seeds are removed. To every cup of fruits are added ¼ cup refined sugar and 2 tbsp. calamansi juice. The mixture is packed in a plastic bag container and stored in a freezer (24 degree F). To serve as juice, enough cold water and sugar are added to taste.
Thoroughly ripe fruit is rinsed and sliced, retaining the skin and seeds. It is put in a pan with enough water to cover, and boiled until soft, with constant stirring. It is removed from the fire and passed through a double cheesecloth. The extract is returned to the fire, boiled until all the scrum has risen, and strained again. To each cup, 1 tbsp. calamansi juice is added and the mixture is boiled again. To the boiling juice is added 1 cup hot dissolved sugar and the mixture is boiled until it hardens on spoon removing all rising scrum in the process.
Guyabano Juice Concentrate
Fully ripe, sound fruits are thoroughly washed with detergent and carefully rinsed in water. They are cut into halves and the skin and seeds are removed. Two cups of water are added to 1 pulp, the mixture is blended to facilitate juice extraction, and strained through a muslin cloth bag. The clear juice is concentrated juice is “cut back” to 160C Brix by adding freshly prepared juice. Ascorbic acid equivalent to 50 mg/cc is added during pasteurization to retard normal oxidation browning in storage. Fortified concentrate is pasteurized at 85 degree C for 5 minutes, hot filled into previously sterilized cans, sealed completely and processed into boiling water for 10 minutes. Cans are immediately cooled in running water and wiped dry.
Source: Bureau of Plant Industry. Production guide: guyabano. Retrieved from http://www.bpi.da.gov.ph/guide_guayabano.php