Researchers from the State University of Campinas (Unicamp) have obtained from the Amazonian fruit, camu-camu, a dehydrated and micro-encapsulated juice with a refreshing flavor, and a vitamin C content equivalent to acerola – 40 times higher than oranges. Vitamin C acts in the prevention of general infections – it increases the natural resistance of the organism – and is recognized for its combat against the free radicals that cause aging, and for helping build up the immune system. In addition to vitamin C, this purplish red fruit contains other antioxidants such as anthocyanins, and a high potassium content, which makes its use recommendable for people with high blood pressure, since it helps the body obtain a better balance of salts in the organism, in particular of sodium chloride (kitchen salt).
The goal of the project, coordinated by Professor Hilary Castle de Menezes, of the School of Engineering of Foodstuffs (FEA), at Unicamp, was to improve the conditions for extracting the juice, to achieve a process of micro-encapsulating the powder resulting from the dehydration of the juice, and to assess its stability over a period of validity of 120 days. “Micro-encapsulation”, explains Hilary, “consists of covering solid particles with a fine layer of an encapsulating material, such as maltodextrin and gum arabic. The enclosed nucleus therefore remains stable and protected from deterioration, fit to be put for on sale”.
Chemical engineer Cristina Maria Araújo Dib Taxi is also taking part in the research. She comes from Belém (PA), where she graduated from the Federal University of Pará (UFPA), to study for her doctor’s degree at Unicamp, with Hilary as her supervisor. Cristina says that the National Institute of Research of Amazonia (Inpa) had verified, in 1960, the existence of 5% of vitamin C by weight in camu-camu – also known in Portuguese as caçari, araçá-azedo and araçá d’água, and as rumberry in English. “Because of this high content – 5000 milligrams per 100 grams – the fruit started being used as an antioxidant (preservative) by the cosmetics industry, which over the last five years has also been putting its juice into a few products, meeting the public’s preference fornatural ingredients.”
Cristina also reveals that camu-camu has already been launched in the United States in capsule form, as a source of vitamin C. The frozen berries are imported from Brazil and sold in the form of dehydrated juice and enclosed in thesame capsules used for the various kinds of allopathic or phytotherapeutic drugs. “There is no concern with color, taste or solubility, because it is a natural medicine and not a food”, says Hilary.
“The fruit is not consumed in its natural state because its taste is extremely acid, so that great quantities of it are left to rot and are lost in their natural surroundings”, Cristina reveals. She turns to people from her circle of friendships in Pará to receive the fruit in Unicamp. The technological study takes into account the need to reduce the acidity in the powdered juice, to make it more palatable, and there is the possibility of including it in other foodstuffs to make them richer in vitamin C.
As there were no technological studies on the subject, the first step was to test three kinds of juice extractors. Besides ensuring better flavor, leaving the seeds intact would allow them to be used for replanting. The best process tested was extraction with brushes, with its more gentle movements of pressure on the fruit. The brushing allows a better juice return from the fruit – slightly more than 50% -, less broken seeds, and a superior final flavor. Having obtained the juice, the next question was: what is the best way of presenting it to the consumer market, so as to guarantee its vitamin C content? It was not enough to dehydrate it, since the particles of powder, in contact with the air, lose vitamin C – as it is easily decomposed – and change the original color through the natural process of oxidation.
The option was to microencapsulate the juice through a piece of equipment called an atomizer, which is normally used by dairy product and juice industries. To do so, the powdered juice was taken to the machine, blended with the encapsulating material. Tests were carried out with maltodextrin and gum arabic – and the latter was chosen for providing a better final result, with less alteration and a longer period of validity. Once the powder was obtained, the researchers analyzed the product over 120 days, while being stored at temperatures of 25°C and 35°C. The powder of the juice was also tested without encapsulation. In this case, the powder became dark and lost stability.
The final stage was to research the most suitable packaging for the preservation of the product. Several were analyzed, of the flexible laminated sachet type, used for soft drink powder. The sachets chosen had layers made up of, from outside to inside, PET (polyethylene terephthalate), paper, aluminum and PET once again. This kind of packaging prevents the entry of light, oxygen and humidity, and has proven to be efficient in the preservation of the product, which remained stable, without molds, yeast, coliforms and pathogenic elements.
The objectives of the project were therefore achieved. Professor Carlos Grosso from the Department of Food Planning in Nutrition, of the FEA, also took part of the project. He was responsible for the quality of the materials and equipment employed and for guidance on the use of encapsulating material. Hilary thinks that the possibility of using camu-camu industrially has economic importance for the Amazonian region. It is possible to create jobs for the harvesting of this native fruit, for planned cultivation,and for processing the juice of the camu-camuthrough microencapsulation.
The vitamin that comes from the marshes
Native to Peruvian and Brazilian Amazonia, the camu-camu (Myrciaria dubia) belongs to the myrtaceae family, the same as the jaboticaba – a Brazilian berry. It grows in areas of wet lands, lakes and rivers, with its branches and roots submerged. Its development is spurred by the hot and humid climate. The harvest from the marshes takes place between December and March, and suffer from the influence of the floods that prevent them from being picked.
There are two varieties: a shrub and a tree. The tree produces more fruit, with more vitamin C: as much as 5000 milligrams (mg) per 100 grams of the fruit. Acerola, the best known fruit for this vitamin, reaches 4600 mg/100g, at the most. The shrub has lower branches and less fruit, with less vitamin. Both are resistant to pests and diseases, and adapt well to changes in temperature and rainfall.
There are regions – upstate Pará, the Ribeira Valley, in São Paulo, and certain areas of Paraná – where the camu-camu is cultivated away from the marshes, but the fruit has less vitamin C (about half of what is found in the native plant). Although the extremely acid taste does not please the human palate, fresh camu-camu is used as bait for fishing the tambacu, a fish from the rivers of the Amazon.
Camu-Camu juice Microencapsulation: achieved through Dehydration and Atomization (nº 99/09020-5); Modality Regular line of assistance for research; Coordinator Hilary Castle de Menezes -Unicamp’s Faculty of Food Engineering; Investment R$ 21,803.85 and US$ 20,963.21