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Food Engineering

Healthy and natural

Studies at Unicamp open the way for the production of isoflavones extracted from soybeans and new uses for propolis

EDUARDO CESARProfessor Park: after Neosugar, the study of the biological properties of propolisEDUARDO CESAR

Brazil already possesses the technology for the production of aglycon isoflavone, a substance found in soybeans (Glycine max) that shows important biological activities. It acts as an anti-cancerigenic (breast and prostrate) and anti-oxidant by neutralizing the action of free radicals, molecules derived from oxygen that are responsible for the aging of the cells of the human body. Isoflavone also helps in the reduction of the levels of cholesterol harmful to cardiovascular health and acts in the combat against fungi that provoke illnesses such as mycosis and cutaneous candidiasis. Furthermore, it is also useful as an assistant in hormonal replacement in place of estrogen, the female hormone that decreases considerably during the menopause period.

The new technique for obtaining isoflavone was developed by professor Yong Kun Park, of the Food Biochemistry Laboratory of the Faculty of Food Engineering (FEA) of the State University of Campinas (Unicamp). Extracted from grains and from products derived from soybeans, the aglycon iosflavones can be offered to the consumer market as a food supplement in the form of capsules or as an ingredient to be added to cakes, chocolates and biscuits, making them healthier.

Digestive transformation
The work of professor Park and his team resulted in a request for a patent for the extraction process and the conversion of the glycosylated isoflavanes of soybeans to their aglycon forms. This process of the transformation of the isoflavones normally occurs in the digestive tract, when digestive enzymes produced by intestinal micro flora transform the glycosylated isoflavone into aglycons, which are then absorbed by the organism. “The idea is to commercially produce the aglycon isoflavone for it to be offered directly in capsule form or for the production of foods, thus allowing for a better absorption and use of the compound by the organism”, explains professor Park.

In the opinion of the researcher, Brazil has ideal conditions to producefood derivatives from soybeans. The country is the second largest exporter of this legume, responsible for 16.9% of world production. The area planted for the 2000/2001 harvest reached 13.7 million hectares, with a production target of some 37 million tons, generating an income through grain, oil and flour of around US$ 4.8 billion. “If someone had to develop this technology, then it had to be us.”

Daily dose
Professor Park has been researching soybeans isoflavones since 1998. “For three years, twenty large American companies have been producing soybeans derivatives for foodstuffs, based on the recommendations of the Food and Drugs Administration (FDA) that suggests the consumption of 25 grams (g) per day of soybeans protein because of its proven activity in reducing and controlling cholesterol and high blood pressure.” In each 100 g of dry sample of soybeans there are 40g of proteins, 30g of glycides, 20g of lipids, 226 mg of calcium, 546 mg of phosphorus and 8.8 mg of iron. Among the chemical components of soybeans are the polyphenolics such as the isoflavones.

Various studies published in international magazines relate the benefits to human health provided by the use of these substances. Among them are those of Lori Coward, of the University of Alabama in the United States, on the anti-tumor activity of soybeans’ isoflavone in Asian and American diets and of Patrícia Murphy, of the Iowa State University also in the United States, on levels of substances similar to estrogen in products of processed soybeans. Besides these properties, the anti-oxidant and anti-fungal actions were also proven by professor Park. The main results of professor Park’s work with soybeans were presented in June 2001 in New Orleans, in the United States, at the 2001 IFT, an annual meeting promoted by the Institute of Food Technology (IFT), and at the 1st Brazilian Symposium on the Benefits of Soybeans to Human Health, promoted by Embrapa-Soja in Londrina in the State of Paraná in May of this year.

Aglycon isoflavones are found in products of traditionally fermented Soybeans, widely consumed in Japan and in other Asian countries. According to professor Park, studies carried out in that country confirm that Orientals possess a large quantity of aglycon isoflavone in blood plasma, a factor that could be responsible for the rate of cancer of the prostrate, breast, colon, uterus, and of problems related to menopause in the Oriental population. In other populations, where the consumption of fermented products of soybeans is smaller, the incidence f these illnesses are higher. “To provide aglycon isoflavone for the production of foods could benefit a large number of people”, says Park.

Industrial process
For the industrial production of isoflavone some preliminary phases become necessary, such as the milling of the grains and degreasing. The degreased flour is submitted to a process of extraction of the isoflavones with solvents in a distillation process. From this content of isoflavones, the glycosilades are converted into aglycons by the action of an enzyme, named beta-glycosidase, during a fermentation process. For the production of beta-glycosidase, Park uses the fungus Aspergillus oryzae, widely used in Japan in biotechnological processes. The soybeans used in the experiments was provided by the Agronomy Institute of Campinas (IAC). There were five different types: IAC 15-1, IAC 15-2, IAC 20, IAC 22 and IAC Foscarin 31-1.

Though he has still not signed a contractfor the transference of his technology, Park already has heard about interest from foreign food companies, which are based in Brazil, for using aglycon isoflavones in the production of foods or as supplements. Other studies by professor Park refer to the analysis of substances present in propolis, a resinous substance collected through bees of the species Apis mellifera from diverse parts of the plants, such as the sprouts, flowers and liquids that leak from the leaves and the stalk.

Sweet beginning
Park’s interest in the study of propolis began in 1991. The constant contact with beekeepers for the isolation of non-conventional sugars of bee honeys, capable of transferring the sacarose of sugarcane into a low calorie sweetener – whose studies ended with the patent for Neosugar together with the Barra sugar refinery in the town of Barra Bonita (SP) – sparked off his interest for the complementary study of the chemical composition and of the biological properties associated with propolis. As shown by the various studies carried out by Park and by the widely written literature on the subject, many of the chemical compounds contained in propolis had already been identified and the majority of them belong to three principal groups: flavonoides, phenolic acids and phenolic esters.

Their concentrations vary depending on the flora of the collecting region and of the genetic variability of the bees. “Brazilian propolis is largely exported to Japan and Europe and brings in to the national beekeepers something in the region of US$ 2 million to US$ 3 million per year. Its quality is considered to be the best in the world due exactly to the Brazilian biodiversity”, says Park. From the beginning in 1993 until 1998, he and his team researched 500 samples of national propolis, obtained in the regions of the South, South West, Central-West and North East of the country, grouping them together into twelve basic sets, each one with a specific objective.

According to the Park’s explanations, of the twelve defined sets, four showed anti-cancerigenic activity, three showed anti-caries activity, and in two anti-HIV activity. This work has already rendered, as well as the innumerable international publications, two patents. One of them, at the beginning of the year, on the use of flavonoids of propolis for the prevention and treatment of dental caries. It was registered by the FEA, in conjunction with the Odontology School of Piracicaba (FOP), also with Unicamp, and the University of Rochester in the United States where one of professor Park’s ex-advisor works.

Propolis from the Amazon
Another patent, for the use of propolis in an anti-HIV capacity (elimination of the virus), was carried out in partnership with the University of North Carolina, also in the United States, and should be confirmed by November of 2001. “The idea now”, he says, “is, as of the next year, to broaden this research to the Amazon region.” Park and his team are going to look for chemical compounds in new types of propolis, characterizing their biological activities. “We believe that this is the way to increase the commercial value of this product and to understand new active principles that can be used in the pharmaceutical and foodstuffs industries.”

The projects
1. Production of Aglycon Isoflavones with High Biological Activity from Soybeans (nº 00/10611-7); Modality Regular line of research assistance; Coordinator Yong Kun Park – Unicamp; Investments R$ 27,125.00 (Soybeans) and R$ 44,444.05 and US$ 48,980.36 (propolis)
2. Identification of Compounds with High Biological Activity from Propolis of the Apis Mellifera Bee (nº 04/08635-6); Modality Regular line of research assistance; Coordinator Yong Kun Park – Unicamp; Investments R$ 27,125.00 (Soybeans) and R$ 44,444.05 and US$ 48,980.36 (propolis)