Fruit residue treated with tannase enzyme has high values of bioactive phenolics
Around 40% of grape phenolic compounds are discarded during the wine production process in Brazil. Beneficial to the human body, these compounds are discarded along with the fruit pomace. With the application of an enzyme produced in the laboratory, Unicamp researcher Isabela Mateus Martins extracted greater quantities of phenolics from the by-product of the juice and wine industry.
The study conducted by her at the Faculty of Food Engineering (FEA) also demonstrated that the extracted phenolics were effective in reducing the inflammatory process in intestinal cells (CACO-2). The reduced inflammation biomarkers were prostaglandin E2 (PGE2), interleukin 8 (IL-8) and transcription factor kappa B (NF-κB).
The author of the research explains that prolonged inflammatory processes in the body can cause physiological dysfunctions and lead to the appearance of diabetes, hypertension, obesity, cancer and inflammatory bowel diseases, such as ulcerative colitis and Crohn's disease. “After treatment with the enzyme tannase in intestinal cells we had an increase of approximately 25% in the anti-inflammatory activity of the extract obtained from grape pomace”, she reveals.
There was also, with the enzymatic treatment, an increase in antioxidant activity and the amount of phenolic compounds, which prevent and delay the formation of free radicals in the body. The researcher reports a 51% increase in the concentration of total phenols compared to the sample without treatment. “We were also able to see an increase in smaller and simpler phenolic compounds, especially gallic acid, quercetin and trannyresveratrol”, he adds.
Underutilized potential
The author of the study explains that grape pomace, especially red grape pomace, is rich in bioactive phenolic compounds. “But this residue ends up going to waste or being underused as soil fertilizer or incorporated into animal feed. Our work demonstrates the potential of bagasse that could be transformed and used, for example, in the manufacture of functional foods, supplements and products for the pharmaceutical industry”, she suggests.
According to data collected by Isabela Martins in her study, global wine and juice production generates around 13 million tons of waste annually. In Brazil, it is estimated that around 150 thousand tons of grape pomace will be generated per year.
The research she developed was part of a doctorate defended with the Postgraduate Program in Food Science at FEA. Some of the work was conducted at the Antioxidants Research Laboratory, belonging to Tufts University, located in the city of Boston, in the United States. At Unicamp, professor Gabriela Alves Macedo, from the Department of Food and Nutrition at FEA, guided the research.
The Unicamp scientist's exchange was financed by the Federal Government's Science without Borders Program. There was also support from the National Council for Scientific and Technological Development (CNPq) and the Coordination for the Improvement of Higher Education Personnel (Capes).
Red grape and tanase
The grape residue treated with the tannase enzyme showed the highest values of bioactive phenolic compounds when compared to the extract without the enzyme treatment. In comparison, red grape pomace also showed better results than white grape pomace. “The two extracts had their antioxidant potential increased after the enzymatic treatments, but that of the red grape that received the treatment with tannase showed a more significant increase”, he compares.
The author of the study clarifies that only the red grape extract, before and after treatment with tannase, was subjected to anti-inflammatory activity tests in intestinal cells. “The objective was to choose the extract with the highest value of phenolic compounds and then test it in intestinal cells. For this reason we only use red grapes.”
The researcher also used two other enzymes to promote the extraction of biactive phenolic compounds: cellulase and pectinase. According to her, unlike tannase, they are enzymes widely used by industry. “Tanase also proved to be better in this comparison.”
