Cattle feed enriched with yerba mate improves meat quality

Collaboration between Brazilian and Danish researchers developed innovative strategies for the production of animal protein and bread.

By Reinaldo José Lopes

Agência FAPESP – Adding a small amount of yerba mate extract to beef cattle feed can be sufficient to produce healthier, tastier meat with a longer shelf life, according to the results of a three-year collaborative research project conducted by Brazilian and Danish scientists to develop strategies for animal protein and bread production.

Supported by FAPESP and Innovation Foundation Denmark (formerly the Danish Council for Strategic Research), the project “Bread and Meat for the Future” concluded with a workshop held in August at the University of São Paulo’s São Carlos Chemistry Institute (IQSC-USP) in Brazil.

The researchers found that broiler chickens benefited similarly from feed enriched with yerba mate (Ilex paraguariensis), an herb that is widely consumed in South America as an infusion. They also developed more efficient and healthier ways to produce cured meat such as Parma ham or corned beef and strategies to use up to 30% cassava flour in industrially produced bread.

“We managed to assemble a highly qualified multidisciplinary team of people who had never worked together, including chemists, microbiologists, agronomists, food engineers and pharmacologists. The experiments we performed had never been attempted in Brazil,” said Daniel Rodrigues Cardoso, a professor at IQSC-USP and coordinator of the initiative on the Brazilian side.

“Today, if someone wants to know how a particular feed affects the metabolic profile of the meat produced, we can answer the question without difficulty thanks to this project,” Cardoso said.

In addition to IQSC-USP and the University of Copenhagen, the project also involved EMBRAPA, the Brazilian Agricultural Research Corporation, and two companies – Centroflora, which supplied the yerba mate extract, and Novozymes, which provided the enzymes used in several experiments – as well as researchers affiliated with other institutions. Brazil invested R$1.4 million (now approximately US$355,000) in the project, matched by a corresponding amount of funding from Denmark.

Tender and stress free

According to the researchers, there is abundant evidence of the potential benefits to human health derived from the consumption of yerba mate. The plant facilitates weight control and moderates oxidation and inflammatory processes, for example.

Its effects were studied in a herd of some 50 cattle supplied with yerba mate extract in doses ranging from 0.25% to 1.5% of their total feed.

There were no changes in animal growth rates or in the amount of beef obtained from each animal. However, the researchers found that the meat was more tender than normal and was rated highly by a group of 100 taste-testers in a blind test.

“It outperformed normal beef in shear testing to measure its textural quality,” said food engineer Renata Tieko Nassu, a researcher at EMBRAPA Southeast Livestock.

Analysis of the different molecules present in the beef showed a significant increase in conjugated linoleic acid (CLA) in meat produced by the animals that received yerba mate supplement.

CLA has anti-inflammatory properties and can also help reduce cholesterol levels in consumers, according to Cardoso. In addition, it is an antioxidant, reducing the formation of highly reactive molecules that can damage cells in the human organism. In addition to the human health benefits, reduced oxidation thanks to increased CLA levels significantly extends the shelf life.

These beneficial effects appear to be mediated by the action of yerba mate on bacteria in the animal’s digestive system. It favors the multiplication of certain microorganisms, which in turn alters the way the animal absorbs nutrients, thereby enhancing meat quality.

The researchers also observed an apparent reduction in stress and an improvement in the animals’ well-being. These factors also helped to improve meat quality.

If the supplement is to be given to cattle on a large scale throughout Brazil, the next step will be to find a cost-effective method of producing yerba mate extract, according to Rymer Ramiz Tullio, another researcher at EMBRAPA Southeast Livestock.

The extract used in the experiments was expensive because it was produced in accordance with pharmaceutical industry standards. “We need to see whether directly administering yerba mate leaves has the same effect,” Cardoso said. “Alternatively, we might be able to process the waste from extract production. This is currently thrown away, and using it would be much more cost-effective.”

More cassava

Increasing the use of cassava flour by the global bread industry was another key goal of the project. Because there are prospects of growth in wheat acreage worldwide, the inclusion of cassava flour in loaves and other bakery products would improve food security in many countries, especially those with a tropical climate.

The main challenge, according to Ulla Kidmose, a researcher at Denmark’s Aarhus University, was compensating for the absence of a gluten protein network, a key ingredient of dough made solely with wheat flour.

“Cassava flour is practically all starch, with very little protein,” she explained. “The gluten in wheat flour is precisely what increases the loaf volume and gives bread made with wheat a smooth texture. These two features make a big difference for the industry.”

The researchers found a solution to this difficulty by choosing the cassava variety best suited to the production of flour and by using an enzyme cocktail to slightly modify the dough fermentation process. These adjustments enabled them to develop a method in which cassava flour accounted for up to a third of the total amount of flour used to make bread.

According to Kidmose, the technology could be transferred immediately to the industry in a cost-effective manner and without much difficulty. “The problem I foresee right now is acceptance, at least by Europeans or the northern hemisphere in general,” she said. “Few people in the region are familiar with cassava.”

For Leif Skibsted, a researcher at the University of Copenhagen and project coordinator on the Danish side, Denmark and Brazil have many interests in common in the field of food science despite differences in climate, crop varieties and livestock. “The basic issues we face are more or less the same in both countries,” he said. Skibsted has visited USP’s São Carlos campus at least once a year since 1998 and was one of Cardoso’s supervisors while he was in Denmark for his sandwich PhD.