Oregano extract is a natural antioxidant in meat products

O oregano extract is an efficient antioxidant which can be used in meat products. The finding comes from experiments carried out by researchers from the Faculty of Animal Science and Food Engineering (FZEA) at USP, in Pirassununga, in which the extract was used in meat products based on sheep meat, replacing chemical additives BHT – butylhydroxy-toluene and sodium erythorbate. “These additives are used in meat products and in the food industry in general, as preservatives and antioxidants. But oregano extract achieved equivalent effects.”, describes Veterinarian Rafaella de Paula Paseto Fernandes.

After testing several herbs and spices to replace chemical additives, such as mint, saffron and rosemary, among others, Rafaella selected oregano, which showed great antioxidant potential. In part of the experiments, the veterinarian made burgers with meat from “discard” sheep. In other words, from animals usually over six years old that are discarded from production systems. “In general, the meat from this type of animal, already considered old, has a more pronounced flavor and a tougher texture, which makes it difficult to sell the cuts in their natural state,” she explains. In addition to replacing the chemical additive, Rafaella also intends, with the positive results, to encourage the consumption of sheep meat, which is not so common in the country.

Before applying the extract, the plant underwent preparation stages: grinding; agitation; centrifugation; filtration; concentration, freeze-drying (drying) and, finally, resuspension of the product in water. “This last stage was necessary since we applied the extract in liquid form to prepare meat products,” he says.

Natural antioxidant

After obtaining the extract, Rafaella verified its effectiveness natural antioxidant from its application in different systems: raw frozen hamburger, cooked sausage and hamburger refrigerated under modified atmosphere. There was no difference in the count of total viable microorganisms and lactic acid bacteria at the end of storage

In the latter, developed during her research internship abroad at the Meat Technology Center in Ourense, Spain, the researcher compared three groups of hamburgers to check their stability during storage for 20 days. In the first set of samples, no additives, chemical or natural (oregano extract), were applied. In the second set, the researcher applied BHT at a concentration of 50 parts per million (ppm). In the third group, the amount of 1,000 ppm was used, which, according to the concentration of the extract, corresponds to 3.5 milliliters (ml) for each kilo of meat mass. “The tests proved, in fact, that oregano extract is as efficient as BHT,” she celebrates.

According to Rafaella, there was no difference in the count of total viable microorganisms and lactic acid bacteria when comparing the two additives at the end of storage. “Furthermore, after 20 days of storage, the extract showed similar inhibition capacity in relation to lipid and protein oxidation”, she says. And to complement the results, the products were also subjected to a sensory analysis in which 14 properly trained tasters evaluated the burgers from various aspects. “It was found that the burger containing natural extract maintained its sensory quality and was well accepted for up to fifteen days of storage”.

Rafaella's studies resulted in the doctoral thesis Use of natural antioxidant extracts obtained from aromatic herbs in the preparation of products based on lamb meat, which was supervised by Professor Mariza Pires de Melo and co-supervised by Professor Marco Antonio Trindade, both from FZEA. Part of the research, which began in 2011 and was completed in 2015, was published earlier this year in the international journals Food Control, vol. 63 and Journal of Food Science and Technology, vol. 53. The study was funded by the São Paulo Research Foundation (Fapesp) and the National Council for Scientific and Technological Development (CNPq).

Source: http://www.fzea.usp.br/?p=12333