Every year Brazil processes 32,000 metric tons of acerola (Malpighia punicifolia) for the manufacture of juice, pulp and extract. Of this total, about 6,500 metric tons of waste remains, consisting of bark, seeds, pulp remnants and a few leaves, which is of little use. According to researchers at São Paulo State University (Unesp), this material, in the form of meal, when fed to pigs makes their meat lighter with a lower fat content. A high amount of fat in pork contributes to increased cholesterol in humans. Acerola increases omega-3 levels in the meat, which helps to prevent cardiovascular disease. The findings are from a study done by Fabrício Rogerio Castelini who specializes in animal husbandry; he did the work for his doctorate at the School of Agriculture and Veterinary Sciences, located on the Jaboticabal campus of Unesp, where he was advised by Professor Maria Cristina Thomaz.
The goal of the research project was to find alternative foods, high in fiber, to be fed to pigs during the end phase—when their weight goes from 70 to 130 kilograms (kg). During this period the animal cannot consume a high-energy diet because the excess accumulates as fat, which affects the meat. “Normally, feeding them foods rich in fiber, in this case acerola meal, makes the animals eat just enough to fill their stomachs and satisfy hunger,” says Castelini. “This process is called qualitative feed restriction.” He conducted two experiments to evaluate the results of including acerola meal in the pig diet. He began by determining the chemical composition and nutritional value of the ingredient. Then, he tried to estimate what would be the effect of including acerola meal at different levels—9%, 18% and 27% of the total diet usually consisting of corn and soybean meal—on performance, digestibility of the diets and characteristics of the carcasses. “In this experiment, we also evaluated meat quality, weights of the organs of the digestive system and economic return indicators,” he says.
The most important result, according to Castelini, was the qualitative improvement of pork loin in relation to the composition of fatty acids. Animals that consumed the largest amount of acerola meal increased their omega-3 fatty acid levels by 21.74%. Omega-3 fatty acids have a preventive action against heart disease. On the other hand, saturated fatty acids are considered to be hypercholesterolemic, that is, they raise cholesterol. The most dangerous of these are myristic, palmitic, and lauric fatty acids. “By including 27% acerola meal in the diet, we observed a reduction of 7.63% in the first and 5.02% in the second, and lauric remained at the same level,” says Castelini. “These acids are associated with the development of degenerative changes in the walls of the arteries and too much consumption of them can cause cardiovascular disease.”
“As to the other variables, there was less weight gain (-39.92%) in animals fed acerola meal, lower average pork belly thickness (-37.13%) and a reduction in the fatty areas in the carcass (-39.84%),” says Castelini. These data would suggest some benefits to consumer health, but reduced weight and pork belly fat can decrease producer profit. Castelini says that slaughterhouses in São Paulo do not have a payment system based on carcass quality. And so because animals fed with acerola meal weigh less, their value is lower. “In São Paulo State, a pig is slaughtered at 90 kilos; if it weighed 120 kilos, the producer profit could be higher with light meat. We believe this scenario could be reversed by creating a niche market that values the excellent quality of the animal carcass,” he says. Renato Celso Cavichioli, the sales manager of Frigorífico Suíno Leve, a slaughterhouse based in São Carlos (São Paulo State), which processes 1,200 pigs per week, believes animals with a lower fat content could succeed in the Brazilian market. “Today consumers are demanding lighter products, and pork with less fat would certainly sell well,” says Cavichioli. He points out that, although breeding has already led to the development of leaner pigs, pork still suffers from preconceived notions.
Júlio Eduardo Rohenkohl, an economist at the Federal University of Santa Maria (USFM), in Rio Grande do Sul, and a specialist in pig farming, also believes there is a potential market opportunity. “Certainly there is room in Brazil and around the world for more lean meats, with less fat and increased omega-3, for example, provided the meat retains its juiciness, color and texture. Foreign companies are exploring qualitative variations and satisfying specific markets.” He believes it is possible to segment the fresh pork market. This would happen with the producer’s guarantee of origin, proper identification of what was used as feed, such as acerola meal, and a meat stamp with the inscription light or lean pork at the final point-of-sale. Another aspect, according to Rohenkohl, is to determine how much the animal will cost with the addition of acerola and a reduction in ingredients such as corn, soybeans and sorghum, for example.
“Regarding the quality of the meat, sensory tests did not detect any difference in flavor or tenderness,” says Castelini. Samples of the meat were tested by 100 people, chosen at random. “When it comes to nutritional content and meat quality, we can recommend the inclusion of acerola waste in pig diets during the end phase, up to a level of 27% of their feed.” As for the cost of the diet, Castelini points out that, at the time of the survey (2012), with corn costing R$0.60 per kilo and acerola meal at R$0.10 per kilo, it proved to be economical. Castelini cautions, however, that any increase in demand for acerola waste could change this equation. “I believe that the most favorable areas for this type of pig feeding would be northwestern São Paulo State and the Brazilian Northeast, where there are more acerola plantations. “But this will depend on cost and freight pricing.”
According to Teresinha Marisa Bertol, a researcher at Embrapa Swine and Poultry, a unit of the Brazilian Agricultural Research Corporation, located in Concórdia (Santa Catarina State), there are only a few groups in Brazil involved in pig feeding research aimed at improving meat quality. “Embrapa is engaged in experiments to raise the omega-3 content in the fat associated with pork, with positive results. We are also studying the effect of diet containing natural antioxidants, such as, for example, grape bagasse, with the aim of improving the quality of pork. Although the meat produced on a large scale in industrial systems is already of good nutritional quality, our goal is to make it even healthier and more attractive.”
1. Acerola meal in food restriction program for heavy pigs (nº 2011/22906-6); Grant Mechanism: Regular Research Grant; Principal Investigator: Maria Cristina Thomaz (Unesp); Investment: R$64,989.45 (FAPESP).
2. Acerola meal in food restriction program for heavy pigs (nº 2011/22563-1); Grant Mechanism: Doctoral scholarship; Principal Investigator: Maria Cristina Thomaz (Unesp); Grant Recipient: Fabricio Rogerio Castelini; Investment: R$93,940.52 (FAPESP).