Avaliaram-se o rendimento de filetagem e os valores percentuais das partes de tilápia tailandesa (Oreochromis spp.), no âmbito de uma empresa em Minas Gerais, durante o período de janeiro a novembro de 2004. Foram processadas 4260 tilápias (2560 quilos), registrando-se os pesos totais dos peixes e de suas partes principais, o desempenho da mão-de-obra e o tempo gasto no processo. Os peixes foram distribuidos em três classes de peso (300 a 600g; 601 a 800g e 801 a 1000g) O rendimento médio de filetagem foi de 31,0%, variando de 28,9% a 33,6%, complementado por 36,0% de cabeça e vísceras, 8,0% de pele, 22,0% de resíduo ósseo e 3,0% de restos de toilet. Não houve diferença no rendimento de filetagem (P>0,05), entre as três classes de pesos. Verificaram-se que as variações dos percentuais e o desempenho dos operários têm impacto na competitividade da empresa.
This experiment was carried out in order to evaluate some technical aspects of the industrial processing of tilapias (Oreochromis spp.), with emphasis on the filefishing profitability in an industry, located in Minas Gerais state, Brazil. During a period between January and November, 2004, 4260 fishes, totalling 2560kg, with individual weights ranging from 300 to 1000g (mean individual weight of 600g) were processed. Data collected comprehended total body weight, and parts weight, such as: head and viscera, filefish, skin, carcass residue and "toilet" residue, aiming to correlating the per cent value of each part, also considering: fish size method of cutting and processing time. The net filefish per cent was 31.0%, ranging between 28.9% to 33.6%, complemented by: head-viscera 36.0%; skin 8.0%; carcass residue 22.0% and toilet 3.0%. No statistical differences in net filefish gains in three different classes of sizes of fishes (300-600g; 601- 800g and 801-100g) (P>0.05) were detected. In addition, the variation of net yield, as well as labor efficiency, had a particular impact in the company competitvity.