Razão entre ômega-6/ômega-3, AGPI/AGS e caracteriazação físico-química do óleo de Colossoma macropomun (tambaqui) cultivados no Estado de Roraima

Abstract

In this paper it was studied the physical-chemical characteristics, qualitative and quantitative analysis of the oil of steak of the fish Colossoma macropomum (tambaqui), which is grown in a semi-intensive regime, in four different places in the State of Roraima. This paper also presents the ratio between unsaturated fatty acids of the omega-6 and omega-3 series. The cities of Alto Alegre, Bonfim and Boa Vista as well as the villages of Uraricoera and Passarão were chosen in this study because they present strategic points that favor the growing of this fish species and it is where the biggest producers of fish in the state are located. In the analysis of the oil of steak of tambaqui fish, the results obtained were: humidity of 68,55±5,85 % and 6,57±2,41 % of total lipid. In the physical-chemical analysis of the oil of fish steak, it was obtained as result an average value for density to 25oC of 0,907±0,002 g/cm3; fusion point of 29,00±0,82 oC; insoluble organic substances in ether 7,07±0,009 %; rendiment 7,07±2,58 %; total lipid 6,57±2,41 %; ash amount 0,042±0,01 %; humidity 0,051±0,005 %; acidity rate 3,75±2,72 mg of KOH/g of oil; acidity in oil acid 1,88±1,36 %; iodine rate 147,65±3,04 g I2/100 g of oil; refraction indice to 40 oC 1,459±0,001 and viscosity using the exponential model proposed by Andrade (1930) pretty adjusted to the experimental data with correlation coefficient above 94 %. It was made thermal gravimetric analysis in nitrogen atmosphere in a break of temperature from 20 to 600 oC where the finetil fatty behavior was observed and compared. In the identification and qualification of the fatty acids, it was used gas chromatograph, where it was made the comparisons of the highest points of the samples with metylated fatty acids (Supelco 37), all of them in the same processing conditions in which four major fatty acids of bigger concentration were identified: linoleic acid (C18:1ω9); palmitic acid (C16:0), linoleic (C18:2ω6) and estearic acid (C18:0) with an average of 24,83±1,68 %, 17,88±1,91 %, 13,86±2,45 % e 9,17±0,78 %, respectively to the fish found in the four locations. The fatty acids of the omega 6 and omega 3 series were identified 20,49±1,62 % and 2,45±0,51 %, respectively, resulting in ratio equal to 8,56; the average concentrations of saturated and unsaturated fatty acids found were 28,56±2,38 % and 56,80±2,37 %, respectively.