Determination of Bellier index in vegetable oils; its application in the peanut oil dosage in mixtures

Abstract

The turbidity temperature (Bellier test) was performed for vegetable edible oils and it was also used for the percentual determination of peanut oil in oil mixtures. Sixty-two samples of peanut oil were analysed (table 1) and the turbidity temperature ranged from 39,7 to 42,5°C (arithmetical average 41,0°C; standard deviation ± 0,80). Seventy-seven samples of olive oil (table 2) presented a turbidity temperature varying from 12,5 to 19,5°C (m = 16,1; σ = ± 1,71). For 32 samples of cotton-seed oil (table 3) we get a range from 18,6 to 21,4°C (m = 19,9; σ = ± 0,86). The turbidity temperature was also determined in 18 samples of other vegetable edible oils: sesame, "patauá", soya-bean, corn, cashew-nut and grape-seed (table 4). Oil mixtures containing peanut oil were made and the turbidity temperature determined in such mixtures (table 5,6,7 and 8). The turbidity temperature depends on the amount of peanut oil present. Thus, through this figure, we can determine roughly the amount of peanut oil in oil mixtures. We also compared the results obtained with three different technics: the "Instituto Adolfo Lutz", the Lacerda of the "Laboratório Bromatológico do Rio de Janeiro" and the "A. O. A. C." processes (table 10).