Occurrence and analysis of aflatoxin M1 in milk produced by Indian dairy species

Figures & data

Figure 1. Calibration curve for standard solutions of AFM₁ with concentrations of 0.05, 0.1, 0.5, 1.0, 5.0, and 10.0 µg L⁻¹ by the HPLC analysis. The standard solutions of concentration ranges from 0.05 to 10 µg L⁻¹ AFM₁ were used to find the calibration/standard curve as described by the following regression equation: Y = −1.6246 + 19.821X, where Y is the area and X is the concentration of AFM₁. The result showed the linearity of the standard curve over the range studied. The coefficient of determination (R²) was 0.9997.

Figure 2. Area-wise variation of AFM₁ in raw milk of different dairy species. This study also conducted with respect to different areas and the data revealed that there is a variation in the concentration of AFM1 in different localities studied.

Table 1. AFM₁ level (µg L⁻¹) in milk of different species in urban semi-urban and rural areas (n = 3) by the HPLC method.

Species	Area	Tested samples	Positive samples	Contamination (%)	Mean ± SD
Buffalo	Urban	50	24	48	0.012 ± 0.005
Buffalo	Semi-urban	50	20	40	0.042 ± 0.078
Buffalo	Rural	50	14	28	0.025 ± 0.065
Cow	Urban	50	26	52	0.008 ± 0.012
Cow	Semi-urban	50	24	48	0.030 ± 0.018
Cow	Rural	50	18	36	0.018 ± 0.010
Goat	Urban	50	20	40	0.016 ± 0.046
Goat	Semi-urban	50	17	34	0.022 ± 0.032
Goat	Rural	50	13	26	0.005 ± 0.002
Sheep	Urban	50	22	44	0.042 ± 0.073
Sheep	Semi-urban	50	18	36	0.018 ± 0.025
Sheep	Rural	50	15	30	0.014 ± 0.065

Note: All experiments were done in triplicates. SD = standard deviation.

Table 2. Occurrence of AFM₁ level in milk of different species (n = 3) by the ELISA method.

Species	Tested samples (n)	Positive samples ^a(n)	Range (n)/AFM1 concentration (ng L^−1)				Mean ± SD^b
			<5	5–20	21–50	>50
Buffalo	50	25	25	11	06	08	42.1 ± 3.4
Cow	50	31	05	09	14	22	30.2 ± 1.8
Goat	50	17	20	17	08	05	38.6 ± 2.1
Sheep	50	20	19	14	11	06	25.7 ± 1.6
Total	200	93	69	51	39	41	34.15 ± 2.2

^a>5 ng L⁻¹ AFM₁.

^bMean ± SD of positive samples (containing > 5 ng L⁻¹ AFM₁).