Use of Fourier transform infrared spectroscopy and multi-variant analysis for detection of butter adulteration with vegetable oil

Figures & data

Table 1. Study plan for adulteration of vegetable oil in butter.

Treatment no.	Butter (%)	Vegetable oil (%)
T0	100	-
T1	-	100
T2	90	10
T3	80	20
T4	70	30
T5	60	40
T6	50	50
T7	40	60

Table 2. AST and color test results of butter with different levels of vegetable oil adulteration.

Treatments	Results of AST test	Results of color test
T0	2 min 40 s	-ve
T1	1 min 48 s	+ve
T2	2 min 36 s	+ve
T3	2 min 32 s	+ve
T4	2 min 27 s	+ve
T5	2 min 19 s	+ve
T6	2 min 5 s	+ve
T7	1 min 57 s	+ve

T₀ = Butter 100%

T₁ = Vegetable 100%

T₂ = Butter 90% and Vegetable oil 10%

T₃ = Butter 80% and Vegetable oil 20%

T₄ = Butter 70% and Vegetable oil 30%

T₅ = Butter 60% and Vegetable oil 40%

T₆ = Butter 50% and Vegetable oil 50%

T₇ = Butter 40% and Vegetable oil 60%

Figure 1. Typical FTIR spectra for butter (100%), vegetable oil (100%), and adulterated butter samples with different levels of vegetable oil.

Figure 2. Hostelling’s T² map for FTIR spectra of butter, vegetable oil, and adulterated samples.

Figure 3. PCA similarity map defined by PC1 and PC2 for the FTIR spectra of butter, vegetable oil, and adulterated samples (VO: Vegetable Oil, B: Butter).

Figure 4. PLS regression-based prediction model developed by FTIR spectra (4000–800 cm⁻¹) obtained from butter, vegetable oil, and adulterated samples.

Figure 5. PLS regression analysis of FTIR spectra (3000–2800 cm⁻¹) obtained from butter, vegetable oil and adulterated samples.