Authentication of butter from lard adulteration using high-resolution of nuclear magnetic resonance spectroscopy and high-performance liquid chromatography

Figures & data

Table 1. Assignments of signals of ¹H-NMR spectra from samples. Signal number agrees with those in Fig. 3.

Signal	Chemical shift (ppm)	Functional group
1	0.83–0.93	–CH3 (saturated, oleic, and linoleic acyl chains)
2	0.93–1.03	–CH3 (acyl chains)
3	1.22–1.42	–(CH2)n– (acyl chains)
4	1.52–1.70	–OCO–CH2–CH2– (acyl chains)
5	1.94–2.14	–CH2–CH = CH– (acyl chains)
6	2.23–2.36	–OCO–CH2–(acyl chains)
7	2.60–2.84	= HC–CH2–CH = (acyl chains)
8	4.10–4.32	–CH2OCOR (glyceryl group)
9	5.20–5.26	>CHOCOR (glyceryl group)
10	5.26–5.40	–CH = CH– (acyl chains)

Figure 1. ¹H-NMR spectra of A: pure lard; and B: pure butter.

Figure 2. ¹H-NMR spectra of butter and lard mixtures showing changes in the height ratio at 2.60–2.84 ppm due to the increase of lard percentages at 0 to 10 ppm.

Table 2. Fatty acid composition of butter and lard by gas chromatography mass spectrometry analysis.

FA^†	Butter	Lard
C14:0	14.79 ± 0.05	1.11 ± 0.02
C16:0	31.29 ± 0.05	23.37 ± 0.22
C16:1	0.00 ± 0.00	1.50 ± 0.02
C18:0	11.62 ± 0.04	13.26 ± 0.18
C18:1	22.77 ± 0.13	40.15 ± 0.31
C18:2	1.64 ± 0.00	17.29 ± 0.09
C18:3	0.74 ± 0.00	0.89 ± 0.02
SFA	61.68	38.34
USFA	25.15	60.2

Table 3. Triacylglycerol (TAG) composition of lard, butter, and other animal fats.

TAG^†	Lard	Chicken fat	Beef fat	Mutton fat	Butter
CClCl	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	4.57 ± 0.52
CpCpLa	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	6.06 ± 0.42
CpCLa	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	5.02 ± 0.64
CCLa	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	12.99 ± 0.02
CLaLa	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	12.34 ± 0.14
LaLaLa	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	15.8 ± 0.18
LaLaM	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	10.46 ± 0.11
LaLaO	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	5.02 ± 0.60
LaLaP	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	3.65 ± 0.06
LaMO	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	5.38 ± 0.07
LaMP	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	5.07 ± 0.06
LaOO	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	4.40 ± 0.00
LaPO	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	6.20 ± 0.02
MOO	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	2.88 ± 0.03
POO	23.37 ± 0.07	28.68 ± 0.02	18.26 ± 0.03	18.58 ± 0.01	1.64 ± 0.02
PPO	8.05 ± 0.12	18.55 ± 0.31	10.95 ± 0.06	11 ± 0.13	1.8 ± 0.02
POS	18.14 ± 0.37	4.38 ± 0.05	22.67 ± 0.14	20.4 ± 0.23	0.4 ± 0.01
PPS	0.91 ± 0.03	1.00 ± 0.00	7.36 ± 0.32	6.4 ± 0.32	0.19 ± 0.00
POL	21.6 ± 0.58	12.52 ± 0.23	0.95 ± 0.12	0.95 ± 0.12	0.00 ± 0.00

Note: TAG: triacylglycerol; C: Capric; La: lauric; M: myristic; P: palmitic; S: stearic; O: oleic; L; linoleic.

Figure 3. ¹³C nuclear magnetic resonance (NMR) spectrum of lard.

Figure 4. Heteronuclear multiple bonds correlation (HMBC) spectrum of lard.

Figure 5. Structural correlation between proton and carbon.