Composition and shear crystallization of milkfat fractions extracted with supercritical carbon dioxide

Figures & data

Figure 1. Total weights of milkfat fractions at the different fractionation pressures.

Table 1. Fatty acid composition of milkfat and its fractions (g/100 g).

Fatty acid		Milkfat	10 MPa		15 MPa		20 MPa		Raffinate
			1 h	6 h	1 h	6 h	1 h	6 h
C4:0	Butyric	2.5±0.2^f	6.1±0.2^e	4.5±0.1^d	3.3±0.2^c	1.8±0.1^b	1.1±0.1^a	-	-
C6:0	Caproic	1.8±0.1^c	3.7±0.2^f	3.0±0.1^e	2.5±0.1^d	1.7±0.1^c	1.2±0.1^b	0.2±0.1^a	0.2±0.1^a
C8:0	Caprylic	1.2±0.1^c	2.5±0.1^e	1.6±0.1^d	1.5±0.1^d	1.3±0.1^c	1.0±0.1^b	0.2±0.1a	0.2±0.1^a
C10:0	Capric	2.6±0.1^c	5.0±0.2^e	3.2±0.1^d	3.2±0.1^d	3.1±0.1^d	2.5±0.1^c	0.9±0.1^b	0.7±0.1^a
C12:0	Lauric	3.2±0.2^bc	5.6±0.2^e	3.6±0.1^d	3.4±0.1^cd	3.4±0.1^cd	3.0±0.1^b	1.6±0.1^a	1.4±0.1^a
C14:0	Myristic	10.9±0.3^d	15.3±0.3^f	12.6±0.3^e	11.2±0.3^d	10.9±0.1^d	10.3±0.2^c	7.9±0.1^b	7.3±0.1^a
C16:0	Palmitic	28.8±0.4^c	30.3±0.5^d	32.1±0.3^e	30.4±0.3^d	28.9±0.2^c	27.8±0.4^b	25.9±0.3^a	26.3±0.4^a
C18:0	Stearic	13.3±0.4^d	8.1±0.2^a	10.7±0.2^b	12.0±0.2^c	13.3±0.2^d	14.1±0.3^e	17.0±0.2^f	19.1±0.2^g
C18:1	Oleic	29.2±0.4^d	18.1±0.4^a	22.9±0.3^b	26.6±0.2^c	29.4±0.3^d	32.7±0.4^e	39.9±0.4^g	38.8±0.4^f
C18:2	Linoleic	2.7±0.1^cd	1.9±0.1^a	2.4±0.1^b	2.6±0.1^c	2.8±0.1^d	3.0±0.1^e	3.2±0.1^f	3.0±0.1^e
C14:1 C15:0 C16:1	Myristoleic Pentadecanoic Palmitoleic	3.8±0.1^d	3.4±0.1^c	3.4±0.1^c	3.3±0.1^bc	3.4±0.1^c	3.3±0.1^bc	3.2±0.1^b	3.0±0.1^a
C 17:0	Margaric
SCFA		5.5±0.2^d	12.3±0.3^g	9.1±0.1^f	7.3±0.2^e	4.8±0.1^c	3.3±0.1^b	0.5±0.1^a	0.4±0.1^a
MCFA		18.6±0.2^d	28.3±0.4^g	21.6±0.2^f	19.8±0.4^e	19.5±0.2^e	17.8±0.3^c	12.1±0.3^b	11.0±0.3^a
LCFA		75.9±0.5^d	59.4±0.4^a	69.3±0.4^b	72.9±0.5^c	75.7±0.3^d	78.9±0.4^e	87.4±0.5^f	88.6±0.3^g
USFA		34.2±0.3^d	21.6±0.4^a	26.9±0.2^b	30.9±0.3^c	34.0±0.2^d	37.5±0.4^e	44.6±0.4^g	43.1±0.3^f
SFA		65.8±0.5^d	78.4±0.4^g	73.1±0.3^f	69.1±0.4^e	66.0±0.4^d	62.5±0.5^c	55.4±0.4^a	56.9±0.5^b

SCFA: short-chain fatty acids (C_4:0–C_8:0); MCFA: medium-chain fatty acids (C_10:0- C_14:0), LCFA: long-chain fatty acids (C_16:0–C_18:2); USFA: unsaturated fatty acids; SFA: saturated fatty acids.

Different letters within the same row indicate significant differences (p < 0.05).

Mean ± SD, n = 4.

Figure 2. Total fatty acid % recovery at the end of each extraction process.

Figure 3. Melting thermograms of fractions produced at (a) 10, (b) 15, (c) 20 MPa, and (d) milkfat and raffinate.

Figure 4. Crystallization thermograms of milkfat and its fractions produced at 10, 15, and 20 MPa.

Figure 5. Viscosity profiles of milkfat and its fractions at 1.0°C/min cooling rate as a function shear rate: (a) viscosity–temperature profile, (b) 10, (c) 25, (d) 50, (e) 100, and (f) 300 s^−1.

Table 2. Nucleation and crystallization onset temperatures (°C) of milkfat and its fractions based on shear crystallization.

Region	Shear rate (s^−1)	Milkfat	10 MPa		15 MPa		20 MPa		Raffinate
			1 h	6 h	1 h	6 h	1 h	6 h
Nucleation	10	22.6±0.3	15.1±0.3	16.4±0.3	18.3±0.3	21.8±0.4	23.8±0.3	25.4±0.4	30.2±0.3
	25	23.1±0.3	17.0±0.2	19.7±0.3	21.2±0.4	22.4±0.4	24.1±0.4	25.6±0.4	30.2±0.3
	50	23.5±0.2	17.6±0.2	21.1±0.3	22.1±0.3	22.6±0.4	24.3±0.3	25.9±0.2	29.4±0.3
	100	23.7±0.2	18.6±0.2	22.1±0.2	22.7±0.3	22.9±0.3	24.4±0.3	26.1±0.3	29.1±0.2
	300	23.7±0.2	19.0±0.2	22.4±0.2	23.5±0.2	23.9±0.3	24.8±0.2	26.4±0.2	29.2±0.2
Growth	10	15.4±0.4	9.4±0.3	12.3±0.3	13.4±0.4	15.2±0.3	16.2±0.4	21.0±0.4	26.0±0.4
	25	15.3±0.4	9.4±0.3	12.4±0.3	13.4±0.4	15.3±0.3	16.3±0.4	21.0±0.4	24.0±0.3
	50	15.2±0.3	9.5±0.3	12.3±0.3	13.4±0.3	15.2±0.3	16.3±0.3	21.0±0.3	23.7±0.2
	100	15.2±0.2	9.4±0.2	12.3±0.2	13.4±0.3	15.3±0.2	17.4±0.3	21.6±0.4	23.8±0.3
	300	15.2±0.2	9.4±0.2	12.4±0.2	13.4±0.3	15.3±0.3	18.3±0.3	21.9±0.2	24.8±0.2

Figure 6. Correlation of palmitic acid content and the change in nucleation onset temperature with shear rate from 10 to 300 s^−1.