Citrus pectin obtained by ultrasound-assisted extraction: Physicochemical, structural, rheological and functional properties

Figures & data

Figure 1. Native pectin extraction yields from C. paradisi and C. reticulata obtained by CE and UAE. ^a–e Different letters between columns indicate significant differences (p < 0.05). Data are the means of three determinations. Abbreviations: PPC, pectins from C. paradisi extracted conventionally; PPU, pectins from C. paradisi extracted by ultrasound; PRC, pectins from C. reticulata extracted conventionally; PRU, pectins from C. reticulata extracted by ultrasound.

Figura 1. Rendimientos de la extracción de pectinas nativas de C. paradisi y C. reticulata obtenidas por EC y EAU. ^a-e Letras diferentes entre columnas indican diferencia significativa (p < 0.05). Los datos son la media de tres determinaciones. Las abreviaturas: PPC, pectinas de C. paradisi extractada convencionalmente; PPU, pectinas de C. paradisi extractada por ultrasonido; PRC, pectinas de C. reticulata extractada convencionalmente; PRU, pectinas de C. reticulata extractada por ultrasonido.

Table 1. Chemical and functional parameters of native pectins from C. paradisi and C. reticulata.

Tabla 1. Parámetros químicos y funcionales de pectinas nativas de C. paradisi y C. reticulata.

	PC	PPC	PRC	PPU	PRU
Chemical parameters
Degree of esterification (%)	84.91 ± 1.14^a	84.25 ± 2.98^a	82.30 ± 2.96^a	72.15 ± 0.11^b	71.81 ± 1.64^b
Galacturonic acid (%)	85.12 ± 1.34^a	76.03 ± 2.68 ^b	63.07 ± 2.52^c	71.01 ± 1.48^d	54.34 ± 1.21^e
Viscosimetric molecular weight (kDa)	92.64 ± 1.09^a	123.60 ± 2.04^b	48.70 ± 0.54^c	95.35 ± 1.78^a	46.59 ± 0.50^d
Functional parameters
WHC (g H2O/g pectin)	2.02 ± 0.20^a	21.78 ± 1.03^b	18.76 ± 1.09^c	15.42 ± 3.46^c	16.61 ± 4.24^c
OHC (g oil/g pectin)	1.26 ± 0.01^a	1.15 ± 0.03 ^b	1.08 ± 0.12^b	1.24 ± 0.08^ab	1.14 ± 0.15^ab
Intrinsic viscosity (dL/g)	4.03 ± 0.04^a	4.98 ± 0.06^b	2.52 ± 0.02^c	4.12 ± 0.05^a	2.45 ± 0.02^d

^a–e Different letters on the same row indicate significant differences (p < 0.05). Data are the means of three determinations. Abbreviations: PPC, pectins from C. paradisi extracted conventionally; PPU, pectins from C. paradisi extracted by ultrasound; PRC, pectins from C. reticulata extracted conventionally; PRU, pectins from C. reticulata extracted by ultrasound.

^a-e Letras diferentes en la misma fila indican diferencia significativa (p < 0.05). Los datos son la media de tres determinaciones. Las abreviaturas: PPC, pectinas de C. paradisi extractada convencionalmente; PPU, pectinas de C. paradisi extractada por ultrasonido; PRC, pectinas de C. reticulata extractada convencionalmente; PRU, pectinas de C. reticulata extractada por ultrasonido.

Figure 2. Infrared spectra of native pectins from C. paradisi and C. reticulata obtained by CE and UAE. Abbreviations: PPC, pectins from C. paradisi extracted conventionally; PPU, pectins from C. paradisi extracted by ultrasound; PRC, pectins from C. reticulata extracted conventionally; PRU, pectins from C. reticulata extracted by ultrasound.

Figura 2. Espectros infrarrojos de pectinas nativas de C. paradisi y C. reticulata obtenidas por EC y EAU. Abreviaturas: PPC, pectinas de C. paradisi extractada convencionalmente; PPU, pectinas de C. paradisi extractada por ultrasonido; PRC, pectinas de C. reticulata extractada convencionalmente; PRU, pectinas de C. reticulata extractada por ultrasonido.

Figure 3. Reduced viscosity vs. concentration of grapefruit pectin-conventional (PPC) dispersed in 100 mM NaCl aqueous solution. The solid line shows a linear relationship between reduced viscosity and pectin concentration. Abbreviations: PPC, pectins from C. paradisi extracted conventionally.

Figura 3. La viscosidad reducida vs la concentración de pectina convencional de pomelo (PPC) dispersa en una solución acuosa de NaCl 100 mM. La línea continua muestra una relación lineal entre la viscosidad reducida y la concentración de pectina. Abreviaturas: PPC, pectinas de C. paradisi extraídas convencionalmente.

Figure 4. Flow curves of pectin solutions (2% w/v) at 25°C. Abbreviations: PPC, pectins from C. paradisi extracted conventionally; PPU, pectins from C. paradisi extracted by ultrasound; PRC, pectins from C. reticulata extracted conventionally; PRU, pectins from C. reticulata extracted by ultrasound.

Figura 4. Curvas de flujo de soluciones de pectina (2% p/v) a 25°C. Abreviaturas: PPC, pectinas de C. paradisi extraídas convencionalmente; PPU, pectinas de C. paradisi extraídas por ultrasonido; PRC, pectinas de C. reticulata extraídas convencionalmente; PRU, pectinas de C. reticulata extraídas por ultrasonid.