Optimization of sunflower head pectin extraction by ammonium oxalate and the effect of drying conditions on properties

Abstract

Pectin is a kind of natural and complex carbohydrates which is extensively used in food, chemical, cosmetic, and pharmaceutical industries. Fresh sunflower (Helianthus annuus L.) heads were utilized as a novel source of pectin extracted by ammonium oxalate. The conditions of the extraction process were optimized implementing the response surface methodology. Under optimal extraction parameters (extraction time 1.34 h, liquid–solid ratio 15:1 mL/g, ammonium oxalate concentration 0.76% (w/v)), the maximum experimental yield was 7.36%. The effect of spray-drying and freeze-drying on the physiochemical properties, structural characteristics, and antioxidant activities was investigated by FT-IR spectroscopy, high performance size exclusion chromatography, and X-ray diffraction. The results showed freeze-drying lead to decrease in galacturonic acid (GalA) content (76.2%), molecular weight (Mw 316 kDa), and crystallinity. The antioxidant activities of pectin were investigated utilizing the in-vitro DPPH and ABTS radical-scavenging systems. This study provided a novel and efficient extraction method of sunflower pectin, and confirmed that different drying processes had an effect on the structure and properties of pectin.

Isolation, Chemical Characterization and Antioxidant Activity of Pectic Polysaccharides of Fireweed (Epilobium angustifolium L.)

“…The radical-scavenging activity of pectins can be ascribed to the presence of hydroxyls and carboxyls in the structure of these polysaccharides [ 14 , 15 ]. Many authors suggest that GalA, as a hydrogen donator, probably plays a key role in the scavenging of free radicals [ 16 , 17 ]. Hence, the HG domain may represent an active structural domain of pectin-mediating antioxidant activity [ 15 , 17 ].…”

Composition, morphology, interfacial rheology and emulsifying ability of soy hull polysaccharides extracted with ammonium oxalate and sodium citrate as extractants

“…Previous studies have pointed out that emulsification activity and the average radius of emulsion droplets is inversely related; the larger is the emulsion particle size, the lower is the emulsification activity. 14,46 Consequently, SHPS exhibited better emulsification dynamics than SHPA, hence, the particle size of the emulsion prepared by SHPS for 30 days was investigated to explore its stability (Fig. 6(C)).…”

“…11 However, the extraction methods, extractant, temperature, and time may affect the physicochemical properties of the polysaccharide. 12,13 Ma et al 14 indicated that the relative molecular weight (M w ) of pectin from sunflower heads that had been extracted with ammonium oxalate was larger than that of sunflower pectin extracted by an ultrasound-assisted method or subcritical water method. The physical and chemical properties of polysaccharides were considerably affected by M w , conformation, and monosaccharide composition.…”

The Active Components of Sunflower (Helianthus annuus L.) Calathide and the Effects on Urate Nephropathy Based on COX-2/PGE2 Signaling Pathway and the Urate Transporter URAT1, ABCG2, and GLUT9

“…However, sunflower calathide, which was considered as an agricultural waste, has not been researched as widely as seeds and pectin. Sunflower head pectin has long been used for functional foods ( 5 , 6 ) and the antioxidant activities of pectin were investigated ( 7 ). Natural low-methoxyl pectin extracted from sunflower head could be served as a potential low-calorie or sugar-free food in health care industry ( 8 ).…”