Extraction and characterization of a pectin from sea buckthorn peel

Abstract

Sea buckthorn peel is the by-product of the sea buckthorn processing, which contains many bioactive compounds. In this paper, sea buckthorn high methoxyl pectin (SBHMP) was obtained, with a yield of 8% and a light-colored. The SBHMP was a high methoxyl with a degree of esterification of 57.75% and uronic acid content of 65.35%. The structural and morphological characterization of SBHMP were analyzed by high-performance liquid chromatography, Fourier-transform infrared spectroscopy, and scanning electron microscopy. Results showed that SBHMP presented a sheet and layered stacked morphological, and was mainly composed of galacturonic acid, arabinose, galactose, rhamnose, and mannose, which indicated that SBHMP mainly consisted of homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) type pectin polysaccharides. In addition, SBHMP also presented significant gel, thickening, and emulsifying properties. The results exhibited that SBHMP could form jelly-like gels under acid and high sucrose conditions, presenting a shear-thinning behavior and increasing apparent viscosity with the enhancement of pectin and sucrose contents. Besides, SBHMP could form oil-in-water emulsions with pectin concentrations of 1.0–3.0%. When the SBHMP concentrations were 2.0 and 3.0%, the emulsions were stable during 7 days of storage. Findings in this paper demonstrated the potential of SBHMP to be a food thickener and emulsifier and support the in-depth utilization of sea buckthorn by-products.

Prospects of sea buckthorn ( Hippophae rhamnoides L.) polysaccharides: preparation, structural characterization, and bioactivities diversity

“…to increase the yield of polysaccharides. These two methods are cost-effective but have certain limitations [31,[34][35] . When using these two methods, the extraction conditions must be carefully optimized, and the pH adjustment range must be controlled to prevent potential degradation of polysaccharides.…”

“…In general, organic reagents or activated carbon and macroporous resins are used to decolorize polysaccharides. According to method by Zhu et al [34] , a solution of crude sea buckthorn polysaccharide was decolorized by adding sodium metabisulfite at a volume concentration of 0.000 4%. While Ma et al [24] used 0.5% (m/m) activated carbon.…”

“…These polysaccharides consist of neutral monosaccharides and glyoxylates and are commonly analyzed using gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS), ion chromatography (IC), and HPLC techniques to determine their monosaccharide fractions [59][60] . The sea buckthorn polysaccharides in Table 2 are heteropolysaccharides composed of various monosaccharides, including Ara, Rha, Xyl, Man, Glc, and Gal, and contain substantial quantities of the glyoxalates GlcA and GalA [34] .…”

“…Farzaliyev et al [35] have isolated low-esterified pectin (DE: 28.8%), consisting of a mixture of linear high-molecular polymers α-D-galacturonic and other polysaccharides with macromolecules including galacturonic acid residues and neutral sugars. Zhu et al [34] have extracted a polysaccharide named SBHMP from sea buckthorn peel and have found it to be a complex pectin with high glyoxylate content (DE: 57.75%), which can be classified as a complex consisting of homogalacturonans (HG) and rhamnogalacturonan I (RG-I) type pectin polysaccharides. The extant scientific literature on sea buckthorn polysaccharides has been chiefly preoccupied with examining those derived from Chinese sea buckthorn, thus offering scant attention to comparative analyses of sea buckthorn sourced from disparate regions.…”

“…Wei et al [32] compared the microstructure of sea buckthorn polysaccharides extracted by HWE and MAE using SEM and found that the MAE-extracted samples had disorganized parenchyma, indicating that MAE accelerated cell damage and promoted polysaccharide release from sea buckthorn better than HWE. A study identified several properties of the sea buckthorn pectin polysaccharide named SBHMP, including its apparent sheet-like and layered stacked structure with a smooth and dense surface as observed by SEM [34] . Zhao et al [65] observed sea buckthorn polysaccharide (HRPI) and found that its microscopic morphology was a blocky structure with rough surface, small interstices and loose arrangement.…”