title: Extraction of pectin from Premna microphylla turcz leaves and its physicochemical properties.
abstract: Premna microphylla turcz leaves (PMTL) have been used for preparing a "green tofu" by Chinese for a long history. Chemical composition analysis indicated alcohol insoluble solids (AIS) of PMTL contained high amount of pectin. Water, ammonium oxalate, hydrochloric acid and sodium hydroxide were used to extract different pectic fractions sequentially. Ammonium oxalate was found to be the most effective extracting agent, reflecting on a high yield (20.61%) and a significant change of morphology of AIS. The resulted oxalate-soluble pectin (OXSP) showed high galacturonic acid content (76.15%) and average molecular weight (980.67kDa), low neutral sugar content (6.41%) and degree of methoxylation (14.90%). All of the characteristics have contributed excellent gelling and thickening properties of OXSP. These results may allow an improved use of PMTL as a resource of low-methoxyl pectin, and observation of the morphology of residues can be helpful for evaluating the efficiency of extracting agents.
authors: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
authors: Jun
authors: J
authors: Chen
authors: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China. Electronic address: liangruihong@ncu.edu.cn.
authors: Rui-hong
authors: RH
authors: Liang
authors: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
authors: Wei
authors: W
authors: Liu
authors: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China. Electronic address: shunjingluo@ncu.edu.cn.
authors: Shun-jing
authors: SJ
authors: Luo
authors: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
authors: Cheng-mei
authors: CM
authors: Liu
authors: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
authors: Shuang-shuang
authors: SS
authors: Wu
authors: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
authors: Zhao-jun
authors: ZJ
authors: Wang
mesh_terms: D002473:Cell Wall / Q000737:chemistry; D002850:Chromatography, Gel; D019686:Lamiaceae / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010368:Pectins / Q000737:chemistry / Q000302:isolation & purification*; D018515:Plant Leaves / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D010368:Pectins
keywords: Alcohol insoluble solids (AIS); Ammonium oxalate; Low-methoxyl pectin; Morphology; Premna microphylla turcz leaves (PMTL)