Isolation and characterization of acetylated LM-pectins extracted from okra pods

K. Alba, A. P. Laws, V. Kontogiorgos

Research output: Contribution to journalArticle

54 Citations (Scopus)

Abstract

Pectin was isolated by aqueous extraction at pH 6.0 or 2.0 from okra (Abelmoschus esculentus L.) pods. An isolation protocol was designed to extract pectin and to study the influence of the extraction pH on their composition and physicochemical properties. The extracted pectin was assessed using sugar compositional analysis (neutral sugars, galacturonic acid, acetyl and methyl contents). FT-IR and NMR spectroscopy, size exclusion chromatography (SEC) and dilute solution viscometry were also used to determine the macromolecular characteristics of isolated pectin. The extraction protocols resulted in the isolation of pectin of high purity as evidenced by their high total carbohydrate (70.0-81.8%) and low protein (4.3-6.3%) contents. Samples contained between 46 and 56% galacturonic acid, had broad molecular weight distributions, a low degree of methylation (40.0 and 24.6%) and high degree of acetylation (52.2 and 37.6%). Neutral sugar analysis showed that the pectin extracted at pH 6.0 contained moreneutral sugars, particularly, galactose (21.7-25.7mol%), rhamnose (10.1-13.2mol%) and arabinose (7.1-7.3mol%) than that extracted at pH 2.0 indicating variations in fine structure. In addition, molecular parameters of the isolated pectins, such as intrinsic viscosity (2.8-4.4dLg-1), critical concentration (0.15-0.45dLg-1) and coil overlap parameter (0.66-1.51), showed that extraction conditions resulted in pectin with different chain morphology. The yield and physico-chemical characteristics of the extracted pectin from okra pods were influenced by the extraction conditions.

LanguageEnglish
Pages726-735
Number of pages10
JournalFood Hydrocolloids
Volume43
DOIs
Publication statusPublished - 1 Jan 2015

Fingerprint

Abelmoschus
Pectins
okra
pectins
pods
Sugars
sugars
galacturonic acid
Acetylation
Methylation
Size exclusion chromatography
Viscosity measurement
Molecular weight distribution
Carbohydrates
Nuclear magnetic resonance spectroscopy
Infrared spectroscopy
Sugar Acids
Rhamnose
Arabinose
viscometry

Cite this

@article{a5751bcc6b764e93a3b746735f9f199c,
title = "Isolation and characterization of acetylated LM-pectins extracted from okra pods",
abstract = "Pectin was isolated by aqueous extraction at pH 6.0 or 2.0 from okra (Abelmoschus esculentus L.) pods. An isolation protocol was designed to extract pectin and to study the influence of the extraction pH on their composition and physicochemical properties. The extracted pectin was assessed using sugar compositional analysis (neutral sugars, galacturonic acid, acetyl and methyl contents). FT-IR and NMR spectroscopy, size exclusion chromatography (SEC) and dilute solution viscometry were also used to determine the macromolecular characteristics of isolated pectin. The extraction protocols resulted in the isolation of pectin of high purity as evidenced by their high total carbohydrate (70.0-81.8{\%}) and low protein (4.3-6.3{\%}) contents. Samples contained between 46 and 56{\%} galacturonic acid, had broad molecular weight distributions, a low degree of methylation (40.0 and 24.6{\%}) and high degree of acetylation (52.2 and 37.6{\%}). Neutral sugar analysis showed that the pectin extracted at pH 6.0 contained moreneutral sugars, particularly, galactose (21.7-25.7mol{\%}), rhamnose (10.1-13.2mol{\%}) and arabinose (7.1-7.3mol{\%}) than that extracted at pH 2.0 indicating variations in fine structure. In addition, molecular parameters of the isolated pectins, such as intrinsic viscosity (2.8-4.4dLg-1), critical concentration (0.15-0.45dLg-1) and coil overlap parameter (0.66-1.51), showed that extraction conditions resulted in pectin with different chain morphology. The yield and physico-chemical characteristics of the extracted pectin from okra pods were influenced by the extraction conditions.",
keywords = "Acetylation, Characterization, Isolation, NMR, Okra, Pectin",
author = "K. Alba and Laws, {A. P.} and V. Kontogiorgos",
year = "2015",
month = "1",
day = "1",
doi = "10.1016/j.foodhyd.2014.08.003",
language = "English",
volume = "43",
pages = "726--735",
journal = "Food Hydrocolloids",
issn = "0268-005X",
publisher = "Elsevier",

}

Isolation and characterization of acetylated LM-pectins extracted from okra pods. / Alba, K.; Laws, A. P.; Kontogiorgos, V.

In: Food Hydrocolloids, Vol. 43, 01.01.2015, p. 726-735.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Isolation and characterization of acetylated LM-pectins extracted from okra pods

AU - Alba, K.

AU - Laws, A. P.

AU - Kontogiorgos, V.

PY - 2015/1/1

Y1 - 2015/1/1

N2 - Pectin was isolated by aqueous extraction at pH 6.0 or 2.0 from okra (Abelmoschus esculentus L.) pods. An isolation protocol was designed to extract pectin and to study the influence of the extraction pH on their composition and physicochemical properties. The extracted pectin was assessed using sugar compositional analysis (neutral sugars, galacturonic acid, acetyl and methyl contents). FT-IR and NMR spectroscopy, size exclusion chromatography (SEC) and dilute solution viscometry were also used to determine the macromolecular characteristics of isolated pectin. The extraction protocols resulted in the isolation of pectin of high purity as evidenced by their high total carbohydrate (70.0-81.8%) and low protein (4.3-6.3%) contents. Samples contained between 46 and 56% galacturonic acid, had broad molecular weight distributions, a low degree of methylation (40.0 and 24.6%) and high degree of acetylation (52.2 and 37.6%). Neutral sugar analysis showed that the pectin extracted at pH 6.0 contained moreneutral sugars, particularly, galactose (21.7-25.7mol%), rhamnose (10.1-13.2mol%) and arabinose (7.1-7.3mol%) than that extracted at pH 2.0 indicating variations in fine structure. In addition, molecular parameters of the isolated pectins, such as intrinsic viscosity (2.8-4.4dLg-1), critical concentration (0.15-0.45dLg-1) and coil overlap parameter (0.66-1.51), showed that extraction conditions resulted in pectin with different chain morphology. The yield and physico-chemical characteristics of the extracted pectin from okra pods were influenced by the extraction conditions.

AB - Pectin was isolated by aqueous extraction at pH 6.0 or 2.0 from okra (Abelmoschus esculentus L.) pods. An isolation protocol was designed to extract pectin and to study the influence of the extraction pH on their composition and physicochemical properties. The extracted pectin was assessed using sugar compositional analysis (neutral sugars, galacturonic acid, acetyl and methyl contents). FT-IR and NMR spectroscopy, size exclusion chromatography (SEC) and dilute solution viscometry were also used to determine the macromolecular characteristics of isolated pectin. The extraction protocols resulted in the isolation of pectin of high purity as evidenced by their high total carbohydrate (70.0-81.8%) and low protein (4.3-6.3%) contents. Samples contained between 46 and 56% galacturonic acid, had broad molecular weight distributions, a low degree of methylation (40.0 and 24.6%) and high degree of acetylation (52.2 and 37.6%). Neutral sugar analysis showed that the pectin extracted at pH 6.0 contained moreneutral sugars, particularly, galactose (21.7-25.7mol%), rhamnose (10.1-13.2mol%) and arabinose (7.1-7.3mol%) than that extracted at pH 2.0 indicating variations in fine structure. In addition, molecular parameters of the isolated pectins, such as intrinsic viscosity (2.8-4.4dLg-1), critical concentration (0.15-0.45dLg-1) and coil overlap parameter (0.66-1.51), showed that extraction conditions resulted in pectin with different chain morphology. The yield and physico-chemical characteristics of the extracted pectin from okra pods were influenced by the extraction conditions.

KW - Acetylation

KW - Characterization

KW - Isolation

KW - NMR

KW - Okra

KW - Pectin

UR - http://www.scopus.com/inward/record.url?scp=84908548862&partnerID=8YFLogxK

U2 - 10.1016/j.foodhyd.2014.08.003

DO - 10.1016/j.foodhyd.2014.08.003

M3 - Article

VL - 43

SP - 726

EP - 735

JO - Food Hydrocolloids

T2 - Food Hydrocolloids

JF - Food Hydrocolloids

SN - 0268-005X

ER -