Extraction and characterization of pectin from dragon fruit (Hylocereus polyrhizus) peel

The national acreage of dragon fruit production increased yearly, which at the same time generated a great amount of the fruit peel, therefore, this thesis was designed to study the extraction of pectin from dragon fruit peel and to determine the pectin characteristics. Pectin was successfully extra...

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Main Author: Mohamad Zahari, Nur Izalin
Format: Thesis
Published: 2013
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spelling my-upm-ir.387762016-03-25T09:11:49Z Extraction and characterization of pectin from dragon fruit (Hylocereus polyrhizus) peel 2013-04 Mohamad Zahari, Nur Izalin The national acreage of dragon fruit production increased yearly, which at the same time generated a great amount of the fruit peel, therefore, this thesis was designed to study the extraction of pectin from dragon fruit peel and to determine the pectin characteristics. Pectin was successfully extracted from dragon fruit peel (DFP) with 30.08% yield at optimum extraction conditions of 67.7 oC for 77 min at pH value of 2.0. The pectin contained 7.81 % moisture, 0.04 % fat, 1.15 % protein, 4.73 % ash and 62.76 % total dietary fibre. The extracted pectin was a heteropolysaccharide which consisted of seven monosaccharides namely galacturonic acid, mannose, rhamnose, galactose, glucose, arabinose and xylose. The total neutral sugar content was 60.95%. Functional groups identification using Fourier transform infrared spectroscopy (FT-IR) and the degree of esterification (DE) derived from FT-IR spectrum confirmed that DFP pectin is a high methoxyl pectin with a DE 62.88%. Molecular weight and polydispersity ratio were determined using high performance size exclusion chromatography with multi angle laser light scattering detector (HPSEC-MALLS). DFP pectin has a molecular weight of 87 kDa with a polydispersity ratio of 8.12 and its estimated root mean square (RMS) radius average was 33 nm. Hunter L*, a*, and b* values of the DFP pectin were 39.95, 34.87 and 20.18, respectively, which showed the light pink color of the extracted pectin. DFP pectin demonstrated non-Newtonion, pseudoplastic characteristic at higher concentrations (2% and 3%) and exhibited several textural characteristics similar to that of citrus and apple pectins. DFP pectin has the highest water holding capacity (5.50 g/g), medium oil holding capacity (1.24 g/g) and swelling capacity (5.50 g/g) when compared to two commercial (citrus and apple) pectins. In addition, DFP pectin demonstrated good emulsifying activity (66.66%), emulsion stability (97.00%), foaming capacity (60.33%) and also foaming stability (64.44%, after 2 hr of foam formation). For application of DFP pectin in pineapple jam, a concentration of 2% of DFP pectin was needed to make the pineapple jam well set. For the sensory characteristics, no significant (p<0.05) differences were observed between the mean scores of the jam produced using DFP and commercial pectins except for the colour attribute. All results suggested that dragon fruit peel had the potential in producing pectin for commercial food industry application. Because of its good hydration properties, DFP pectin might be suitable to be used as thickening, emulsifying, stabilizing and foaming agent in food. Pitahayas Pectin 2013-04 Thesis http://psasir.upm.edu.my/id/eprint/38776/ masters Universiti Putra Malaysia Pitahayas Pectin
institution Universiti Putra Malaysia
collection PSAS Institutional Repository
topic Pitahayas
Pectin

spellingShingle Pitahayas
Pectin

Mohamad Zahari, Nur Izalin
Extraction and characterization of pectin from dragon fruit (Hylocereus polyrhizus) peel
description The national acreage of dragon fruit production increased yearly, which at the same time generated a great amount of the fruit peel, therefore, this thesis was designed to study the extraction of pectin from dragon fruit peel and to determine the pectin characteristics. Pectin was successfully extracted from dragon fruit peel (DFP) with 30.08% yield at optimum extraction conditions of 67.7 oC for 77 min at pH value of 2.0. The pectin contained 7.81 % moisture, 0.04 % fat, 1.15 % protein, 4.73 % ash and 62.76 % total dietary fibre. The extracted pectin was a heteropolysaccharide which consisted of seven monosaccharides namely galacturonic acid, mannose, rhamnose, galactose, glucose, arabinose and xylose. The total neutral sugar content was 60.95%. Functional groups identification using Fourier transform infrared spectroscopy (FT-IR) and the degree of esterification (DE) derived from FT-IR spectrum confirmed that DFP pectin is a high methoxyl pectin with a DE 62.88%. Molecular weight and polydispersity ratio were determined using high performance size exclusion chromatography with multi angle laser light scattering detector (HPSEC-MALLS). DFP pectin has a molecular weight of 87 kDa with a polydispersity ratio of 8.12 and its estimated root mean square (RMS) radius average was 33 nm. Hunter L*, a*, and b* values of the DFP pectin were 39.95, 34.87 and 20.18, respectively, which showed the light pink color of the extracted pectin. DFP pectin demonstrated non-Newtonion, pseudoplastic characteristic at higher concentrations (2% and 3%) and exhibited several textural characteristics similar to that of citrus and apple pectins. DFP pectin has the highest water holding capacity (5.50 g/g), medium oil holding capacity (1.24 g/g) and swelling capacity (5.50 g/g) when compared to two commercial (citrus and apple) pectins. In addition, DFP pectin demonstrated good emulsifying activity (66.66%), emulsion stability (97.00%), foaming capacity (60.33%) and also foaming stability (64.44%, after 2 hr of foam formation). For application of DFP pectin in pineapple jam, a concentration of 2% of DFP pectin was needed to make the pineapple jam well set. For the sensory characteristics, no significant (p<0.05) differences were observed between the mean scores of the jam produced using DFP and commercial pectins except for the colour attribute. All results suggested that dragon fruit peel had the potential in producing pectin for commercial food industry application. Because of its good hydration properties, DFP pectin might be suitable to be used as thickening, emulsifying, stabilizing and foaming agent in food.
format Thesis
qualification_level Master's degree
author Mohamad Zahari, Nur Izalin
author_facet Mohamad Zahari, Nur Izalin
author_sort Mohamad Zahari, Nur Izalin
title Extraction and characterization of pectin from dragon fruit (Hylocereus polyrhizus) peel
title_short Extraction and characterization of pectin from dragon fruit (Hylocereus polyrhizus) peel
title_full Extraction and characterization of pectin from dragon fruit (Hylocereus polyrhizus) peel
title_fullStr Extraction and characterization of pectin from dragon fruit (Hylocereus polyrhizus) peel
title_full_unstemmed Extraction and characterization of pectin from dragon fruit (Hylocereus polyrhizus) peel
title_sort extraction and characterization of pectin from dragon fruit (hylocereus polyrhizus) peel
granting_institution Universiti Putra Malaysia
publishDate 2013
_version_ 1747811751443824640