Enzymatic, antioxidant activities and stability of bromelain-polyphenol precipitate in pineapple juice

Bromelain, a cysteine protease derived from pineapple, is highly susceptible to denaturation. To stabilize its enzymatic activity, polyphenols from cashew leaf extract with antioxidant activity and protein-binding characteristic was used to precipitate bromelain in pineapple juice and formed bromela...

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Main Author:	Poh, Shiang Shiew
Format:	Thesis
Language:	English
Published:	2012
Subjects:	TP Chemical technology
Online Access:	http://eprints.utm.my/id/eprint/78397/1/PohShiangShiewMFChE2012.pdf
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spelling	my-utm-ep.783972018-08-26T04:56:27Z Enzymatic, antioxidant activities and stability of bromelain-polyphenol precipitate in pineapple juice 2012-02 Poh, Shiang Shiew TP Chemical technology Bromelain, a cysteine protease derived from pineapple, is highly susceptible to denaturation. To stabilize its enzymatic activity, polyphenols from cashew leaf extract with antioxidant activity and protein-binding characteristic was used to precipitate bromelain in pineapple juice and formed bromelain-polyphenol precipitate subsequently. Nutraceutical properties (bromelain and antioxidant activities) and effect of temperature and pH on free and precipitated bromelain w'ere evaluated and compared. Bromelain from pineapple juice was successfully precipitated with cashew polyphenols. The bromelain activity of bromelainpolyphenol precipitate was retained at about 65 %, 63 % and 40 % of its original activities by precipitating w'ith 1.5 %, 1.0 % and 0.5 % cashew polyphenols respectively. 1.5 % and 1.0 % bromelain-polyphenol precipitates were found to have 15 % greater antioxidant activity than pineapple juice. 1.5 % and 1.0 % precipitates were shown to have good heat resistance by displaying 7 and 3.5 times lower denaturation rate constants respectively as compared to free bromelain. All bromelain-polyphenol precipitates exhibited stable bromelain activity and antioxidant activity at temperature range of 25 °C - 85 °C, whereas free bromelain showed an activity declination. Kinetics of thermal inactivation (E, AH, AG and AS ) showed that the precipitate was more thermostable than free bromelain. Bromelain-polyphenol precipitate exhibited an increased bromelain activity over alkaline pH whereas free bromelain was stable at acidic and neutral pH. Besides, the precipitate displayed a high and stable antioxidant activity at acidic region. The study showed that precipitating of bromelain with cashew polyphenols could stabilize bromelain activity, increase antioxidant capacity and improve stability in response to temperature and pH. These results suggested that precipitating of bromelain with polyphenols could be a new method for enhancing the nutraceutical properties of enzyme. 2012-02 Thesis http://eprints.utm.my/id/eprint/78397/ http://eprints.utm.my/id/eprint/78397/1/PohShiangShiewMFChE2012.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:98686 masters Universiti Teknologi Malaysia, Faculty of Chemical Engineering Faculty of Chemical Engineering
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	TP Chemical technology
spellingShingle	TP Chemical technology Poh, Shiang Shiew Enzymatic, antioxidant activities and stability of bromelain-polyphenol precipitate in pineapple juice
description	Bromelain, a cysteine protease derived from pineapple, is highly susceptible to denaturation. To stabilize its enzymatic activity, polyphenols from cashew leaf extract with antioxidant activity and protein-binding characteristic was used to precipitate bromelain in pineapple juice and formed bromelain-polyphenol precipitate subsequently. Nutraceutical properties (bromelain and antioxidant activities) and effect of temperature and pH on free and precipitated bromelain w'ere evaluated and compared. Bromelain from pineapple juice was successfully precipitated with cashew polyphenols. The bromelain activity of bromelainpolyphenol precipitate was retained at about 65 %, 63 % and 40 % of its original activities by precipitating w'ith 1.5 %, 1.0 % and 0.5 % cashew polyphenols respectively. 1.5 % and 1.0 % bromelain-polyphenol precipitates were found to have 15 % greater antioxidant activity than pineapple juice. 1.5 % and 1.0 % precipitates were shown to have good heat resistance by displaying 7 and 3.5 times lower denaturation rate constants respectively as compared to free bromelain. All bromelain-polyphenol precipitates exhibited stable bromelain activity and antioxidant activity at temperature range of 25 °C - 85 °C, whereas free bromelain showed an activity declination. Kinetics of thermal inactivation (E, AH, AG and AS ) showed that the precipitate was more thermostable than free bromelain. Bromelain-polyphenol precipitate exhibited an increased bromelain activity over alkaline pH whereas free bromelain was stable at acidic and neutral pH. Besides, the precipitate displayed a high and stable antioxidant activity at acidic region. The study showed that precipitating of bromelain with cashew polyphenols could stabilize bromelain activity, increase antioxidant capacity and improve stability in response to temperature and pH. These results suggested that precipitating of bromelain with polyphenols could be a new method for enhancing the nutraceutical properties of enzyme.
format	Thesis
qualification_level	Master's degree
author	Poh, Shiang Shiew
author_facet	Poh, Shiang Shiew
author_sort	Poh, Shiang Shiew
title	Enzymatic, antioxidant activities and stability of bromelain-polyphenol precipitate in pineapple juice
title_short	Enzymatic, antioxidant activities and stability of bromelain-polyphenol precipitate in pineapple juice
title_full	Enzymatic, antioxidant activities and stability of bromelain-polyphenol precipitate in pineapple juice
title_fullStr	Enzymatic, antioxidant activities and stability of bromelain-polyphenol precipitate in pineapple juice
title_full_unstemmed	Enzymatic, antioxidant activities and stability of bromelain-polyphenol precipitate in pineapple juice
title_sort	enzymatic, antioxidant activities and stability of bromelain-polyphenol precipitate in pineapple juice
granting_institution	Universiti Teknologi Malaysia, Faculty of Chemical Engineering
granting_department	Faculty of Chemical Engineering
publishDate	2012
url	http://eprints.utm.my/id/eprint/78397/1/PohShiangShiewMFChE2012.pdf
_version_	1747817979253358592

Enzymatic, antioxidant activities and stability of bromelain-polyphenol precipitate in pineapple juice

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