Effect of additives and food processing conditions on Benzyl glucosinolate hydrolysis products in Carica papaya
Glucosinolate are sulphur-containing secondary metabolites found largely in Brassicaceae family. Glucosinolate undergoes hydrolysis readily upon cell rupture, such as cutting and cooking, by the naturally-occurring enzyme myrosinase to form mainly isothiocyanates and/or simple nitriles. Isothiocyana...
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| Format: | Thesis |
| Language: | English English |
| Published: |
2012
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| Online Access: | https://eprints.ums.edu.my/id/eprint/42323/1/24%20PAGES.pdf https://eprints.ums.edu.my/id/eprint/42323/2/FULLTEXT.pdf |
| _version_ | 1825716018694062080 |
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| author | Gayathri Nagappan |
| author_facet | Gayathri Nagappan |
| author_sort | Gayathri Nagappan |
| collection | UMS |
| description | Glucosinolate are sulphur-containing secondary metabolites found largely in Brassicaceae family. Glucosinolate undergoes hydrolysis readily upon cell rupture, such as cutting and cooking, by the naturally-occurring enzyme myrosinase to form mainly isothiocyanates and/or simple nitriles. Isothiocyanates are known to possess anticarcinogenic properties while nitriles are largely inactive. Benzyl isothiocyanate, a hydrolysis product of benzyl glucosinolate, is one of the most potent anticancer agents. However, formation of benzyl isothiocyanate is depending upon reaction conditions where benzyl nitrile is formed at the expense of benzyl isothiocyanate. Thus, the potential health benefits of benzyl isothiocyanate may be surpassed by the ineffective benzyl nitrile. In this study, the factors influencing the formation of benzyl isothiocyanate were investigated to understand further the benzyl glucosinolate hydrolysis pathway in different parts of papaya (Carica papaya). The results showed that the concentration (dry weight), of benzyl isothiocyanate was found greater in papaya leaf with 349 μM followed by 24 μM in unripe fruit and 12 μM in flower. The highest amount of benzyl isothiocyanate produced was observed at room temperature (25oC) where it decreases gradually as the temperature increases up to 80oC. Comparing three common domestic methods of cooking vegetable i.e. blanching, boiling and slow heating, the results show that the high temperature treatment produced mainly benzyl nitrile; while slow heating up to 40oC produced more benzyl isothiocyanate. Both hydrolysis products were found largely leached into the cooking liquid (soup). The production of benzyl isothiocyanate was optimum at pH 6 – 7. Meanwhile, the addition of both ferrous and ferric ions (0 – 10 mM) favors the formation of benzyl nitrile. Conveniently, adding an iron-chelating agent, EDTA, has shown an increasing trend in the formation of benzyl isothiocyanate. A small amount of ascorbic acid enhanced the formation of benzyl isothiocyanate, however, higher concentration inhibits its production. Overall, this work has shown that to ensure an optimum uptake of this beneficial compound from papaya leaf, unripe fruit or flower consumption, food preparation practices have to be favoring the formation of benzyl isothiocyanate. |
| first_indexed | 2025-03-05T01:34:36Z |
| format | Thesis |
| id | ums.eprints-42323 |
| institution | Universiti Malaysia Sabah |
| language | English English |
| last_indexed | 2025-03-05T01:34:36Z |
| publishDate | 2012 |
| record_format | dspace |
| spelling | ums.eprints-423232024-12-18T07:27:38Z https://eprints.ums.edu.my/id/eprint/42323/ Effect of additives and food processing conditions on Benzyl glucosinolate hydrolysis products in Carica papaya Gayathri Nagappan QK710-899 Plant physiology Glucosinolate are sulphur-containing secondary metabolites found largely in Brassicaceae family. Glucosinolate undergoes hydrolysis readily upon cell rupture, such as cutting and cooking, by the naturally-occurring enzyme myrosinase to form mainly isothiocyanates and/or simple nitriles. Isothiocyanates are known to possess anticarcinogenic properties while nitriles are largely inactive. Benzyl isothiocyanate, a hydrolysis product of benzyl glucosinolate, is one of the most potent anticancer agents. However, formation of benzyl isothiocyanate is depending upon reaction conditions where benzyl nitrile is formed at the expense of benzyl isothiocyanate. Thus, the potential health benefits of benzyl isothiocyanate may be surpassed by the ineffective benzyl nitrile. In this study, the factors influencing the formation of benzyl isothiocyanate were investigated to understand further the benzyl glucosinolate hydrolysis pathway in different parts of papaya (Carica papaya). The results showed that the concentration (dry weight), of benzyl isothiocyanate was found greater in papaya leaf with 349 μM followed by 24 μM in unripe fruit and 12 μM in flower. The highest amount of benzyl isothiocyanate produced was observed at room temperature (25oC) where it decreases gradually as the temperature increases up to 80oC. Comparing three common domestic methods of cooking vegetable i.e. blanching, boiling and slow heating, the results show that the high temperature treatment produced mainly benzyl nitrile; while slow heating up to 40oC produced more benzyl isothiocyanate. Both hydrolysis products were found largely leached into the cooking liquid (soup). The production of benzyl isothiocyanate was optimum at pH 6 – 7. Meanwhile, the addition of both ferrous and ferric ions (0 – 10 mM) favors the formation of benzyl nitrile. Conveniently, adding an iron-chelating agent, EDTA, has shown an increasing trend in the formation of benzyl isothiocyanate. A small amount of ascorbic acid enhanced the formation of benzyl isothiocyanate, however, higher concentration inhibits its production. Overall, this work has shown that to ensure an optimum uptake of this beneficial compound from papaya leaf, unripe fruit or flower consumption, food preparation practices have to be favoring the formation of benzyl isothiocyanate. 2012 Thesis NonPeerReviewed text en https://eprints.ums.edu.my/id/eprint/42323/1/24%20PAGES.pdf text en https://eprints.ums.edu.my/id/eprint/42323/2/FULLTEXT.pdf Gayathri Nagappan (2012) Effect of additives and food processing conditions on Benzyl glucosinolate hydrolysis products in Carica papaya. Masters thesis, Universiti Malaysia Sabah. |
| spellingShingle | QK710-899 Plant physiology Gayathri Nagappan Effect of additives and food processing conditions on Benzyl glucosinolate hydrolysis products in Carica papaya |
| title | Effect of additives and food processing conditions on Benzyl glucosinolate hydrolysis products in Carica papaya |
| title_full | Effect of additives and food processing conditions on Benzyl glucosinolate hydrolysis products in Carica papaya |
| title_fullStr | Effect of additives and food processing conditions on Benzyl glucosinolate hydrolysis products in Carica papaya |
| title_full_unstemmed | Effect of additives and food processing conditions on Benzyl glucosinolate hydrolysis products in Carica papaya |
| title_short | Effect of additives and food processing conditions on Benzyl glucosinolate hydrolysis products in Carica papaya |
| title_sort | effect of additives and food processing conditions on benzyl glucosinolate hydrolysis products in carica papaya |
| topic | QK710-899 Plant physiology |
| url | https://eprints.ums.edu.my/id/eprint/42323/1/24%20PAGES.pdf https://eprints.ums.edu.my/id/eprint/42323/2/FULLTEXT.pdf |
| work_keys_str_mv | AT gayathrinagappan effectofadditivesandfoodprocessingconditionsonbenzylglucosinolatehydrolysisproductsincaricapapaya |