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Development of natural dye based biodegradable colourimetric intelligent packaging sensor labels
Dissertation (MSc (Applied Sciences Chemical Technology))--University of Pretoria, 2021.
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2021
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| _version_ | 1867613706640162816 |
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| access_status_str | Open Access |
| author2 | Manyala, Ncholu I. |
| author_browse | Manyala, Ncholu I. |
| author_facet | Manyala, Ncholu I. |
| collection | Thesis |
| dc_rights_str_mv | © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MSc (Applied Sciences Chemical Technology))--University of Pretoria, 2021. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/81175 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:40:24.731Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2021 |
| publishDateRange | 2021 |
| publishDateSort | 2021 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/81175 Development of natural dye based biodegradable colourimetric intelligent packaging sensor labels Manyala, Ncholu I. u14442907@tuks.co.za Pillai, Sreejarani Dlamini, Khulekani UCTD Chemical technology Colourimetric indicators Anthocyanins Storage stability TVBN Poultry Carbon dioxide Green pepper In-package Engineering, built environment and information technology theses SDG-02 Engineering, built environment and information technology theses SDG-03 Engineering, built environment and information technology theses SDG-09 Engineering, built environment and information technology theses SDG-12 Engineering, built environment and information technology theses SDG-13 Dissertation (MSc (Applied Sciences Chemical Technology))--University of Pretoria, 2021. Colourimetric indicators were prepared using anthocyanins, poly(vinyl alcohol) and cellulose nano-fibre by the electro-spinning technique. The indicator label containing 2000 ppm anthocyanin was found to be the optimal dye concentration. Fourier-transform infrared spectroscopy and X-ray diffraction results confirmed that the anthocyanin was incorporated into the poly(vinyl alcohol)-cellulose nano-fibre. The anthocyanin solution displayed pH dependent colour changes with solutions below pH 4 appearing rose red; at pH 5 and beyond it turns pink at pH 6 and eventually turns violet at pH 8. Blue-green was observed at pH 10. At highly alkaline pH 14 it turns yellow. Similar results were obtained when the anthocyanin containing indicator label was exposed to solutions of pH’s in the range 1 – 10 with the indicator label colour changing from red to green respectively. The indicator label was subjected to storage stability tests over 40 days by storing under nitrogen atmosphere, refrigeration conditions and at room temperature. The indicator label exhibited a high degree of colour stability with colour change (ΔE<4) under all conditions. The indicator label also showed significant colour changes from blue to violet to purple and ultimately pink when it was placed within the package of fresh cut green pepper for 7 days ambient conditions. These colour changes are a direct consequence of the increased carbon dioxide concentrations in the package resulting from deterioration of pepper at room temperature. Colour changes resulting from accumulating Total volatile basic nitrogen (TVBN) were also observed when the indicator label was placed in the headspace of packaged fresh chicken with the label changing from light pink to grey from day 1 to day 7 at room temperature storage. The results show that the label has great potential to be used as a visual in-package indicator of poultry products. Poultry and green peppers are food products with a potential for in-package quality detection by this indicator label. The results of the current work offer a new possibility to the applicability of water soluble, biodegradable indicators as real time quality detectors of bell pepper/chicken meat; it can be used alongside the best before date. Further work ought to be conducted to evaluate the effectiveness of this in-package freshness indicator label for fresh-cut pepper/chicken meat at different temperature conditions. Application of this freshness indicator for other fresh-cut fruit and vegetables also need to be further investigated Keywords: Colourimetric indicators, anthocyanins, storage stability, TVBN, poultry, carbon dioxide, green pepper, in-package CSIR mi2026 Chemical Engineering MSc (Applied Sciences Chemical Technology) Restricted SDG-02: Zero hunger SDG-03: Good health and well-being SDG-09: Industry, innovation and infrastructure SDG-12: Responsible consumption and production SDG-13: Climate action 2021-08-05T13:43:54Z 2021-08-05T13:43:54Z 2021 2021 Dissertation * S2021 http://hdl.handle.net/2263/81175 en © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | UCTD Chemical technology Colourimetric indicators Anthocyanins Storage stability TVBN Poultry Carbon dioxide Green pepper In-package Engineering, built environment and information technology theses SDG-02 Engineering, built environment and information technology theses SDG-03 Engineering, built environment and information technology theses SDG-09 Engineering, built environment and information technology theses SDG-12 Engineering, built environment and information technology theses SDG-13 Development of natural dye based biodegradable colourimetric intelligent packaging sensor labels |
| title | Development of natural dye based biodegradable colourimetric intelligent packaging sensor labels |
| title_full | Development of natural dye based biodegradable colourimetric intelligent packaging sensor labels |
| title_fullStr | Development of natural dye based biodegradable colourimetric intelligent packaging sensor labels |
| title_full_unstemmed | Development of natural dye based biodegradable colourimetric intelligent packaging sensor labels |
| title_short | Development of natural dye based biodegradable colourimetric intelligent packaging sensor labels |
| title_sort | development of natural dye based biodegradable colourimetric intelligent packaging sensor labels |
| topic | UCTD Chemical technology Colourimetric indicators Anthocyanins Storage stability TVBN Poultry Carbon dioxide Green pepper In-package Engineering, built environment and information technology theses SDG-02 Engineering, built environment and information technology theses SDG-03 Engineering, built environment and information technology theses SDG-09 Engineering, built environment and information technology theses SDG-12 Engineering, built environment and information technology theses SDG-13 |
| url | http://hdl.handle.net/2263/81175 |