Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Formulation and application of novel bioactive edible coatings to extend storage and shelf life of pomegranate whole fruit and arils
Thesis (PhDAgric)--Stellenbosch University, 2022.
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | en_ZA |
| Published: |
Stellenbosch : Stellenbosch University
2022
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613911302275072 |
|---|---|
| access_status_str | Open Access |
| author | Kawhena, Tatenda Gift |
| author2 | Opara, Umezuruike Linus |
| author_browse | Kawhena, Tatenda Gift Opara, Umezuruike Linus |
| author_facet | Opara, Umezuruike Linus Kawhena, Tatenda Gift |
| author_sort | Kawhena, Tatenda Gift |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhDAgric)--Stellenbosch University, 2022. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/126281 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:43:40.048Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2022 |
| publishDateRange | 2022 |
| publishDateSort | 2022 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/126281 Formulation and application of novel bioactive edible coatings to extend storage and shelf life of pomegranate whole fruit and arils Kawhena, Tatenda Gift Opara, Umezuruike Linus Fawole, Olaniyi Amos Tsige, Alemayehu Ambaw Stellenbosch University. Faculty of Agrisciences. Dept. of Horticulture. Pomegranate -- Growth Pomegranate -- Postharvest technology Pomegranate industry Pomegranate -- Economic aspects Edible coatings Bioactive compounds Fruit -- Postharvest losses -- Prevention UCTD Thesis (PhDAgric)--Stellenbosch University, 2022. ENGLISH ABSTRACT: The growth of the pomegranate (Punica granatum L.) fruit industry is limited by high postharvest losses along the supply chain caused by weight loss and incidence of physiological and pathological disorders. Although several postharvest technologies have been applied to reduce these losses, substantial losses still occur, causing negative financial impact on all pomegranate industry stakeholders. Therefore, the development and application of new science-based technologies to reduce postharvest losses in pomegranate fruit is a priority. The overall aim of this research study was to formulate bioactive edible coatings for pomegranate whole fruit and arils to extend storage and shelf life. In Section I, Paper 1 and Paper 2 highlighted the potential of edible coatings as a postharvest treatment for pomegranate fruit during cold storage and shelf life. Section II studies (Paper 3 and 4) applied gum Arabic and methyl cellulose coatings enriched with either thyme or lemongrass essential oils on pomegranate whole fruit and arils. Gum Arabic (1.5% w/v) coatings combined with thyme oil (0.25 or 0.5% w/v) significantly (p ≤ 0.05) reduced weight loss, microbial proliferation and maintained postharvest quality of arils for 8 days of storage (5 ⁰C and 95 ± 2% relative humidity). Similarly, gum Arabic (1.5% w/v) coating containing pomegranate peel extract (1% w/v) and lemongrass essential oil (0.1% v/v) significantly (p ≤ 0.05) reduced respiration rate and incidence of decay for 6 weeks of storage (5 ± 1 °C and 90% relative humidity). Section III (Paper 5 and 6) followed up on the results in Section II by optimizing selected coatings developed in Paper 3 and 4. In Paper 5, lemongrass essential oil was the best antifungal agent against tested microbes (Botrytis cinerea and Penicillium spp.) and the minimum inhibitory concentrations against Botrytis cinerea and Penicillium spp., were 1.5 (% v/v) and 3 (% v/v), respectively. Sodium alginate and chitosan-based coatings formulated with lemongrass essential oil (1.5 or 3% v/v) completely inhibited spore germination and reduced the decay severity of ‘Wonderful’ pomegranate during shelf life. In Paper 6, response surface methodology was used to develop an optimized coating containing gum Arabic (0.5% w/v), maize starch (0.5% w/v), lemongrass oil (3% v/v), and glycerol (1.5% v/v). In Section IV (Paper 7 and 8), the optimized coating developed in Section III was applied on whole ‘Wonderful’ pomegranate fruit and the moisture loss characteristics (Paper 7) and the effects when combined with different polyliners (Paper 8) were investigated. The optimized coating significantly (p ≤ 0.05) reduced weight loss by minimizing the rate of increase in transpiration rate. In Paper 8, the combination of coatings with Xtend® polyliners was the most effective treatment to maintain the quality of ‘Wonderful’ pomegranates during storage (5 ± 1 °C and 95 ± 2% relative humidity). Overall, this research showed that edible coatings minimized postharvest losses in pomegranate whole fruit and arils. The study provides important scientific information to assist prospective studies to develop edible coatings for other fruit types for future application at packhouse level and other food industries. AFRIKAANSE OPSOMMING: Die groei van die granaat (Punica granatum L.) vrugtebedryf word beperk deur hoë na- oes verliese tydens die voorsieningsketting wat veroorsaak word deur gewigsverlies en die voorkoms van fisiologiese en patologiese afwykings. Alhoewel verskeie na-oes tegnologieë toegepas word om hierdie verliese te verminder, vind aansienlike verliese steeds plaas, wat ‘n negatiewe finansiële impak op alle industrie-rolspelers in die granaatbedryf veroorsaak. Daarom is die ontwikkeling en toepassing van nuwe wetenskap-gebaseerde tegnologieë om na- oes verliese in granaatvrugte te verminder, 'n prioriteit. Die oorkoepelende doel van hierdie navorsingstudie was om bioaktiewe eetbare bedekkings vir granaatheel vrugte en granaat korrels te formuleer om berging en raklewe te verleng. Afdeling I in Hoofstuk 1 en Hoofstuk 2 het die potensiaal van eetbare bedekkings uitgelig as 'n na-oesbehandeling vir granaatvrugte tydens koelberging en raklewe. Afdeling II- studies (Hoofstuk 3 en 4) het Arabiese gom- en metielsellulose-bedekkings, verryk met óf tiemie- óf sitroengras-essensiële olies, op granaat-heelvrugte en granaat korrels toegepas. Arabiese gom (1.5% w/v) bedekkings gekombineer met tiemieolie (0.25 of 0.5% w/v) het aansienlik (p ≤ 0.05) gewigsverlies, en mikrobiese proliferasie verminder en na-oes kwaliteit van granaat korrels gehandhaaf vir 8 dae van berging (5 ⁰C en 95 ± 2% relatiewe humiditeit). Net so het Arabiese gom (1.5% w/v)-bedekking wat granaatskil-ekstrak (1% w/v) en sitroengras-essensiële olie (0.1% v/v) bevat, die respirasietempo en die voorkoms van verval vir 6 weke opberging (5 ± 1 °C en 90% relatiewe humiditeit)aansienlik verminder (p ≤ 0.05). Afdeling III (Hoofstuk 5 en 6) het die resultate in Afdeling II opgevolg deur geselekteerde bedekkings wat in Hoofstuk 3 en 4 ontwikkel is te optimaliseer. In Hoofstuk 5 was sitroengras-essensiële olie die beste antifungale middel teen getoetste mikrobes (Botrytis cinerea en Penicillium spp.) en die minimum inhiberende konsentrasies teen B. cinerea en Penicillium spp., was onderskeidelik 1.5 (% v/v) en 3 (% v/v). Natriumalginaat- en chitosan- gebaseerde bedekkings wat met sitroengras-essensiële olie (1,5 of 3% v/v) geformuleer is, het spoorontkieming heeltemal geïnhibeer en die graad van verval van die ‘Wonderful’ granaat gedurende rakleeftyd verminder. In Hoofstuk 6 is reaksie-oppervlakmetodologie gebruik om 'n geoptimaliseerde deklaag te ontwikkel wat Arabiese gom (0.5% w/v), mieliestysel (0.5% w/v), sitroengrasolie (3% v/v) en gliserol (1.5%) bevat v/v). In Afdeling IV (Hoofstuk 7 en 8), is die geoptimaliseerde deklaag wat in Afdeling III ontwikkel is, op heel ‘Wonderful’ granaatvrugte toegedien en die vogverlieseienskappe (Hoofstuk 7) en die effekte wanneer gekombineer met verskillende polivoerings (Hoofstuk 8), is ondersoek. Die geoptimaliseerde laag het aansienlik (p ≤ 0.05) gewigsverlies verminder deur die tempo van toename in transpirasietempo te minimaliseer. In Hoofstuk 8 was die kombinasie van bedekkings met Xtend® polivoerings die doeltreffendste behandeling om die kwaliteit van 'Wonderful' granate tydens berging te handhaaf (5 ± 1 °C en 95 ± 2% relatiewe humiditeit). Oor die algemeen het hierdie navorsing getoon dat eetbare bedekkings na-oes verliese in heel granaat vrugte en granaat korrels verminder het. Die studie verskaf belangrike wetenskaplike inligting om voornemende studies te help om eetbare bedekkings vir ander vrugtetipes te ontwikkel vir toekomstige toediening op pakhuisvlak en ander voedselindustrieë. Doctorate 2022-10-10T07:15:54Z 2023-01-23T06:50:13Z 2022-10-10T07:15:54Z 2022-12 Thesis http://hdl.handle.net/10019.1/126281 en_ZA Stellenbosch University x, 356 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Pomegranate -- Growth Pomegranate -- Postharvest technology Pomegranate industry Pomegranate -- Economic aspects Edible coatings Bioactive compounds Fruit -- Postharvest losses -- Prevention UCTD Kawhena, Tatenda Gift Formulation and application of novel bioactive edible coatings to extend storage and shelf life of pomegranate whole fruit and arils |
| title | Formulation and application of novel bioactive edible coatings to extend storage and shelf life of pomegranate whole fruit and arils |
| title_full | Formulation and application of novel bioactive edible coatings to extend storage and shelf life of pomegranate whole fruit and arils |
| title_fullStr | Formulation and application of novel bioactive edible coatings to extend storage and shelf life of pomegranate whole fruit and arils |
| title_full_unstemmed | Formulation and application of novel bioactive edible coatings to extend storage and shelf life of pomegranate whole fruit and arils |
| title_short | Formulation and application of novel bioactive edible coatings to extend storage and shelf life of pomegranate whole fruit and arils |
| title_sort | formulation and application of novel bioactive edible coatings to extend storage and shelf life of pomegranate whole fruit and arils |
| topic | Pomegranate -- Growth Pomegranate -- Postharvest technology Pomegranate industry Pomegranate -- Economic aspects Edible coatings Bioactive compounds Fruit -- Postharvest losses -- Prevention UCTD |
| url | http://hdl.handle.net/10019.1/126281 |
| work_keys_str_mv | AT kawhenatatendagift formulationandapplicationofnovelbioactiveediblecoatingstoextendstorageandshelflifeofpomegranatewholefruitandarils |