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Controlled atmosphere storage systems for long-term storage of ‘Granny Smith’ apple
Thesis (MScAgric)--Stellenbosch University, 2025.
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867614137383649280 |
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| access_status_str | Open Access |
| author | Mouton, Abraham Coenrad |
| author2 | Crouch, E. M. |
| author_browse | Crouch, E. M. Mouton, Abraham Coenrad |
| author_facet | Crouch, E. M. Mouton, Abraham Coenrad |
| author_sort | Mouton, Abraham Coenrad |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MScAgric)--Stellenbosch University, 2025. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/132254 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:47:15.645Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/132254 Controlled atmosphere storage systems for long-term storage of ‘Granny Smith’ apple Mouton, Abraham Coenrad Crouch, E. M. Jooste, M. M. Crouch, I. J. Botes, W. J. Stellenbosch University. Faculty of AgriSciences. Dept. of Horticultural Science. Apples -- Storage -- Quality control Protective atmospheres Apples -- Effect of temperature on Apples -- Effect of oxygen on Apples -- Postharvest technology Granny Smith apples -- Quality -- South Africa UCTD Thesis (MScAgric)--Stellenbosch University, 2025. Mouton, A. C. 2025. Controlled atmosphere storage systems for long-term storage of ‘Granny Smith’ apple. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/fbe24335-cf27-4cf2-963e-299139096057 ENGLISH ABSTRACT: In long-term pome fruit storage, new methodologies tend to push the limits of low O₂. Lowered O₂ benefits storage by supressing fruit respiration and C2H4 biosynthesis. Dynamic controlled atmosphere (DCA) methodologies allow storage near the anaerobic compensation point (ACP), enabling beneficial effects from low anaerobic metabolite concentrations, while supressing C2H4 biosynthesis and action. Considering the costly nature of storage infrastructure, it is critical to know how these methodologies compare in maintaining fruit quality and the suppression of disorders, such as superficial scald. This study assessed various low O₂ long-term storage methodologies, including DCA‑CF (≈ 0.4 - 0.6 kPa O₂, 0.5 or 1.5 kPa CO₂ season depending), DCA‑CF with C2H4 scrubbing, DCA‑RQ (0.4 kPa O₂ safety limit, 1 kPa CO₂) with RQ breakpoint of 2.0 (DCA‑RQ2.0), and a static CA system marketed as an extreme low oxygen system (XLO; 1.6 kPa O₂, 1 kPa CO₂ season 1 and 0.9 kPa O₂, 0.5 kPa CO₂ season 2) with C2H4 scrubbing. Whilst DCA treatments emphasise the lowering of O₂, XLO is a static system which employs higher O₂ concentrations but relies on C2H4 scrubbing to inhibit ripening. A seasonal control was stored at -0.5 °C in regular atmosphere (RA) for 16 weeks before shelf-life evaluations commenced, to confirm fruit’s susceptibility to ripening and physiological disorders such as superficial scald, as all treatments excluded the C2H4 inhibitor 1-methylcyclopropene (1-MCP). Fruit were stored for 9 months under the respective low O₂ treatments at -0.5 °C, before being packed. Given that shipping is done under RA conditions, ripening is no longer supressed by low O₂, making shipping simulations critical when comparing storage technologies. A 6-week shipping simulation at -0.5 °C and 10 days shelf-life at 20 °C, was included. Fruit from the RA seasonal control were highly susceptible to superficial scald. DCA treatments largely inhibited superficial scald, however, in the first season the occurrence of O₂ leakage hindered O₂ lowering in one RQ replicate. XLO-treated fruit developed excessive superficial scald after shelf-life. Lowering the XLO O₂ setpoint in the second season, gave more acceptable fruit quality, however fruit quality was inferior to DCA treatments. DCA‑RQ was limited by the default lowest O₂ safety limit of 0.4 kPa, preventing further reductions even when RQ readings indicated it was possible. Although the DCA‑CF with C2H4 scrubbing treatment had significant advantages above DCA‑CF alone after shelf-life in the second season, with respect to ground colour, the differences might not be of economic consequence. This study identified cumulative O₂ and 𝑡𝐴𝐵𝑂𝑉𝐸 0.7 k O₂ as standard units of measure for comparing treatments, irrespective whether they use static O₂ setpoints, or are dynamically regulated. These units explained the majority of variation in fruit quality and superficial scald, moreover the model showed stronger predictability over time. This study concludes that the cumulative O₂ experienced, and its minimization is more critical than the DCA storage system methodology and that, in 1-MCP free long-term storage there is an additional benefit to DCA type O₂ control above that of static CA. AFRIKAANSE OPSOMMING: In die langtermyn opberging van kernvrugte, neig nuwe metodieke om die limiete van lae O2-opberging te verskuif. Verlaagde O2 bring voordele ten opsigte van onderdrukking van vrugrespirasie en C2H4 biosintese. Dinamies beheerde atmosfeer (DBA) tegnieke laat opberging naby die anaërobiese kompensasiepunt (AKP) toe. Dit lei tot voordelige effekte weens lae konsentrasies van anaërobiese metaboliete wat naby die AKP ontwikkel, terwyl respirasie as ook die vervaardiging en werking van etileen onderdruk word. Gegewe die hoë kostes van stoorinfrastruktuur, is dit krities om te verstaan hoe die verskillende stoortegnieke vergelyk in die onderhouding van vrugkwaliteit en onderdrukking van fisiologiese defekte, soos oppervlakkige brandvlek. Hierdie studie het verskeie lae-O2 langtermyn opbergingsmetodieke vergelyk, insluitend DBA met chlorofilfluoressensie (DBA-CF) (≈ 0.4 - 0.6 kPa O2, 0.5 of 1.5 kPa CO2 afhangend van seisoen), DBA-CF met etileen skrobbing, DBA respirasie kwosiënt (RK) met ‘n RK-breekpunt van 2.0 (DBA-RK2.0) (0.4 kPa O2 lae suurstof limiet, 1 kPa CO2), en ‘n statiese beheerde atmosfeer (BA) wat bemark word as ekstreme lae suurstof (ELS; 1.6 kPa O2, 1 kPa CO2 seisoen 1 en 0.9 kPa O2, 0.5 kPa CO2 seisoen 2) met etileen skrobbing. Terwyl DBA- behandelings op die verlaging van O2 fokus, is ELS ‘n statiese stelsel wat hoër O2-konsentrasies gebruik en op etileenskrobbing staatmaak om vrug rypwording te inhibeer. ‘n Seisoenale kontrole is vir 16 weke onder gewone atmosfeer (GA) opgeberg, gevolg deur ‘n raklewe tydperk. Dit is gedoen om die vrugte se vatbaarheid vir rypwording en fisiologiese defekte soos oppervlakkige brandvlek te bepaal aangesien die vrugte nie met 1-metielsiklopropeen (1-MCP) behandel is nie. Vrugte is vir 9 maande onder die verkillende behandelings by -0.5 °C opgeberg, waarna dit verpak en vir 6 weke by -0.5 °C GA opgeberg is om verskeping te simuleer. Aangesien verskeping onder GA plaasvind, word rypwording nie meer deur lae O2 onderdruk nie, wat verskepings simulasies van kritieke belang maak wanneer stoormetodieke vergelyk word. Daarna is raklewe vir 10 dae by 20 °C gesimuleer. Die seisoenale kontrole het getoon dat die vrugte hoogs vatbaar vir oppervlakkige brandvlek was. Die DBA-behandelings het oppervlakkige brandvlek tot ‘n groot mate beheer. In die eerste seisoen het ‘n O2- lekkasie in een van die herhalings van die DBA-RK2.0 egter die verlaging van O2 verhinder. ELS-behandelde vrugte het oormatige oppervlakkige brandvlek en oorrypheid tydens raklewe ontwikkel. ‘n Verlaging van die ELS O2-stelpunt het meer aanvaarbare vrugkwaliteit gelewer in die tweede seisoen, maar was steeds minder effektief as die DBA-behandelings. Rakende die DBA-behandelings, was die DBA-RK-behandeling deur sy standaard laagste O2-veiligheidsgrens van 0.4 kPa beperk. Dit het verdere verlaging van O2-vlakke verhoed, selfs wanneer RK-vlakke aangedui het dat dit moontlik was. Alhoewel DBA-CF met etileenskrobbing statistiese voordele bo DBA-CF alleen getoon het na raklewe in die tweede seisoen, met betrekking tot agtergrondkleur, was die verskille moontlik nie van ekonomiese belang nie. Verder het die studie twee gestandaardiseerde potensiële maatstawwe geïdentifiseer om lae O2- behandelingste vergelyk, ongeag of statiese of dinamiese O2-stelpunte gebruik word - naamlik kumulatiewe O2 en ure bo 0.7 kPa O2. Hierdie maatstawwe het ‘n beduidende deel van die variasie in vrugkwaliteit verduidelik en het met elke agtereenvolgende evaluasie, na opberging, ‘n sterker voorspellingskrag getoon. Die gevolgtrekking van die studie is dat die kumulatiewe O2 wat ervaar word tydens opberging en die beperking daarvan van groter belang is as die DBA metodiek, en dat in die geval van langtermyn appel opberging, in die afwesigheid van 1-MCP behandeling, presteer DBA tipe suurstof regulasie beter as statiese BA. Masters 2025-05-30T14:21:19Z 2025-05-30T14:21:19Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/132254 en Stellenbosch University xv, 152 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Apples -- Storage -- Quality control Protective atmospheres Apples -- Effect of temperature on Apples -- Effect of oxygen on Apples -- Postharvest technology Granny Smith apples -- Quality -- South Africa UCTD Mouton, Abraham Coenrad Controlled atmosphere storage systems for long-term storage of ‘Granny Smith’ apple |
| title | Controlled atmosphere storage systems for long-term storage of ‘Granny Smith’ apple |
| title_full | Controlled atmosphere storage systems for long-term storage of ‘Granny Smith’ apple |
| title_fullStr | Controlled atmosphere storage systems for long-term storage of ‘Granny Smith’ apple |
| title_full_unstemmed | Controlled atmosphere storage systems for long-term storage of ‘Granny Smith’ apple |
| title_short | Controlled atmosphere storage systems for long-term storage of ‘Granny Smith’ apple |
| title_sort | controlled atmosphere storage systems for long term storage of granny smith apple |
| topic | Apples -- Storage -- Quality control Protective atmospheres Apples -- Effect of temperature on Apples -- Effect of oxygen on Apples -- Postharvest technology Granny Smith apples -- Quality -- South Africa UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/132254 |
| work_keys_str_mv | AT moutonabrahamcoenrad controlledatmospherestoragesystemsforlongtermstorageofgrannysmithapple |