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Development of value-added dried pomegranate arils and juice powder: Effects of cultivar, harvest maturity and storage duration of whole fruit
Thesis (PhDAgric)--Stellenbosch University, 2020.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : Stellenbosch University
2020
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| _version_ | 1867613902623211520 |
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| access_status_str | Open Access |
| author | Adetoro, Adegoke Olusesan |
| author2 | Fawole, Olaniyi |
| author_browse | Adetoro, Adegoke Olusesan Fawole, Olaniyi |
| author_facet | Fawole, Olaniyi Adetoro, Adegoke Olusesan |
| author_sort | Adetoro, Adegoke Olusesan |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhDAgric)--Stellenbosch University, 2020. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/109409 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:43:31.605Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2020 |
| publishDateRange | 2020 |
| publishDateSort | 2020 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/109409 Development of value-added dried pomegranate arils and juice powder: Effects of cultivar, harvest maturity and storage duration of whole fruit Adetoro, Adegoke Olusesan Fawole, Olaniyi Opara, Umezuruike Linus Manley, Marena Caleb, Oluwafemi Stellenbosch University. Faculty of AgriSciences. Dept. of Horticulture. Pomegranate -- Growth -- South Africa Pomegranate arils -- Quality Pomegranate -- Storage Pomegranate -- Preservation Pomegranate -- Seeds -- Postharvest technology UCTD Thesis (PhDAgric)--Stellenbosch University, 2020. ENGLISH ABSTRACT: In South Africa, the increasing rate of pomegranate fruit production, processing and research has witnessed tremendous growth due to consumer interest in its high concentration of bioactive compounds. However, the edible part of the fruit (arils) has a short shelf-life of five to seven days. Agro-processing through drying reduces postharvest losses, improves the shelf-life and increases the storability of the product. Before drying, several pre-treatments, are carried out to preserve the quality attributes of the product, however, little is known about the effects of blanch-assisted drying of pomegranate arils and the prospects of developing high quality pomegranate juice powder (PJP) for formulation and/or fortification to promote product diversification within the agro-processing industry. Therefore, the overall aim of this study was to develop value-added and shelf-stable dried products from pomegranate aril with potential for multiple applications and to provide science-based tools for processing and preservation of the nutritional components. This thesis is divided into seven papers that is organised into four themes. Theme A comprised of the general introduction and comprehensive literature review. Theme B (Papers 1, 2 and 3) investigated dried arils of three pomegranate cultivars (Acco, Herskawitz and Wonderful) for optimum quality attributes. Paper 1 shows that ‘Wonderful’ had 8.1% and 22.4% higher total soluble solids (TSS) than ‘Herskawitz’ and ‘Acco’, respectively. In Paper 2, dried arils of fruit at commercial and late harvest had significantly (p<0.05) higher TSS than at early harvest. Paper 3 studied the effects of cold storage of whole fruit (cv. Wonderful) harvested at commercial maturity. This paper showed that after 12 weeks of cold storage, arils dried in hot-air had better colour retention based on total colour difference, (TCD = 3.02 vs 23.6) and retained 46% higher TSS compared with freeze-dried arils. Theme C provided information on the process optimization of dried arils. In Paper 4, blanched samples of ‘Wonderful’ (7 h) ‘Acco’ (7 h) and ‘Herskawitz’ (8 h), had shorter drying times than unblanched samples (11, 15 and 20 h), respectively. The results from Paper 5 showed that blanching at 90°C, 30s and 100°C, 60s reduced enzyme activity by 76% and 68%, respectively, compared to unblanched samples; this also indicates less browning of blanched arils. Development of value-added juice powder with multiple applications in the food industry and extended shelf-life (Theme D, Paper 6), showed that juice powder made with maltodextrin appeared 44% redder (a*) than with gum arabic. Similarly, total anthocyanin retention was 54% higher in maltodextrin than waxy starch. In Paper 7, results showed that at the end of 12 weeks storage, PJP packed in aluminium foil laminated pouches (AFLP) had lower moisture content (6.1%) and water activity (0.54) than other packaging materials, indicating better storability of PJP packed in AFLP. In conclusion, the quality of dried arils from ‘Wonderful’ at commercial harvest maturity was retained better than other cultivars and harvest maturities. Also, blanching at 90°C, 30s retained the quality of dried arils and was thus recommended as a viable aril pre-treatment condition. Finally, maltodextrin produced PJP had better quality retention compared to gum arabic and waxy starch. AFRIKAANSE OPSOMMING: In Suid-Afrika het die toenemende tempo van die produksie, verwerking en navorsing van granaatvrugte geweldige gegroei as gevolg van die belangstelling van verbruikers in hierdie vrug se hoë konsentrasie van bioaktiewe verbindings. Die eetbare deel van die vrugte (pitte) het egter 'n kort rakleeftyd van vyf tot sewe dae. Agro-verwerking deur middel van droging verminder na- oes verliese, verleng die rakleeftyd, en verbeter die produk se bergbaarheid. Voor die droging van die pitte, is verskeie voorbehandelings uitgevoer om die kwaliteitseienskappe van die produk te behou. Die effek van blansjeer-gesteunde droging van granaatpitte is onbekend, net soos die vooruitsigte om hoë gehalte granaatsappoeier (GPS) te ontwikkel vir formulering- en/of fortifiseringsdoeleindes, om sodoende diversifikasie in die landbouverwerkingsbedryf te bevorder. Gevolglik was die oorwegende doel van hierdie studie om waardetoevoegende en rakstabiele gedroogde produkte van granaatpitte te ontwikkel, wat vir veelvoudige toepassings nuttig kan wees, en om wetenskaplike hulpmiddels te verskaf vir die verwerking en bewaring van die voedingskomponente. Hierdie proefskrif is verdeel in sewe hoofstukke wat vier temas vorm. Tema A bestaan uit die algemene inleiding en omvattende literatuuroorsig. Tema B (Hoofstukke 1, 2, en 3) ondersoek die gedroogde pitte van drie granaatkultivars (Acco, Herskawitz en Wonderful) vir optimale kwaliteitseienskappe. Hoofstuk 1 wys dat 'Wonderful' onderskeidelik 8,1% en 22,4% meer totaal oplosbare vaste stowwe (TOVS) as 'Herskawitz' en 'Acco' bevat. In Hoofstuk 2 het gedroogde granaatpitte wat op kommersiële en laat oes rypheid gepluk is, beduidend (p <0,05) hoër TOVS as vroeër geoesde granate getoon. Hoofstuk 3 bestudeer die effekte van koel berging op heel vrugte (kv. Wonderful) wat op kommersiële volwassenheid geoes is. Hierdie hoofstuk toon aan dat granaatpitte wat in warm lug gedroog is, na 12 weke van koel berging hul kleur beter behou ten opsigte van totale kleurverskil (TKV = 3.02 teenoor 23.6), en ook oor 46% meer TOVS beskik in vergelyking met gevriesdroogde pitte. Tema C verskaf inligting oor die prosesoptimalisering van gedroogde granaatpitte. Die droogtye in Hoofstuk 4 van geblansjeerde 'Wonderful' (7 h) 'Acco' (7 h) en 'Herskawitz' (8 h) monsters was onderskeidelik korter as ongeblansjeerde monsters (11, 15 en 20 h). Die resultate van Hoofstuk 5 het gewys dat blansjering by 90° C, 30s en 100° C, 60s ensiemaktiwiteit met onderskeidelik 76% en 68% verlaag het in vergelyking met ongeblansjeerde monsters; dit dui ook op minder verbruining van geblansjeerde pitte. onderskeidelik 76% en 68% verlaag het in vergelyking met ongeblansjeerde monsters; dit dui ook op minder verbruining van geblansjeerde pitte. Ontwikkeling van waardetoegevoegde sappoeier met verskeie toepassings in die voedselindustrie en 'n verlengde rakleeftyd (Tema D, Hoofstuk 6), dui aan dat sappoeier met maltodekstrien 44% rooier (a*) as dié met Arabiese gom vertoon. Net so was die totale retensie van antosianiene 54% hoër in sappoeier met maltodekstrien as wasagtige stysel. In Hoofstuk 7 het GSP verpak in aluminiumfoelie gelamineerde sakkies (AFLS) aan die einde van 12 weke se opberging 'n laer voginhoud (6.1%) en wateraktiwiteit (0.54) gehad as ander verpakkingsmateriale, wat beter stoorbaarheid van GSP in AFLS verpakking aandui. Ten slotte is die kwaliteit van gedroogde granaatpitte van 'Wonderful' op kommersiële oesrypheid beter behou as ander kultivars en oestye. Ook, tydens die blansjering by 90° C, het die gehalte van die gedroogde granaatpitte behoue gebly en word dit dus aanbeveel as 'n lewensvatbare voorbehandeling. Om af te sluit het maltodekstrien-geproduseerde GSP 'n beter gehalte retensie gehad in vergelyking met Arabiese gom en wasagtige stysel. Doctoral 2020-11-14T07:39:28Z 2021-02-01T07:54:04Z 2020-11-14T07:39:28Z 2021-02-01T07:54:04Z 2020-12 Thesis http://hdl.handle.net/10019.1/109409 en_ZA Stellenbosch University xiii, 213 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Pomegranate -- Growth -- South Africa Pomegranate arils -- Quality Pomegranate -- Storage Pomegranate -- Preservation Pomegranate -- Seeds -- Postharvest technology UCTD Adetoro, Adegoke Olusesan Development of value-added dried pomegranate arils and juice powder: Effects of cultivar, harvest maturity and storage duration of whole fruit |
| title | Development of value-added dried pomegranate arils and juice powder: Effects of cultivar, harvest maturity and storage duration of whole fruit |
| title_full | Development of value-added dried pomegranate arils and juice powder: Effects of cultivar, harvest maturity and storage duration of whole fruit |
| title_fullStr | Development of value-added dried pomegranate arils and juice powder: Effects of cultivar, harvest maturity and storage duration of whole fruit |
| title_full_unstemmed | Development of value-added dried pomegranate arils and juice powder: Effects of cultivar, harvest maturity and storage duration of whole fruit |
| title_short | Development of value-added dried pomegranate arils and juice powder: Effects of cultivar, harvest maturity and storage duration of whole fruit |
| title_sort | development of value added dried pomegranate arils and juice powder effects of cultivar harvest maturity and storage duration of whole fruit |
| topic | Pomegranate -- Growth -- South Africa Pomegranate arils -- Quality Pomegranate -- Storage Pomegranate -- Preservation Pomegranate -- Seeds -- Postharvest technology UCTD |
| url | http://hdl.handle.net/10019.1/109409 |
| work_keys_str_mv | AT adetoroadegokeolusesan developmentofvalueaddeddriedpomegranatearilsandjuicepowdereffectsofcultivarharvestmaturityandstoragedurationofwholefruit |