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Investigation into the assimilation of free amino nitrogen from bread waste during yeast proliferation
Thesis (MSc)--Stellenbosch University, 2023.
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| Format: | Thesis |
| Language: | en_ZA en_ZA |
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Stellenbosch : Stellenbosch University
2023
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| _version_ | 1867614136828952576 |
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| access_status_str | Open Access |
| author | Botha, Dewald Du Plessis |
| author2 | Hayward, Stefan |
| author_browse | Botha, Dewald Du Plessis Hayward, Stefan |
| author_facet | Hayward, Stefan Botha, Dewald Du Plessis |
| author_sort | Botha, Dewald Du Plessis |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MSc)--Stellenbosch University, 2023. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/128978 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA en_ZA |
| last_indexed | 2026-06-10T12:47:15.075Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2023 |
| publishDateRange | 2023 |
| publishDateSort | 2023 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/128978 Investigation into the assimilation of free amino nitrogen from bread waste during yeast proliferation Botha, Dewald Du Plessis Hayward, Stefan Strauss, Erick Tait, Timo Stellenbosch University. Faculty of Science. Dept. of Biochemistry. Bread -- Nutrition Amino acids Amino compounds -- Analysis Yeast -- Nutritional aspects Fermentation Amino nitrogen Yeast -- Metabolism Food waste -- Environmental aspects UCTD Thesis (MSc)--Stellenbosch University, 2023. ENGLISH ABSTRACT: Bread is a staple food in many economies. It is nutrient rich, cheap, and modern bakeries provide it in excess to be able to meet supply within stringent quality control parameters. Overproduction and consumer underutilisation, however, often result in accumulated bread going to waste if suitable valorisation methods are not available. Yet, unused bread is often returned to production facilities unaltered and may easily be processed to a dried commodity with a stable shelf life. Dried bread crumb is especially applicable to the agricultural industry as a feed additive, but it is also attractive in the biotechnology sector to sustain microbial growth for industrial and pharmaceutical applications. Ethanol is an attractive end-product due to its applicability in various industries, whether related to food and beverages, chemicals, or pharmaceutical sectors. This study therefore aims to establish a process to liberate sugars and free amino compounds from bread waste, relevant to alcoholic fermentation in yeast. Dried bread waste was processed enzymatically to hydrolyse polysaccharides to fermentable sugars and, following fermentation and distillation, alcohol yields of 10% alcohol by volume (ABV) was achieved. Moreover, high performance liquid chromatography coupled to UV/Vis detection was used to establish an analytical method for the quantification amino acids. Analysis of these nitrogen containing compounds revealed that a substantial amount of protein and essential amino acids are left following distillation to support a secondary fermentation. After proteolytic digestion of the dried wash, a nutrient rich mixture was obtained that promoted and supported the growth of yeast in the presence of a suitable carbohydrate source such as sucrose. This nutrient source was shown to be comparable to conventional commercial alternatives. Although the crude yeast nutrient resulted in slower exponential phase it ultimately proved to be superior in sustaining greater yeast biomass. This thesis describes the successful generation of a yeast nutrient from a bread waste product which was obtained after valorisation of bread waste in a bioethanol production process, thus creating a solution to bread waste that may with further development be waste free. AFRIKAANSE OPSOMMING: Brood word geklassifiseer as 'n stapelvoedsel in baie ekonomieë. Dit is ryk aan voedingstowwe, dit is goedkoop, en in moderne bakkerye word dit in oormaat vervaardig om, binne kwaliteitsbeheer- parameters, aan die vraag na aanbod te kan voldoen. Oorproduksie en onderbenutting van brood lei egter dikwels tot ‘n produk wat tot niet gaan omdat geskikte metodes vir die hergebruik daarvan ontbreek. Tog word onverbruikte brood dikwels onveranderd na produksiefasiliteite teruggestuur. Op die stadium kan dit egter steeds maklik verwerk word tot 'n gedroogde kommoditeit wat 'n stabiele raklewe het. Gedroogde broodkrummels kan veral in die landboubedryf gebruik word as 'n voerbymiddel. Dit kan egter ook in die biotegnologiesektor aangewend word om die groei van mikrobes te ondersteun vir industriële en farmaseutiese toepassings. Etanol afkomstig van gisfermentasie is 'n aantreklike eindproduk omdat dit gebruik kan word in verskeie industrieë, soos voedsel en drank, chemikalieë of farmaseutiese sektore. Hierdie studie beskryf dus 'n proses om die suikers en vrye amino-stikstof vanuit brood afval vry te stel wat gevolglik deur gis tydens alkoholiese fermentasie gebruik kan word. Gedroogde broodafval is ensiematies behandel om polisakkariede tot fermenteerbare suikers te hidroliseer. Na fermentasie en distillasie is ‘n alkoholopbrengs van 10% alkohol per volume (ABV) behaal. ‘n Analitiese hoëdrukvloeistofchromatografie metode is ontwikkel vir die kwantifisering van aminosure – ontleding van stikstofbevattende verbindings met hierdie metode het aangedui dat 'n aansienlike hoeveelheid proteïene en essensiële aminosure oorbly na distillasie wat sekondêre fermentasie kan ondersteun. 'n Voedingsryke mengsel is dus verkry deur die gedroogde broodoorblyfsels na distilasie proteolities te verteer en verder te verwerk tot ‘n droë poeier. Hierdie poeier kan die groei van gis in die teenwoordigheid van 'n geskikte koolhidraatbron soos sukrose bevorder en ondersteun wat vergelykbaar is met ‘n kommersieël-beskikbare alternatief. Hierdie tesis beskryf die suksesvolle gebruik van afvalbrood om 'n gisvoedingstof te vervaardig vanuit 'n afvalproduk wat afkomstig is van ‘n bio-etanolproduksieproses. Met gevolg is 'n oplossing gevind vir die verwerking van broodafval wat met verdere ontwikkeling self afvalvry kan wees. Masters 2023-12-01T10:45:32Z 2024-01-08T17:57:54Z 2023-12-01T10:45:32Z 2024-01-08T17:57:54Z 2023-12 Thesis https://scholar.sun.ac.za/handle/10019.1/128978 en_ZA en_ZA Stellenbosch University xvii, 102 pages : illustrations (some color) application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Bread -- Nutrition Amino acids Amino compounds -- Analysis Yeast -- Nutritional aspects Fermentation Amino nitrogen Yeast -- Metabolism Food waste -- Environmental aspects UCTD Botha, Dewald Du Plessis Investigation into the assimilation of free amino nitrogen from bread waste during yeast proliferation |
| title | Investigation into the assimilation of free amino nitrogen from bread waste during yeast proliferation |
| title_full | Investigation into the assimilation of free amino nitrogen from bread waste during yeast proliferation |
| title_fullStr | Investigation into the assimilation of free amino nitrogen from bread waste during yeast proliferation |
| title_full_unstemmed | Investigation into the assimilation of free amino nitrogen from bread waste during yeast proliferation |
| title_short | Investigation into the assimilation of free amino nitrogen from bread waste during yeast proliferation |
| title_sort | investigation into the assimilation of free amino nitrogen from bread waste during yeast proliferation |
| topic | Bread -- Nutrition Amino acids Amino compounds -- Analysis Yeast -- Nutritional aspects Fermentation Amino nitrogen Yeast -- Metabolism Food waste -- Environmental aspects UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/128978 |
| work_keys_str_mv | AT bothadewaldduplessis investigationintotheassimilationoffreeaminonitrogenfrombreadwasteduringyeastproliferation |