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Variation in barley quality and its impact on malting and brewing
Thesis (PhDFoodSc)--Stellenbosch University, 2025.
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867613748596834304 |
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| access_status_str | Open Access |
| author | Fox, Glen Patrick |
| author2 | Manley, Marena |
| author_browse | Fox, Glen Patrick Manley, Marena |
| author_facet | Manley, Marena Fox, Glen Patrick |
| author_sort | Fox, Glen Patrick |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhDFoodSc)--Stellenbosch University, 2025. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/132370 |
| institution | Stellenbosch University (South Africa) |
| last_indexed | 2026-06-10T12:41:04.390Z |
| 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:10019.1/132370 Variation in barley quality and its impact on malting and brewing Fox, Glen Patrick Manley, Marena Stellenbosch University. Faculty of AgriSciences. Dept. of Food Science. Barley -- Quality Malt -- Composition Wort Brewing industry -- Technological innovations Enzymes -- Mechanism of action Brewing Proteins -- Measurement UCTD Thesis (PhDFoodSc)--Stellenbosch University, 2025. Fox, G. P. 2025. Variation in barley quality and its impact on malting and brewing. Unpublished doctoral dissertation. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/0d2949a4-94ae-4ffc-a735-36f29ad823e7 ENGLISH ABSTRACT: Barley has been used for thousands of years in malting and brewing. While other grains are used due to local production benefits, or the requirement for gluten-free beer, barley has been the benchmark for grain quality needed in malting and brewing. Complex grain traits like grain size, protein content and composition, starch content and structure are controlled by multiple genes, as well as the growing environment. Hence, multiple trials over several years are required to assess the potential malting and brewing quality of breeding lines. Conversely, enzymes like beta-amylase are controlled by single genes. The malting and brewing industry has provided well-defined quality determination methods over several decades. Breeding programs use some of these in assessing malt and wort quality. However, some methods were developed long ago but may now be redundant. For example, the main method to measure malt quality, i.e. malt extract, is based on an old style of mashing called decoction. This multistep process entails boiling of part of the mash which are then added back to the full mash resulting in a jumped increase in temperature. This allows some enzymes to keep hydrolyzing specific substrates and helps poor to average modified malts. It can make these malts appear to have better quality. The single step hot temperature mash at 65oC show the best potential of all malts and is more relevant for the majority of commercial breweries. For success in breeding and grading commercial barley where thousands of samples are tested, a high throughput method, i.e. near-infrared spectroscopy has been used successfully. This technology was first developed for protein and moisture content of grains, but it can also be used for liquid samples, and many additional traits in grain and malt such as starch, beta-glucan or malt extract. In liquid samples, wort quality such as extract, fermentable sugars or free amino nitrogen are key quality traits that should ideally be measured routinely in breeding programs. Breeding programs would benefit from using an NIR instrument that could scan solid and liquid samples for the high throughput of grain, malt and wort. For the latter, understanding the fermentable sugar profile, wort beta-glucan content and total free amino nitrogen content in wort would be more informative of enzyme action in malting and mashing. To gain a deeper understanding of the environmental effect on grain quality, proteomics can be used to comprehend the metabolic pathways during grain-filling and how it influences final grain quality. Proteomics can also be used during malting to assess the expression of enzymes and changes in the substrates proteases act on. This area has significant potential to allow breeders and the malting industry to improve protein modification by selecting breeding lines and varieties that can hydrate faster to a desired level of modification. Over the last three decades of research, our understanding of genetic and environmental control of more complex traits for grain and malt quality has improved due to using various new methodologies. High throughput technologies for rapid screening thousands of samples, and new ‘omics methods provided data on thousands of proteins and metabolites gave insights into the complex nature of grain, malt and beer chemistry. With this large amount of data and information available, the malting and brewing industry now has greater opportunities to deal with changing climates and improving processing due to the unknowns in standard grain and malt analysis. AFRIKAANSE OPSOMMING: Gars word al vir duisende jare in mout en brou gebruik. Hoewel ander graansoorte soms gebruik word as gevolg van plaaslike produksievoordele of die behoefte aan glutenvrye bier, bly gars steeds die maatstaf vir graankwaliteit wat nodig is vir mout en brou. Kompleksse graankenmerke soos korrelgrootte, proteïeninhoud en -samestelling, asook styselinhoud en -struktuur, word deur veelvuldige gene en groeitoestande beheer. Gevolglik is proewe oor jare nodig om die mout- en broukwaliteit van teellyne te bepaal. Daarteenoor word ensieme soos beta-amilase deur enkele gene beheer. Die mout- en broubedryf het oor dekades goed gedefinieerde kwaliteitmetodes ontwikkel wat deur teelprogramme gebruik word. Sommige van die metodes is egter lank gelede ontwikkel en kan dalk nou uitgedien wees. Byvoorbeeld, die hoofmetode om moutkwaliteit te meet, naamlik moutekstrak, is gebaseer op 'n ou styl van maisering genaamd dekoksie. Hierdie multi-stap proses behels die kook van 'n deel van die mas, wat dan weer by die volle mas gevoeg word, wat 'n skielike temperatuurstyging veroorsaak. Dit laat sekere ensieme toe om spesifieke substrate verder af te breek en help swak tot gemiddeld gemodifiseerde moute. Dit kan maak dat hierdie moute beter kwaliteit blyk te hê as wat werklik die geval is. Die enkelstap warm temperatuurmas teen 65°C wys die ware potensiaal van alle moute en is meer relevant vir die meeste kommersiële brouerye. Vir sukses in die teel- en kommersiële graanbeoordeling, waar duisende monsters getoets word, is 'n hoë-deurset metode soos naby-infrarooi (NIR) spektroskopie suksesvol gebruik. Hierdie tegnologie is aanvanklik ontwikkel om proteïen- en voginhoud van graan te meet, maar dit kan ook gebruik word vir vloeistofmonsters, en vir bykomende eienskappe in graan en mout soos stysel, beta-glukaan of moutekstrak. In vloeistofmonsters kan wortkwaliteit soos ekstrak, fermenteerbare suikers of vrye amino-stikstof belangrike kwaliteitskenmerke wees wat ideaal gesproke roetinegewys in teelprogramme gemeet moet word. Teelprogramme sal baat vind by die gebruik van 'n NIR-instrument wat soliede en vloeibare monsters kan skandeer, vir die hoë-deurset analise van graan, mout en wort. Vir wortkwaliteit spesifiek sal insigte in die fermenteerbare suikerprofiel, wort-beta-glukaan inhoud en totale vrye amino-stikstofinhoud meer inligting verskaf oor die ensiemaktiwiteit tydens mout en maisering. Om die omgewing se invloed op graankwaliteit beter te verstaan, kan proteomika gebruik word om die metaboliese prosesse tydens graanvulling te begryp en hoe dit graankwaliteit beïnvloed. Proteomika kan ook tydens vermouting gebruik word om die uitdrukking van ensieme en veranderinge in die substrate waarop proteases inwerk, te bepaal. Hierdie veld het potensiaal om telers en die moutbedryf te help om proteïenmodifikasie te verbeter deur teellyne en variëteite te kies wat vinniger hidreer tot die verlangde vlak van modifikasie. Die afgelope drie dekades het ons begrip van die genetiese en omgewingsbeheer van kompleksse eienskappe vir graan- en moutkwaliteit verbeter, danksy die gebruik van nuwe metodologieë. Hoë-deurset tegnologieë vir die vinnige sifting van duisende monsters, en nuwe 'omika-metodes’, het insigte gegee in die komplekse aard van graan-, mout- en bierchemie. Die mout- en broubedryf het nou groter geleenthede om veranderende klimaatstoestande en verbeterde verwerking aan te pak, asook om die onsekerhede in standaard graan- en moutontledings te oorkom. Doctoral 2025-06-05T07:52:39Z 2025-06-05T07:52:39Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/132370 Stellenbosch University 325 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Barley -- Quality Malt -- Composition Wort Brewing industry -- Technological innovations Enzymes -- Mechanism of action Brewing Proteins -- Measurement UCTD Fox, Glen Patrick Variation in barley quality and its impact on malting and brewing |
| title | Variation in barley quality and its impact on malting and brewing |
| title_full | Variation in barley quality and its impact on malting and brewing |
| title_fullStr | Variation in barley quality and its impact on malting and brewing |
| title_full_unstemmed | Variation in barley quality and its impact on malting and brewing |
| title_short | Variation in barley quality and its impact on malting and brewing |
| title_sort | variation in barley quality and its impact on malting and brewing |
| topic | Barley -- Quality Malt -- Composition Wort Brewing industry -- Technological innovations Enzymes -- Mechanism of action Brewing Proteins -- Measurement UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/132370 |
| work_keys_str_mv | AT foxglenpatrick variationinbarleyqualityanditsimpactonmaltingandbrewing |