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Maize (Zea mays) bran as a biorefinery feedstock for the co-extraction of nutraceuticals and functional food compounds
Thesis (MEng)--Stellenbosch University, 2024.
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| Format: | Thesis |
| Language: | en_ZA en_ZA |
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Stellenbosch : Stellenbosch University
2024
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| _version_ | 1867613901171982336 |
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| access_status_str | Open Access |
| author | Nkhoma, Mcphancio |
| author2 | Chimphango, Annie Fabian Abel |
| author_browse | Chimphango, Annie Fabian Abel Nkhoma, Mcphancio |
| author_facet | Chimphango, Annie Fabian Abel Nkhoma, Mcphancio |
| author_sort | Nkhoma, Mcphancio |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MEng)--Stellenbosch University, 2024. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/130554 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA en_ZA |
| last_indexed | 2026-06-10T12:43:30.254Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2024 |
| publishDateRange | 2024 |
| publishDateSort | 2024 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/130554 Maize (Zea mays) bran as a biorefinery feedstock for the co-extraction of nutraceuticals and functional food compounds Nkhoma, Mcphancio Chimphango, Annie Fabian Abel Stellenbosch University. Faculty of Engineering. Dept. of Chemical Engineering. Process Engineering. Functional foods Extraction (Chemistry) Green chemistry Organic compounds Prebiotics Thesis (MEng)--Stellenbosch University, 2024. ENGLISH ABSTRACT: The interest in extracting functional food compounds such as prebiotics, antioxidants, and nutraceuticals from renewable resources has increased as they offer several health benefits. Functional compounds such as ferulic acid (FA), xylooligosaccharides (XOS), and proteins have been extracted mainly from lignocellulosic material such as wheat bran. This study investigated the feasibility of biorefining three types of maize bran (white, yellow, and purple) using green methods based on green chemistry principle (such as enzymes, organic acids, and emerging technologies such as microwave treatment) to co-produce xylooligosaccharides, proteins, and phenolic acids. The main objective was to compare the selective extraction of protein, ferulic acid, and xylooligosaccharides based on yields and functional properties. The protein was extracted from the maize brans under mild alkaline conditions, while the xylooligosaccharides and ferulic acid were extracted using microwave-assisted-lemon juice extraction and microwave-assisted enzymatic extraction, respectively. The target was to extract the xylooligosaccharides with a degree of polymerization of at least 2, phenolic compounds with high antioxidant activity (at least 80%), and protein with increased solubility. The profiling showed that yellow maize bran has more hemicellulose (51.89 ± 0.48 %), followed by white maize bran (44.44 ± 0.27 %) and purple maize bran (38.37 ± 0.44) with the least hemicellulose content. The extraction conditions were optimised using Box-Behnken statistical design based on yield for protein and XOS. In addition to yield, the FA optimization included total phenolic content and antioxidant activity. In the mild alkaline extraction of protein, sodium bicarbonate concentration was varied from 0.5 – 1.5 M, time from 1–3 h, and temperature from 30 – 50 °C). The optimisation of ferulic acid recovery from destarched maize bran was conducted by varying the extraction time from 2 to 6 h, solid loading from 5 to 15% w/v, and enzyme dosage from 40 to 80 U). Furthermore, the optimisation of XOS extraction conditions varied temperature (110 – 130 °C), time (2 – 6 h) and lemon juice concentrations (50 –100 v/v%). The optimised conditions for the protein extraction were: time, 2 h; concentration, 1 M; and temperature 40 °C with a protein yield of 5.48 and 7 %w/w in yellow maize bran and purple maize bran, respectively. The application of microwave treatment increased the production of FA by more than 20 %. Specifically, the yield of FA increased from 0.81 to 3.84 mg/g in purple maize bran, from 0.4 to 3.98 mg/g in yellow maize bran, and from 0.28 to https://scholar.sun.ac.za iii 4.25 mg/g in white maize bran. The XOS yields obtained from purple maize bran, yellow maize bran, and white maize bran were 24.41, 23.41, and 23.53%, respectively, with degrees of polymerization of 15.82, 15.85, and 15.93 for XOS from white, yellow, and purple maize bran, respectively. These results demonstrate the potential application of the extracted xylooligosaccharides as prebiotics in the food industry. The findings of the present study suggest that yellow and purple maize bran are suitable sources of protein, ferulic acid, and xylooligosaccharides, while white maize bran is well-suited for ferulic acid and xylooligosaccharides. AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar. Masters 2024-03-05T08:25:59Z 2024-04-26T21:50:22Z 2024-03-05T08:25:59Z 2024-04-26T21:50:22Z 2024-03 Thesis https://scholar.sun.ac.za/handle/10019.1/130554 en_ZA en_ZA Stellenbosch University x, 145 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Functional foods Extraction (Chemistry) Green chemistry Organic compounds Prebiotics Nkhoma, Mcphancio Maize (Zea mays) bran as a biorefinery feedstock for the co-extraction of nutraceuticals and functional food compounds |
| title | Maize (Zea mays) bran as a biorefinery feedstock for the co-extraction of nutraceuticals and functional food compounds |
| title_full | Maize (Zea mays) bran as a biorefinery feedstock for the co-extraction of nutraceuticals and functional food compounds |
| title_fullStr | Maize (Zea mays) bran as a biorefinery feedstock for the co-extraction of nutraceuticals and functional food compounds |
| title_full_unstemmed | Maize (Zea mays) bran as a biorefinery feedstock for the co-extraction of nutraceuticals and functional food compounds |
| title_short | Maize (Zea mays) bran as a biorefinery feedstock for the co-extraction of nutraceuticals and functional food compounds |
| title_sort | maize zea mays bran as a biorefinery feedstock for the co extraction of nutraceuticals and functional food compounds |
| topic | Functional foods Extraction (Chemistry) Green chemistry Organic compounds Prebiotics |
| url | https://scholar.sun.ac.za/handle/10019.1/130554 |
| work_keys_str_mv | AT nkhomamcphancio maizezeamaysbranasabiorefineryfeedstockforthecoextractionofnutraceuticalsandfunctionalfoodcompounds |