Optimizacija ekstrakcijskih uvjeta hemicelulozne frakcije mahune graška

master's thesis

• Title (english): Optimization of extraction conditions of pea pod hemicellulose fraction
• Author: Matea Modec
• Mentor: Draženka Komes (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Chemistry and Technology of Carbohydrates and Confectionery Products); Zagreb
• Defense date and country: 2017-09-28, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U skladu sa svjetskim trendovima iskorištavanja biljnih ostataka za izdvajanje vrijednih sastojaka, cilj ovog rada je optimizirati ekstrakcijske uvjete izdvajanja ksilana iz hemicelulozne frakcije mahune graška, s potencijalnom primjenom u prehrambenoj, ali i drugim industrijama. U tu svrhu praćen je utjecaj delignifikacije te promjena koncentracije kalijevog hidroksida i duljina trajanja alkalne ekstracije. U izdvojenim frakcijama hemiceluloze i celuloze primjenom HPLC metode, uz prethodnu PMP derivatizaciju, odredit će se monomerni sastav ugljikohidrata. Približno 41 % suhe tvari sirovine čine strukturni polisaharidi, u čijem sastavu dominiraju ksiloza i glukoza, odnosno ukupni glukan i ukupni ksilan. Udjel ksilana u mahuni graška je 11,7 %, odnosno približno četvrtina udjela strukturnih polisaharida. Primijenjenim postupcima izdvojene su tri frakcije: topljiva i netopljiva hemiceluloza te celulozni ostatak. Od 100 % inicijalno prisutne ksiloze u originalnom uzorku, u topljivoj i netopljivoj hemiceluloznoj frakciji je, nakon niza ekstrakcija, iskorištenje ksiloze u većini uzoraka bilo oko 100 %, što znači da nije došlo do značajne degradacije ksilana tijekom primijenjenih ekstrakcijskih postupaka. Veliki utjecaj na iskorištenje imala je delignifikacija, koja je povećala ekstraktibilnost hemiceluloze. Promjena koncentracije KOH (2M i 4M) i vremena trajanja alkalne ekstrakcije (2h i 4h) nije imala značajan utjecaj na ekstrakciju ksilana. Mahuna graška je dobar izvor ksilana, koji se izdvaja uglavnom u netopljivoj hemiceluloznoj frakciji homopolimernog sastava.

Abstract (english)

In accordance with the world trends in exploitation of plant residues for obtaining valuable ingredients, the aim of this study was to optimize the extraction conditions of xylan from the hemicellulose fraction of the pea pod, with the potential usage in the food industry, as well as the other industries. Extraction conditions that were optimazed are: delignification, concentration of KOH in the alkal extraction and also the duration of this extractions. In the separated fractions of hemicellulose and cellulose using the HPLC method, with the previous PMP derivatization, the monomeric carbohydrate composition will be determined. Structural polysaccharides, whose composition is dominated by xylose and glucose (total glucan and total xylan) make approximately 41 % of dry matter of the raw material. The content of xylan in pea pod is 11.7 %, or approximately one quarter of the share of structural polysaccharides. Three fractions were isolated using different extraction conditions: the soluble and the insoluble hemicellulose and the cellulose residue. In most samples, utilization of xylose in the soluble and the insoluble hemicellulose fraction after a series of extraction steps was about 100 % of the initially present xylose, meaning there was no significant degradation of xylan during the extraction procedures applied. Delignification of samples, which helped the extraction of hemicellulose, had a great influence on such high utilization rates. The change in KOH (2M and 4M) and alkaline extraction time (2h and 4h) did not have a significant effect on xylan extraction. Pea pod is a good source of xylan, which is mostly separated in the insoluble hemicellulose fraction of hompolymeric composition.

• Keywords: hemiceluloza; HPLC; ksilan; mahuna graška
• Keywords (english): hemicellulose; HPLC; pea pod; xylan
• Language: croatian
• URN:NBN: urn:nbn:hr:159:175163
• Study programme: Title: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka prehrambenog inženjerstva (magistar/magistra inženjer/inženjerka prehrambenog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-11-09 13:32:26