master's thesis
Paste properties of acetylated cross-linked starches from wheat and potato

Anita Jelašac (2010)
Josip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Department of Food Technologies
Sub-department of Carbohydrates Technology
Metadata
TitleSvojstva pasti umreženih i acetiliranih škrobova pšenice i krumpira
AuthorAnita Jelašac
Mentor(s)Jurislav Babić (thesis advisor)
Abstract
Škrob je polisaharid građen od sitnih zrnaca/granula. Koristi se kao dodatak za poboljšanje teksture mnogih prehrambenih proizvoda, jedan je od glavnih izvora energije u prehrani ljudi (više od 50 %), a u prehrambenoj industriji se uglavnom upotrebljavaju modificirani škrobovi kao sredstvo za ugušćivanje, stabiliziranje, želiranje, vezanje arome i dr. Cilj ovog istraživanja bio je prirediti dvostruko modificirane škrobove pšenice (dvije sorte: Golubica i Srpanjka) i krumpira kemijskim postupkom modifikacije; acetiliranjem acetanhidridom (AA, 8%) te nakon acetiliranja provesti umrežavanje sa natrijevim tripolifosfatom (STPP, 2,5 ili 5%). Nakon priprave modificiranih škrobova ispitivana su reološka svojstva pasti (nativnih i modificirani škrobova) Brabenderovim mikrovisko analyzerom, kapacitet bubrenja te indeks topljivosti. Rezultati su pokazali da različiti škrobovi i različit udio reagensa za umrežavanje (2,5 ili 5% STPP) uzrokuje sniženje ili povišenje viskoznosti škrobnih pasti te sniženje ili povišenje temperatura želatinizacije u donosu na nativne škrobove. Viskoznost paste i temperatura želatinizacije modificiranih škrobova ovisi o stupnju umreženja te stupnju supstitucije koji ovise o vrsti škroba te udjelu reagensa. Modifikacijom škroba sa acetanhidridom dolazi do reakcija supstitucije, a s STPP-om; osim umreženja dolazi i do reakcija supstitucije pri čemu nastaje monoškrob fosfat (ester škroba).
Keywordsstarch acetylation cross-linking rheological properties
Parallel title (English)Paste properties of acetylated cross-linked starches from wheat and potato
Committee MembersDrago Šubarić
Jurislav Babić
Mirela Kopjar
Daliborka Koceva Komlenić
GranterJosip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Lower level organizational unitsDepartment of Food Technologies
Sub-department of Carbohydrates Technology
PlaceOsijek
StateCroatia
Scientific field, discipline, subdisciplineBIOTECHNICAL SCIENCES
Food Technology
Engineering
Study programme typeuniversity
Study levelgraduate
Study programmeFood Technology and Process Engineering
Academic title abbreviationdipl. ing.
Genremaster's thesis
Language Croatian
Defense date2010-11-18
Parallel abstract (English)
Starch is polysaccharide made from minute granules. It is used as food additive to improve texture of numerous foodstuff and a basic source of energy in human nutrition (more than 50%). In food industry modified starch is mostly used to achieve specific functional properties, for example, thickening, water retenrtion, to provide proper texture, etc. The aim of this research was to prepare double modified wheat (two varieties: Golubica and Srpanjka) and potato starches by chemical process of modification; acetylation with acetic anhydride (AA, 8%) followed by cross-linking with sodium tripolyphosphate (STPP, 2,5 either 5%). Rheological paste properties (natural and modified starch) were tested by Brabender Micro visco analyzer, and swelling power and solubility index after starch modification were determined. Results showed that starch type and amount of reagent for cross-linking (2,5 or 5% STPP) caused lowering or increasing viscosity of starch paste and lowering or increasing gelatinization temperature compared natural starch. Paste viscosity and gelatinization temperature of modified starches depended on degree of cross-linking and degree of substitution which depended on starch type and reagent amount. Starch modification with acetic anhydride resulted in substitution reaction, while STPP resulted in crosslinking and substitution reaction by which monostarch phosphate(starch ester) was formed in addition to distarch phosphate.
Parallel keywords (Croatian)škrob pšenični škrob škrob krumpira acetiliranje umrežavanje reološka svojstva
Resource typetext
Access conditionAccess restricted to students and staff of home institution
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:109:954520
CommitterSanda Hasenay