doctoral thesis
Influence of trehalose addition on quality properties of strawberry pastes

Mirela Kopjar (2007)
Josip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Department of Food Technologies
Sub-department of Fruits and Vegetables Technology
Metadata
TitleUtjecaj dodatka trehaloze na kvalitetu paste od jagoda
AuthorMirela Kopjar
Mentor(s)Vlasta Piližota
Abstract
Zahtjevi potrošača za što kvalitetnijim prehrambenim proizvodima danas su izraženiji nego ikada. Kako bi se udovoljilo zahtjevima potrošača, velika pažnja se posvećuje razvoju novih proizvoda ili pak poboljšavanju svojstava, a time i kvalitete, već postojećih proizvoda (npr. dodatkom različitih sastojaka, poboljšanjem procesa proizvodnje, uključujući pakiranje i drugo). Najznačajniji čimbenici kvalitete su aroma, boja i tekstura. Paste od jagoda se koriste kao punilo za čokolade, energetske pločice i druge proizvode koji sadrže voće. U industriji se paste od jagode pripremaju procesom evaporacije i bez dodatka šećera trehaloze. Kako bi se poboljšala kvaliteta voćne paste osim industrijskog postupka pripreme upotrijebljena je i liofilizacija, te je ispitivan utjecaj dodatka različitih koncentracija trehaloze na aromu, teksturu, boju, sadržaj antocijana i antioksidativna aktivnost. Također je praćen utjecaj različitih načina pakiranja (u atmosferi dušika i u zraku) tijekom skladištenja na sobnoj temperaturi tijekom 5 mjeseci na aromu, boju i teksturu. Trehaloza je jedan od najstabilnijh šećera. S obzirom da je razvijen enzimski proces njezine proizvodnje koji je uvelike smanjio njenu cijenu, očekuje se sve veća primjena trehaloze u prehrambenoj industriji zbog njezinog pozitivnog djelovanja na različita svojstva kvalitete proizvoda. Dodatak trehaloze uzrokovao je promjenu svojstava paste od jagode bez obzira jesu li uzorci bili podvrgnuti evaporiraciji ili liofilizaciji u odnosu na uzorke bez dodatka trehaloze. Sadržaj voćnih estera se je povisio dodatkom trehaloze u odnosu na uzorke bez dodatka trehaloze. Trehaloza je također pozitivno djelovala na teksturu, očuvanje boje i sadržaj antocijana u uzorcima. Liofilizirani uzorci su bili kvalitetniji u odnosu na uzorke proizvedene evaporiranjem. Sadržaj voćnih estera, očuvanje boje i sadržaj antocijana je bio veći u liofiliziranim uzorcima nego u evaporiranim. Nakon skladištenja (5 mjeseci), uzorci s dodanom trehalozom su i dalje imali veći sadržaj voćnih estera i antocijana.
Keywordsstrawberry pastes sugars evaporation freeze-drying aroma anthocyanin
Parallel title (English)Influence of trehalose addition on quality properties of strawberry pastes
Committee MembersJanez Hribar (committee chairperson)
Vlasta Piližota (committee member)
Drago Šubarić (committee member)
Marjan Simčič (committee member)
GranterJosip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Lower level organizational unitsDepartment of Food Technologies
Sub-department of Fruits and Vegetables Technology
PlaceOsijek
StateCroatia
Scientific field, discipline, subdisciplineBIOTECHNICAL SCIENCES
Food Technology
Engineering
UDK66
APPLIED SCIENCES. MEDICINE. TECHNOLOGY
Chemical technology. Chemical and related industries
Study programme typeuniversity
Study levelpostgraduate
Study programmeFood Engineering
Academic title abbreviationdr. sc.
Genredoctoral thesis
Language Croatian
Defense date2007-01-19
Parallel abstract (English)
Today, costumer’s demands for higher quality of food products are more pronounced than ever. To satisfy costumer’s demands, high attention is paid to new product development or improvement of properties of existing product (by addition of different ingredients, improvement of processing, packaging ect.). The most important quality factors are aroma, texture and colour. Strawberry pastes are used as fillings for chocolates, energy bars and other products that contain fruit. In industry, strawberry pastes are prepared by evaporation and without trehalose addition. To improve quality of this product, next to industrial process of preparation, freeze-drying was used. Its influence and influence of different concentrations of trehalose addition on aroma, texture, colour, anthocyanin content and free radical scavenging activity were studied. Influence of different atmospheres (nitrogen and air) for packaging during storage for 5 months at room temperature on mentioned properties were also studied. Trehalose is one of most stable sugars. Since enzymatic process for its production is developed its price is lower, so it is expected that its use in food industry will grow because trehalose have positive effect on different quality properties of products. Addition of trehalose caused property change of strawberry pastes in both evaporated and freeze-dried samples in comparation to samples without trehalose addition. Fruity esters content was higher in samples when trehalose was added. Trehalose also had positive effect on texture, colour degradation and retention of anthocyanins in samples. Freeze-drying also improves quality of product. Fruity esters content, retention of anthocyanins and retention of colour were higher in freeze-dried samples. After storage, samples with trehalose added had higher content of fruity esters and anthocyanin content.
Parallel keywords (Croatian)paste od jagoda šećeri evaporacija liofilizacija aroma antocijani
Extent130 str.; 30 cm
Versionaccepted version
Resource typetext
Access conditionAccess restricted to students and staff of home institution
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
Noteaccepted version
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:109:082719
CommitterIvana Šuvak