Utjecaj procesa proizvodnje na fizikalno-kemijska i senzorska svojstva soka jagode

undergraduate thesis

• Title (english): Influence of the production process on chemical physical and sensory characteristics of strawberry juice
• Author: Ivana Abramović
• Mentor: Branka Levaj (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Technology of Fruits and Vegetables Preservation and Processing); Zagreb
• Defense date and country: 2009-09-15, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Istraživanje je provedeno na jagodama sorte Alba. Sokovi su proizvedeni na četri načina i to prešanjem soka dobivenog sa i bez depektinizacije blanširane i neblanširane jagode. U procesu proizvodnje bistrih sokova matični sok dobiven prešanjem podvrgnut je procesima bistrenja tako da su dodani enzimi za bistrenje. Za proizvodnju mutnih sokova nije bio potreban ovaj proces. Svi sokovi su potom pasterizirani i punjeni u staklene boce te hermetički zatvoreni. U ovom radu proučavan je utjecaj procesa proizvodnje na fizikalnokemijska i senzorska svojstva mutnih i bistrih sokova jagode. Od fizikalno-kemijskih svojstava odreñena je topljiva i netopljiva suha tvar, ukupni i direktno reducirajući šećeri te saharoza, pH – vrijednost i ukupna kiselost. Dobiveni rezultati pokazuju da proces proizvodnje ne utječe bitno na fizikalno-kemijska svojstva. Tijekom ispitivanja senzorskih svojstava korištene su tehnika bodovanja i tehnika jednostavnog niza. Uzimajući u obzir sve karakteristike koje su ocijenjivane najbolje ocijenjeni sokovi su sok koji su dobiven postupkom depektinizacije svježe pulpe za bistre sokove, a mutni sok koji je dobiven depektinizacijom blanširane pulpe.

Abstract (english)

The research focused on the Alba variety of strawberries. The juice was produced with one part of the strawberries blanched and the other left thermally untreated. Half of both parts were then treated with depectinisation enzymes prior to the pressing process. Juices obtained were each divided once again so that one half could be treated with clarification enzymes prior to the pasteurization. This thesis investigated the influence of different production processes on chemical, physical and sensory properties of the strawberry juice by measuring soluble and insoluble dry matter, total and directly reducing sugars, sucrose content, pH and total acidity. Results suggest the production process does not significantly alter the physical and chemical properties of the juices. Sensory properties were evaluated using grading and simple ranking tests. Considering all of the assayed characteristics best scores were given to the clear juice which underwent a depectinisation and a clarification process and a cloudy juice produced by blanching of the strawberries, depectinisation of the pulp and the clarification process.

• Keywords: jagoda; šećeri; kiselost; suha tvar; senzorika
• Keywords (english): strawberry; sugar; acidity; dry matter; sensory
• Language: croatian
• URN:NBN: urn:nbn:hr:159:181462
• Study programme: Title: Food Technology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka prehrambene tehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka prehrambene tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Repository: Repository of the Faculty of Food Technology and Biotechnology
• Created on: 2017-05-18 12:13:28