Utjecaj obrade propionskom i askorbinskom kiselinom na ukupnu boju i fizikalno-kemijske parametre rezane salate pakirane u vakuumu

master's thesis

• Title (english): Influence of treatment with propionic and L-ascorbic acid on total colour and physical and chemical parameters in vacuum-packed shredded lettuce
• Author: Verica Dragović - Uzelac
• Mentor: Verica Dragović - Uzelac (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: 2008-05-12, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Svrha ovog rada je ispitati mogućnost primjene propionske i L-askorbinske kiseline (pojedinačno ili u kombinaciji) u sprječavanju promjene boje i aktivnosti polifenoloksidaze (PPO) u narezanoj salati tip kristalka (sorte Igloo) pakirane vakuumiranjem u vrećice od polipropilena (PP) debljine 60-65 μm. Pri tome su praćene promjene ukupne, topljive i netopljive suhe tvari, pH vrijednosti, ukupne kiselosti, reducirajćih šećera, ukupne boje i senzorskih svojstava narezane salate nakon obrade navedenim kiselinama i tijekom skladištenja pri temperaturi od 4°C. Rezultati istraživanja pokazali su da se obrada s L-askorbinskom kiselinom ili smjesom askorbinske i propionske kiseline može uspješno primijeniti za sprječavanje aktivnosti PPO minimalno procesirane salate, pakirane vakuumiranjem u vrećice od PP tijekom 6 dana pri temperaturi od 4°C. Nakon 6. dana u svim uzorcima dolazi do porasta stupnja posmeđivanja i aktivnosti enzima PPO. Na temelju rezultata kolorimetrijskog određivanja boje utvrđene su najveće promjene kvalitete u netretiranom (kontrolnom) uzorku salate. Uzorak tretiran sa smjesom askorbinske i propionske kiseline imao je jače izraženo zeleno i žuto obojenje i veću čistoću boje. Najbolje vizualno svojstvo boje odnosno najbolje očuvanu boju, imao je uzorak tretiran sa smjesom askorbinske i propionske kiseline. Uzorci obrađeni navedenim otopinama bolje su senzorski ocjenjeni (miris, teksturu i okus) od neobrađenog uzorka.

Abstract (english)

The aim of this study was to investigate the possibility of the application of propionic and L-ascorbic acids (individually or in combination) in preventing changes of colour and activity of polyphenoloxidase (PPO) of shredded lettuce (type iceberg, sort Igloo), vacuum-packed into 60-65 μm thick polypropylene bags (PP). In order to get a complete insight into their effects, the changes in total, soluble and insoluble matter, pH value, total acidity, reducible sugars, total colour, as well as sensory properties of the shredded lettuce after processing and during storage at 4°C were studied. The results had shown that treated with ascorbic acid or with a mixture of propionic and ascorbic acid may successfully prevent activity of PPO of the minimally processed lettuce if it is vacuum-packed into PP bags and stored 6 days at 4°C. After six days in all samples were increased browning and activity of PPO. According to the results of colorimetric measurements of colour the higher decreasing of quality parameters in untreted (control) samples was observed. The samples treated with a mixture of propionic and ascorbic acid had stronger green and yellow colour and higher pure colour. The best visual properties or the best occurred colour had sample treated with a mixture of propionic and ascorbic acid. The samples treated with the described solutions had better sensory properties (aroma, texture and taste) than the untreated samples.

• Keywords: obrada askorbinskom kiselinom; obrada propionskom kiselinom; polifenoloksidaza; salata sorte Igloo; ukupna boja
• Keywords (english): chemical treatment with ascorbic and propionic acid; polyphenoloxidase; lettuce sort Igloo; total colour
• Language: croatian
• URN:NBN: urn:nbn:hr:159:837157
• Study programme: Title: Food Technology; specializations in: Food Engineering; Course: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo (diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-05 08:22:47