Održivost svježeg sira pakiranog u vakuumu i modificiranoj atmosferi

master's thesis

• Title (english): Quality and shelf life of fresh cheese packed under vacuum and modified atmosphere
• Author: Iva Marasović
• Mentor: Irena Barukčić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Technology of Milk and Milk Products); Zagreb
• Defense date and country: 2017-09-25, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Proizvedeni svježi sir od kravljeg mlijeka pakiran je u atmosferi zraka, vakuumu te modificiranoj atmosferi s dva omjera plina (60% N2:40% CO2; 70% N2:30% CO2) te su uzorci skladišteni u hladnjaku 18 dana. Uzorci su izuzimani i analizirani svaka tri dana. Kiselost je padala (s početnih 4,66 na 4,47), a broj naraslih kolonija mikroorganizama postupno rastao tijekom skladištenja u svim uzorcima, s tim da su te promjene kod uzoraka pakiranih u modificiranoj atmosferi i vakuumu bile znatno usporene (kiselost ne pada ispod 4,50). Svi uzorci postigli su visoke senzorske ocjene (17,63 – 19,73), no uz minimalne razlike najbolje ocjene postigli su uzorci pakirani u modificiranoj atmosferi s omjerom plinova 70% CO2:30% N2 (prosječan broj bodova 18,26). Vrijednosti ostalih ispitivanih parametara također su pokazali kako vakuum i modificirana atmosfera znatno produljuju rok trajanja uz očuvanje fizikalno-kemijskih i senzorskih svojstava svježeg sira.

Abstract (english)

After production process, the fresh cheese was packed under normal atmosphere, vacuum and modified atmosphere with two types of gases in different ratio (60% N2:40% CO2; 70% N2:30% CO2) and stored in fridge for 18 days. The analysis was conducted every three days. Results showed that during a storage period acidity (from 4,66 to 4,47) was decreasing steadily, while colonies of microorganisms were multiplying However, samples of a fresh cheese packed under vacuum and modified atmosphere retard the decrease of acidity (no result under 4,50) and microbiological growth. Scores of sensory evaluations were high for all samples (17,63 – 19,73) but the best result had a sample packed under MA with ratio 70% CO2:30% N2 (average score 18,26). Other analysis confirmed that packaging under vacuum and MA can prolonged shelf life of fresh cheese while preserving its physico - chemical and sensory characteristics.

• Keywords: svježi sir; vakuum; modificirana atmosfera; pakiranje; trajnost
• Keywords (english): fresh cheese; vacuum; modified atmosphere; packaging; shelf life
• Language: croatian
• URN:NBN: urn:nbn:hr:159:681025
• 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: 2017-11-16 10:36:18