Optimizacija uvjeta proizvodnje kefirnog napitka na tršćanom šećeru

master's thesis

• Title (english): The optimisation of process parameters in production of kefir drink using cane sugar as sucrose source
• Author: Dominik Piškor
• Mentor: Mladen Pavlečić (mentor)
• Committee member: Božidar Šantek (član povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Biochemical Engineering, Industrial Microbiology and Malting and Brewing Technology); Zagreb
• Defense date and country: 2020-10-20, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Kefirni napitak, predstavlja funkcionalan proizvod, dobre nutritivne vrijednosti, dobiven fermentacijom šećerne hranjive podloge kroz 2-4 dana pri sobnoj temperaturi pomoću združene kulture kefirnih zrnaca. Također, pokazuje i probiotička svojstva te ima antihiperglikemijski, antimutageni i antioksidativni utjecaj na čovjekov organizam. Iako pokazuje brojna pozitivna svojstva, industrijska proizvodnja kefirnog napitka još uvijek predstavlja izazov zbog nedovoljno istraženih uvjeta fermentacije te različitog i nedovoljno poznatog sastava združene kulture mikroorganizama. Za napredak u tehnologiji proizvodnje kefirnog napitka potrebno je optimizirati procesne parametre te ispitati utjecaj različitih izvora ugljika, što uvelike utječe na sam proces proizvodnje kefirnog napitka. U ovom istraživanju određene su optimalne temperature i koncentracije saharoze za proizvodnju kefirnog napitka ( 25 ℃ i 60 g L-1) pri čemu je kao izvor ugljika korišten tršćani šećer. Također, ispitivan je i utjecaj dodatka sladila (eritrol, ksilitol i stevia) na proizvodnju kefirnog napitka na tršćanom šećeru prilikom čega nije utvrđen negativan utjecaj na sam bioproces, što bi značilo da ih se moglo dodati u finalni proizvod nakon, ali i za vrijeme fermentacije.

Abstract (english)

Kefir drink represents a functional product, with great nutritive value, made by fermentation of sugary medium through 2-4 days at room temperature by consortium of microorganisms contained in water kefir grains. It also has proven probiotic properties, which has antihyperglycemic, antimutagenic, and antioxidative effects of human body. Although kefir drink has many positive properties, its industrial production is still very limited. Varying fermentation conditions, and poorly known consortium of microorganisms in water kefir grains makes the process of kefir drink production very hard to precisely define. The breakthrough in industrial production of kefir drink is possible only if the process parameters are well known. Different substrates could also have a great impact on kefir drink production, and they could also give better sensoric properties to the final product. In this study, the optimum temperature and substrate concentrations were defined (25 ℃ / 60 g L-1). Cane sugar was the main source of sucrose, which was used to make the sugary medium, which was later sterilised and inoculated with 10 g of kefir drink grains. The effects of sweeteners (erythrol, xylitol and steviol) on production of kefir drink on cane were studied, where there were no negative effects of sweeteners on the bioprocess itself discovered, which makes them eligible to use after, but also during the fermentation process.

• Keywords: kefirni napitak; tršćani šećer; zaslađivači; optimizacija proizvodnje
• Keywords (english): kefir drink; cane sugar; sweeteners; production optimisation
• Language: croatian
• URN:NBN: urn:nbn:hr:159:734225
• Study programme: Title: Bioprocess Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva (magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-01-21 11:20:41