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Title:CHARACTERIZATION OF SLOVENIAN APPLE JUICE WITH RESPECT TO ITS GEOGRAPHICAL ORIGIN AND AGRICULTURAL PRODUCTION PRACTICE
Authors:Bizjak Bat, Karmen (Author)
Ogrinc, Nives (Mentor) More about this mentor... New window
Mozetič Vodopivec, Branka (Mentor) More about this mentor... New window
Files:.pdf Karmen_Bizjak_Bat.pdf (3,97 MB)
 
Language:English
Work type:Doctoral dissertation (mb31)
Tipology:2.08 - Doctoral Dissertation
Organization:FPŠ - Graduate School
Abstract:Determination of food authenticity is an important issue in quality control and food safety. Recent studies predict a growing demand for natural and more authentic food and beverage products. The quality and authenticity of apple juice is also of a great economic importance since the popularity and demand for apple juice consumption has increased. The growth of the market for organically produced apples and apple juice is due to the increasing demand for healthy food requirements, protection of the environment and the promotion of biotic diversity. Organic foods have a higher nutritional and health value, but they are more expensive, because their production is more difficult and less profitable. In addition to how food is produced, consumers are increasingly placing emphasis on food products of specific region, which are known for their unique natural flavours and taste. The presented thesis is based on four separate but closely interrelated studies, in which a combination of different isotopic ratios of bioelements (2H/1H, 13C/12C, 15N/14N, 18O/16O), multi-element analysis, and major primary and secondary metabolite profiles were exploited to differentiate the geographical origin and agricultural production practice (organic vs integrated/conventional) of Slovenian apples. These parameters were used to establish the first database of authentic Slovenian apple juice, which can be used to verify the authenticity of commercially available apple juice in Slovenia. The first preliminary study was entitled “Organic Cultivation ~ Geographical Origin (OCGO)” and was performed using apples from the 2009 growing season. Its aim was to examine the use of stable isotope and multi-element data for determining the geographical origin and agricultural production practice of fresh apple juices. Fruits of six apple (Malus domestica Borkh) cultivars (Topaz, Idared, Golden Delicious, Goldrush, Gala, Gloster) were collected from four different geographical regions of Slovenia (Alpine, Dinaric, Pannonian and Mediterranean) grown under organic and integrated/conventional orchard management systems. The results revealed that stable isotope parameters in sugar, pulp and water were the most significant variables for differentiating between the regions. Good separation was achieved between the geographical regions in Slovenia based on the δ18O and δ2H values in water and Rb and S levels in the apple fruit juice. The most significant variables that distinguished between organically and integrated/conventionally cultivated apples were the 15N/14N ratio and antioxidant activity of the apple juice. Significant differences were also observed in the ascorbic acid content of the juice. Based on these results the number and types of apples and the minimum number of samples needed from the same region for determining geographical origin were determined. The second study was called “Organic ~ Conventional Apple Cultivation” (OCAC) and was performed in 2010 and 2011 in a Gala apple orchard. The aim was to determine the effect of different fertilizers allowed either in organic or conventional/integrated agricultural regimes on different parameters. Quality parameters, isotopic composition of C in sugars and in pulp together with N and elemental analysis were investigated. The following five fertilizers were applied: Biosol and Plantella organic (organic) and Ca cyanamide, KAN and UREA (mineral) at a rate of 60 and 120 kg of nitrogen per hectare. From the obtained data it was possible to differentiate between organic and integrated/conventional apple production when taking into account the following parameters: mass, skin and flesh firmness (SFF), total soluble solids (TSS), and the content of Cl as well as δ15N and δ13C in the pulp. The “Organic Cultivation ~ Geographical Origin” (OCGO) study, which took place during the 2011 and 2012 growing seasons included a greater number of samples and samples from five different geographical regions: Alpine, Dinaric,
Keywords:apple juice, geographical origin, agricultural production practice, biomarkers, phenol compounds, elements, stable isotopes, Slovenia
Year of publishing:2016
Source:Nova Gorica
COBISS_ID:4376315 Link is opened in a new window
URN:URN:SI:UNG:REP:CZ4TU9IB
Views:3490
Downloads:354
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Secondary language

Language:Slovenian
Title:KARAKTERIZACIJA SLOVENSKEGA JABOLČNEGA SOKA GLEDE NA GEOGRAFSKO POREKLO IN NAČIN PRIDELAVE JABOLK
Abstract:Nedavne študije nakazujejo na povečevanje zanimanja za pristnost hrane in pijače s strani potrošnika. Določitev pristnosti pa je pomembna tudi z vidika nadzora nad varnostjo in kakovostjo živil. Povečevanje priljubljenosti in povpraševanje po jabolčnem soku, pa vpliva na to, da sta kakovost in pristnost le-tega tudi velikega gospodarskega pomena. Rast tržišča z ekološkimi pridelki, med katerimi so tudi jabolka in iz njih pridelan jabolčni sok, je pogojena s povečanim povpraševanjem po zdravi hrani, z zahtevami po varstvu okolja in s spodbujanjem biotske raznovrstnosti. Organska hrana ima večjo hranilno vrednost in je bolj zdrava, vendar pa je na drugi strani tudi dražja, ker je njena proizvodnja težja in zaradi tega manj donosna. Poleg pridelave dajejo potrošniki vedno večji poudarek tudi geografskemu izvoru proizvodov, ki so zaradi tega edinstveni po okusu in vonju. Predložena doktorska disertacija obsega 4 ločene, vendar med seboj tesno povezane poskuse, v kateri sem želela z določitvijo izotopskih razmerij različnih bioelementov (2H/1H, 13C/12C, 15N/14N, 18O/16O), elementno sestavo, ter profilom glavnine primarnih in sekundarnih metabolitov najti tiste parametre, ki omogočajo razlikovanje slovenskih jabolk po geografskem poreklu ali glede na način pridelave (organska vs. integrirana/konvencionalna). Ustvarjena je bila tudi prva baza podatkov pristnih slovenskih jabolčnih sokov, ki je bila kasneje uporabljena za testiranje komercialnih jabolčnih sokov dostopnih na slovenskem trgu. Predposkus imenovan OCGO (Ekološka pridelava ~ Geografsko poreklo) 2009, je bil izveden v rastni sezoni 2009. Namen tega poskusa je bil preučiti uporabo stabilnih izotopov in multi-elementno analizo za določanje geografskega porekla in načina pridelave jabolčnih sokov. Zbrala sem vzorce šestih sort jabolk (gala, gloster, gold rush, zlati delišes, topaz in idared) iz štirih slovenskih geografskih regij (panonska, mediteranska, dinarska in alpska). Sedem vzorcev je bilo ekološko, dvanajst pa konvencionalno pridelanih. Rezultati so pokazali, da na ločitev po geografskem poreklu signifikantno vplivajo stabilni izotopi določeni v sladkorjih, pulpi in vodi, ki so sestavni del jabolčnega soka. Jabolka iz omenjenih slovenskih regij so bila ločena na podlagi δ18O in δ2H vrednosti v vodi ter vsebnosti rubidija in žvepla v iztisnjenem jabolčnem soku. Kot statistično najbolj signifikantni parametri za razlikovanje med organsko in integrirano/konvencionalno pridelanimi jabolki pa so se izkazali 15N/14N razmerje, antioksidacijski potencial in vsebnost vitamina C. Na podlagi opisanega predposkusa je bilo določeno potrebno število vzorcev in sort jabolk ter minimalno število vzorcev iz posamezne slovenske geografske regije za razvrstitev le teh glede na geografsko poreklo. Drugi poskus, ki sem ga poimenovala Organska ~ konvencionalna pridelava jabolk (OCAC), je potekal v letih 2010 in 2011, v sadovnjaku jabolk sorte Gala. Cilj je bil ugotoviti vpliv različnih gnojil dovoljenih v ekološki ali v integrirani/konvencionalni pridelavi na različne parametre. Določeni so bili parametri kakovosti, izotopska sestava C v sladkorjih ter C in N v pulpi ter elementna analiza. Jablanam so bila aplicirana naslednja gnojila: Biosol in Plantella organik (organska) ter apneni dušik, KAN in UREA (mineralna) v količini, s katero je bilo zagotovljeno 60 oziroma 120 kg dušika na hektar. Rezultati so pokazali, da je razlikovanje med jabolki, pognojenimi z različnimi gnojili mogoče na podlagi naslednjih parametov: povprečne mase plodov, trdote jabolk (SFF), celokupne suhe snovi (TSS), vsebnosti klora ter δ15N in δ13C vrednosti v pulpi. Poskus “Ekološka pridelava ~ Geografsko poreklo" (OCGO) je potekal v rastnih sezonah 2011 in 2012 in je glede na OCGO 2009 vključeval večje število vzorcev iz petih različnih geografskih regij: alpske, dinarske, panonske, mediteranske in submediteranske. Izbrane so bile tri sorte jabolk: idared in zlati delišes pridelana na integriran/konvencionale
Keywords:jabolčni sok, geografsko poreklo, način pridelave jabolk, biomarkerji, fenolne komponente, elementi, stabilni izotopi, Slovenija


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