Repository Faculty of Agriculture University of Zagreb
Not a member yet
3827 research outputs found
Sort by
Perspectives and challenges of biogas business in the context of the current energy crisis
No full textGospodarenje otpadom predstavlja jedan od izazova suvremenog društva u Hrvatskoj i Europi. Bioplinska postrojenja nude održivo rješenje za upravljanje biootpadom, pretvarajući organske tvari u obnovljivu energiju putem anaerobne razgradnje. Nedavni geopolitički događaji, poput rata u Ukrajini, izazvali su poremećaje na energetskim tržištima, dodatno naglasivši potrebu za obnovljivim izvorima energije u čemu bioplinska postrojenja imaju bitnu ulogu. Ipak, rast cijena žitarica tijekom 2022. godine doveo je do povećanja troškova za postrojenja koja se značajno oslanjaju na te sirovine. Ovaj rad, kroz deskriptivnu analizu tržišnih trendova u bioplinskom sektoru i studiju slučaja postrojenja Bioel d.o.o., uz intervju s njegovim predstavnikom, istražuje mogućnosti i izazove za razvoj bioplinskog sektora u Hrvatskoj. Zaključak rada naglašava kako je diversifikacija sirovina usmjerena na troškovno otpornije resurse s manjim cjenovnim oscilacijama, ključni preduvjet dugoročne održivosti bioplinskih postrojenja.Waste management is one of the challenges of modern society in Croatia and Europe. Biogas plants offer a sustainable solution for bio-waste management by converting organic matter into renewable energy through anaerobic digestion. Recent geopolitical events, such as the war in Ukraine, have disrupted energy markets, further highlighting the need for renewable energy sources, in which biogas plants play an essential role. However, the rise in cereal prices in 2022 has led to an increase in costs for plants that rely heavily on these commodities. This paper examines the opportunities and challenges for the development of the biogas sector in Croatia through a descriptive analysis of market trends in the biogas sector and a case study of the Bioel d.o.o. plant and an interview with its representative. The conclusion of the paper emphasizes that feedstock diversification, aiming at more cost-resistant resources with less price volatility, is an important prerequisite for the development of the biogas sector in Croatia
The effect of breed management on dairy cattle farm profitability
No full textPronalaženje modela za poboljšanje proizvodnje je kontinuiran proces u cilju
osiguravanja stabilne i dugoročne proizvodnje mlijeka. Povećanje proizvodnje mlijeka po
kravi rezultira potrebom za manjim brojem krava, a što za posljedicu ima deficit teladi za
tov. Telad mliječnih pasmina koja neće biti korištena u remontu stada osim kao tovna telad
nema značajnu ekonomsku vrijednost. Posljednjih desetljeća povećava se interes za
tehnologijom križanja mliječnih krava s bikovima mesnih pasmina u cilju osiguravanja teladi
s poželjnijim tovnim svojstvima i ujedno i veće prodajne cijene.
Od 1717 upravitelja mliječnih farmi utvrđeno je da je samo 22,89% upravitelja
dovoljno upoznato s tehnologijom križanja mliječnih krava i bikova mesnih pasmina te je
potvrđena hipoteza o nepoznavanju tehnologije od strane upravitelja mliječnih farmi. Zbog
nepoznavanja ili raspolaganja pogrešnim informacijama, samo 9,4% upravitelja je izjavilo
spremnost na primjenu programa križanja. 15,8% upravitelja je primijenilo tehnologiju
križanja od kojih 44,5% smatra da križanje može doprinijeti profitabilnosti mliječne farme. Iz
rezultata istraživanja se zaključuje da postoji velika potreba za edukacijom upravitelja
mliječnih farmi iz područja tehnologije križanja.
Mogućnost primjene tehnologije križanja istražena je stopom remonta s hipotezom
da je moguće križati do 30% holštajn krava u stadu. Hipoteza nije potvrđena zbog utvrđene
visoke stope remonta (44,64%) i slabe plodnost (67,4% - 69,6%) te udjela ženske teladi
zadržane u uzgoju u odnosu na broj oteljenih krava (45,1% - 46%). Križanje do 30% krava
u stadu holštajn farmi je moguće samo uz primjenu oplodnje krava seksiranim holštajn
sjemenom u svrhu osiguravanja dostatnog ženskog remontnog pomlatka. Ekonomska
opravdanost primjene tehnologije križanja na 30% matičnog stada krava holštajn farmi
potvrđena je analizama ekonomskih pokazatelja poslovanja farmi dobivenih anketom u 44
holštajn farmi. Ekonomski pokazatelji su potvrdili pozitivan doprinos primjene križanja
uspješnijem poslovanju holštajn farmi, s time da je doprinos bio značajniji u farmama s
manjim brojem krava i nižom proizvodnjom mlijeka po kravi.
Utjecaj pasminske strukture i veličine mliječnih stada na laktacijski prihod analiziran
je pomoću 386.916 standardnih laktacija (305 dana) farmi koje uzgajaju samo holštajn,
samo simentalsku i koje uzgajaju ove dvije pasmine (dvopasminske farme). Holštajn krave
u holštajn farmama imale su veću proizvodnju mlijeka (936,2 kg), mliječne masti i proteina
u odnosu na holštajn krave u dvopasminskim farmama, te posljedično i veći prosječni
laktacijski prihod od 1.772,75 HRK. Simentalske krave u simentalskim farmama proizvode
manju količinu mlijeka (473,7 kg), mliječne masti i proteina u odnosu na simentalske krave
u dvopasminskim farmama i posljedično simentalke u dvopasminskim farmama ostvaruju
veći prosječni laktacijski prihod od 1.055,31 HRK. Rezultati istraživanja ukazuju da holštajn
krave imaju bolja, a simentalske lošija svojstva mliječnosti u jednopasminskim farmama, te
posljedično holštajn krave ostvaruju veću, a simentalske manji laktacijski prihod u
jednopasminskim stadima. Veličina farme ima veliki utjecaj na svojstva mliječnosti,
vjerojatno jer se proizvodnja mlijeka na farmama s većim brojem krava provodi na višoj
razini tehnologije i menadžmenta, stoga krave na većim farmama imaju poželjnija svojstava
mliječnosti. Hipoteza da pasminska struktura i veličina stada farmi utječe na svojstva
mliječnosti i laktacijski prihod mliječnih krava je potvrđena.
Istražen je i utjecaj spola teleta na svojstva mliječnosti holštajn i simentalskih krava.
Analiza je pokazala da su krave koje su otelile žensku telad u prvoj laktaciji imale veću
mliječnost (p<0,0001), ali nešto manji udio mliječne masti i proteina (p<0,01). Utvrđen je i
pozitivan utjecaj ženskog teleta na mliječnost u drugoj laktaciji (p<0,0001). Potvrđena je
hipoteza da je upravljanjem spolom teladi moguće povećati proizvodnju mlijeka i laktacijski
prihod mliječnih krava. Krave obje istražene pasmine koje su u prvoj bređosti otelile žensku
telad su imala bolja svojstva mliječnosti i posljedično veći laktacijski prihod.Finding models to improve production is a continuous process in order to secure
stable and long-term milk production. The increase in milk production per cow results in the
need for fewer cows, and consequently in a shortage of calves for fattening. Calves of dairy
breeds that will not be used for the replacement of the herd, except as fattening calves,
have no significant economic value. In recent decades, there has been an increasing
interest in the technology of crossing dairy cows with bulls of meat breeds to ensure calves
with more desirable fattening properties and higher selling prices.
Out of 1,717 managers of dairy farms, it was determined that only 22,89% of
managers were familiar enough with the technology of crossing dairy cows with bulls of
meat breeds, and the hypothesis of lack of knowledge about the technology among dairy
farm managers was confirmed.
Due to a lack of knowledge or wrong information, only 9.4% of managers stated their
willingness to implement the crossbreeding program. 15.8% of managers applied
crossbreeding technology, of which 44.5% believe that crossbreeding can contribute to the
profitability of the dairy farm. From the obtained results, it is concluded that there is a great
need for the education of managers of dairy farms in the field of crossbreeding technology.
The possibility of applying the crossbreeding technology was investigated by the
replacement rate with the hypothesis that it is possible to crossbreed up to 30% of Holstein
cows in the herd. The hypothesis was not confirmed due to the determined high
replacement rate (44.64%), low fertility (67.4% - 69.6%), and the share of female calves
kept in breeding compared to the number of calved cows (45.1% - 46%). Crossbreeding of
up to 30% of cows in the herd of Holstein farms is possible only with the application of
artificial insemination of cows with sexed Holstein semen to ensure sufficient female
replacement offspring. The economic validity of the application of crossbreeding technology
on 30% of the maternal herd of cows on Holstein farms was confirmed by analyses of
economic indicators of farm operations obtained from a survey in 44 Holstein farms.
Economic indicators confirmed the positive contribution of the application of crossbreeding
to the successful business of Holstein farms, with the fact that the contribution was more
significant in farms with a smaller number of cows and lower milk production per cow. The
influence of breed structure and size of dairy herds on lactation income was analyzed using
386,916 standard lactation (305 days) of Holstein-only, Simmental-only farms, and farms
with these two breeds (dual-breed farms). Holstein cows in Holstein farms had a higher
production of milk (936.2 kg), milk fat and protein compared to Holstein cows in two-breed
farms, and consequently, a higher average lactation income of HRK 1,772.75. Simmental
cows in Simmental farms produce a smaller amount of milk (473.7 kg), milk fat and protein
compared to Simmental cows in dual-breed farms, and consequently Simmental cows in
two-breed farms achieve a higher average lactation income of HRK 1,055.31. The results
indicate that Holstein cows have better, and Simmental cows have lower milk yield
properties in single-breed farms, and consequently, Holstein cows achieve higher and
Simmental cows lower lactation income in single-breed herds. The size of the farm has a
great influence on milk yield properties, probably because milk production on farms with a
larger number of cows is carried out at a higher level of technology and management,
therefore cows on larger farms have more desirable milk yield properties. The hypothesis
that the breed structure and herd size of farms affect the milk yield and lactation income of
dairy cows was confirmed.
The influence of calf gender on milk yield properties of Holstein and Simmental cows
was also investigated. The analysis showed that cows that gave birth to female calves in
the first lactation had higher milk yield (p<0.0001), but a slightly lower proportion of milk fat
and protein (p<0.01). A positive influence of the female calf on milk yield in the second
lactation was also determined (p<0.0001). The hypothesis that by managing the gender of
calves it is possible to increase milk production and lactation income of dairy cows was
confirmed. Cows of both researched breeds that gave birth to female calves in their first
pregnancy had better milk yield properties and consequently, higher lactation income
Comparasion of the essential oil content of hydrangea petals by different methods of extraction and drying
No full textHortenzija (Hydrangea) je listopadni grm iz porodice Hydrangeaceae, čiji se cvatovi koriste u
dekorativne svrhe, kako u svježem stanju, tako i kao sušene latice. Kvaliteta i sadržaj eteričnog
ulja u ovim laticama mogu se značajno mijenjati ovisno o metodama sušenja i ekstrakcije, što
je ključno za očuvanje njihovih estetskih i funkcionalnih svojstava.
Ovaj diplomski rad istražuje utjecaj različitih metoda sušenja i ekstrakcije na sadržaj eteričnog
ulja u laticama hortenzije. U istraživanju su korištene latice hortenzija u tri boje (ružičasta,
ljubičasta i bijela) i primijenjena su dva načina sušenja – konvekcijsko i podtlačno – pri
temperaturama od 40, 50 i 60°C. Za ekstrakciju eteričnog ulja korištene su metode vodene
destilacije i ekstrakcije otapalima.
Analiziran je sadržaj eteričnog ulja i promjene u boji latica primjenom kolorimetra, prije i nakon
sušenja. Na temelju dobivenih rezultata, utvrđeno je koji način sušenja i ekstrakcije najbolje
čuva kvalitetu i količinu eteričnog ulja te estetske karakteristike latica. Svi podaci su statistički
obrađeni kako bi se identificirali optimalni uvjeti za očuvanje eteričnih ulja iz latica hortenzija.Hydrangea is a deciduous shrub from the Hydrangeaceae family, with flowers used for
decorative purposes both in their fresh state and as dried petals. The quality and essential oil
content in these petals can vary significantly depending on the drying and extraction methods,
which is crucial for preserving their aesthetic and functional properties.
This thesis investigates the impact of different drying and extraction methods on the essential
oil content in hydrangea petals. The study utilized hydrangea petals in three colors (pink,
purple, and white) and applied two drying methods—convective and vacuum—at
temperatures of 40, 50, and 60°C. Essential oil extraction was performed using water
distillation and solvent extraction methods.
The analysis focused on essential oil content and color changes of the petals, measured using
a colorimeter, both before and after drying. The results determined which drying and
extraction methods best preserved the quality and quantity of essential oil as well as the
aesthetic characteristics of the petals. All data were statistically analyzed to identify the
optimal conditions for maintaining essential oils from hydrangea petals
Variations in the shape of scales and otoliths of two fish populations of the Sunja River from different habitats
No full textOvim radom se istražuje utjecaj izgradnje hidroelektrane Klipić na rijeci Sunji na oblik otolita i ljusaka kod dviju vrsta riba: klena (Squalius cephalus) i sunčanice (Lepomis gibbosus). Cilj je utvrditi razlike u obliku otolita i ljusaka iznad i ispod brane te usporediti njihovu upotrebljivost u razlikovanju različiih populacija istraživanih vrsta riba. Istraživanje se temelji na metodama geometrijske morfometrije. Uzorkovanje je provedeno na tri lokacije rijeke Sunje: iznad brane (lokacije Staza i Mlin) i ispod brane (lokacija Klipić). Analize su pokazale značajne razlike u obliku ljusaka klena između lokacija Staza i Klipić, dok su kod sunčanica uočene razlike između lokacija Mlin i Klipić. Otoliti klena pokazali su značajne razlike između lokacija Staza i Klipić, dok razlike u otolitima sunčanica nisu bile značajne. Rezultati ukazuju na utjecaj brane na morfološke karakteristike riba i potvrđuju da otoliti i ljuske mogu biti korisni u proučavanju promjena u ribljim populacijama.This study examines the impact of the Klipić hydroelectric power plant, built in the Sunja River, on the shape of otoliths and scales in two fish species: the chub (Squalius cephalus) and the pumpkinseed (Lepomis gibbosus). The aim is to identify differences in otolith and scale shapes between fish populations above and below the dam and to compare their effectiveness in distinguishing these populations. The geometric morphometric methods were used to test this aim. Sampling was conducted at three locations along the Sunja River: above the dam (Staza and Mlin) and below the dam (Klipić). The analyses revealed significant differences in chub scale shape between Staza and Klipić locations, while pumpkinseed scales differed significantly between Mlin and Klipić. Chub otoliths showed significant differences between Staza and Klipić, whereas differences in pumpkinseed otoliths were not significant. The results indicate the dam's impact on fish morphological characteristics and confirm that otoliths and scales can be useful for studying changes in fish populations
Amphelographic evaluation of clone candidates of the ‘Trnjak crni’ variety under the conditions of the Imotski vineyard
No full text'Trnjak crni' je gospodarski značajna sorta vinove loze na području Vinogorja Imotski. S obzirom na povijest uzgoja na spomenutim prostorima u populaciji ove sorte uočena je unutarsortana varijabilnost te je 2020. godine na području tog vinogorja započela klonska selekcija. U postupku selekcije odabrani su trsovi kod kojih su uočene pozitivne promjene u nekim gospodarski važnim svojstvima. Odabrani elitni trsovi razmnoženi su u klonske linije 2021. godine u matičnom nasadu na području Vinogorja Imotski radi daljnje selekcije. Istraživanje se provelo na 22 klonske linije sorte 'Trnjak crni' posađenih u matičnom nasadu u Vinogorju Imotski. Utvrdile su se najvažnije gospodarske karakteristike na po 10 trsova svake klonske linije. U tehnološkoj zrelosti utvrdio se broj grozdova po trsu, prosječna masa grozda te prirod. Utvrđene su signifikantne razlike između klonskih kandidata za sljedeća svojstva: masa grozda, masa bobe, osnovni pokazatelji kakvoće mošta (šećer, ukupna kiselost, pH, organske kiseline) i polifenoli. Utvrđene razlike između klonskih kandidata će biti podloga za daljnju selekciju najboljih klonskih kandidata koji će se koristiti za komercijalnu proizvodnju.'Trnjak crni' is an economically significant grape variety in the Imotski Vineyard area. Given the history of cultivation in the mentioned areas, intravarietal variability has been observed within this variety's population, and clonal selection began in 2020 in this vineyard region. During the selection process, vines showing positive changes in some economically important traits were chosen. The selected elite vines were propagated into clonal lines in 2021 in a mother vineyard in the Imotski Vineyard area for further selection. The research was conducted on 22 clonal lines of the 'Trnjak crni' variety planted in the mother vineyard in the Imotski Vineyard area. The most important economic characteristics were determined on 10 vines of each clonal line. At technological maturity, the number of clusters per vine, the average cluster weight, and the yield were determined. Significant differences were found among the clonal candidates for the following traits: bunch weight, berry weight, basic must parameters (sugar, total acidity, pH, organic acids), polyphenols, and volatile compounds. The identified differences between the clonal candidates will be used for further selection of the best clonal candidates to be used for commercial production
Comparative analysis of irrigation water quality within the Smart Agriculture Network project
No full textNavodnjavanje je agrotehnička mjera koja je važna za Mediteransko područje, a u bududnosti de se i povedati njezin značaj ukoliko se nastave sve češde pojave suša i visokih temperatura. Maslina (Olea europaea L.) je kultura koja je vrlo rasprostranjena na Mediteranu te dobro prilagođena klimatskim uvjetima mediteranskog područja, međutim za postizanje optimalne kvalitete i odgovarajudih prinosa zahtjeva navodnjavanje. Cilj rada je bio osim obroka navodnjavanja i trenutka početka navodnjavanja koji su definirani tijekom provedbe projekta SAN, utvrditi i kakvodu vode za navodnjavanje usporednom analizom pojedinačnih uzoraka, godina i lokacija uzorkovanja. Unutar SAN projekta provedene su analize vode za navodnjavanje na dvije lokacije, maslinik u Žmanu i maslinik u Novigradu. Uzorci od 1 L su uzeti tijekom srpnja, rujna i studenog u 2019. g., a u 2020. g. tijekom travnja, srpnja i rujna iz sustava za navodnjavanje te dostavljeni u ovlašteni laboratoriji gdje je napravljena analiza vode. Prema analizama vode određeni su izabrani kemijski parametri kakvode vode: irigacijski koeficijent (Ki), SAR vrijednost i elektrovodljivost (EC). Obavljena je deskriptivna statistička analiza usporedbe izmjerenih vrijednosti parametara kvalitete vode. Usporednom analizom prosječnih vrijednosti parametara kakvode vode za navodnjavanje prema lokacijama i godinama, voda za navodnjavanje na lokaciji Žman 2019. godine je imala najviše vrijednosti irigacijskog koeficijenta (48,61), najviše vrijednosti SAR-a (124,48) te najmanju elektrovodljivost (0,31 dS/m) dok su najviša utvrđena elektrovodljivost (39,28 dS/m) i najniži irigacijski koeficijent (5,03) bili 2019. na lokaciji Novigrad, a najniža SAR vrijednost (35,75) je bila 2020. g. na lokaciji Novigrad. Primjena zaslanjenih voda u navodnjavanju može imati dugoročne negativne posljedice stoga je vrlo važno provoditi daljnje analize kakvode vode te koristiti samo vodu odgovarajude kakvode prema parametrima koji su unaprijed određeni. Određivanje Ki, SAR i EC je posebno bitno za područje Mediterana bududi da je na tom području česta pojava zaslanjenih ili alkaliziranih voda.Irrigation is an agrotechnical measure that is important for the Mediterranean area, and its significance will increase in the future if droughts and high temperatures continue to occur more frequently. Olive (Olea europaea L.) is a crop that is very widespread in the Mediterranean and well adapted to the climatic conditions of the Mediterranean area, however, to achieve optimal quality and adequate yields, irrigation is required. The aim of the work was, in addition to the irrigation rations and the moment of the start of irrigation, which were defined during the implementation of the SAN project, to determine the quality of irrigation water by comparative analysis of individual samples, years and locations of sampling. Within the SAN project, irrigation water analyzes were carried out at two locations, an olive grove in Žman and an olive grove in Novigrad. Samples of 1 L were taken during July, September and November in 2019, and in 2020 during April, July and September from the irrigation system and delivered to authorized laboratories where water analysis was done. According to water analyses, selected chemical parameters of water quality were determined: irrigation coefficient (Ki), SAR value and electrical conductivity (EC). A descriptive statistical analysis of the comparison of measured values of water quality parameters was performed. By comparative analysis of the average values of irrigation water quality parameters according to locations and years, the irrigation water at the Žman location in 2019 had the highest values of the irrigation coefficient (48.61), the highest SAR values (124.48) and the lowest electrical conductivity (0 .31 dS/m) while the highest determined electrical conductivity (39.28 dS/m) and the lowest irrigation coefficient (5.03) were in 2019 at the Novigrad location, and the lowest SAR value (35.75) was in 2020. at the Novigrad location. The use of saline water in irrigation can have long-term negative consequences, therefore it is very important to carry out further analyzes of water quality and to use only water of appropriate quality according to parameters that have been determined in advance. The determination of Ki, SAR and EC is especially important for the Mediterranean area, since there is a frequent occurrence of saline or alkalized waters in that area
Biogas production of cheese whey before and after curd production
No full textGlavni nusproizvod u proizvodnji sira jest sirutka koja sadrži velike koncentracije organske
tvari. Odlaganjem sirutke u okoliš povećava se opasnost pojave eutrofikacije. S obzirom da
danas težimo smanjenju odlaganja i zbrinjavanja otpada, jedan od načina upravljanja otpadom
je iskorištenje nusproizvoda s ciljem dobivanja novih proizvoda s dodanom vrijednošću. Zbog
svojeg sastava koji je bogat organskim komponentama, sirutka se može koristiti u proizvodnji
bioplina. Bioplin je energent koji se danas u RH koristi za proizvodnju električne i toplinske
energije u kogeneracijskim sustavima, a dugoročno može pozitivno utjecati na ugljični otisak
različitih lanaca vrijednosti. U ovom radu radila se usporedba prinosa bioplina i metana iz šest
uzoraka sirutke dobivene prije i poslije proizvodnje skute. Također, prikazane su
međuzavisnosti pojedinog uzorka o parametrima kao što su udio suhe tvari, udio vode, te udio
makro i mikro elemenata koji utječu na kvalitetu sirovine, te ovisnost prinosa bioplina i
kemijske potrošnje kisika.The main by-product in cheese production is whey, which contains high concentrations of
organic matter. Disposing of whey in the environment increases the risk of eutrophication.
Since we are striving today to reduce waste disposal and management, one way to manage
waste is to utilize by-products with the aim of creating new products with added value. Due
to its composition, which is rich in organic components, whey can be used in biogas
production. Biogas is an energy source that is currently used in Croatia for the production of
electricity and heat in cogeneration systems, and in the long term, it can positively impact the
carbon footprint of various value chains. This study compared the yield of biogas and methane
from six whey samples obtained before and after the production of ricotta. Additionally, the
interdependencies of individual samples with parameters such as dry matter content, water
content, and the content of macro and microelements affecting the quality of the raw material
were presented, as well as the dependence of biogas yield on chemical oxygen demand
Determination of free amino acids during the ripening of "Paški sir" cheese
No full textPaški sir jedan je od najpoznatijih hrvatskih tradicionalnih sireva, a proizvodi se od mlijeka autohtone Paške ovce na otoku Pagu. Specifična mediteranska klima, aromatični biljni pokrov i djelovanje bure daju mlijeku i siru jedinstven okus. Zrenje je ključna faza u proizvodnji Paškog sira, tijekom koje enzimi pokreću sintetske i kataboličke procese koji izravno utječu na kvalitetu sira. Tijekom zrenja sira, uslijed proteolitičkih procesa, dolazi do razgradnje proteina pri čemu nastaju slobodne aminokiseline koje utječu na formiranje specifičnog mirisa, okusa i arome Paškog sira. Sastav i udio ovih aminokiselina značajno utječu na teksturu i senzorska svojstva sira, uključujući njegovu završnu aromu, koja se mijenja ovisno o trajanju zrenja. Uzorci Paškog sira (n=15) različite zrelosti (0., 30., 60., 90., 120. dana) prikupljeni su u mini sirani u Kolanu. Sastav slobodnih aminokiselina u siru određen je vezanim sustavom tekućinske kromatografije visokog učinka - spektometrija masa (HPLC-MS/MS) bez kemijske modifikacije. Priprema uzoraka provedena je u Referentnom laboratoriju za mlijeko i mliječne proizvode Zavoda za mljekarstvo Agronomskog fakulteta Sveučilišta u Zagrebu, a HPLC-MS/MS analize provedene su u Laboratoriju za spektometriju masa i funkcionalnu proteomiku u Zavodu za fizičku kemiju, u Institutu Ruđer Bošković. Ukupna količina slobodnih aminokiselina povećavala se zrenjem. U Paškom siru utvrđeno je da su prevladavale glutaminska kiselina, valin, fenilalanin, leucin i lizin. 60. dana zrenja najviši udio utvrđen je za glutaminsku kiselinu (1319,05 ± 415,03 mg/100 g suhe tvari), valin (1635,15 ± 443,31 mg/100 g suhe tvari), fenilalanin (1661,14 ± 342,58 mg/100 g suhe tvari), leucin (2032,29 ± 541,02 mg/100 g suhe tvari) i lizin (891,88 ± 575,92 mg/100 g suhe tvari). Na temelju dobivenih rezultata, zrenje Paškog sira ne smije biti kraće od 60 dana jer nakon toga dolazi do daljnje razgradnje slobodnih aminokiselina koje značajno doprinose njegovom karakterističnom okusu.Cheese „Paški sir“ is one of the most famous traditional Croatian cheeses and is made from the milk of the indigenous Paška sheep on the island of Pag. The special Mediterranean climate, the aromatic vegetation and the effect of the bora give milk and cheese a unique flavour. Ripening is a key stage in the production of cheese „Paški sir“, during which enzymes trigger synthetic and catabolic processes that directly affect the quality of the cheese. During cheese ripening, proteolytic processes break down proteins, producing free amino acids that influence the formation of the specific odour, flavour and aroma of cheese „Paški sir“. The composition and proportion of these amino acids have a significant influence on the texture and sensory properties of the cheese, including its final flavour, which changes depending on the ripening period. Samples of cheese „Paški sir“ (n=15) with different ripening periods (0, 30, 60, 90, 120 days) were collected in a small cheese dairy in Kolan. The composition of free amino acids in the cheese was determined using a coupled system of high performance liquid chromatography - mass spectrometry (HPLC-MS/MS) without chemical modification. Sample preparation was performed in the Reference Laboratory for Milk and Dairy Products of the Department of Dairy Science, Faculty of Agriculture, University of Zagreb, and HPLC-MS/MS analyses were performed in the Laboratory of Mass Spectrometry and Functional Proteomics in the Department of Physical Chemistry, Ruđer Bošković Institute. The total amount of free amino acids increased as the cheese ripened. Glutamic acid, valine, phenylalanine, leucine and lysine were found to be the predominant amino acids in cheese „Paški sir“. On the 60th day of ripening, the highest concentrations were found for Glutamic acid (1319.05 ± 415.03 mg/100 g dry matter), Valine (1635.15 ± 443.31 mg/100 g dry matter), Phenylalanine (1661.14 ± 342.58 mg/100 g dry matter), Leucine (2032.29 ± 541.02 mg/100 g dry matter) and Lysine (891.88 ± 575.92 mg/100 g dry matter). Based on these results, it is recommended that the ripening period for Paški sir should not be less than 60 days, as the further degradation of free amino acids after this time significantly improves the distinctive flavour of the cheese
Development of viticulture and winery of the western Istrian area
No full textU ovom se radu prikazuje i opisuje povijest razvoja vinarstva i vinogradarstva na vinogorju zapadne Istre. Prikazani su podatci o temperaturi, padalinama, vlažnosti zraka koji utječu na razvoj vinarstva i vinogradarstva. Opisana su obilježja tla, opisan je sortiment i najvažnije autohtone sorte sa područja Istre. Prikazani su podatci o površinama pod vinogradima, a na kraju se nalazi zamisao u kojemu bi se smjeru trebalo razvijati vinarstvo i vinogradarstvo zapadnog Istarskog vinogorja.This work shows and describes history of development in western Isrian area. It shows data about temperature, rainfall and air humidity that impact development of the western Istrian area. Data describe soil, describe assortment and the most important domestic varieties in Istrian area. Data shows surfaces under vineyard production and in the end there is a thought on which way viticulture and winery of the western Istrian area should be going
The impact of edible coatings on the occurrence of gray mold botrytis cinerea during the storage of mandarin fruits
No full textViše od 40% voća i povrća ubranog diljem svijeta propadne. Veliki postotak tog gubitka
povezan je s gljivičnim patogenima koji uzrokuju truljenje nakon berbe, poput Botrytis cinerea.
Rješenje ovog problema komplicirano je zbog ograničenja fungicida dostupnih za kontrolu
rasta tog gljivičnog patogena i nameće potrebu za ekološki prihvatljivim alternativama.
Primjenom jestivih omotača na voće prije skladištenja može se na ekološki prihvatljiv način
spriječiti propadanje svježih proizvoda nakon berbe. Jestivi omotači imaju značajnu ulogu u
smanjenju gubitaka poslije berbe kao što su gubitak vlage, sazrijevanje i fizikalno-kemijski
gubici. U ovom radu ispitan je utjecaj tri vrste jestivih omotača (kitozan, zein i kombinacija
'sloj po sloj' kitozana i zeina) na pojavu sive plijesni Botrytis cinerea na plodovima mandarine
tijekom skladištenja. Plodovi mandarine tretirani kitozanom pružaju najveću zaštitu na širenje
infekcije sive plijesni u odnosu na tretman zeinom i otopinom kitozan-zeina. Tretman otopinom
kitozan-zeina pokazao je stabilizaciju i porast TSS uz kontroliran pad TA, što se pokazalo kao
najbolja kombinacija za očuvanje kvalitete mandarina tijekom dužeg skladištenja.More than 40% of fruits and vegetables harvested worldwide fail. A large percentage of this loss is
associated with fungal pathogens that cause rotting after harvest, like Botrytis cinerea. The solution
to this problem is complicated due to the limitations of fungicides available to control the growth
of this fungal pathogen and imposes the need for environmentally friendly alternatives. Applying
edible coatings to fruits before storage can prevent the deterioration of fresh products after harvest
in an environmentally friendly way. Edible coatings play a significant role in reducing post-harvest
losses such as moisture loss, maturation and physicochemical losses. In this paper, the influence of
three types of edible coatings (chitosan, zein and combination of chitosan and zein) on the
appearance of gray mold Botrytis cinerea on mandarin fruits during storage was examined.
Mandarin fruits treated with chitosan provide the highest resistance to the spread of gray mold
infection compared to treatment with zein and chitosan-zein solution. The treatment with chitosanzein
solution showed stabilization and an increase in TSS with a controlled decrease in TA, which
proved to best combination for preserving the quality of mandarins during longer storage