Multicolor tisak i njegova postojanost na ubrzano starenje

Visoku kvalitetu višebojne reprodukcije nemoguće je zamisliti bez upotrebe dodatnih bojila. Prilikom proizvodnje ekskluzivne ambalaže primjenjuju se dodatne PANTONE boje kojima se omogućuje bolja ponovljivost tiska. U grafičkoj industriji trenutno se koriste 1114 PANTONE nijansi dobivenih miješanjem 15 baznih pigmenata plus crna i bijela. Česta varijanta je da se PANTONE boje pokušavaju realizirati i pomoću standardnih procesnih boja (CMYK) čiji rezultat ponekad nije kvalitetom zadovoljavajući. U ovom radu usporedila se mogućnost realizacije 6 karakterističnih PANTONE tonova koje u različitim omjerima sadržavaju narančasto i zeleno bojilo (mali, srednji i veliki udio). Pritom su se eksperimentalni PANTONE tonovi realizirati na dva načina: otiskivanjem principom 4/0 (iz CMYK-a) i otiskivanjem 5/0 (CMYK+G i CMYK+O). Preduvjet tome je kvalitetno izvršeno otiskivanje osnovnih bojila. Pritom je nužno utvrditi koliki su ostvareni nanosi bojila (optička gustoća obojenja punog tona) odnosno kakva je krivulja reprodukcije (prirasti rastertonske vrijednosti). Nakon toga se određuju njihova kolorna odstupanja i varijacije u odnosu na standardni PANTONE (digitalni katalog). U drugom dijelu eksperimenta PANTONE otisci se izlažu simuliranom starenju u Solar box 1500 primjenjujući pritom metodu HR ISO 12 040-2004 (UV svjetlost dobivena zračenjem xsenonske lampe snage 550 W/m2 uz primjenu 320 nm filtra, temperature zraka od 50°C i relativne vlažnosti zraka od 65%). Drugim riječima vrši se proces ubrzanog starenja (u vremenskim intervalima od 0h, 6h, 12h, 24h, 48h, 96h, 144h i 250h) kako bi se utvrdila realna uporaba tako proizvedenih otisaka odnosno buduće kartonske ambalaže. Nakon provedenog eksperimenta mjerenja su pokazala da žuto bojilo doživljava najveću promjenu tokom starenja, a cijan bojilo se najmanje mijenja od svih mjerenih bojila. Tako se PANTONE tonovi s većim udjelom žutog bojila ne preporučuju tiskati peterobojnom metodom jer su razlike u odnosu na standardni CMYK zanemarive

A Comparative Study of some Local Genotypes with Commercial Cultivar of Black Elder (Sambucus nigra L.) Regarding Vegetative and Reproductive Traits

The main goal of this study was to evaluate three black elder (Sambucus nigra L.) genotypes (“Prigorje”, “Korčula”, “Zagreb”) and compare them with cv. Haschberg as standard cultivar. Diameter of inflorescences, cluster mass, berry/stem mass ratio, mass of 10 berries and SSC were higher in season 2014 than in season 2015, while length of one-year-old shoot and flowering density showed no significant differences. Interaction between season and genotype (S × G) was not significant for any of studied parameters. Genotype “Korčula” had significantly smaller diameter of inflorescence (11.26 ± 1.5 cm) than genotypes “Prigorje”, “Zagreb” and cv. Haschberg (16.81 ± 2.38, 18.05 ± 2.39, 17.5 ± 2.23 cm, respectively). Genotype “Korčula” (0.09 ± 0.03 flowers·cm-1) had significantly smaller flowering density than genotypes “Prigorje”, “Zagreb” and cv. Haschberg (0.15 ± 0.07, 0.15 ± 0.04, 0.16 ± 0.04 flowers·cm-1, respectively). Genotype “Korčula” had significantly smaller cluster mass (23.35 ± 10.71 g) than genotypes “Prigorje”, “Zagreb” and cv. Haschberg (54.07 ± 22.09, 56.24 ± 22.76, 67.29 ± 24.56 g, respectively). Cv. Haschberg had significantly higher mass of 10 berries (1.35 ± 0.2 g) than genotypes “Zagreb” (1.15 ± 0.17 g) and “Korčula” (1.14 ± 0.19 g). Genotype “Zagreb” had significantly higher value of total soluble solids (10.23 ± 1.74 %Brix) than genotype “Korčula” (8.99 ± 1.89 %Brix). Among studied genotypes and cv. Haschberg no significant differences were found for length of one-year-old shoot. Since no significant differences were recorded between cv. Haschberg and genotypes “Zagreb” and “Prigorje” in majority of parameters, these genotypes should be further evaluated for longer period in order to bring final conclusions about their commercial and breeding potential

Influence of Different Netting Structures on Codling Moth and Apple Fruit Damages in Northwest Croatia

During the vegetation season of 2015 exclusion nets were set up in IPM apple orchard in Krapina (Croatia) to test their effectiveness in preventing the attack of codling moth to apple fruits. Nets were the same in mesh size (2.4 x 4.8 mm) but different in color (white, red, yellow) in order to examine their effect on vegetative growth and quality of apples. To assess the presence of pest, weekly sampling of codling moth on pheromone traps in protected and unprotected (control) net rows was conducted. Single row netting structures resulted in a highly significant reduction of codling moth catches on pheromone traps in comparison to the unprotected control in the experimental orchard. The percentage of codling moth infested fruits during the harvest time was considerably lower, in the protected net rows in comparison with unprotected rows. The lowest percentage of damaged fruits was recorded under the red net (0.96%), followed by white net (1.04%) and yellow net (2.86%). Percentage of damaged fruits in unprotected row amounted to 11.39%. Considering the fact that the mean net efficiency amounted to almost 90%, these results confirm the effectiveness of netting structures in the protection of apple fruits from CM damages

Utjecaj crvene foto selektivne mreže na kakvoću ploda jabuke \u27Granny Smith\u27 nakon čuvanja u hladnjači i života na polici

The present study was conducted with aim to test the effect of red photo-selective nets (Agritech S.r.l., Eboly, Italy) on \u27Granny Smith\u27 apple postharvest quality. The fruits have been harvested on optimal harvest date from orchard near city of Zadar where red photo-selective nets were used. Afterwards fruits were stored in regular air storage at 0°C for 4 months and then kept for 7 days at room temperature (shelf life). After harvest, cold storage and shelf life fruits grown under red net had significantly lower total soluble solid (SSC) content. After cold storage, superficial scald index and share of fruits with strong and very strong superficial scald severity were significantly higher in fruits grown under red net while for share of fruits with low superficial scald severity situation was opposite. After shelf life, fruits grown under red net had significantly higher titratable acidity (TA), but lower weight loss and SSC/TA ratio. It can be concluded that, due to greater susceptibility to superficial scald, prevention measures (optimal harvest time, 1-MCP and CA storage) should be applied when red photo-selective net is used on superficial scald-susceptible apple varieties.Cilj ovog istraživanja je utvrditi utjecaj crvene fotoselektivne mreže (Agritech S.r.l., Eboli, Italija) na kakvoću plodova jabuke \u27Granny Smith\u27 nakon skladištenja i života na polici. Plodovi su ubrani u optimalnom roku u voćnjaku lociranom pokraj Zadra, Hrvatska gdje je korištena crvena fotoselektivna mreža. Nakon berbe plodovi su tijekom 4 mjeseca skladišteni u običnoj hladnjači pri 0°C te potom 7 dana na sobnoj temperaturi (život na polici). Plodovi uzgajani ispod crvene mreže su nakon berbe, skladištenja u hladnjači i života na polici imali signifikantno manji sadržaj topljive suhe tvari. Nakon završetka skladištenja u hladnjači indeks površinskog scalda te udio plodova sa jakim i iznimno jakim simptomima površinskog scalda je bio signifikantno veći na plodovima uzgojenima ispod crvene mreže, dok je za udio plodova sa blagim simptomima površinskog scalda situacija bila suprotna. Nakon života na polici plodovi uzgojeni ispod crvene mreže su imali signifikantno veću titracijsku kiselost, ali manji kalo i omjer topljive suhe tvari i titracijske kiselosti. Može se zaključiti da zbog veće osjetljivosti na površinski scald preventivne mjere (optimalan rok berbe, 1-MCP i čuvanje u kontroliranoj atmosferi) trebaju biti primijenjene kada se crvena fotoselektivna mreža koristi na sortama jabuke osjetljivima na površinski scald

The Heating and Cooling of ‘Idared’ Apple with Respect to the Duration of the Hot Water Dip Heat Treatment

A research was conducted on the effect of heat treatments on the heating and cooling of the ‘Idared’ apple fruit. The heat treatment was performed as hot water dip (HWD), where fruit were dipped into water at 50 °C, for two, four and six minutes (HWD 500C 2’, HWD 500C 4’ and HWD 500C 6’, respectively). The aim of the study was to determine the effect of heat treatments on the warming and cooling on the fruit which was observed by thermographic images recorded every minute for the duration of 12 minutes in total. The fruit treated with HWD 50°C 6’ achieved the highest temperature (50.6 0C), followed by HWD 500C 4’ (48.2 0C) and HWD 500C 2’ (44.3 0C). The damage to fruit caused by high temperatures (heat damage) was visible only on the fruit treated with HWD 50°C 6’. The differences in maximal temperature of fruit surface were statistically different among all three exposures for the whole duration of recording, meaning that the duration of the hot water dip treatment significantly affects the intensity of fruit cooling after heat treatment

Analysis of Acoustic Impulse Method for Determining Firmness and other Quality Parameters of \u27Gloster\u27 Apple

A comparative study regarding standard fruit quality measurements (fruit mass, firmness, soluble solids concentration, starch conversion rate and Streif index) and acoustic properties (resonant frequency, peak width, resonant frequency/peak width ratio and stiffness) were conducted in ‘Gloster’ apples during two seasons. The findings obtained indicate no significant differences between seasons in studied quality parameters as well as in acoustic properties. The fruits were characterized with unusual high mass and high variation in resonant frequency and peak width, especially in season-I. In about 50% of examined fruit, the acoustic signal was not typical with one clearly visible peak, and appeared with two or, in few cases, even three peaks that were sometimes of similar height. The fruit mass was negatively correlated with resonant frequency, but correlation coefficient was lower in season-I and less significant than in season-II. Correlation coefficient between fruit mass and peak width was the same in both seasons. Although positive correlation existed between fruit mass and resonant frequency/peak ratio in both seasons, correlation coefficient in season-I was higher and more significant than in season-II. Correlation between fruit mass and stiff ness existed only in season-II. Resonant frequency was positively correlated with peak width only in season-I. Stiff ness was positively correlated with Streif index and peak width only in season-II. Though not significant, higher variations in acoustic properties than standard quality measurements still indicate some usefulness of acoustic impulse method for determination of fruit quality of ‘Gloster’ apple. However, further research is needed to elucidate the significance of individual acoustic parameters and their relation to fruit quality

Effect of Timing and Rates of NAA Chemical Thinner on Fruit Quality of apple cv. \u27Granny Smith\u27

Fruit thinning in apple crop plays a critical role to achieve marketable king size fruits with better fruit quality apples. The thinning experiments were conducted using naphthaleneacetic acid (NAA) at different concentrations (0, 10, 15 and 20 μl·l-1) applied at three timings [full bloom (FBT), fruit (FT) and the combination of both (FBT + FT)] in order to evaluate the optimum level of thinner with best application timing on fruit quality attributes of cv. \u27Granny Smith\u27 fruits. Statistically significant differences were found regarding the effect of timing, concentration and combination of both, timing and concentrations, on firmness, soluble solids concentration (SSC) and titratable acidity (TA), while there were no significant differences with addition of timing for SSC/TA ratio, fruit mass and starch degradation level. The highest fruit mass (195.09 g) and TA (0.67%) was achieved using NAA at 20 μl·l-1 in FT time while NAA at 15 μl·l-1 resulted in highest fruit firmness (7.25 kg cm-2), SSC (13.04° Brix) in FBT time. SSC/TA ratio was the highest (25.31) at FT time with the same NAA dosage. However, the highest starch degradation was achieved at FBT + FT time with 15 μl·l-1. It can be concluded that application of 10 μl·l-1 NAA at FBT + FT time is recommended to achieve best results since it favourably affected the most quality parameters

Usporedba obojenja kod obostranog ofsetnog tiska

U ovom radu će se govoriti o ofsetom tisku općenito, o strojevima i principu ofsetnog tiska, te o kontroli i upravljanju ofsetnog tiska kako bi se moglo shvatiti zašto dolazi do odstupanja unutar naklade. Poglavito će se obraditi poteškoće kod promjene gustoće obojenja na otiscima obostranog ofsetnog tiska. Kroz mjerenja mjernih stripova na otiscima iz jedne naklade obostrano otisnutog ĉasopisa na Heidelberg Speedmaster stroju sa šest tiskovnih agregata pokušat će se objasniti eventualna nastala odstupanja od predviĊene kvalitete tiska. Bazirati će se mjerenja na odstupanja jedne strane otiska u odnosu na drugu stranu otiska te će se pokušati objasniti uzroke eventualnih odstupanja. Koristiti će se vizualna kontrola otisaka, te spektrofotometrijska mjerenja za kontrolu nanosa bojila na stripovima