Statistical Evaluation of Dynamic Changes of ‘Idared’ Apples Colour During Storage

Colour changes on fruit during storage from brighter to darker nuances are caused by chemical reactions which oft en have degradative changes as a consequence. In this paper, evaluation of colour changes was done in CIE Lab colour model by using Minolta colorimeter CR-300 and in RGB colour model by applying digital image analysis method. In the aim of increasing of sample representativity analyzed apples were taken from different positions on trees and from different trees in orchard that was planted in 1983. Apples were harvested at a big commercial orchard in two different harvest times during one season. 30 apple pieces of Idared cultivar were analyzed immediately after harvest and periodically during storage for 20 weeks at 0 oC and 85-88% relative humidity. Apple temperature of all analyzed samples during storage period was T=0±0.4 oC. Mean colour change of apple skin determined in CIE Lab was ΔEab=1.53, while in RGB color model was ΔERGB=1.81. Total apple skin colour changes in Lab colour model was ΔEab=5.90, while in RGB colour model was ΔERGB=8.48. Both methods showed apple skin colour changes in the same way. Correlation between results was found to be 0.32 (p<0.05)

Quality of Cabbage Cultivars Intended for Fermentation in the Ogulin Region

Fresh cabbage intended for fermentation should have solid and robust heads with the soluble dry matter content above 3% and light coloured external leaves. Heads are prepared in a 5.5% sodium chloride concentration brine. Biological fermentation proceeds at a temperature of 18-22 °C, in the dark and under anaerobic conditions. The research objective is to find out whether the quality of fresh and fermented cabbage of hybrid cultivars can compete with and replace the cultivar ´Varaždinski´ in the production area of Ogulin. Cabbage ´Varaždinski´ was the predominant and also the referent cultivar, while the other studied cultivars were ´Junior´, ´Kilor´, ´Krautman´ and ´Satellite´ from the Ogulin production area. The quality of fresh raw material during the two trial years was defined by the content of dry matter of 6,63- 8,74%, soluble dry matter of 4,0-6,0%, lactic acid of 0,1-0,4%, pH-value of 5,65-6,40, L-ascorbic acid of 151,83-359,11 mg/100 g dry matter and NaCl of 0,09-0,18%. The quality of fermented products during the two trial years was defined by the content of dry matter of 6,00-6,98%, soluble dry matter of 4,97-5,70%, lactic acid of 0,88-1,26%, pH-value of 3,62-4,18, L-ascorbic acid of 63,81-213,23 mg/100 g dry matter and NaCl of 1,53-2,56%. No significant differences between fresh cabbage cultivars were determined by the analysis of variance in the contents of dry matter, soluble dry matter, % of lactic acid, pH value, % of NaCl and L-ascorbic acid. In the first research year, significant differences between cultivars were determined in the content of L- ascorbic acid and the pH value. In the second research year, significant differences were determined in the content of L- ascorbic acid between 60 and 90 days of fermentation. The results indicate that the cultivar ´Varaždinski´ can be replaced in the Ogulin region by the studied hybrid cultivars

Thin-layer drying of mint (Mentha piperita) leaves

List paprene metvice (Mentha piperita) bio je sušen u elemen-tarnom (tankom) sloju u sušnici na temperaturama zraka raspona od 35 do 60 °C. Porast temperature radnog medija (zraka) značajno je smanjio vrijeme sušenja lista. Podaci o sušenju lista paprene metvice analizirani su i u pogledu difuzije u periodima sušenja.The thin-layer drying of mint leaves for a temperature range of 35–60 °C was determined in a (cabinet) dryer. The increase in air temperature significantly reduced the drying time of the mint leaves. Drying data of this material were analysed to obtain diffusivity values from the falling rate-drying period

The Quality of Fresh Tomato Fruit Produced by Hydroponic

The quality of fresh tomatoes (Lycopersicon esculentum Mill.) planted in rockwool in hydroponic system is defined by their internal parameters: contents of dry matter and soluble dry matter (°Bx), total acidity (% citric acid), pH, % NaCl and L-ascorbic acid. Research was carried out during 2003 and included 21 cultivars. Tomato plants were planted into rockwool slabs 100 cm x 15 cm x 7.5 cm. Three plants were planted 33 cm apart in 11.25 L of substrate. The trial was laid out according to the randomized complete block design with four replications, and sampling was carried out during three harvests in: June, July and August. The dry matter content was 4.29% (cultivar ΄Syta΄) to 6.21% (cultivar ΄Delfine΄), and content of soluble dry matter was 3.0% (cultivar ΄Brooklyn΄) to 4.5% (΄Lustro΄ and ΄72-503΄). Total acidity amounted from 0.19% (cultivar ΄Syta΄) to 0.45% (cultivar ΄Lustro΄), and pH values ranged from 4.20 (cultivar ΄20377΄) to 4.68 (cultivar ΄Syta΄). Salt content ranged from 0.08% (΄Campeon΄ and ΄F 18402΄) to 0.13% (΄Brooklyn΄ and ΄E 27.31299΄), and L-ascorbic acid content ranged from 260.40 (cultivar ΄Antinea΄) to 458.30 mg/dry matter (cultivar ΄F 18402΄). By studying the basic chemical composition of selected cultivars, significant differences in their soluble dry matter and pH were revealed but only at the first sampling

Sweet Potato [Ipomoea batatas (L.) Lam] Yield Influenced by Seedlings and Mulching

Sweet potato [Ipomoea batatas (L.) Lam] needs a yearly minimum of three month with air temperatures above 15º C for its growth and development. For the purpose of achieving the highest possible sweet potato yield during a relatively short vegetation period in continental part of Croatia, a trial with differently produced seedlings and polyethylene (PE) mulch was set up. A trial was set up to study the production of seedlings from dormant sweet potato root sprouts by standard methods, and the most recent method of seedling production in containers, along with testing black PE-fi lm mulched soil, and uncovered soil. The method of seedlings production had significant effect on the yield. Higher mass of marketable roots was achieved by growing seedling with a substrate lump about the root, as compared to the seedlings produced by traditional procedure. Compared to the uncovered soil, a significantly higher yield of marketable roots was obtained with black PE-film mulch

QUALITY OF “ SHREDDED” SAUERKRAUT FROM OGULIN

Karakteristike svježeg kupusa namijenjenog za fermentaciju su čvrste i tvrde glavice s količinom topljive suhe tvari od 3 do 5% i svjetlijom bojom vanjskih listova. Glavice se nakon čišćenja režu u rezance ujednačene širine na stroju za rezanje. Pripremljeni rezanci se važu i miješaju s 2,25 % natrijevog klorida. Temperatura biološke fermentacije je 18-22 °C u tamnom prostoru i u anerobnim uvjetima. Natrijev klorid izdvaja stanični sok zbog osmoze, te se stvaraju uvjeti za razvoj heterofermentacijskih bakterija. Nastala mliječna kiselina i dodan natrijev klorid predstavljaju osnovne čimbenike konzerviranja kupusa. Sorta kupusa Varaždinski najzastupljenija je i ujedno referalna sorta, a druge istraživane sorte su Junior F1, Kilor F1, Krautman F1 i Satelite F1 s proizvodnog područja Ogulina. Kakvoća svježe sirovine i fermentiranog proizvoda kroz dvije godine definirana je količinom suhe tvari (%), topljive suhe tvari (%), % mliječne kiseline, pH-vrijednošću, količinom L-askorbinske kiseline (mg/100 g suhe tvari) i % NaCl. Sorta kupusa Varaždinski kao referalna sorta dala je prosječno bolje rezultate u količini NaCl i mliječne kiseline u svježoj sirovini i gotovom proizvodu. Sorta Krautman F1 vodeća je po količini L-askorbinske kiseline u svježoj sirovini i gotovom proizvodu. Kilor F1 ima više ukupne suhe tvari u svježem i fermentiranom proizvodu, a Satelite F1 ima veću kiselost i količinu topljive suhe tvari u svježem i fermentiranom proizvodu. Sorta Junior F1 nije pokazala značajnije odstupanje od prosječnih vrijednosti u svježoj sirovini i gotovom proizvodu. Vrijednosti analiza svježe sirovine i fermentiranog proizvoda nakon 30, 60 i 90 dana skladištenja daju značajno mjesto sorti Krautman F1 i veću zastupljenost na proizvodnim površinama Ogulina.Fresh cabbage intended for fermentation should have solid and robust heads with the soluble dry matter content above 3% and light coloured external leaves. Shredded cabbage is directly mixed with 2.25% NaCl. Biological fermentation proceeds at a temperature of 18-22 °C, in the dark and under anaerobic conditions. Sodium chloride extracts cell juice through osmosis, thus creating conditions for the development of heterofermentation bacteria. The formed lactic acid and the added sodium chloride are the main factors of cabbage pickling. The Varaždin cabbage cultivar was the predominant and also the reference cultivar, while the other studied cultivars were Junior F1, Kilor F1, Krautman F1 and Satellite F1 from the Ogulin production area. The quality of fresh raw material and of fermented products during the two trial years was defined by dry matter (%), soluble dry matter (%), lactic acid (%), pH-value, L-ascorbic acid (mg/100 g dry matter) and NaCl (%) content. The Varaždin cultivar rendered the best results for NaCl and lactic acid in fresh raw material and in the final product, while Krautman F1 was the best cultivar regarding the L-ascorbic content acid in fresh raw material and in the final product. Junior F1 had a higher soluble and total dry matter content in fresh and in fermented cabbage. The fermented product of Kilor F1 had higher acidity, while there were no notable aberrations from average values in the Satellite F1 fresh raw material or in its fermented product. Results of the fresh raw material and fermented product analyses after 30, 60 and 90 days of storage point to the advantage of the cultivar Krautman F1 and the justification of its higher share in the production areas of Ogulin