Theoretical Potential of Post-harvest Residues in Međimurje County for Energy Generation

Međimurje County, because of its relatively developed agricultural production has a great potential to collect and utilize agricultural residues in energy production. Instability of prices of energy-generating products, together with increase of ecological awareness, make renewable sources and, therefore, agricultural residues, more and more interesting raw material for energy production. The aim of this work was to determine the theoretical potential and availability of post-harvest residues under sustainability conditions in the agricultural sector in the Međimurje County area. Availability of agricultural residues makes it possible to estimate the amount of biomass, needed for energy production in the research area. The calculation includes the following agricultural crops: corn, wheat, barley and rapeseed. The results show that there are 22,846 tonnes of residues after corn production, 5,285 tonnes of residues after wheat production, 2,853 tonnes of residues after barley production and 2,686 tonnes of residues after production of rapeseed available in the County, for energy production

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

Lemon balm (Melissa officinalis L.) leaves pre-drying by using low energy laser beam

A laboratory laser beam drying method for lemon balm (Melissa officinalis L.) is presented. The aim of this study was to determine the possibility of using lasers as a pre-treatment for drying the lemon balm leaves and also to determine the variation of water content during the treatment. Leaves were illuminated from one side during a period of 180 s with 100 mW and 200 mW lasers. Both sources of coherent light were in the red part of the visible spectrum with wavelengths of 650 nm. Freshly harvested lemon balm leaves with 75.64% of water content were used for the analysis. Low-energy laser beam treatment for a period of 180 s resulted in the reduction of water content of 0.307% for 100 mW laser treatment and 0.31% for the 200 mW laser treatment. Amounts of energy emitted by low energy lasers are relatively small. Therefore, lasers thermal influence is negligible so it can be concluded that laser activity on lemon balm leaves is based solely on biostimulation. The proposed method allows effective reduction of water content without causing damage to the plant material. For practical application, dryers with integrated laser diode network were proposed. Low energy coherent radiation treatment represents an inexpensive and environmentally safe method that does not pollute the environment. This method also provides close control of the process, and in spite of the greater cost of energy, the overall increase in drying efficiency and throughput can bring about significant economic savings.</p

Mathematical Models of Influence of Total Admixtures and Kernel Moisture on Hectoliter Weight of Wheat

Da bi se utvrdilo da li se odnosi između hektolitarske mase, ukupnih primjesa i njihovih komponenata te vlage zrna pšenice mogu matematički modelirati, kroz trogodišnje razdoblje (1997.–1999. godina) uzimani su uzorci pšenice prilikom prijama u jednom silosu na području sjeverozapadne Hrvatske. Namjera istraživanja bila je, odrediti utjecaj prije navedenih veličina jedne na drugu ali bez podataka o sortama i agrotehnici odnosno, snimiti stanje upravo onako kako ono izgleda kod prijama kako pšenice uzgojene uz višu agrotehniku, tako i kod pšenice uzgojene na niskoj agrotehnici. Svake godine uzeto je 20 slučajno odabranih uzoraka. U svim uzorcima određena je hektolitarska masa, vlaga u zrnu i ukupne primjese, a u zadnjoj godini istraživanja (1999. godina) određene su i pojedinačne vrijednosti crnih i bijelih primjesa kao i njihovih komponenti. Pomoću koeficijenta korelacije prikazan je utjecaj prije navedenih veličina jedne na drugu, kao i utjecaj komponenti crnih i bijelih primjesa na hektolitarsku masu i vlagu zrna. Međusobni utjecaj nabrojenih veličina matematički je modeliran pomoću linearnih jednadžbi. U trogodišnjem razdoblju istraživanja u prosjeku hektolitarska masa i ukupne primjese su u negativnoj korelaciji (r=–0,38; P<0,01). U negativnoj korelaciji su i hektolitarska masa i vlaga zrna (r=–0,37; P<0,01). Kada se raspon vlaga u zrnu koje su utvrđene u istraživanju podijeli na četiri manja raspona onda se još bolje može vidjeti koji od odabranih raspona vlage zrna najbolje korelira sa hektolitarskom masom i ukupnim primjesama. U 1998. godini to su bili rasponi od 12,5–13,5% (r=–0,67; P<0,05) i 13,6–14,5% vlage u zrnu (r=–0,85; P<0,05), a u 1999. godini raspon od 13,6–14,5% vlage u zrnu (r=–0,83; P<0,05). Na hektolitarsku masu više su utjecale crne primjese od bijelih, a od crnih primjesa na hektolitarsku masu najviše utječe udio korovskog sjemena. Između crnih primjesa i hektolitarske mase utvrđena je negativna korelacija (r=–0,56; P<0,01), baš kao i između udjela korovskog sjemena i hektolitarske mase (r=–0,55; P<0,05). Analizom omjera između hektolitarske mase, ukupnih primjesa, crnih i bijelih primjesa iznad 70,8 kg/hl smanjivao se sadržaj ukupnih i crnih primjesa, a povećavao se sadržaj bijelih primjesa. Analizom omjera između vlage te crnih, bijelih i ukupnih primjesa, utvrđeno je da se povećanjem vlage iznad 11% povećao i sadržaj bijelih primjesa, a sadržaj ukupnih i crnih primjesa se smanjio. Rezultati istraživanja pokazuju da matematičko modeliranje za navedene veličine nije pouzdano jer su koeficijent determinacije za prikazane primjese, vlagu u zrnu i hektolitarsku masu mali. Jedino je u drugoj godini istraživanja jednadžba omjera za hektolitarsku masu i ukupne primjese pokazala veći koeficijent determinacije (0,6068). Koeficijenti determinacije (R2) za linearne jednadžbe promatranih veličina u istraživanju su mali, što nam govori da će se ovakvi odnosi između hektolitarske mase, vlage u zrnu i ukupnih primjesa, vlage u zrnu i crnih i bijelih primjesa vrlo teško ponovno pojaviti.With the purpose of determining if relationships between hectoliter weight, total admixtures and their components and kernel moisture can be mathematically modeled, wheat kernel samples were taken at the point of entering a silo in anorthwestern Croatia in a period of three years (1997–1999). The intention of the research was to determine mutual interaction of the above mentioned factors, with taking no consideration of data connected to varieties or agrotechnology. It means that the purpose was to get insight into the actual situation at the entry point of the silo, with wheat grown with the higher level of agrotechnology as well the wheat grown with a lower level of agrotechnology. Twenty samples were taken every year at random. Hectoliter weight, kernel moisture and total admixtures were measured for every sample, and in the last year of the research (1999) the amounts of black and white admixtures as well as their components. The mutual interaction among the above mentioned factors as well as the influence of white and black admixture components on the hectoliter weight and the kernel moisture were shown with help of a correlation coefficient. The mutual interaction among the above mentioned factors was mathematically modeled by means of linear equations. Hectoliter weight and total admixtures showed negative average correlation in the three-year research period (r=–0.38; P<0.01), and so did hectoliter weight and kernel moisture (r=–0.37; P<0.01). When the range of various levels of kernel moisture that were found in the research is divided into four smaller ranges, it enables us to clearly see which of the chosen kernel moisture level ranges best correlates with hectoliter weight and total admixtures. In 1998 those were ranges of 12.5–13.5% kernel moisture (r=–0.67; P<0.05) and 13.6–14.5% kernel moisture(r=–0.85;P<0.05), and in the year 1999 it was the range of 13.6–14.5% kernel moisture (r=–0.83; P<0.05). Analysis of ratio of hectoliter weight, total admixtures, black and white admixtures above 70.8 kg/hl showed a decrease of total and black admixtures content, and an increase in white admixtures content. Analysis of the ratio between moisture and black, white and total admixtures showed that a moisture increase above 11% results in an increase of white admixtures content, and a decrease in total and black admixtures content. Research results indicate that mathematical modeling of the above mentioned factors is not reliable because the determination coefficients for the shown admixtures, kernel moisture and hectoliter weight are too low. It was only in the second research year that the ratio equation for hectoliter weight and total admixtures showed a higher determination coefficient (0.6068). Determination coefficients (R2) for linear equations of the factors in the research are low, which indicates that the relationships of this kind between hectoliter weight, kernel moisture and total admixtures, as well as those between kernel moisture and black and white admixtures are not likely to occur again

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

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

Chemical and Sensory Characteristics of Three Apple Cultivars (Malus x domestica Borkh.)

Chemical and sensory characteristics of three apple cultivars ‘Idared’, ‘Granny Smith’ and ‘Pink Lady’ were investigated. Cultivar Idared is predominant in cultivation and on the market in Republic of Croatia, while ‘Pink Lady’ is only present in certain regions of Croatia because of specific growing requirements; however in the world market it achieves very good results. Fruit of analyzed cultivars was grown in Neretva Valley, and harvested in optimal maturity time. Differences in fruit firmness, total acids and soluble solids were determined. Cultivar Pink Lady had significantly highest firmness (7.3 kg cm-2), in comparison to ‘Granny Smith’ (6.4 kg cm-2) and ‘Idared’ (4.5 kg cm-2). Total acids were highest in ‘Granny Smith’ (0.69 %, expressed as malic acid), somewhat lower in ‘Pink Lady’ (0.54 %) and significantly lower in cultivar Idared (0.45 %). Values obtained for soluble solids (oBrix) ranged from 16.4 for Pink Lady, 15.4 for ‘Idared’ and 12.5 for cultivar ‘Granny Smith’. Characteristics of firmness, juiciness, relation between sugars and acids, aroma and general impression were valued by sensory test. Cultivar Idared received lowest grades for most characteristics, except for juiciness, which is its predominant characteristic. Cultivar Granny Smith got good grades for firmness, juiciness, aroma and general impression, while relationship between sugars and acids got low grades. Cultivar Pink Lady got the highest grades from testers, which is in agreement with chemical analysis and cultivar Idared had the lowest grades, while cultivar Granny Smith was well accepted because of its freshness. Result of this research will be used for recommendation of cultivars when planting new orchards

Chemical Composition and Antioxidant Capacity of Three Plum Cultivars

The aim of this study was to determine the chemical composition and antioxidants capacity of three plum cultivars, namely ‘Top’, ‘Elena’ and ‘Bistrica’. Fruits were harvested and following parameters were determined: dry matter, total acids (TA), total soluble solids (TSS), pH, vitamin C, total phenols, nonflavonoids and antioxidant capacity. Differences between cultivars for most of the chemical parameters were observed. The cultivar ‘Bistrica’ showed higher values of dry matter, TSS, vitamin C and pH value, while ‘Top’ had higher total acids value and lowest TSS, dry matter, vitamin C and pH. Total phenolics content varied from 157.70 mg in ‘Elena’ to 344.10 mg in ‘Bistrica’, expressed as gallic acid equivalents (GAE), on fresh weight basis. ‘Top’ contains the highest amount of non-flavonoids among cultivars studied. Therefore, ‘Bistrica’ and ‘Top’ show the highest antioxidant capacity, as well. There were significant differences between total phenolics and non-flavonoids content between ‘Elena’ and other two cultivars, while antioxidant capacity showed no significant difference (p ≤ 0.05). Total antioxidant capacity of fruits ranged from 3.10 mmol/kg in ‘Elena’ to 3.17 mmol/kg in ‘Top’ and ‘Bistrica’

Influence of Fruit Thinning and Summer Pruning on the Yield and Fruit Quality of Peach Cultivar \u27Royal Gem\u27

Peach is one of the most important fruit species for human consumption. In the peach cultivation many pomotechnical treatments are conducted and some of the most interesting are summer pruning and fruit thinning. By implementation of mentioned pomotechnical treatments higher fruit quality can be achieved which is nowadays very important for the market fruit value. In this research the influence of summer pruning and fruit thinning in different combinations on the pomological characteristics and physico-chemical properties of peach fruit cultivar ‘Royal Gem’ was studied. Implemented pomotechnical treatments differently affected the studied properties. The highest yield was determined in control (7.23 kg tree-1) while the lowest (4.38 kg tree-1) in treatment 2 (fruit thinning without summer pruning). Fruit thinning and summer pruning significantly influenced on the increase of average fruit weight, fruit firmness and fruit diameter. The lowest fruit weight (75.74 g) was determined in control while the highest fruit weight (92.93 g) was determined in treatment 3 (summer pruning without fruit thinning). The highest fruit diameter (57.69 mm) was also determined in treatment 3 while the lowest in control (52.59 mm). The highest fruit firmness (4.14 kg/cm2) was in treatment 1. For chemical quality properties no significant differences have been determined due to the implemented pomotechnical treatments. The pomotechnical treatments conducted in this research showed to be effective for improving the fruit quality while the best results were achieved by treatment of fruit thinning

Theoretical Potential of Post-harvest Residues in Međimurje County for Energy Generation

Međimurje County, because of its relatively developed agricultural production has a great potential to collect and utilize agricultural residues in energy production. Instability of prices of energy-generating products, together with increase of ecological awareness, make renewable sources and, therefore, agricultural residues, more and more interesting raw material for energy production. The aim of this work was to determine the theoretical potential and availability of post-harvest residues under sustainability conditions in the agricultural sector in the Međimurje County area. Availability of agricultural residues makes it possible to estimate the amount of biomass, needed for energy production in the research area. The calculation includes the following agricultural crops: corn, wheat, barley and rapeseed. The results show that there are 22,846 tonnes of residues after corn production, 5,285 tonnes of residues after wheat production, 2,853 tonnes of residues after barley production and 2,686 tonnes of residues after production of rapeseed available in the County, for energy production