Influence of osmotic and convective drying on thephysical properties of quince (Cydonia oblonga Mill.)

Važnost istraživanja fizičkih osobina ogleda se u tome, što su neke od tih osobina prvo što se uočava na sušenom voću. Druge fizičke osobine spoznaju se tokom konzumiranja. Osim toga, fizičke osobine su i od značaja prilikom projektovanja opreme za preradu poljoprivrednih proizvoda. Predmet istraživanja doktorske disertacije su promene fizičkih osobina dunje tokom osmotskog i konvektivnog sušenja. Istraživane su promene sledećih osobina: vlažnosti, zapremine, mehaničkih osobina i boje. Kao dodatak osnovnim merenjima obavljene su hemijska i senzorska analiza finalnog proizvoda. Eksperiment osmotskog sušenja obavljen je kao dvofaktorni. Faktori eksperimenta su temperatura i koncentracija osmotskog rastvora. U eksperimentu je korišćena dunja sorte leskovačka. Ovu sortu odlikuje prijatna aroma, oblik i dimenzije pogodne za sušenje. Disperzionom analizom rezultata merenja fizičkih osobina tokom eksperimenta osmotskog sušenja potvrđeno je da izabrani nivoi temperature i koncentracije osmotskog rastvora utiču na promenu vlažnosti dunje tokom 180 minuta osmotskog sušenja. U slučaju povećanja mase suve materije disperzionom analizom potvrđen je statistički značajan uticaj koncentracije i interakcije koncentracije i temperature na promenu ispitivane veličine. Najintenzivnije promene vlažnosti i povećanja suve materije izmerene su u prvih 20 minuta osmotskog sušenja. Promena oblika dunje u formi kocke, do kojih dolazi tokom osmotskog sušenja je anizotropna. Razlog anizotropnog skupljanja tkiva može biti orijentacija vlakana i nehomogena struktura materijala. Promena zapremine izražena je zapreminskim skupljanjem SV. Izvedena je jednačina kojom je utvrđena zavisnost promene zapremine od količine razmenjene materije tokom osmotskog sušenja. Najveća promena zapremine izmerena je pri osmotskom sušenju pri najvišim vrednostima temperature i koncentracije osmotskog rastvora. Mehaničke osobine dunje tokom osmotskog sušenja predstavljene su sa dva pokazatelja, otpornošću na razaranje i modulom elastičnosti. Otpornost na razaranje je u ovoj tezi originalno predstavljena parametrom f. Ovaj parameter predstvalja relativnu promenu sile razaranja tokom osmotskog sušenja. Disperzionom analizom utvrđen je uticaj temperature osmotskog rastvora na mehaničke osobine dunje. Osmotski rastvor temeperature 60oC izaziva omekšavanje tkiva dunje. Međutim, omekšavanje tkiva dunje pozitivno utiče na čvrstoću krajnjeg proizvoda. Kao drugi pokazatelj mehaničkih osobina upotrebljen je modul elastičnosti. Promene modula elastičnosti slične su promenama f parametra. Na osnovu promena oba pokazatelja mogu se doneti isti zaključci o uticaju faktora eksperimenta na mehaničke osobine tkiva dunje. Tkivo dunje je izloženo vazduhu tokom konvektivnog sušenja intenzivno menja boju. U eksperimentu je upotrebljen sumpordioksid kao zaštita od tamnjenja tkiva. Ukupna promena boje najveća je na uzorcima dunje koji su sušeni rastvorom koncentracije 65oBx. Međutim, tokom konvektivnog sušenja ističe se pozitivan uticaj ovog tretmana na promenu boje dunje. Veća količina saharoze koja se zadržava na površini uzoraka dunje predstavlja barijeru između između materijala i vazduha i spračava tamnjenje tkiva. Regresionom analizom rezultata merenja promene vlažnosti, zapremine i boje pronađeni su empirijski modeli koji opisuju merene veličine tokom osmotskog sušenja. Jednačine odabrane za modelovanje promene vlažnosti proširene su uticajnim faktorima u bezdimenzionalnom obliku. Proširenjem matematičkih modela stiče se njihova univerzalnost u opsegu istraživanih vrednosti temperature i koncentracije osmotskog rastvora. Primenjeni modeli mogu se uspešno koristiti za predviđanje svih merenih veličina. Uspešnost modela potvrđena je visokim vrednostima koeficijenta korelacije i niskim vrednostima srednje procentualne greške. Senzorskim analizama obavljenim panelnim ispitivanjem, uzorci tretirani osmotskim rastvorom ocenjeni su kao kvalitetniji od onih koji su samo konvektivno osušeni. Poređenjem rezultata kvantitativnih i kvalitativnih analiza može se zaključiti da osmotsko sušenje kao predtretman konvektivnom sušenju pozitivno utiče na kvalitet sušene dunje kao finalnog proizvoda.  The importance of researching physical properties lies in the fact that some of these properties are what we first notice about dried fruit. Other physical properties are experienced during consumption. Moreover, physical properties are also important when designing equipment for processing agricultural products. The subject of the research in this doctoral dissertation is changes in physical properties of quince during osmotic and convective drying. The investigation included changes in the following properties: moisture, volume, mechanical properties and colour. Apart from the basic measurements, the research also included chemical and sensory analyses of the final product. The experiment of osmotic drying was performed as a two-factor experiment, while factors were the temperature and the concentration of osmotic solution. The variety of quince used in the experiment was “Leksovačka”, which is a variety with a pleasant aroma, and the shape and dimensions suitable for drying. Dispersion analysis of the measured results in the experiment of osmotic drying showed that the temperature and concentration of osmotic solution affect the changes in moisture of quince during 180 minutes of osmotic drying. In the case of the increased mass of dry matter, analysis of variance pointed to statistically significant effect of concentration and interaction of concentration and temperature on the change in the examined size. The most intense changes in moisture and increase of dry matter were measured in the first 20 minutes of osmotic drying. The change of the shape of quince into the shape of a cube, which occurs during osmotic drying, is anisotropic. The reason of anisotropic shrinkage of tissue can be fibre orientation and inhomogeneous structure of the material. The volume change is expressed in volumetric shrinkage SV. The equation derived was used to determine the dependence of the change in volume on the amount of the matter exchanged during osmotic drying. The greatest change in volume was measured during osmotic drying at the highest values of temperature and the highest values of concentration of osmotic solution. Mechanical properties of quince during osmotic drying were represented by two indicators: resistance to rupture and modulus of elasticity. Resistance to rupture in this thesis was originally presented by the parameter f. This parameter represents a relative difference of force of rupture. Dispersion analysis determined the effect of the temperature of osmotic solution on mechanical properties of quince. The solution temperature of 60oC causes softening of the quince tissue. However, softening of the tissue has positive effects on firmness of the final product. The other indicator of mechanical properties was modulus of elasticity. The changes in the modulus of elasticity are similar to the changes of the parameter f. The changes in both indicators lead to the same conclusions about the impact of the factors of the experiment on the mechanical properties of quince tissue. Quince tissue exposed to air changes its colour intensely. In this experiment, sulphur dioxide is used as protection against darkening of the tissue. The total colour change was the greatest in the quince samples dried using a solution with the concentration of 65oBx. However, during convective drying one can see the positive impact of this treatment on the colour change in quince. A larger amount of saccharose which is retained on the surface of the samples acts as a barrier between the material and the air, preventing darkening of the tissue. Regression analysis of the measured results of the changes in moisture, volume and colour, generated empirical models that describe the measured values during osmotic drying. The equations selected for modelling of moisture changes were extended to include influential factors in dimensionless form. What is achieved by extending the mathematical models is universality of the models in the range of the investigated values of temperature and concentration of osmotic solution. The used models can be successfully applied for prediction of all of the measured values. The successfulness of the model is confirmed by high values of the correlation coefficient and low values of the mean percentage error. Sensory analyses performed using panel testing showed that the samples treated with osmotic solution were evaluated to be of higher quality than the samples that were only convectively dried. By comparing the results of quantitative and qualitative analyses, it can be concluded that osmotic drying, as a pre-treatment to convective drying, positively affects the quality of dried quince as a final product

Osmotic Drying of Apricot (Prunus armeniaca) in Sucrose Solution

Osmotic drying is a process of partial removal of water by submersing fruits in sucrose solution. The goal of this paper is to examine kinetic features of osmotic drying of apricot halves in sucrose solution. For osmotic drying of apricot halves in a thick immovable layer, a planned experiment was conducted. Experimental results were used to create an empirical model of osmotic drying kinetics which expresses the influence of analyzed experiment factors on water loss (WL). The experiment factors were temperature of osmotic solution, varied at two levels, 35 °C and 60 °C, and sucrose concentration varied at two levels, 50 °Bx and 65 °Bx. Using regression analysis of experimental data for water loss (WL) at statistical probability of 99 %, parameters of empirical model and correlation coefficient were calculated for the proposed mathematical model. Experimental results were approximated using the derived equation. Conformance of experimental results with the empirical model was evaluated using correlation coefficient (R). Correlation coefficient calculated for the proposed model was high, R = 0.976. It indicates fi ne agreement between experimental and model values for water loss

Rationalization of Sucrose Solution Using During the Fruit Osmotic Dehydration

The model of sustainable energy production of dried fruit conducted by using combined technology – the model that has been developed at the Faculty of Agriculture in Novi Sad – includes osmotic dehydration of fruit in sucrose solution. During the process of dehydration the moisture content of the solution is increased due to mass transfer of moisture from fruit. This article examines different models of recycling and concentrating of the solution. Thus, the model for concentrating of the solution has been chosen according to this analysis, and it has been applied within its own technology. Evaporators of the low temperature solution have been used and they are based on the solar energy source. Two types of devices have been made on the basis of the heating process of evaporating. One type is filled with the stainless steel shavings, while the other type is based on the fillings by plates. The paper presents the evaluation model of the benefits of this concentrating manner as well as the evaluation criterion of the evaporators’ fillings types. The energy support used here was an original solar air heater of semi-concentrated type

Mehaničke osobine semena soje različitih frakcija

Knowledge of mechanical properties of agricultural materials is important for designing and exploitation of agricultural machines and equipment, as well as for successful preservation of biological values of seed during drying, processing and storage. As the shape of soybean seeds is generally round, they can be graded by a simple procedure, using different sieve settings. In this study we assessed the impact of seed grade on the mechanical properties of seed of the soybean varieties which differed in seed size. The initial tangent modulus of elasticity and maximum rupture force were used as indices of mechanical properties of seed, and they were discussed in detail in the paper. The values of the initial tangent modulus of elasticity went down as seed size increased. The lowest value, 9.26 N/mm2, was recorded for grade 6.0 to 6.5 mm in the variety Balkan. The highest value, 18.84 N/mm2, was recorded for grade 4.0 to 4.5 mm in the variety Victoria. Unlike the values of the initial tangent modulus of elasticity, the values of maximum rupture force increased in proportion with increase in seed size. The highest value, 176.18 N, was recorded for grade 5.5 to 6.0 mm in the variety Victoria, and the lowest value, 92.15 N, was recorded for grade 4.0 to 4.5 mm in the variety Balkan. .Poznavanje mehaničkih osobina poljoprivrednih materijala je veoma važno prilikom konstruisanja i eksploatacije poljoprivrednih mašina i opreme ali je neophodno i za očuvanje bioloških vrednosti semena prilikom sušenja, skladištenja i procesa dorade. Seme soje na osnovu fizičkih osobina ima okruglast oblik pa je moguće kalibraciju uraditi jednostavnim postupkom pomoću sita raznih dimenzija i otvora. U radu je ispitan uticaj frakcija na mehaničke osobine semena soje za sorte koje se karakterišu različitom krupnoćom zrna. Kao pokazatelji mehaničkih osobina semena korišćeni su početni tangentni modul elastičnosti i maksimalna sila razaranja koji su detaljno prikazani u radu. Vrednosti početnog tangentnog modula elastičnosti su sa povećanjem dimenzije zrna imale manje vrednosti. Tako je najmanja vrednost zabeležena kod sorte Balkan za frakciju 6,0-6,5 mm od 9,26 N/mm2, dok je najveća vrednost zabeležena kod sorte Victoria za frakciju 4,0-4,5 mm od 18,84 N/mm2.Za razliku od početnog tangentnog modula elastičnosti, vrednosti maksimalne sile razaranja su se povećavale sa povećanjem dimenzija semena, tako da je najveća vrednost zabeležena kod sorte Victoria za frakciju 5,5-6,0 mm od 176,18 N dok je najmanja vrednost zabeležena kod sorte Balkan za frakciju 4,0-4,5mm od 92,15 N.

Uticaja smera obrtanja rotora rotacione sitnilice na ekološke aspekte obrade zemljišta

Influence the direction rotor rotary tiller on the ecological aspects of soil tillage was investigated under field conditions. Quality of soil tillage was determined by measuring the bulk density and the structure coefficient. Bulk density the tilled soil ranged from 1.015 to 1.186 g/cm3 at stubble field, 0.990 to 1.151 g/cm3 at soybean field and 0.995 to 1.066 g/cm3 at ploughed field. For conventional rotor rotation direction measured significantly lower values of bulk density at 5-10 cm depth testing done on soybean field. The lower value of bulk density in conventional rotor rotation direction result of excessive fragmentation of soil in greater depth. Soil tillage was a statistically significant increase in the value of the structure coefficient. After soil tillage, the structure coefficient values ranged from 0.68 to 2.22 at stubble field, 0.78 to 1.84 at soybean field and 1.16 to 2.64 at ploughed field. The higher the value of the structure coefficient represents higher quality of soil cultivation. In the case of reverse rotor rotation direction, measured significantly higher structure coefficient values compared to conventional rotor rotation direction.Uticaj smera obrtanja rotora rotacione sitnilice na ekološke aspekte obrade zemljišta ispitivan je u poljskim uslovima. Kvalitet obrade zemljišta određen je merenjem zapreminske mase i koeficijenta strukturnosti zemljišta. Zapreminska masa na obrađenom zemljištu kretala se u granicama 1,015-1,186 g/cm3 na strništu, 0,990-1,151 g/cm3 na sojištu i 0,995-1,066 g/cm3 na oranom zemljištu. Za istosmerno obrtanje rotora izmerene su statistički značajno niže vrednosti zapreminske mase na dubini 5-10 cm za ispitivanje izvedeno na sojištu. Niža vrednost zapreminske mase zemljišta pri istosmernom obrtanju posledica je prekomernog usitnjavanja zemljišta na većoj dubini. Obradom zemljišta došlo je do statistički značajnog povećanja vrednosti koeficijenta strukturnosti zemljišta. Nakon obrade zemljišta vrednosti koeficijenta strukturnosti kretale su se u granicama 0,68-2,22 na strništu, 0,78-1,84 na sojištu i 1,16-2,64 na oranom zemljištu. Viša vrednost koeficijenta strukturnosti predstavlja viši kvalitet obrade zemljišta. Pri suprotnosmernom obrtanju rotora, izmerene su statistički značajno više vrednosti koeficijenta strukturnosti u odnosu na istosmerno obrtanje rotora

PRIMARY WHEAT (Triticum aestivum) SEED TEXTURE GLAVNE OSOBINE SEMENA PŠENICE (Triticum aestivum)

ABSTRACT The results of some physical properties three domestic wheat cultivars are presented in this paper. Three axial dimensions of the seed length, width and thickness were measured only at equilibrium moisture content. The length of Simonida kernel is 5

Linuron residue findings in chamomile flowers

Text The aim of this study was to highlight the influence of herbicide usage in agriculture on linuron residues in chamomile flower. It was collected six chamomile flower samples. The validated LC-MS/MS method according to SANTE/11813/2017 was applied in the quantitative analyses. Two samples were with no linuron detection, while all the other detected concentrations exceeded maximum residue limit of 0.1 mg/kg. The detected concentrations were in the range 0.89 to 1.90 mg/kg

Essential oil quality of chamomile grown in Province of Vojvodina

Chamomile (Matricaria chamomilla L., Asteraceae) is one of the most popular medicinal plants used as a herb infusion for treating numerous ailments, including sleep disorders, anxiety, digestion and intestinal conditions etc. Chamomile essential oil is used in a wide variety of consumer goods such as detergents, soaps, toiletries, cosmetics, pharmaceuticals, perfumes, confectionery food products, soft drinks, distilled alcoholic beverages (hard liquor) and as insecticide. According to the European Pharmacopoeia, there are two types of essential oils, one rich in bisabolol oxides and the other in α-bisabolol, which are preferred for tea brewing because of its sweet, grassy, and slightly fruity aroma. From the other side, varieties rich in chamazulene and β-farnesene have bitter taste, and because of that they are low valuable raw material. According to the results of the essential oil composition obtained from three different chamomile samples grown in Province of Vojvodina, it could be concluded that domestic cultivars “Banatska” and “Tetraploidna” contains β-farnesene as dominant compound, while the content of bisabolol oxides and α-bisabolol was lower than required standards in European Pharmacopoeia. Because of that they could not be classified as quality raw material. The German cultivar “Mabamille” grown in agroecological conditions of Vojvodina region, with 37.5% of α-bisabolol can be classified as a bisabolol rich type, and as high quality row material.Kamilica (Matricaria chamomilla L., Asteraceae) je jedna od najpopularnijih lekovitih biljaka koja se upotrebljava u obliku infuza (čaja) za lečenje mnogih stanja i bolesti, uključujući poremećaje sna, napetost, probleme organa za varenje itd. Etarsko ulje kamilice se koristi u mnogim granama industrije: hemijskoj (kao dodatak deterdžentima), kozmetičkoj (u sapunima, sredstvima za ličnu higijenu), farmaceutskoj, parfimerijskoj i prehrambenoj industriji (u slatkišima, alkoholnim i bezalkoholnim pićima) i kao insekticid. Prema Evropskoj Farmakopeji, postoje dva tipa etarskog ulja kamilice, prvi koji je bogat bisabolol oksidima i drugi bogat α-bisabololom. Oba tipa su poželjna u industriji čajnih napitaka zbog njihovog slatkog, osvežavajućeg ukusa blago voćne arome. Sa druge strane, varijeteti bogati hamazulenom i β-farnezenom imaju gorak ukus i zbog toga predstavljaju manje vrednu biljnu sirovinu. Na osnovu rezultata hemijskog sastava etarskog ulja tri različita uzorka kamilice gajene u Pokrajini Vojvodini od strane individualnih poljoprivrednih proizvođača, može se zaključiti da domaće sorte “Banatska” i “Tetraploidna” sadrže β-farnezen kao dominantnu komponentu, dok je sadržaj bisabolol oksida i α-bisabolola niži nego što zahtevaju standardi u Evropskoj Farmakopeji, zbog čega se ne mogu kategorisati kao kvalitetni biljni materijal. Nemačka sorta “Mabamille” gajena u agroekološkim uslovima pokrajine Vojvodine, sa 37,5% α-bisabolola pripada bisabolol tipu kamilice i predstavlja visoko kvalitetnu sirovinu