38 research outputs found
Osvrti: Izbor u počasno zvanje professor emeritus – dr. sc. Branko Tripalo, redoviti profesor u trajnom zvanju u mirovini
Sensory evaluation of dandelion (Taraxacum officinale Weber) enriched pasta
Zahvaljujući znanstvenim istraživanjima i dokazima koji govore u prilog tomu da su prehrana i zdravlje usko povezani, potrošači se okreću skupini prehrambenih proizvoda koje nazivamo funkcionalnim, a kojoj pripadaju i obogaćeni proizvodi. Tjestenina je popularna i pogodna namirnica za obogaćivanje dodatkom različitih sastojaka. Cilj ovog rada bio je pripremiti svježu tjesteninu, odnosno svježe široke rezance obogaćene različitim udjelima osušenih i pulveriziranih listova maslačka te utvrditi prihvatljivost svježih i kuhanih svježih uzoraka od strane potrošača. U tu svrhu
pripremljena su i ocijenjena po 4 (četiri) uzorka širokih rezanaca, svježih i kuhanih svježih, s različitim udjelima listova maslačka. Podaci dobiveni senzorskom procjenom obrađeni su i analizirani u programima Microsoft Excel te IBM SPSS Statistics 25. Rezultati su prikazani kao aritmetička
sredina ± standardna devijacija. U analizi podataka korištena je jednosmjerna analiza varijance (ANOVA) uz Tukeyev post-hoc test. Tjestenina obogaćena sušenim i pulveriziranim listovima maslačka ocijenjena je visokim ocjenama od strane potrošača. Iz dobivenih rezultata senzorske
procjene može se zaključiti da je najprihvatljiviji uzorak kontrolni uzorak, a od širokih rezanaca obogaćenih maslačkom onaj s udjelom 10 % sušenih i pulveriziranih listova maslačka na ukupne suhe sastojke i u slučaju svježih i u slučaju kuhanih svježih uzoraka. Podaci pokazuju da za neka senzorska
svojstva postoje statistički značajne razlike između uzoraka, pogotovo za uzorke s najvećim udjelom listova maslačka.Thanks to scientific research and evidence that supports the fact that nutrition and health are closely related, consumers are turning to the group of food products that we call functional foods, which also includes enriched products. Pasta is a popular and suitable food for enrichment by adding different ingredients. The aim of this work was to prepare fresh pasta, i.e. fresh wide noodles enriched with different proportions of dried and pulverized dandelion leaves, and to determine the acceptability of fresh and cooked fresh samples by consumers. For this purpose, 4 (four) samples of wide noodles, fresh and cooked fresh, with different proportions of dandelion leaves in the product recipe were prepared and evaluated. The data obtained from the sensory evaluation were processed and analyzed in Microsoft Excel and IBM SPSS Statistics 25 programs. The results are presented as arithmetic means ± standard deviation. One-way analysis of variance (ANOVA) with Tukey\u27s post-hoc test was used in data analysis. Pasta enriched with dried and pulverized dandelion leaves has been rated highly by consumers. From the obtained results of sensory evaluation, it can be concluded that the most acceptable sample is the control sample, and of the wide noodles enriched with dandelion, the one with a proportion of 10 % of dried and pulverized dandelion leaves to the total dry ingredients, both in the case of fresh and in the case of cooked fresh samples. The data show that for some sensory properties there are statistically significant differences between the samples, especially for the samples with the highest proportion of dandelion leaves
Antioxidant Properties of Whole Grain Cereals
Cereals have a long history of use by humans. Cereals and cereal products are staple foods, and are important source of energy, carbohydrate, protein, fibre, vitamins (E, B) and minerals (Zn, Mg, Fe) in both developed and developing countries. The health aspects of whole grain cereals have long been known, but the antioxidant profile of whole grains has only recently been introduced to the antioxidant research community where mostly fruits and vegetables are in focus. In vitro experiments confirm antioxidant richness of whole grains and their specific fractions, but further in vivo investigations are needed to confirm the activity. Great variety of whole grain antioxidants suggest that regular consumption
of whole grain cereals may have a significant role in slowing down degenerative processes and prevention of chronic diseases
Possibilities of olive cake utilization in energy production
U radu su istražene mogućnosti dobivanja energije iz komine masline u odabranoj otočnoj mikroregiji. Godišnja proizvodnja komine masline u odabranoj mikroregiji iznosi 2.065 tona. Od te količine moguće je dobiti 530 MWh/godišnje električne energije koja se može iskoristi na različite načine, od iskorištavanja u kućanstvima do iskorištavanja u manjim pogonima kao što su npr. pogoni za desalinizaciju morske vode. Korištenjem komine kao energenta rješava se problem njenog neadekvatnog odlaganja. Ona više ne bi završavala na divljim odlagalištima te tako ugrožavala okoliš, a ovisnosti o varijanti korištenja komine kao energenta moglo bi se zaposliti i dio lokalnog stanovništva.The aim of this paper was to investigate the potential energy production from olive cake in a specific region of islands in the Adriatic sea, which has a yearly olive cake production of 2,065 tons. Energy production potential from this quantity of olive cake is approx. 530 MWh of electric power per year, which can be differently utilised on behalf of great manig of energy consumers such as households or small-capacity plants for production of drinking water. Utilization of olive cake in energy production could contribute to waste management because it would not be deposited as waste, thus causing pollutions. Moreover, utilization of olive cake in energy producton could contribute to providing work for the local community
The effect of high pressure treatment on the quality of chicken breast meat
In the present work, the effect of high pressure processing (HPP) (0, 100, 200 and 300 MPa) and different treatment time (5 and 10 minutes) on the moisture uptake, cooking yield, colour and texture, as well as microbial population of chicken breast fillets was investigated. The application of high hydrostatic pressure resulted in a modification of quality parameters of chicken breast meat. By increasing pressure and time of the treatment the moisture uptake was reduced: samples treated with 300 MPa for 10 min had the lowest moisture uptake values. Cooking yield was not affected by HPP treatments. Increased pressure affected the colour by increasing L*, a* and b* values (only HPP treatment of 100 MPa in duration of 5 and 10 minutes did not affect colour of chicken breast meat). Lower pressures (100 and 200 MPa) tenderized, whereas elevated pressure (300 MPa) increased hardness in chicken breast fillets. Higher level of pressure (300 MPa) reduced bacteria count by about 3.0 – 5.3 log (CFU/g), depending on the microorganism and duration of the process
Amino Acid Composition, Urease Activity and Trypsin Inhibitor Activity after Toasting of Soybean in Thick and Thin Layer
The objective of this study was to determine amino acid content, urease activity and trypsin inhibitor activity in soybean grain for polygastric animals’ feed aft er toasting with the aim to introduce thick layer in toasting technology. Hence, soybean was toasted both in thick and thin layer at 130 oC during 10 minutes. In order to properly monitor the technological process of soybean thermal processing, it was necessary to study crude protein content, urease activity, trypsin inhibitor activity and amino acid composition of soybean in natural and toasted samples. Results demonstrate that protein content in soybean toasted in thick and thin layer was found to be slightly increased while urease activity was reduced in relation to non-treated sample. Study also established a significant reduction of trypsin inhibitor activity aft er toasting, at higher extent in thin layer toasting. Amino acid content of soybean was slightly increased in relation to natural sample, as well as difference between amino acid content in samples toasted in thick and thin layers
Utjecaj veličine čestica posija prosa i njihove prethodne obrade ksilanazom na fizikalna, senzorska i nutritivna svojstva bezglutenskog kruha
Research background. Millet bran is a by-product rich in dietary fibre, micronutrients and bioactive compounds which are often deficient in a gluten-free diet. Previously, cryogenic grinding has been shown to improve the functionality of bran to some extent, although it offered limited benefits for bread making. This study aims to investigate the effects of adding proso millet bran depending on its particle size and xylanase pretreatment on the physicochemical, sensory and nutritional properties of gluten-free pan bread.
Experimental approach. Coarse bran (d50=223 μm) was ground to medium size (d50=157 μm) using an ultracentrifugal mill or to superfine particles (d50=8 μm) using a cryomill. Millet bran presoaked in water (for 16 h at 55 °C) with or without the addition of fungal xylanase (10 U/g) replaced 10% of the rice flour in the control bread. Bread specific volume, crumb texture, colour and viscosity were measured instrumentally. Along with proximate composition, the content of soluble and insoluble fibre, total phenolic compounds (TPC) and phenolic acids as well as total and bioaccessible minerals of bread were assessed. Sensory analysis of the bread samples included a descriptive, hedonic and ranking test.
Results and conclusions. Dietary fibre content (7.3-8.6 g/100 g) and TPC (42-57 mg/100 g) on dry mass basis of the bread loaves depended on bran particle size and xylanase pretreatment. The effect of xylanase pretreatment was most evident in the loaves with medium bran size in terms of higher content of fibre soluble in ethanol (45%) and free ferulic acid content (5%), improved bread volume (6%), crumb softness (16%) and elasticity (7%), but lower chewiness (15%) and viscosity (20-32%). Bread bitterness and dark colour were increased after adding medium-sized bran but its bitter aftertaste, crust crookedness, crumb hardness and graininess were reduced with xylanase pretreatment. Although bran addition impaired protein digestibility, it enriched the bread with iron (341%), magnesium (74%), copper (56%) and zinc (7.5%). Xylanase pretreatment of the bran resulted in the improved bioaccessibility of zinc and copper of the enriched bread compared to the control and bread without xylanase.
Novelty and scientific contribution. Application of xylanase to medium sized bran obtained by ultracentrifugal grinding was more successful than its application to superfine bran obtained by the multistage cryogrinding as it resulted in more soluble fibre in gluten-free bread. Moreover, xylanase was proven beneficial in maintaining desirable bread sensory properties and mineral bioaccessibility.Pozadina istraživanja. Posije prosa su nusproizvod bogat prehrambenim vlaknima, mikronutrijentima i bioaktivnim spojevima, kojih često nema dovoljno u bezglutenskoj prehrani. Prethodna su istraživanja pokazala da kriogeno mljevenje u određenoj mjeri poboljšava funkcionalnost posija, iako su njegove prednosti u izradi kruha bile ograničene. Svrha je ovoga rada bila istražiti učinak veličine čestica posija prosa i njihove prethodne obrade ksilanazom na fizikalno-kemijska, senzorska i nutritivna svojstva bezglutenskog kruha.
Eksperimentalni pristup. Krupne posije (d50=223 μm) samljevene su do srednje veličine (d50=157 μm) pomoću ultracentrifugalnog mlina, ili do vrlo finih čestica (d50=8 μm) pomoću kriomlina. Posijama prosa prethodno namočenih u vodi (16 sati na 55 °C) s dodatkom fungalne ksilanaze (10 U/g) ili bez nje zamijenjeno je 10 % rižinog brašna u kontrolnom kruhu. Specifični volumen, tekstura sredine, boja i viskoznost kruha određeni su instrumentalno. Uz kemijski sastav, određeni su udjeli topljivih i netopljivih vlakana, ukupnih fenolnih spojeva i fenolnih kiselina te ukupnih i biološki dostupnih mineralnih tvari u kruhu. Senzorska analiza uzoraka kruha uključivala je deskriptivni i hedonistički test, te test rangiranja.
Rezultati i zaključci. Sadržaj prehrambenih vlakana (7,3–8,6 g/100 g) i ukupnih fenolnih spojeva (42–57 mg/100 g) u suhoj tvari kruha ovisio je o veličini čestica posija i prethodnoj obradi ksilanazom. Učinak prethodne obrade ksilanazom bio je najočitiji u kruhu s posijama srednje veličine čestica, koji je imao veće udjele vlakana topljivih u etanolu (45 %) i slobodne ferulinske kiseline (5 %), veći volumen (6 %), mekoću (16 %) i elastičnost sredine (7 %), te smanjenu žvakljivost (15 %) i viskoznost (20-32 %). Gorčina i tamna boja kruha su se povećale dodatkom posija srednje veličine, ali njegov gorak okus, popucanost kore, tvrdoća sredine i zrnatost smanjeni su prethodnom obradom ksilanazom. Iako je dodatak posija smanjio probavljivost proteina, obogatio je kruh željezom (341 %), magnezijem (74 %), bakrom (56 %) i cinkom (7,5 %). Prethodna obrada posija ksilanazom rezultirala je poboljšanom biološkom dostupnošću cinka i bakra u obogaćenom kruhu, u usporedbi s kontrolnim uzorkom i kruhom dobivenim bez prethodne obrade posija ksilanazom.
Novina i znanstveni doprinos. Prethodna obrada ksilanazom imala je veći učinak na posije srednje veličine dobivenim ultracentrifugalnim mljevenjem, nego na vrlo fine posije dobivene višestrukim kriomljevenjem, jer je povećala udjel topljivih vlakana u bezglutenskom kruhu. Nadalje, obrada ksilanazom bila je korisna za zadržavanje poželjnih senzorskih svojstava kruha i biološke dostupnosti mineralnih tvari
Bread-Making Quality of Standard Winter Wheat Cultivars
The purpose of this study was to define an impact of the cultivar, year and cultivation area of the standard Croatian winter wheat on the bread-making quality. The bread-making quality of cultivars ‘Divana’, ‘Žitarka’ and ‘Sana’ from the crop years 1998, 2000, 2002, 2004 and 2006, and from Zagreb and Osijek location was analyzed. Wheat from the cultivar tests cultivated under the same agro technological conditions was used for this testing. The tested winter wheat bread-making quality primarily depended on the genetic properties of cultivar.
However, climatic changes occurring during the last 10 years, particularly the increase in temperatures and quantity of rainfalls in the period of the grain development, ripening and harvest, had a negative influence on the wheat breadmaking quality. Even though the average values of tested quality factors were within the expected range, a significant dependence of the cultivar Divana breadmaking quality upon the cultivation climate conditions was proven. Sana cultivar has proven to be the most stable, whereas its bread-making quality was the lowest. For all three cultivars the bread-making quality has been decreasing in the last 10 years, although the quality of winter wheat from the Zagreb area was higher since the climate conditions were more favourable
Gluten-Free Bread Production by the Corn Meal and Soybean Flour Extruded Blend Usage
The most common disease caused by cereal protein ingestion is celiac disease. This can be treated only by a diet that excludes all foods containing wheat, barley, rye and oat proteins. Corn meal (CM) and defatted soybean fl our (DSF) blend processed by High Temperature Short Time (HTST) extrusion cooking for gluten-free bread production was investigated. Corn meal and soybean fl our were extruded in three different proportions (w/w): 100 CM / 0 DSF; 87.5 CM / 12.5 DSF; 75 CM / 25 DS. After milling extruded fl our blends were combined in a 1:1 mixture with rice fl our for gluten-free bread making. Rheological properties of dough (viscosity and water absorption), baking characteristics, dough and bread yield, were investigated with or without different hydrocolloids addition. Protein content and sensory properties of the gluten-free breads were determined. Bread produced with extruded blend of 75 CM / 25 DSF with addition of guar gum had the biggest volume, the best crumb elasticity, softness and porosity. All bread samples made of extruded flours had high protein content (more than 10% db) and good sensory properties
PRETREATMENT TECHNOLOGIES IN BIOETHANOL PRODUCTION FROM LIGNOCELLULOSIC BIOMASS
Proizvodnja bioetanola, kao obnovljivoga goriva, dosad se uglavnom temeljila na sirovinama na bazi jednostavnih šećera ili škroba. Međutim, budući da se te sirovine koriste u ljudskoj prehrani i ishrani životinja, proizvodnja bioetanola iz istih smatra se neekonomičnom. Stoga je cilj buduću proizvodnju bioetanola temeljiti na lignoceluloznoj biomasi, odnosno na sirovinama poput poljoprivrednih i šumskih ostataka. Lignocelulozna biomasa po sastavu se sastoji od lignina, hemiceluloze i celuloze. Upravo kompleksnost strukture lignocelulozne biomase uvjetuje primjenu različitih tipova predtretmana, koji prethode procesu hidrolize celuloze i hemiceluloze na fermentabilne šećere. Predtretmani mogu biti fizikalni (mehaničko usitnjavanje, piroliza), fizikalno-kemijski (autohidroliza, eksplozija u tekućem amonijaku, eksplozija u CO2), kemijski (ozonoliza, kiselinska hidroliza, alkalna hidroliza, oksidativna delignifikacija) i biološki (pomoću mikroorganizama).Bioethanol is today most commonly produced from corn grain and sugar cane. It is expected that there will be limits to the supply of these raw materials in the near future. Therefore, lignocellulosic biomass, namely agricultural and forest waste, is seen as an attractive feedstock for future supplies of ethanol.
Lignocellulosic biomass consists of lignin, hemicellulose and cellulose. Indeed, complexicity of the lignocellulosic biomass structure causes a pretreatment to be applied prior to cellulose and hemicellulose hydrolysis into fermentable sugars. Pretreatment technologies can be physical (mechanical comminution, pyrolysis), physico-chemical (steam explosion, ammonia fiber explosion, CO2 explosion), chemical (ozonolysis, acid hydrolysis, alkaline hydrolysis, oxidative delignification, organosolvent process) and biological ones