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The aim of this paper was to determine the impact of the extrusion process on chemical composition, total starch content, starch damage and the bioaccessibility of zinc (Zn) and selenium (Se), using different extrusion temperature profiles: 140/170/170 °C, 150/180/180 °C, 160/190/190 °C and adding different content of agrofortified wheat with Zn and Se to corn grits: 10, 20, 30 and 40%. The protein and mineral content of the wheat fortified with Zn and Se was significantly higher compared to the corn grits, and the wheat fortified with Zn had the highest protein content (14.28 ± 0.76%) of all observed raw materials. Starch content increased after the extrusion process with no significant differences with increasing extrusion temperature, while the addition of different proportions of wheat fortified with Zn and Se decreased starch content. In addition, the extrusion process significantly increased the starch damage without significant change by increasing extrusion temperature. Addition of different proportions of wheat fortified with Zn and Se reduced starch damage values in proportion to the added content of fortified wheat. As the temperature and the proportion of added wheat increased, the total Zn content in the extrudates increased. The bioaccessibility of Zn also increased with increasing extrusion temperature, with no statistical difference in values for most samples due to the addition of different proportions of fortified wheat. Total Se content increased with increasing proportion of fortified wheat and decreased with increasing extrusion temperature. There was no significant difference in the bioaccessibility of Se by increasing the extrusion temperature and the proportion of enriched wheat.

The aim of this paper was to investigate the influence of Zn‐ and Se‐fortified wheat flour addition to the corn grits at 90:10, 80:20, 70:30, 60:40 ratios on the hardness, fracturability, expansion ratio, bulk density, color, and sensory attributes of the extrudates. Extrusion was performed at three temperature profiles: 140/170/170 °C, 150/180/180 °C, and 160/190/190 °C. With an increase in the proportion of Zn‐ and Se‐ fortified wheat flour and temperature increase, all observed physical characteristics of extrudates decreased. The lightness of all the samples increased after the extrusion. The total color change increased with the addition of Zn‐ and Se‐fortified wheat flour. Sensory characteristics showed that the samples with a lower percentage of added Zn‐ and Se‐fortified wheat flour had better scores and acceptability, compared to the samples with a higher fortification ratio., Cilj ovoga rada bio je utvrditi utjecaj ekstruzije zamjesa kukuruzne krupice i pšeničnoga brašna obogaćenog Zn i Se, u omjerima 90:10, 80:20, 70:30, 60:40, na tvrdoću, lomljivost, ekspanzijski omjer, nasipnu masu, boju i senzorska svojstva. Ekstruzija je provedena na tri temperaturna profila: 140/170/170 °C, 150/180/180 °C i 160/190/190 °C. Povećanjem udjela pšeničnoga brašna obogaćenog Zn i Se i povećanjem temperature, vrijednosti svih fizikalnih svojstava su se smanjile. Svi uzorci su nakon ekstruzije posvijetlili. Ukupna promjena boje povećava se dodavanjem pšeničnoga brašna obogaćenog Zn i Se. Senzorska svojstva pokazuju bolju ukupnu ocjenu i prihvatljivost uzoraka s nižim postotkom dodanoga pšeničnog brašna u usporedbi s uzorcima s većim udjelima dodanoga pšeničnog brašna.

The aim of this research was to evaluate the effect of extruder die temperature (90, 100, 110 °C) and flour moisture (25, 30, 35%) on properties of extrusion-modified flours from wheat (Kraljica, Olimpija) and hull-less barley (GZ-10, GZ-11) cultivars. Flours were extruded in laboratory single screw extruder and micro viscoamylographic, farinographic properties, sedimentation and falling number were determined. The results showed that viscosity values decreased and stability of flours increased after extrusion, both during shearing at high temperatures and regarding retrogradation. Although barley flours were in B2 and C1 quality category before extrusion, after extrusion all flours were within A1 or A2 category. Sedimentation values significantly decreased after extrusion, and falling number depended largely on extrusion conditions. By careful selection of cultivar, flour moisture, and extrusion conditions flours with desired properties may be produced., Cilj ovog istraživanja bio je odrediti utjecaj temperature na izlazu ekstrudera (90, 100, 110 °C) i vlažnosti brašna (25, 30, 35 %) na svojstva brašna pšenice (Kraljica, Olimpija) i golozrnog ječma (GZ-10, GZ-11) modificiranih ekstruzijom. Brašna su ekstrudirana u jednopužnom laboratorijskom ekstruderu te su određena mikro viskoamilografska, farinografska svojstva, sedimentacija i proj padanja. Rezultati su pokazali da se viskoznost brašna smanjuje, a stabilnost brašna povećava nakon ekstruzije, i to i tijekom miješanja na visokim temperaturama i po pitanju sklonosti retrogradaciji. Iako su brašna ječma bila u skupinama kvalitete B2 i C1 prije ekstruzije, nakon ekstruzije sva ispitivana brašna bila su u skupini A1 ili A2. nakon ekstruzije značajno su opale vrijednosti sedimentacije, a broj padanja ovisio je o uvjetima ekstruzije. Pomnim odabirom sorte, vlažnosti brašna i uvjeta ekstruzije mogu se proizvedi brašna željenih svojstava.

In this work, wheat flour is replaced with extruded sugar beet pulp (SBPEs) in the amount of 5, 10 and 15% during the production of cookies. The influence of the percentage of sugar beet pulp in the SBPEs (ratios of corn grits to sugar beet pulp in extrudates were 85:15, 70:30, and 55:45), the size of the SBPE particles (

The extrusion process enables the processing of different types of raw materials and obtaining finished products in a short period of time. Raw materials rich in starch and protein are most often used in the extrusion process, and one of the most popular is corn grits. The aim of this study was to examine the influence of moisture content (30 and 35%) on the properties of extruded flours of 6 different corn varieties of the Agricultural Institute Osijek. The extrusion process was performed on a laboratory single-screw extruder using the following conditions: extrusion temperature profile – 80/100/120 ˚C ; nozzle diameter – 4 mm ; screw configuration – 4:1. The following parameters were determined on the obtained extrudates, after drying at room temperature: expansion ratio, bulk density, water absorption index, water solubility index and rheological properties using a Brabender Micro- visco-amylograph. The results were compared to non-extruded corn flours. The obtained results showed that the increase in the moisture content did not significantly affect the expansion ratio and the bulk density of the extrudates. The extrusion process and the increase in moisture content significantly influenced the increase in the water absorption index and the water solubility index. Compared to non-extruded samples, almost all extruded samples had lower peak viscosity and their good stability was found when mixed at high temperatures, while non- extruded samples showed a greater retrogradation tendency.

Ferulic acid is the most abundant phenolic acid in cereals (70-90% of total phenolic compounds). The outer layers of grain have been shown to contain much higher levels of ferulic acid than endosperm. The aim of this study was to determine the effect of the extrusion process with different temperature in teh die section (90, 100 and 110 °C), and the moisture content (25, 30 and 35%) on total phenols and ferulic acid on wheat and hulless barley flour (56.21 µg/gDW), while the total phenolic content was more similar in both flours (752 and 779 µg GAE/ gDW, respectively). In extruded wheat flours a slight decrease of ferulic acid was noticed compared to the non-extruded flour. On the other hand, in hulless barley flours ferulic acid content was significantly increased after the extrusion process. The extrusion had a negative effect on the total phenolic content and this negative effect was the lowest in the extruded samples with the moisture content of 25%, both of wheat and barley flours (426 and 449 µg GAE/ gDW, respectively).

The aim of this study was to examine the possibility of improving the nutritional value of the cookies using sugar beet pulp, the by-product of the sugar industry. Sugar beet pulp has a high content of dietary fiber, with a perfect balance of 2/3 of insoluble fibers – it has a high content in cellulose (21%), hemicellulose (27%) and pectin (23%). The pressed sugar beet pulp is rich in potassium, sodium, calcium and magnesium. The pulp raw proteins have a digestibility of 75% and contain essential amino acids - lysine, methionine, cysteine and threonine. In this work, in the cookies, wheat flour is replaced with extruded sugar beet pulp (ratio of corn grits and sugar beet pulp in extrudates was 55:45) in the amount of 5, 10 and 15%. Chemical analysis of cookies showed that with the increase in the percentage of substitution of wheat flour with extruded sugar beet pulp during the production of cookie samples, there has been a significant increase in the content of dietary fibers from 2.02% to 6.28%, proteins from 5.50% to 7.15% and minerals from 0.45% to 0.72%, compared to the control sample.

A modern life requires fast preparation of healthful and nutritionally valuable food. Therefore, instant food products are often used. In recent years, various instantiation techniques have been developed and it is possible to use different raw materials for instant food production. One of the relatively new technique is the extrusion process. The aim of this study was to produce extruded mixtures of corn grits and bean flour, and investigate the possibility of their application in production of instant porridge. The mixtures of corn grits and bean flour (70:30, 50:50 and 30:70 d.w.b.) with 17% of moisture content were extruded in laboratory single screw extruder Brabender 19/20 DN. After the extrusion, the samples were air-dried overnight at room temperature. Expansion ratio, bulk density and color of obtained extrudates were determined. For the production of instant porridge recipes three different mixtures of spices were used: salt, parsley, pepper, garlic (mixture 1) ; salt, Vegeta, pepper (mixture 2) and salt, celery, pepper, garlic (mixture 3). For the sensory evaluation, instant porridges were prepared with classic procedure of mixing in hot water. Analysis was performed by the panel of 6 trained panelists, and following attributes were rated: color, taste, smell, consistency and aftertaste. The obtained results for the expansion ratio (ER) and bulk density (BD), as a important physical properties which are indirectly related to the degree of structure disturbance, showed that the addition of bean flour to crn grits resulted in decerease of ER and increase of BD. Furthemore, the addition of bean flour and extrusion process resulted in significant color change. By sensory evaluation it was found that the instant porridges based on the extruded mixture of corn:bean 30:70 had very high overall sensory score, where the porridge seasoned with mixture 3 of spices (salt, celery, pepper, garlic) is rated as the best prridge. Finally, it can be concluded the extrusion process can be successfully used for instantiation of corn grits:bean flour mixture, which give a high sensory acceptable products with addition of dfferent spice mixtures.

Snack products are a popular product type since they are tasty and easy to consume regarding chewing and preparation. They can be directly (second generation / 2G) or indirectly expanded (third generation / 3G). Since this is energy dense, nutritionally rather poor product category, the aim of this research was to increase nutritional value of the corn-based snacks with defatted Camelina sativa L. press cake (DCC) and to produce 3G snacks by supercritical CO2 extrusion process (SCFX). DCC is by-product of oil production rich in polyphenols, fibre and protein. The residual oil in cake can cause problems during extrusion and it was extracted from the cake by supercritical-CO2 extraction and defatted cake was obtained. DCC was added to corn grits in ratios of 3, 6 and 9% d. m. Prepared samples were extruded in laboratory single screw extruder at temperature profile: 90/110/120 °C with the injection of supercritical CO2 (injection pressure: 140 bar) during the extrusion process in between of second and third heating zone. Obtained extrudates were air-dried, and then expanded by microwave heating, milled and analysed. Polyphenol content was determined by Folin-Ciocalteau method, antioxidant activity by DPPH radical scavenging activity, total colour change (∆E) by Chroma meter Konica Minolta CR-400, acrylamide (AA) and hydroxymethylfurfural (HMF) by single LC-MS/MS method for determination of both compounds. The obtained results showed that the addition of DCC to corn grits resulted in increased polyphenol contents and antioxidant activity, but SCFX plus microwave heating (SCFX + MV) decreased those values compared to non-extruded samples. Furthermore, addition of DCC and SCFX + MV resulted in significant colour change, where the total colour change (ΔE) increased with the addition of DCC. Results for AA and HMF showed that all values for AA were under limit of detection (< 3.79 ppb) and values for HMF were lower after SCFX + MV than in non-extruded samples. HMF values increased with the addition of DCC, but they are still low enough to create no concern for consumption. Final conclusion is that the extruded corn snack products were successfully improved with DCC, and supercritical CO2 can be used for production of 3G snacks. Both are good examples for development of new products with increased nutritional value and retained valuable components.

Oilseed cakes are generated as a by-product in the production of oil. They represent a rich source of protein and dietary fibers, so in the recent years started their application in the production of various types of food products, mainly bakery (bread, biscuits, tortillas) and protein supplements. One of the areas where new product development, including application of oilseed cakes, can have large impact is most certainly production of extruded snack products, which are consumed worldwide, by all age-groups from toddlers to seniors. The objective of this research was to increase nutritional value of the extruded corn-based snacks with pumpkin (Cucurbita pepo L.) oilseed cake, which is defatted by supercritical CO2 extraction. Defatted pumpkin cake (DPC) was added to corn grits in 3, 6 and 9% d. m., and 1% of pectin was added with the aim to produce products with properties of ready-to-eat snacks. Prepared samples with 15% of moisture content were extruded in the laboratory single screw extruder at temperature profile 135/170/170 °C, using a screw with compression ratio 4:1 and die with 4 mm diameter. Obtained extrudates were air-dried overnight, and physical properties of extrudates were determined. The obtained results showed that addition of DPC resulted in decrease of expansion ratio (ER) and increase of bulk density (BD) of obtained snack products. Furthermore, addition of DPC and extrusion process resulted in significant colour change, where the total colour change (ΔE) increased proportionally to the amount of DPC. Extrusion process resulted in the increase of water absorption index (WAI) and water solubility index (WSI). Final conclusion is that the extruded corn snack products were successfully improved with DPC, which is rich in nutritional components, and this can be a good example for development of new products.

Extruded snack products are one of the most popular snacks consumed all over the world.Usually they are not fortified with nutrients, but they can be very good source of nutrients, because of their prevalence.Consequently, the objective of this research was to increase nutritional value of the extruded corn-based snacks with defatted hemp (Cannabis sativa L.) cake. Hemp seeds contains 25 – 35% lipids, 20 – 25% protein and 20 – 30% carbohydrate, 10 – 15% insoluble fibers, and minerals.[1] In production of oil by cold pressing, cake is by-product rich in protein, fibre and polyphenols. Usually 10 – 14% of oil resides in cake and may cause problems during extrusion due to low friction in barrel and fat oxidation. The residual oil was extracted from the cake by supercritical-CO2 extraction and defatted cake was obtained. Defatted hemp cake was added to corn grits in 3, 6 and 9% d. m., 1% pectin was added and mixture moisture was set to 15%. Prepared samples were extruded in laboratory single screw extruder with 4 mm round die, screw with compression ratio of 4:1, at temperature profile: 135/170/170 °C. Obtained extrudates were air-dried and resistant starch content was determined according to AOAC 2002.02 method, [2] starch damage according to AACC 76-31, [3] polyphenol content by Folin-Ciocalteau, [4] antioxidant activity by DPPH radical scavenging activity[4] and soluble and insoluble dietary fiber according to AOAC 991.43.[5] Although extrusion resulted in decrease of resistant starch and polyphenol contents, resistant starch and polyphenol contents in extruded samples increased to addition of defatted hemp cake, while starch damage decreased. There was no significant difference between antioxidant activity of non- extruded and extruded samples, while it increase with addition of defatted hemp cake. Even extrusion resulted in decrease of fiber content, soluble, insoluble and total dietary fiber increased proportionally to addition of defatted hemp cake. Extruded snack products were successfully fortified with defatted hemp cake and it is well applied waste of oil industry. Since the hemp cake is rich in nutritional components, this can be a good example for development of new products.

By-products of plant food processing, which are rich in fibre and bioactive compounds, have attracted much attention for their functionality and potential as food ingredients in recent years. Extrusion, as a continuous process with high versatility and productivity, offers a good avenue to incorporate different types of by-products in ready-to-eat snacks and breakfast cereals. In addition, incorporating of these by-products can improve nutritional value of extruded products that are otherwise carbohydrate-rich, high glycaemic products. The aim of this study was to investigate the possibility of application brewer’s spent grain (BSG), sugar beet pulp (SBP) and apple pomace (AP) in production of corn snack products. By-products were mixed with corn grits at different ratios (0/100 ; 5/95 ; 10/90 and 15/85), where in the mixtures with BSG and SBP pectin was added at level 1% d. m., with the aim to produce products with properties of ready-to-eat snacks. Prepared samples with 15% of moisture content were extruded in the laboratory single screw extruder at temperature profile 135/170/170 °C, using a screw with compression ratio 4:1 and die with 4 mm diameter. Obtained extrudates were air-dried overnight, and physical and sensory properties of extrudates were determined. The obtained results showed that addition of by-products to corn grits resulted in decrease of expansion ratio (ER) and fracturability, whereas bulk density (BD) and hardness of extrudates increased. Acceptable scores in sensory evaluation received all samples with brewer's spent grain and sugar beet pulp (with addition of 1% pectin), and samples with 5 and 10% of apple pomace. It can be concluded that these three by-products can be successfully incorporated in corn grits with the aim of production acceptable expanded corn snack products.

Extrusion is one of the most significant processes in food industry, where corn grits is often used as main raw material. In order to increase nutritive value and improve physical and chemical properties, in corn grits can be added flours of different grains, dehydrated fruits and vegetables, etc. Cocoa shell as a by-product of cocoa beans processing is a significant problem in the food industry. Since it is a good source of dietary fiber and polyphenols, it could be used as raw material for development of new products. Therefore, the aim of this study was to investigate the influence of extrusion process and cocoa shell addition (in proportions of 5%, 10% and 15%) on properties of extrudates based on corn grits. On obtained extrudates physical properties were determined, which included: expansion ratio, bulk density, texture, color, water absorption index and water solubility index. It was established that addition of cocoa shell resulted in decrease of expansion ratio and fracturability, but in increase of bulk density and hardness of extrudates. Extrusion caused lightening of control sample of corn grits, but darkening of extrudates with added cocoa shell. Water absorption index and water solubility index increased significantly after extrusion. From all above it can be concluded that cocoa shell can be successfully added to corn grits in order to produce new extruded products.

Extrusion is a modern procedure for processing different types of raw materials and production of wide range of food products, where the corn grits are often used as main raw materials. Therefore the aim of this study was to determine the effect of screw configuration (4:1 and 1:1), moisture content (15% and 20%) and particle size of corn grits (>500 µm and

Extrusion is a significant process in food the industry, where corn grits is often used as the main raw material to which various types of flours can be added to increase nutrition value and to improve physicochemical properties. Chickpea (Cicer arietinum L.) is one of the world’s most important grain legumes because it is a valuable source of protein, minerals and vitamins, and plays a very important role in human diets in many areas of the world. The aim of this study was to determine the effect of chickpea flour addition (5%, 10% and 15%) on properties of corn grits extrudates. Samples with 15% of moisture content were extruded in the laboratory single screw extruder at temperature profile 135/170/170 °C, using a screw with compression ratio 4:1 and die with 4 mm diameter. Obtained extrudates were air- dried, and physical and rheological properties were determined. The obtained results showed that the addition of chickpea flour to corn grits resulted in increase of expansion ratio (ER) and fracturability, whereas bulk density (BD) and hardness of extrudates decreased. Addition of chickpea flour and extrusion process resulted in significant colour change, where the total colour change (ΔE) increased proportionaly to the chickpea level, with more pronounced change in extruded products. After extrusion process, peak, hot and cold viscosity were decreased in all samples, and the extruded samples were less prone to retrogradation.

The aim of this research was to examine potentiality of enrichment of extruded corn products by addition of rye, which is a rich source of dietary fibers and bioactive components. Corn grits with particle size ≤500 µm and grits with particle size >500 µm were used. Rye flour was added in 20% (d. m.). Extrudates were produced in laboratory single screw extruder at 135/170/170 °C. Rye addition caused a decrease of expansion ratio, lightness and fracturability and an increase of bulk density, colour saturation and hardness of extrudates. When grits of larger particle size were used, lightness of samples increased after extrusion, while it decreased for smaller particle size. Starch damage largely increased after extrusion, as well as absorption index and solubility, while viscosity decreased. Rye addition decreased starch damage.

The aim of this research was to investigate potential of brewers' spent grain (BSG) application in production of modified maize flour with increased fibre content. Dried BSG was added to maize grits in 5%, 10% and 15% (d.m). Obtained mixtures were set to moisture content 15% and extruded in laboratory single screw extruder at temperature profile 135/170/170 °C, with screw configuration 4:1 and 4 mm die. Extrudates were air-dried overnight and milled in laboratory mill with 2 mm sieve. Water absorption index (WAI) and water solubility index (WSI) were determined according to Anderson et al. (1969), resistant starch (RS) according to AOAC 2002.02, soluble and insoluble dietary fibre content according to AOAC 991.43, and starch damage according to AACC 76-31.01 method. Addition of BSG caused significant increase of insoluble fibre content and slight increase of soluble fibre content and RS content. This was followed by slight increase of WAI and WSI, since RS and soluble fibre have affinity towards water. After extrusion significant starch damage combined with significant increase of soluble fibre content caused extensive increase of WAI and WSI. Since soluble dietary fibres have proven beneficial health effect, modified extruded maize flour with added BSG has potential in functional food production. However, additional research is needed to determine its technological properties and suitability for bakery, pasta and/or biscuit production.

In order to improve the nutritional value and physico-chemical properties of corn extrudates, a part of corn grits is usually replaced with flour of other cereals, pseudocereals, dehydrated fruits and vegetables, etc. The aim of this study was to determine the effect of millet flour addition (5%, 10% and 15%) on properties of corn grits extrudates. Samples with 15% of moisture content were extruded in the laboratory single screw extruder at temperature profile 135/170/170 °C, using a screw with compression ratio 4:1 and die with 4 mm diameter. Physical, thermophysical and rheological properties of the obtained extrudates were investigated in relation to non-extruded samples. The obtained results showed that addition of millet resulted in increase of expansion ratio (ER) and fracturability, and decrease of bulk density (BD) and hardness of extrudates. Addition of millet and extrusion process resulted in significant colour change, where the total colour change (ΔE) increased proportionally to the amount of millet flour. After extrusion process peak viscosity and viscosities at 92 °C and at 50 °C decreased, and the extruded samples were less prone to retrogradation.

Introduction: Apple pomace, as a main by-product in production of apple juice, cider and related products, is a nutritionally valuable raw material, rich in pectins, dietary fibres, polyphenols, etc. Because of that, apple pomace can be incorporated in various types of products, usually in production of cookies and bread. Objective: The aim of this research was to investigate the potential of apple pomace application in production of corn snack products. Materials and methods: Dried apple pomace was added in corn grits in proportions of 5, 10 and 15%. Prepared mixtures with 15% of moisture content were extruded in the laboratory single screw extruder. Obtained extrudates were air-dried overnight and milled in laboratory mill prior the analysis. Total, soluble and insoluble dietary fibres, resistant starch, starch damage, antioxidant activity, total polyphenols, acrylamide and hydroxymethylfurfural content were determined. Results: Addition of apple pomace significantly increased dietary fibres and polyphenol content, as well as antioxidant activity. After extrusion process starch damage and antioxidant activity significantly increased, while resistant starch content and total polyphenol content decreased. Furthermore, extrudates with higher portions of apple pomace had higher content of acrylamide and hydroxymethylfurfural, but these concentrations were low and it can be concluded that these products are safely for consumers. Conclusion: Results obtained in this investigation show that apple pomace can be successful incorporated in corn grits with the aim of production nutritionally more valuable corn snack products.

Cilj ovog istraživanja bio je utvrditi mogućnost primjene nusproizvoda prehrambene industrije (pivski trop, izluženi repini rezanci i trop jabuke), u udjelima 5, 10 i 15 %, u proizvodnji kukuruznih snack proizvoda, odnosno aditiva u proizvodnji pekarskih proizvoda. Istraživanje je obuhvatilo određivanje fizikalnih, reoloških i kemijskih svojstava neekstrudiranih i ekstrudiranih uzoraka te senzorskih svojstava odabranih snack proizvoda. Dobiveni rezultati pokazuju kako se dodatkom nusproizvoda smanjio ekspanzijski omjer i lomljivost, a povećala tvrdoća i nasipna masa ekstrudata. Dodatak nusproizvoda i postupak ekstruzije imali su značajan utjecaj na promjenu boje i osnovni kemijski sastav. Nadalje, viskoznost vrha te topla i hladna viskoznost smanjene su dodatkom nusproizvoda i postupkom ekstruzije. Ekstruzijom se značajno povećao indeks apsorpcije i indeks topljivosti u vodi te stupanj oštećenosti škroba. Dodatkom nusproizvoda značajno se povećao udio netopljivih i topljivih vlakana. Ekstruzija je uzrokovala smanjenje udjela netopljivih vlakana i rezistentnog škroba, a povećanje udjela topljivih vlakana i nerezistentnog škroba. Udio ukupnih polifenola smanjio se, a antioksidativna aktivnost kod većine uzoraka povećala se nakon provedenog procesa ekstruzije. Veći udjeli akrilamida i hidroksimetilfurfurala utvrđeni su kod bolje ekspandiranih uzoraka te ekstrudata s većim udjelom nusproizvoda. Prihvatljivu senzorsku ocjenu dobili su svi uzorci s pivskim tropom i repinim rezancima (uz dodatak 1 % pektina) te uzorci s 5 i 10 % tropa jabuke. The aim of this study was to investigate the possibility of using food industry by-products (brewer's spent grain, sugar beet pulp and apple pomace), in proportions of 5, 10 and 15%, in production of corn snack products or additives in production of bakery products. The research included determination of physical, rheological and chemical properties of non-extruded and extruded samples, and sensory properties of selected snack products. The obtained results show that the addition of by-products decreased expansion ratio and fracturability, and increased hardness and bulk density of extrudates. By-products addition and extrusion process had a significant effect on color change and basic chemical composition. Furthermore, peak, hot and cold viscosities decreased with addition of by-products and after extrusion process. Extrusion significantly increased water absorption and water solubility index, and starch damage. With addition of by-products content of insoluble and soluble dietary fiber significantly increased. Extrusion caused a reduction of insoluble fiber and resistant starch content, and increase of soluble fiber and non-resistant starch content. Total phenolic content decreased, and antioxidant activity in most of samples increased after extrusion process. Higher contents of acrylamide and hydroxymethylfurfural were found in samples with better expansion, and extrudates with higher content of by-products. Acceptable scores in sensory evaluation received all samples with brewer's spent grain and sugar beet pulp (with addition of 1% pectin), and samples with 5 and 10% of apple pomace.

Extrusion is a continuous cooking and shaping (forming) process designed to give unique physical and chemical functionality to food materials. It is a popular unit operation for producing a variety of food products from numerous ingredients requiring a wide range of processing conditions. Extrusion technology also has many advantages such as the versatility, high productivity, low cost, unique product shapes and high product quality. Corn, wheat and rice are the main raw materials for production of extrudates, but the production of extrudates with addition of other flour types is now used widely in the food process industry, both for final products and for modification of flours for bakery industry. Barley is the fourth major cereal crop produced in the world, which is consumed around the world mostly in the malted form in brewing and bakery industry. In recent years barley has gained popularity due to the functional properties of its bioactive compounds such as β-glucan, arabinoxylan, oligosaccharides, tocols and phenolic compounds. The aim of this study was to determine the effect of barley flour addition to corn grits (ratio grits : flour = 80 : 20) on physical properties of extrudates. Prepared samples with 15% of moisture content were extruded in the laboratory single screw extruder at temperature profile 135/170/170 °C, using screw with compression ratio 4:1 and die with 4 mm diameter. Obtained extrudates were air-dried, and physical properties of extrudates were determined. Addition of barley flour to corn grits resulted in decrease of expansion ratio (ER) and fracturability, and in increase of bulk density (BD) and hardness of extrudates. Extrusion cooking caused an increase of water absorption index (WAI) and water solubility index (WSI), but the addition of barley flour resulted in decrease of WAI and increase of WSI. Damage of starch (DS) and resistant starch (RS) content were significantly changed after extrusion process, where the DS increased and RS decreased. The obtained results of textural and expansion properties indicate that extrudates don't have acceptable sensory properties as final products, but can be used as modified flours in bakery industry.

Extrusion is a significant process in food industry, where corn grits is often used as main raw material to which various types of flours can be added to increase nutrition value and to improve physicochemical properties. Chickpea (Cicer arietinum L.) is one of the world’s most important grain legumes because it is a valuable source of protein, minerals and vitamins, and plays a very important role in human diets in many areas of the world. The aim of this study was to determine the effect of chickpea flour addition (5%, 10% and 15%) on properties of corn grits extrudates. Samples with 15% of moisture content were extruded in the laboratory single screw extruder at temperature profile 135/170/170 0C, using a screw with compression ratio 4:1 and die with 4 mm diameter. Obtained extrudates were air-dried, and physical and rheological properties were determined. Expansion ratio (ER) was determined according to Brnčić et al. (2008) ; Bulk density (BD) was calculated according to the method of Alvarez-Martinez et al. (1988) ; Texture properties of extrudates were determined by texture analyzer TA.XT2Plus ; Pasting properties were measured using a Micro Visco-Analyser ; Colour was measured using Chroma Meter CR-300 in CIE-Lab and CIE-LCh colour spaces. The obtained results showed that addition of chickpea flour to corn grits resulted in increase of expansion ratio (ER) and fracturability, whereas bulk density (BD) and hardness of extrudates decreased. Addition of chickpea flour and extrusion process resulted in significant colour change, where the total colour change (ΔE) increased proportionally to chickpea level, with more pronounced change in extruded products. After extrusion process, peak, hot and cold viscosities were decreased in all samples, and the extruded samples were less prone to retrogradation.

Corn grits is a basic raw material for production of snack products, but recently various types of flours and dehydrated fruits and vegetables are used to increase nutritive value of these products. Apple pomace, as inexpensive and primary by-product of apple juice and cider production, is a good source of dietary fibres, polyphenols and pectin. Because of that, the aim of this study was to investigate the effect of dehydrated apple pomace addition (5, 10 and 15%) on properties of corn snack products. Prepared samples with 15% of moisture content were extruded in the laboratory single screw extruder at temperature profile 135/170/170 °C, using a screw with compression ratio 4:1 and die with 4 mm diameter. Obtained extrudates were air-dried, and expansion ratio (ER), bulk density (BD), texture and colour were determined. The results showed that ER and fracturability of extrudates decreased, and BD increased with addition of apple pomace. Hardness of extrudates increased with addition of apple pomace, but not significantly for extrudates with 5 and 10% of apple pomace. Results for colour analysis indicated that extruded samples were darker and total colour change (∆E) increased proportionally to addition of apple pomace, with more pronounced change in extruded samples.

Rye is second to wheat, the most commonly used grain in the production of bread, although not widely used as an ingredient for extruded products. The aim of this study was to determine the effect of rye flour addition to corn grits (ratio grits:flour = 80:20) on extrudates properties. Prepared samples with 15% of moisture content were extruded in the laboratory single screw extruder at temperature profile 135/170/170 °C, using a screw with compression ratio 4:1 and die with 4 mm diameter. Obtained extrudates were air-dried, and physical and rheological properties of extrudates were determined. Addition of rye resulted in decrease of the expansion ratio (ER) and fracturability of extrudates and increase of bulk density (BD) and hardness. Extrusion resulted in the increase of water absorption indeks (WAI) and water solubility indeks (WSI), as well as the significant damage of starch in all samples, but addition of rye resulted in reduced starch damage. Rye flour addition and extrusion process decreased peak viscosity and viscosities at 92 °C and at 50 °C, and the extruded samples were less prone to retrogradation.

Production of extrudates with different flour type addition is now used widely in the food process industry, both for final products and for modification of flours for bakery industry. The aim of this study was to determine the effect of black oat and oat flour addition to corn grits (ratio grits:flour = 80:20) on extrudates properties. Prepared samples with 15% of moisture content were extruded in the laboratory single screw extruder at temperature profile 135/170/170 °C, using screw with compression ratio 4:1 and die with 4 mm diameter. Obtained extrudates were air-dried, and physical and rheological properties of extrudates were determined. Addition of black oat and oat flour to corn grits resulted in decrease of expansion ratio (EO) and fracturability, and in increase of bulk density (BD) and hardness of extrudates. Extrusion of all samples resulted in increase of water absorption index (WAI) and water solubility index (WSI), but in decrease of peak, hot and cold viscosity, with more pronounced effect on corn grits without flour addition. The obtained extrudates don't have acceptable sensory properties as final products, but can be used as modified flours in bakery industry.

Effect of chestnut flour (CF) addition (10, 15 and 20%) and processing parameters on quality of durum pasta was investigated. Pasta was produced on laboratory press (moisture content of mixtures was set to 36%, mixing time was 10 min) and on laboratory single screw extruder at temperature profile 80/90/90 °C, using a screw with compression ratio 1:1 (moisture content of mixtures was set to 30%, mixing time was 10 min). Pasta samples were air dried and sensory evaluation of uncooked and cooked pasta samples was performed as well as determination of colour, optimum cooking time, water absorption and texture profile analysis (hardness, adhesiveness, cohesiveness). Results showed that extruded pasta samples (EPS) had decreased cooking loss, shorter cooking time and lower apsorption of water in relation to samples produced on laboratory press (LPS). EPS and LPS showed increase in cooking tolerance with addition of CF. Overall, EPS were scored with a higher point then LPS. EPS were darker then LPS. There were differences in colour between uncooked, dried and cooked pasta samples. Addition of CF decreased L* and b* parameter and increased a* in uncooked, as well as in dried and cooked pasta samples. EPS showed higher hardness in relation to LPS, and the addition of CF decreased hardness of both samples.

The aim of this research was to determine properties of extrudates produced from semolina with moisture set to 15% and 20%. Semolina was extruded in extruder Do-Coder, Brabender 19/20 DN ; GmbH, Duisburg, Germany at temperature profile 135/170 °C, with screw 4:1 and 4 mm die, and extrudate diameter, expansion ratio, texture and viscosity were determined. The obtained results showed that extrudate diameter and expansion increased proportionally to semolina moisture, as well as hardness of extrudates, whereas fracturability wasn’t influenced by moisture content. Water absorption index of semolina increased after extrusion proportionally to moisture content of raw semolina. In addition, extrusion resulted in increase of peak viscosity and breakdown, with more pronounced effect on semolina with 20% moisture. Raw semolina was most stable during shearing at high temperatures expressed as breakdown value, whereas samples extruded at 20% moisture were least prone to retrogradation, which was expressed as “setback”.

Spelt is grain that, because of its chemical composition, recently has attracted increased attention in the production of various food products. Since the extrusion process is used worldwide for the modification or quality improvement of different flour types, the aim of this study was to determine the effect of non-extruded and extruded spelt on dough properties and quality of cookies. Non-extruded and extruded spelt were used to prepare the cookies by replacing wheat flour (T-500) in ratio of 20%. Rheological properties of flour were determined by Brabender Amylograph test, and dough properties by Brabender Extensograph and Farinograph test. The obtained results showed that spelt flour had lower peak, hot and cold viscosity values in relation to wheat flour, with more pronounced difference for extruded spelt. By addition of non-extruded and extruded spelt flour, water absorption, development time and dough softening increased, whereas quality number slightly decreased. Furthermore, these substitutions strengthened the dough, mainly by decreasing its extensibility and, in extruded spelt addition, also by increasing the resistance to extension. The sensory evaluation of cookies was determined on a 100-point scale. Replacement of wheat flour with non-extruded and extruded spelt decreased total sensory point, with significantly decrease for extruded flour.

Extrusion is a modern procedure for processing different types of raw materials and is used for production a wide range of food products. Corn grits is a basic raw material of different extruded food products. The aim of this research was to determine the effect of moisture content (15% and 20%) and particle size of corn grits (Specijal and Resli) on the properties of extruded products. Grits were extruded on the laboratory single screw extruder Brabender 19/20 DN, at temperature profile 135/170/170 °C, using screw with compression ratio 4:1 and die with 4 mm diameter. Physical, rheological and thermophysical properties of the obtained extrudates, and starch damage were determinated. The results showed that higher moisture content decreased the expansion ratio and fragility, but increased bulk density and hardness of extrudates, regardless of granularity. Properties of corn grits viscosity were significantly changed by extrusion, with more pronounced effect in grits extruded with lower moisture content, in which starch damage was also significantly higher.

Proizvodnja ekstrudata iz različitih vrsta brašna danas je često primjenjivan proces u prehrambenoj industriji. Cilj ovog rada bio je utvrditi utjecaj postupka ekstruzije na svojstva smjesa kukuruzne krupice s heljdinim i kestenovim brašnom (omjeri krupica : brašno = 70 : 30; 50 : 50 i 30 : 70). Smjese vlažnosti 25 % ekstrudirane su pri dva temperaturna profila: 80/90 °C i 75/180 °C. Dobivenim ekstrudatima ispitana su fizikalna, termofizikalna i reološka svojstva te probavljivost u odnosu na neekstrudirane uzorke. Utvrđeno je povećanje ekspanzijskog omjera i smanjenje nasipne mase pri višoj temperaturi ekstruzije, kao i povećanje lomljivosti te smanjenje tvrdoće većine ekstrudata kod više temperature. Ekstruzija je uzrokovala potamnjivanje i povećanje intenziteta boje uzoraka, i to proporcionalno temperaturi ekstruzije. Moć upijanja vode povećala se, i to znaĉajnije pri višoj temperaturi. Ekstruzija je uzrokovala smanjenje udjela rezistentnog škroba (RS). Udio proteina kod većine uzoraka povećao se, a udio masti smanjio nakon provedenog procesa ekstruzije. Ekstruzija je uzrokovala smanjenje viskoznosti vrha. Udio ukupnih polifenola i antioksidativna aktivnost povećali su se dodatkom heljdinog i kestenovog brašna, ali je ekstruzija uzrokovala njihovo smanjenje. Production of extrudates from different types of flour is used widely in the food industry. The aim of this study was to determine the effect of extrusion process on the properties of mixtures of corn meal with buckwheat and chestnut flour (ratio meal : flour = 70 : 30, 50 : 50 and 30 : 70). Blends (25% moisture) were extruded at two temperature regimes: 80/90 °C and 75/180 °C. Physical, thermophysical and rheological properties, and digestibility of the obtained extrudates were investigated in relation to non extruded samples. Results showed an increase in expansion ratio and the reduction of bulk density at the higher extrusion temperature, and increased fragility and decrease in extrudate hardness of most of extrudates produced at the higher temperatures. Extrusion resulted in darker color and increased intensity of color, proportionally to extrusion temperature. Water absorption index increased proportionally to extrusion temperature. Extrusion caused a reduction of the resistant starch content and peak viscosity. Protein content in most samples increased, and fat content decreased after the extrusion process. Total polyphenol content and antioxidant activity increased by the addition of buckwheat and chestnut flour, but the extrusion caused their decrease.

Production of extrudates from different types of flour is now used widely in the food process industry, both for final products production and for modification of flours for bakery industry. The aim of this research was to determine the effect of extrusion process on the properties of mixtures of corn meal with buckwheat and chestnut flour (ratio meal: flour = 70/30, 50/50 and 30/70). Blends (water content 25%) were extruded at two temperature regimes: 80/90 °C and 75/180 °C. Physical, thermophysical and rheological properties, chemical composition and resistant starch content of the obtained extrudates were investigated. Results showed an increase in expansion ratio and the reduction of bulk mass at the higher extrusion temperature, increased fragility and decreased hardness of most of extrudates produced at the higher temperatures. In relation to non-extruded samples, color intensity and water absorption index increased proportionally to extrusion temperature. Viscosity changed significantly, and resistant starch (RS) content decreased by extrusion.

Cilj ovog istraživanja bio je utvrditi utjecaj postupka ekstruzije na biodostupnost cinka i selena primjenom različitih temperatura ekstruzije: 170 °C, 180 °C i 190 °C te dodavanjem biofortificirane pšenice cinkom i selenom u udjelima 10, 20, 30 i 40 % u proizvodnji kukuruznih snack proizvoda. Istraživanje je obuhvatilo određivanje fizikalnih, reoloških i kemijskih svojstava neekstrudiranih i ekstrudiranih uzoraka te biodostupnosti cinka i selena, kao i senzornih svojstava odabranih snack proizvoda. Dobiveni rezultati pokazuju kako je ekstruzija pri različitim temperaturama imala utjecaj na sva fizikalna svojstva ekstrudata. Dodavanjem različitih udjela biofortificirane pšenice smanjio se ekspanzijski omjer i lomljivost, dok su se nasipna masa i tvrdoća povećale. Postupak ekstruzije pri različitim temperaturama, kao i dodavanje različitih udjela biofortificirane pšenice, značajno su utjecali na promjenu boje. Proces biofortifikacije sirovina značajno je povećao udio minerala i proteina. Vrijednosti viskoznosti značajno su se smanjile pri različitim temperaturnim profilima ekstruzije i različitim udjelima pšenice. Različiti temperaturni profili doveli su do povećanja sadržaja ukupnog škroba i većeg oštećenja škroba, dok su se vrijednosti tih svojstava smanjile dodavanjem različitih udjela pšenice biofortificirane cinkom i selenom. Proces ekstruzije pokazao je pozitivan učinak na biodostupnost i cinka i selena. Prihvatljivu senzorsku ocjenu dobili su svi uzorci ekstrudata, s naglaskom na to da su veći utjecaj na senzorska svojstva imali različiti udjeli dodane biofortificirane pšenice nego temperature ekstruzije. The aim of this study was to determine the impact of the extrusion process on the bioaccessibility of Zn and Se, using different extrusion temperatures: 170 °C, 180 °C and 190 °C and addition of biofortified wheat with Zn and Se in contents of 10, 20, 30 and 40%, in the production of corn snack products. The research included determination of physical, rheological and chemical properties of non-extruded and extruded samples and bioaccessibility of Zn and Se, as well as sensory properties of selected snack products. The obtained results show that extrusion at different temperatures affected all physical properties of extrudates. The addition of different proportions of biofortified wheat reduced the expansion ratio and fracturability, while bulk density and hardness increased. The extrusion process at different temperatures as well as the addition of different proportions of biofortified wheat significantly affected the color change. The process of biofortification of raw materials has significantly increased the contents of minerals and proteins. The values of viscosity decreased significantly at different temperature profiles and different proportions of wheat. Different temperature profiles led to an increase in total starch content and greater starch damage, while the values of these properties decreased with the addition of different proportions of wheat biofortified with Zn and Se. The extrusion process showed a positive effect on the bioaccessibility of both zinc and selenium. All samples of extrudates received an acceptable sensory score, where the different proportions of added biofortified wheat had a greater impact on the sensory properties than extrusion temperatures.

Trop aronije predstavlja kruti ostatak nakon prešanja aronije. Ovaj vrijedni nusproizvod bogat je izvor prvenstveno polifenolnih komponenti, ali i prehrambenih vlakana, vitamina i minerala. Cilj ovog diplomskog rada je ispitati mogućnost primjene tropa aronije u proizvodnji ekstrudiranih snack proizvoda na bazi kukuruzne krupice. Osušeni trop aronije dodavan je u kukuruznu krupicu u udjelima 4, 8 i 12 % s. tv. te su zamjesi pripremljeni na 15 % vlage i ekstrudirani u laboratorijskom jednopužnom ekstruderu uz primjenu parametara ekstruzije prikladnih za proizvodnju direktno ekspandiranih snack proizvoda. Rezultati ovog istraživanja pokazuju kako se dodatkom nusproizvoda tropa aronije smanjio ekspanzijski omjer i tvrdoća, nasipna masa ekstrudata se povećala, dok se lomljivost nije značajno promijenila. Također, dodatak tropa aronije kao i sam postupak ekstruzije iznimno su utjecali na boju ekstrudata. Procesom ekstruzije se značajno povećao indeks apsorpcije i indeks topljivosti u vodi te je došlo do smanjenja udjela netopljivih vlakana, a povećanja udjela topljivih vlakana. Proces ekstruzije uzrokovao je smanjenje udjela ukupnih polifenola i antioksidativne aktivnosti kod većine uzoraka. The chokeberry pomace is a solid residue after pressing the chokeberry. This valuable by-product is primarily a rich source of polyphenolic components, but also dietary fiber, vitamins and minerals. Therefore, the aim of this thesis is to examine the possibility of using chokeberry pomace in the production of extruded snack products based on corn grits. Dried chokeberry pomace was added in proportions of 4, 8 and 12%, in production of corn snack products. These mixtures were prepared at 15% moisture and extruded in a laboratory single-screw extruder using extrusion parameters suitable for the production of expanded snack products. The results of this study show that the addition of chokeberry pomace decreased the expansion ratio and hardness, the bulk density of the extrudate increased, while the fracturability did not change significantly. Also, the addition of chokeberry pomace as well as the extrusion process itself had an exceptional effect on the color of the extrudates. The extrusion process significantly increased the water absorption index and water solubility index, and the content of insoluble fibers decreased, while the content of soluble fibers increased. The extrusion process caused a decrease in the content of total polyphenols and antioxidant activity in most samples.

Jedinstvenost i praktičnost ekstruzijskog kuhanja pridonijele su popularnosti ovog procesa na tržištu. Proces ekstruzije omogućuje obradu različitih vrsta sirovina i dobivanje gotovih proizvoda u kratkom vremenskom periodu. U postupku ekstruzije najčešće se koriste sirovine bogate škrobom i proteinima, a jedna od najpopularnijih je kukuruzna krupica. Cilj ovog diplomskog rada bio je odrediti utjecaj vlažnosti zamjesa na svojstva ekstrudiranih brašna različitih sorti kukuruza dobivenih od Poljoprivrednog instituta Osijek. Korištene su vlažnosti od 30 i 35 %. Postupak ekstruzije bio je proveden na laboratorijskom jednopužnom ekstruderu te su ispitivani sljedeći parametri: ekspanzijski omjer, nasipna masa, boja, indeks apsorpcije vode (WAI), indeks topljivosti u vodi (WSI) i reološka svojstva Brabenderovim Mikro-visko-amilografom. Rezultati su uspoređeni s rezultatima za neekstrudirana brašna kukuruza. Dobiveni rezultati pokazali su da povećanje vlažnosti nije značajno utjecalo na porast eksponencijalnog omjera (EO) i nasipnu masu ekstrudata (BD). Proces ekstruzije i povećanje vlažnosti značajno je utjecalo na povišenje indeksa apsorpcije vode (WAI) i indeksa topljivosti ekstrudata u vodi (WSI). U usporedbi s neekstrudiranim uzorcima ekstrudirani uzorci su postigli tamniju i intenzivniju boju, te su svrstani u domenu crvene i žute boje. Procesom ekstruzije također je smanjena viskoznost vrha gotovo svih uzoraka te je potvrđena dobra stabilnost prilikom miješanja na visokim temperaturama, a najveću sklonost retrogradaciji pokazali su neekstrudirani uzorci. Extrusion cooking is one of the most popular process sin the market due to its uniqueness and convenience. The extrusion process enables processing of different types of raw materials and obtaining finished products in a short period of time. Raw materials rich in starch and protein are most commonly used in the extrusion process, and corn grits is one of the most popular. The aim of this thesis was to determine the influence of the moisture content on the properties of extruded flours of different corn obtained from the Agricultural Institute of Osijek. Moisture content of 30% and 35% were used. The extrusion process was performed on a laboratory single screw extruder and the following parameters were tested: expansion ratio, bulk density, color, water absorption index (WAI), water solubility index (WSI), and rheological properties using a Brabender Micro-visco-amylograph. The results were compared with those for non-extruded corn grits. The obtained results showed that the increase in moisture did not significantly influence the increase of the expansion ratio (EO) and the bulk density of the extrudate (BD). The extrusion process and the increase in moisture content significantly influenced the increase in the water absorption index (WAI) and the extrudate solubility index in water (WSI). Compared to non-extruded samples, extruded samples achieved a darker and more intense color and were classified as red and yellow. The extrusion process also reduced the peak viscosity of almost all the samples and confirmed good stability when mixed at high temperatures, with the highest tendency for retrogradation of the non-extruded samples.

U ovom radu ispitivan je utjecaj ekstruzije pri različitim temperaturnim profilima na svojstva kukuruznog škroba. Korišteni temperaturni profili su 90/100/120 °C, 100/115/140 °C i 110/140/160 °C. Ispitivani parametri su boja, kapacitet bubrenja, indeks topljivosti u vodi, bistroća (prozirnost) pasti te reološka svojstva škrobnih pasti određenih Brabenderovim mikro visko-amilografom. Modifikacijom se mijenjaju kemijska i fizikalna svojstva škroba što dovodi do povećanja njegove industrijske primjene. Uspoređujući rezultate nativnog škroba s rezultatima modificiranih škrobova vidljivo je da je ekstruzija uvelike pridonijela poboljšanju svojstava škroba. Povišenjem temperature ekstruzije došlo je do sniženja početne temperature želatinizacije, smanjenja viskoznosti škrobnih pasti, veće stabilnosti pri višim temperaturama i smanjenja stupnja retrogradacije. Kapacitet bubrenja i indeks topljivosti u vodi povećali su se s povišenjem temperaturnog profila ekstruzije. Bistroća škrobnih pasti povećala se proporcionalno s temperaturom ekstruzijskog kuhanja, dok je boja ekstrudata bila sve tamnija pri višim temperaturama. In this paper, the influence of extrusion cooking at various temperature profiles on the properties of corn starch was studied. The temperature profiles used in study were 90/100/120 °C, 100/115/140 °C and 110/140/160 °C. Examined parameters were color, swelling capacity, water salubility index, paste clarity (transparency), and rheological properties of starch determined by Brabender's micro visco-amylograph. With modification the physical and chemical properties of starch are changed, which leads to an increase in the industrial use of starch. Comparing the results of native starch with the results of modified starches it is apparent that extrusion greatly contributed to the improvement of starch properties. Increasing the extrusion temperature resulted in lowering the initial gelatinization temperature, decreasing the viscosity of starches, higher stability at higher temperatures and decreasing the retrogradation rate. Swelling capacity and water solubilty index increased with increament of the extrusion temperature profile. Paste clarity increased proportionally to the temperature of extrusion cooking, while the higher extrusion temepratures resulted in darker color of starches.

Cilj ovog istraživanja je bio ispitivanje fizikalnih svojstava ekstrudiranih snack proizvoda na bazi kukuruzne krupice s dodatkom raženih posija od 10 različitih uzoraka raži prikupljenih slučajnim odabirom od hrvatskih proizvođača te određivanje količine ergot alkaloida pomoću LC/MS-MS metode. Ražene posije su dodavane u kukuruznu krupicu u udjelima 10 i 20 %. Zamjesi s 15 % vlage ekstrudirani su u jednopužnom laboratorijskom ekstruderu, nakon čega su osušeni na zraku i provedene su analize. Utvrđeno je da je dodatak raženih posija u kukuruzne snack proizvode imao veliki utjecaj na fizikalna svojstva i udio ergot alkaloida. Dodatkom raženih posija došlo je do smanjenja ekspanzijskog omjera te povećanja nasipne mase kod gotovo svih uzoraka u odnosu na uzorak kukuruznog snack proizvoda bez dodatka raženih posija. Tvrdoća ekstrudata smanjena je dodatkom raženih posija, dok utjecaj na lomljivost nije bio tako značajan, pri čemu su vrijednosti kod većine uzoraka također smanjene. Dodatak raženih posija i proces ekstruzije imali su značajan utjecaj na promjenu boje, uz izraženiji utjecaj kod većeg udjela posija. Gotovo svi ekstrudirani snack proizvodi imali su manji udio ukupnih ergot alkaloida u odnosu na uzorke sirovih raženih posija, dok se ekstruzijom povećao udio paspalne kiseline. The aim of this study was to investigate the physical properties of extruded snack products based on corn grits with the addition of rye branform 10 different rye samples collected randomly from Croatian manufacturer, and determination ergot alkaloids quantity by using LC/MS-MS method. Rye brans were added to the corn grits in shares of 10 and 20%. Mixtures with 15% moisture content were extruded in a single laboratory extruder and than air-dried and analyzed. It was found that the addition of rye bran in corn snack products had a major influence on the physical properties and the quantity of ergot alkaloids. With the addition of rye bran the expansion ratio decreased, while the bulk density in almost all samples increased compared to the sample of corn snacks without of rye bran. The hardness of the extrudate was reduced by the addition of rye bran, while the influence on the fracturability was not so significant, where the values of most samples also reduced. The addition of rye bran and the extrusion process had a significant effect on the color change, with a more pronounced influence in the higher proportion of bran. Almost all extruded snack products had a lower quantity of total ergot alkaloids, compared to samples of raw rye bran, while with the extrusion process quantity of paspalic acid increased.

Cilj ovog rada bio je utvrditi utjecaj procesa ekstruzije na svojstva smjesa pšeničnog brašna i pivskog tropa. Omjeri smjesa (pšenično brašno:pivski trop) korišteni u istraživanju su 85:15, 70:30, 55:45. Smjese vlažnosti 30 % ekstrudirane su pri temperaturnom profilu 70/90/110 °C. Istraživanjem su se određivala fizikalna i reološka svojstva neekstrudiranih i ekstrudiranih uzoraka. Utvrđeno je da se dodatkom pivskog tropa smanjuje viskoznost ekstrudata. Ekstruzija smanjuje vrijednost broja padanja, a većim udjelom pivskog tropa u smjesi vrijednost broja padanja nastavila se smanjivati. Budući da se ekstruzijom smanjuje udio proteina, sedimentacijske vrijednosti kod ekstrudiranih uzoraka su niske. Ekstruzija utječe na sposobnost upijanja vode povećavajući moć upijanja, a ona se smanjivala povećanjem udjela pivskog tropa. Zbog narušenog glutena nije zabilježena značajna stabilnost tijesta. Farinografski broj kvalitete podjednako je visok u svim uzorcima pa svi pripadaju A1 skupini kvalitete. The aim of this study was to determine extrusion process impact on mixture of wheat flour and brewer’s spent grain properties. Mixture ratios (wheat flour:brewer’s spent grain) used in this study are 85:15, 70:30, 55:45. Mixtures, at the humidity of 30%, have been extruded on temperature profile 70/90/110°C. In this study the physical and rheological properties of non-extruded and extruded samples have been determined. It has been proven that, with the addition of brewer’s spent grain, the viscosity of extrudates is reduced. Extrusion decreases the falling number values, and with increasing content of brewer’s spent grain in mixture the values of falling number continues to decrease. Since the extrusion decreases the protein content, sedimentation values at the extruded samples are low. Extrusion influences the water absorption capability by increasing it, while the water absorption capability has been decreased with addition of brewer’s spent grain. Due to poor quality of gluten, significant stability of dough hasn’t been noticed. Farinograph quality number has been equally high within all samples, so each of them is classified as A1 quality group.

Ekstruzija je vrlo značajan proces u prehrambenoj industriji, a kao sirovina za ekstruziju često se koristi kukuruzna krupica. U današnje vrijeme svijest potrošača o kvalitetnoj prehrani je na visokoj razini. Zbog poboljšanja svojstava i nutritivne vrijednosti proizvoda u krupicu se mogu dodavati različiti dodaci. Također, negativne promjene u hrani koje nastaju zbog visoke temperature, mogu se smanjiti primjenom superkritične \(CO_{2}\) ekstruzije (SCFX). Cilj ovog rada bio je ispitati utjecaj SCFX ekstruzije i dodatka odmašćene pogače lješnjaka (u udjelima od 3 %, 6 % i 9 %) na svojstva SCFX ekstrudata. Dobivenim SCFX ekstrudatima ispitana su fizikalna i reološka svojstva te su rezultati uspoređeni s neekstrudiranim uzorcima. Utvrđeno je da dodatkom pogače lješnjaka dolazi do smanjenja ekspanzijskog omjera i povećanja nasipne mase ekstrudata. SCFX ekstruzija uzrokovala je potamnjivanje svih uzoraka. Indeks apsorpcije vode povećao se nakon SCFX ekstruzije kod svih uzoraka, dok se indeks topljivosti u vodi povećao samo kod čiste krupice i dodatka 3 % pogače lješnjaka. Postupkom SCFX ekstruzije i dodatkom pogače lješnjaka došlo je do smanjenja viskoznosti vrha, a SCFX ekstrudati su imali manju sklonost retrogradaciji. Extrusion is very significant process in food industry, where corn grits is often used as main raw material. Today consumers are very aware and sensitive about nutrition quality. In order to enhance nutritive value and physical and chemical properties of extruded products, various supplements can be added to corn grits. Also, negative changes in food resulting from high temperatures, can be reduced by using supercritical \(CO_{2}\) extrusion (SCFX). The aim of this study was to investigate the properties of SCFX corn extrudates with addition of defatted hazelnut cake (with a share of 3%, 6% and 9%). Physical and rheological properties of the SCFX extrudates were investigated in relation to non-extruded samples. Results showed a decrease in expansion ratio and increase of bulk density with addition of hazelnut cake. SCFX extrusion caused decrease of lightness in all samples. Water absorption index was increased after SCFX extrusion process for all samples, while water solubility index was increased only for control corn grits and sample with addition of 3% hazelnut cake. Addition of hazelnut cake and SCFX extrusion process decreased peak viscosity and SCFX extrudates were less prone to retrogradation.

Cilj ovog rada bio je utvrditi utjecaj temperaturnog profila ekstruzije na svojstva pšeničnog i ječmenog brašna. Smjese vlažnosti 30 % ekstrudirane su pri tri različite temperature na glavi ekstrudera: 90, 100 i 110 °C. Određena su fizikalna i reološka svojstva ekstrudiranih i neekstrudiranih uzoraka. Istraživanjem je utvrđeno da djelovanjem ekstruzije dolazi do smanjenja viskoznosti vrha te tople i hladne viskoznosti. Sedimentacijske vrijednosti smanjile su se postupkom ekstruzije vjerojatno zbog narušavanja strukture proteina, uz izraženiji utjecaj kod ispitivanih uzoraka pšenice. Dok je broj padanja uzoraka pšenice postupkom ekstruzije smanjen, kod ječma se broj padanja povećao proporcionalno povećanju temperature ekstruzije. Farinografskim ispitivanjem utvrđeno je da postupak ekstruzije uzrokuje povećanje dužine razvoja i otpora tijesta te povećanje upijanja vode bez obzira na ispitivani uzorak pšenice ili ječma, dok se stupanj omekšanja uglavnom smanjio uz izuzetak za uzorak Pšenice 2. Farinografski broj kvalitete bio je veći kod sirovih uzoraka pšenice u odnosu na ječam, a postupkom ekstruzije vrijednosti su se povećale kod gotovo svih uvjeta ekstruzije. The aim of this paper was to determine the influence of the temperature profile of the extrusion on the properties of wheat and barley flours. Mixtures with 30% of moisture were extruded at three different temperatures on the extruder head: 90, 100 and 110 ° C. The physical and rheological properties of extruded and non-extruded samples were determined. In the study it was found that extrusion process reduces the peak, hot and cold viscosities. Sedimentation values were reduced by extrusion, probably due to the deterioration of the protein structure, with a more pronounced influence on wheat samples. While the falling number of wheat samples by extrusion was reduced, in barley samples the falling number was increased proportionaly to the increase of extrusion temperature. By farinographic examination, it was found that the extrusion procedure caused an increase of development time, resistance of the dough and water absorption regardless to the sample of wheat or barley, while the degree of softening generally decreased with the exception of the Pšenica 2 sample. Farinograph quality number of raw samples was higher in wheat samples compared to barley, and the values increased at the almost all conditions of extrusion.