Postupkom hladnog prešanja iz sjemenki lana i jezgre lješnjaka proizvodi se jestivo ulje visoke nutritivne vrijednosti. U ovom radu istraživan je utjecaj dodatka antioksidanasa (prirodni, sintetski) ...i sinergista na oksidacijsku stabilnost mješavine lješnjakovog i lanenog ulja (50:50). Od prirodnih antioksidanasa korišteni su ekstrakt kadulje, ekstrakt ružmarina, ekstrakt nara, mješavina tokoferola, eterično ulje konopljike, lavande, slatkog pelina, divlje mrkve, smilja, a od sintetskih propil galat. Određivanje oksidacijske stabilnosti mješavine ulja te utjecaj dodatka antioksidansa i sinergista provedeno je testom ubrzane oksidacije ulja Schaal Oven testom. Rezultat oksidacije mješavine ulja izražen je peroksidnim brojem. Primjenom standardnih metoda u ulju su određeni osnovni parametri kvalitete (peroksidni broj, slobodne masne kiseline, voda, netopljive nečistoće). Rezultati ispitivanja pokazuju da ekstrakt ružmarina (sa i bez limunske kiseline) efikasnije štiti mješavinu ulja od oksidacijskog kvarenja u odnosu na druge ispitivane antioksidanse. Eterično ulje slatkog pelina ne pokazuje utjecaj na stabilizaciju ove mješavine ulja.
The process of cold pressing linseed and hazelnut kernels produces edible oil of high nutritional value. In this paper, the influence of addition antioxidants (natural, synthetic) and synergists on the oxidative stability of mixture hazelnut and linseed oil (50:50) was investigated. The testing was carried out using the natural antioxidants sage extract, rosemary extract, pomegranate extract, tocopherol mixture, essential oil of hemp, lavender, sweet wormwood, wild carrot, immortelle, and synthetic propyl gallate. The oxidative stability of the oil mixture and the effect of addition of antioxidant and synergists were determined by the accelerated oil oxidation test, the Schaal Oven test. The result of the oil mixture oxidation was expressed by the peroxide value. The basic quality parameters (peroxide value, free fatty acids, water, insoluble impurities) were determined by applying the standard methods to oil. The results of testing indicated that rosemary extract (with and without citric acid) protect the oil mixture from oxidative spoilage more effectively than compared to other tested antioxidants. The essential oil of sweet wormwood shows no effect on the stabilization of this oil mixture.
U ovom radu istraživan je utjecaj procesnih parametara prešanja sjemenki crnog kima na prinos hladno prešanog ulja te njegovu kvalitetu. Prešanje sjemenki crnog kima provedeno je na laboratorijskoj ...pužnoj preši za proizvodnju hladno prešanih biljnih ulja. Prešanjem su dobivena tri proizvoda: sirovo ulje, uljni talog i pogača. Prilikom prešanja mijenjani su procesni parametri: frekvencija elektromotora, temperatura grijača glave preše i nastavak za izlaz pogače. Nakon prešanja provedena je sedimentacija (prirodno taloženje) proizvedenog sirovog ulja te vakuum filtracija kako bi se uklonile krute čestice. Primjenom standardnih metoda određeni su parametri kvalitete hladno prešanog ulja crnog kima: slobodne masne kiseline, peroksidni broj, udio netopljivih nečistoća i udio vlage. Primjenom plinske kromatografije određen je sastav masnih kiselina u ulju. Dobiveni rezultati istraživanja pokazuju da je prešanje crnog kima primjenom nastavka za izlaz pogače veličine 5 mm, temperature grijača glave preše 110 °C i frekvencije elektromotora 20 Hz proizvedena najveća količina sirovog i hladno prešanog ulja crnog kima. U sastavu masnih kiselina ulja crnog kima dominiraju linolna i oleinska masna kiselina.
This thesis, discusses the influence and quality of process parameters of pressing black cumin seeds on the yield of cold pressed oil. Pressing black cumin seeds was carried out on laboratory screw press for the production of cold pressed vegetable oils. Three products were obtained by pressing: crude oil, sludge oil and cake. During pressing, the process parameters were changed: the frequency of the electric motor, the temperature of the heater of the press head and the extension for the outlet of the cake. After pressing, sedimentation (natural precipitation) of the produced crude oil and vacuum filtration were performed to remove solid particles. Using standard methods, the quality of parameters of cold-pressed black cumin oil were determined: free fatty acids, peroxide value, insoluble impurities content and moisture content. The composition of fatty acids in oil was determined using gas chromatography. The obtained research results show that the pressing black cumin using a 5 mm cake outlet extension, a press heater head temperature of 110 ° C and an electric motor frequency of 20 Hz produced the largest amount of crude and cold-pressed black cumin oil. In the composition of fatty acids black cumin oil is dominated by linoleic and oleic fatty acids.
The effect of turmeric powder and a mix of turmeric powder and black pepper on the physicochemical properties of ice cream samples was examined. Enriched ice creams were manufactured by adding ...turmeric powder at levels of 0.5 %, 1.0 % and 2.0 %, with or without 0.02 % black pepper and compared with the control ice cream sample. Samples were analysed for proximate composition, pH value, water activity (aw), rheological properties, overrun, fat destabilization, hardness, melting properties, and colour parameters. The results of the study showed that the addition of spices significantly increased pH values (from 6.66 to 6.73), total solids (from 36.43 to 37.53 %), and carbohydrate contents (from 21.47 to 22.53 %) of the samples. Furthermore, this enrichment leads to an increase in the viscosity (from 0.44 to 0.70 Pa s) and thixotropic behaviours of ice cream mixes. Enriched ice creams had higher air incorporation, lower fat destabilization degree, and softer texture. In terms of melting properties, the melting resistance of ice cream samples was enhanced with the addition of spices. The colour properties of ice creams were significantly (p<0.05) affected by turmeric addition, while there was no difference between samples with and without black pepper. To conclude, turmeric powder and black pepper can be used for the development of functional turmeric-black pepper ice cream with acceptable physicochemical properties.
Despite the efforts to control mycotoxin contamination worldwide, extensive contamination has been reported to occur in food and feed. The contamination is even more intense due to climate changes ...and different stressors. This study examined the impact of fullerol C60(OH)24 nanoparticles (FNP) (at 0, 1, 10, 100, and 1000 ng mL−1) on the secondary metabolite profile of the most relevant foodborne mycotoxigenic fungi from genera Aspergillus, Fusarium, Alternaria and Penicillium, during growth in vitro. Fungi were grown in liquid RPMI 1640 media for 72 h at 29 °C, and metabolites were investigated by the LC-MS/MS dilute and shoot multimycotoxin method. Exposure to FNP showed great potential in decreasing the concentrations of 35 secondary metabolites; the decreases were dependent on FNP concentration and fungal genus. These results are a relevant guide for future examination of fungi-FNP interactions in environmental conditions. The aim is to establish the exact mechanism of FNP action and determine the impact such interactions have on food and feed safety.
he chocolate industry is constantly developing new products with different fillings, toppings, flavours, etc. Chocolates with alcoholic filling are popular, especially with young adults. In ...chocolates with alcoholic filling different kinds of thickeners can be used to increase the viscosity of the filling and make production easier. In this study, we examined cocoa shells, a by-product of the chocolate industry, as a new ingredient and thickener of an alcoholic filling. Chocolates with bitter herbal liqueur were produced in a ball mill with four different fillers. A comparison of guar gum and cocoa shell as thickeners was conducted. The influence of the filling ingredients on the stability of the filled chocolate was determined by measuring colour and gloss over 30 days of accelerated fat bloom. The results showed that chocolates for which the cocoa shell was used were more stable than chocolates where guar gum was used. Evaluation of sensory properties of chocolates with bitter herbal liqueur and different thickeners was conducted by the trained sensory panel. The highest-rated, after sensory assessment, were dark chocolates that contained cocoa shells in the filling. Also, an online questionnaire was conducted to examine consumer preference for a new product. According to the results, it can be concluded that the production of this chocolate would be desirable.
The aim of this work was to investigate the influence of cold storage at 2 °C for 180 days on water content, total acids, reducing and total sugar, antioxidant activity, polyphenol oxidase activity, ...and polyphenol profile of three Croatian traditional apple cultivars (‘Kanadska Reneta’, ‘Ilzer Rosenapfel’, ‘Wagener’). A significant variation in polyphenol profile of apple cultivars under investigation was noted. The most represented polyphenols in all apple cultivars were procyanidin B2 followed by chlorogenic acid, epigallocatechin, epicatechin, and phloridzin. After storage, the content of procyanidin B2 and chlorogenic acid was higher, while content of epigallocatechin after storage was lower in all investigated apple cultivars. Water content before storage ranged between 79.17 and 80.76 %, and after storage between 75.62 and 78.56 %. Total acids, polyphenol oxidase activity, and flavonoids had decreased during storage, while reducing and total sugar content was higher after storage. Moreover, after storage, cultivar ‘Kanadska Reneta’ had the highest antioxidant activity measured by both ABTS and DPPH methods, 1.65 and 0.70 mmol trolox kg–1, respectively. A significant variation in polyphenol profile of apple cultivars under investigation was noted. The most represented polyphenols in all apple cultivars were procyanidin B2, followed by chlorogenic acid, epigallocatechin, epicatechin, and phloridzin. After storage, the content of procyanidin B2 and chlorogenic acid was higher, while content of epigallocatechin after storage was lower in all investigated apple cultivars. Overall, it can be concluded that investigated apple cultivars, after storage, preserved most of the antioxidants and functional properties.
Chocolate production is a complex process during which numerous chemical reactions occur. The most important processes, involving most of the reactions important for development of the proper ...chocolate flavor, are fermentation, drying and roasting of cocoa bean, and chocolate conching. During fermentation, formation of important precursors occurs, which are essential for further chemical reactions in the following processes of chocolate production. Roasting is one of the most important processes due to the occurrence of Maillard's reactions, during which aroma compounds are formed. In this paper, we have reviewed the most important chemical reactions that occur with proteins, carbohydrates, lipids, and polyphenols. Additionally, we present other components that may be naturally present or form during the production process, such as methylxanthines, aldehydes, esters, ketones, pyrazines, acids, and alcohols.
Starch has been an inexhaustible subject of research for many decades. It is an inexpensive, readily-available material with extensive application in the food and processing industry. Researchers are ...continually trying to improve its properties by different modification procedures and expand its application. What is mostly applied in this view are their chemical modifications, among which organic acids have recently drawn the greatest attention, particularly with respect to the application of starch in the food industry. Namely, organic acids naturally occur in many edible plants and many of them are generally recognized as safe (GRAS), which make them ideal modification agents for starch intended for the food industry. The aim of this review is to give a short literature overview of the progress made in the research of starch esterification, etherification, cross-linking, and dual modification with organic acids and their derivatives.
U ovom radu pripremljene su mješavine na osnovi polietilena niske gustoće (PE-LD) i termoplastičnog škroba (TPS) s ciljem dobivanja biorazgradljivog polimernog materijala za primjenu kao ambalažnog ...materijala. Provedena je karakterizacija toplinskih, mehaničkih svojstava kao i propusnost vodene pare zbog izrazitog hidrofilnog karaktera škroba. Dodatak TPS-a u PE-LD/TPS mješavinama utječe na porast stupnja kristalnosti do udjela od 20 mas. % zbog nukleacijskog učinka TPS-a. Prekidno naprezanje i prekidno istezanje smanjuju se porastom udjela TPS-a u PE-LD/TPS mješavinama, dok modul elastičnosti raste. Temperatura početka razgradnje pomiče se na niže temperature, što ukazuje na smanjenje toplinske stabilnosti PE-LD-a dodatkom TPS-a. Glicerol kao plastifikator škroba utječe na povećanje toplinske stabilnosti škroba, no pokazuje negativan učinak na propusnost vodene pare.
Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna .
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.
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