Dubravka Novotni

• PhD
• Professor (Full) at University of Zagreb

Sourdough fermentation is rarely used for gluten-free flatbread (GFFB), a product that is challenging to produce, especially when using high-fiber ingredients that bring nutritional benefits but lead to physical deterioration. The aim of this study was therefore to evaluate the fermentation performance of carob flour (CSPF), proso millet flour (PMF...

Sourdough fermentation of bran can overcome the technological problems encountered in bread making but favors the activity of endogenous β-glucanase leading to a degradation of β-glucans. This study investigated the effects of high-intensity ultrasound (US) pretreatment of oat bran (OB) and barley bran (BB) on its β-glucans content, properties, and...

Sourdough fermentation of bran can overcome the technological problems encountered in bread making but favors the activity of endogenous β-glucanase leading to a degradation of β-glucans. This study investigated the effects of high-intensity ultrasound (US) pretreatment of oat (OB) and barley (BB) bran on its β-glucans content, properties, and pres...

This study examined the effects of pulsed electric field (PEF) treatment on enzymes, non-starch polysaccharides, and bread-making potential of oat and barley flour. Enzyme activity, microstructure, β-glucan extractability, molecular weight (Mw) and structure of non-starch polysaccharides, dough rheology, and flat bread properties were determined. A...

Dough retardation is commonly used to extend dough shelf-life, but it poses a challenge for flatbreads due to their large surface. This study explored the sourdough fermentation of oats and barley, addressing challenges in the retardation of dough for flatbread. Sourdough, using flour only or flour blended with bran (3:1), was fermented with a LIVE...

This study examined the effects of pulsed electric field (PEF) treatment on enzymes, non-starch polysaccharides, and bread making potential of oat and barley flour. Enzymes activity, microstructure, β-glucans extractability, molecular weight (Mw) and structure of non-starch polysaccharides, dough rheology and flat bread properties were determined....

Legume flours can nutritionally enrich gluten-free bread but can also negatively affect its flavour. Although sourdough fermentation can improve bread flavour, its application to legume–cereal gluten-free matrices has been scarcely investigated. The aim of this study was to determine the effects of partial replacement (25%) of wholemeal rice with y...

Betaine is a non-essential amino acid with proven functional properties and untapped potential for cereal food enrichment. While 3D printing represents a viable approach for manufacturing enriched cereal-based foods with novel shapes and textures, it is crucial to consider the impact of printing parameters and post-processing on the betaine content...

The increasing demand for greater utilization of byproducts in the food industry has been driven by growing interest in environmental sustainability. This paper examines the market potential and consumer attitudes toward whole-grain and sustainable cookies made with food byproducts and edible films. Additionally, particular attention was given to e...

Current agricultural practices using cereals and pseudocereals generate large amounts of lignocellulosic biomass, currently considered as waste, and other by-products during grain processing that are currently underutilized. In general, cereal and pseudocereal by-products can be a source of multiple compounds including proteins and peptides, dietar...

The process of three-dimensional (3D) printing is of greatest interest to food science and engineering community because it offers numerous opportunities for innovative food design, new product formulations and personalized nutrition. Of particular interest are food inks based on cereal flours or starches, whose unique rheological properties make t...

Peka has been used as the main baking tool for baking bread on a hearth. It has been in existence in Croatia since ancient times. The word peka itself is the name of the special bell-shaped lid for covering bread dough during baking. The peka lid is covered over with hot embers and ashes to provide the heat necessary for baking. The know-how of bak...

Cookie consumption can change the serum level of oxidized low-density lipoprotein (oxLDL) and oxLDL receptors, both playing important roles in the pathogenesis of atherosclerosis and cardiovascular diseases. This study investigated the nutritional value and the antioxidant activity of whole grain cookies in which 24% of the cocoa powder was substit...

Cereal bran possesses enzymes and antinutrients which should be reduced for their usability as a food ingredient high in dietary fiber, minerals, and antioxidants. This study investigated the influence of high-intensity ultrasound on enzymatic and antioxidant activities, phytic acid content (PA), and functional and rheological properties of oat and...

Oat and barley bran are high in dietary fiber (β-glucans), minerals, and antioxidants, have high activity of enzymes, but possess also antinutrients. This study aimed to investigate the influence of high-intensity ultrasound on enzyme and antioxidant activities, phytic acid content, as well as functional and rheological properties of oat and barley...

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 e...

Edible coatings and films provide an environmentally-conscious alternative to plastic food packaging options. This study investigated physico-chemical, morphological and thermal properties of edible coatings and films based on chitosan and gum arabic (GA) enriched with grape seed extract (GSE). Their influence on the quality and shelf-life of whole...

Interest in healthier snacks is on the rise. 3D printing of healthier snacks enables the use of alternative ingredients such as grain by-products, but also presents challenges such as dough darkening and post-process deformations. This work aimed to investigate the influence of the amount of oil (10–30% on flour basis), xylanase activity (17–57 U/g...

Since there are no products in the European market labelled as low-FODMAP (low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols), patients with irritable bowel syndrome and non-celiac wheat sensitivity often consume gluten-free products. These naturally contain little FODMAP, but have poorer sensory properties and lower...

Food personalization and customization is now easier due to 3D printing, but the printing performance of gluten-free cereal material has hardly been explored. This research investigated the suitability of four gluten-free powder blends for snack 3D printing. The blends were analyzed for their powder properties, and a selected blend served as a mode...

Gluten free bakery products often contain high levels of starch and refined rice flour, ingredients that are hypoallergenic but of low nutritive value. Pumpkin seed cake is a gluten free, nutrient‐dense by‐product of the oil industry, unfortunately still mainly used as animal feed. This study aimed to optimize the use pumpkin seed cake (10‐30 %) fl...

Bran can enrich snacks with dietary fibre but contains fructans that trigger symptoms in people with irritable bowel syndrome (IBS). This study aimed to investigate the bioprocessing of wheat and amaranth bran for degrading fructans and its application (at 20% flour-based) in 3D-printed snacks. Bran was bioprocessed with Saccharomyces cerevisiae al...

Flavor is one of the most important, but also the least researched parameter of bread quality. Numerous volatile compounds that contribute to the flavor profile of bread are usually extracted by the headspace solid-phase microextraction (HS-SPME) method. The development of a reliable and sensitive HS-SPME method requires the selection and optimizat...

3D printing is an emerging technology that offers the ability to produce tailor-made foods. This work addresses the physical properties of 3D-printed snacks enriched with wheat bran as a function of flour type (oat, barley), addition of acidity regulators (citric acid, sodium bicarbonate), printing temperature (20 °C, 30 °C, 40 °C), and bran pre-pr...

Gluten-free bread is often characterised by poor nutritional value and bioactive profile. Legume flours have potential for its enrichment, but the effect of sourdough fermentation of legume matrices on the phenolics and antioxidant capacity of bread is scarcely investigated. Thus, this study aimed was to determine the effect of partial replacement...

Wheat bran has a short shelf life, which could be prolonged by reducing the activity of enzymes in lipid degradation. In this study, high-intensity ultrasound treatment (400 W, 80% amplitude, 15 min), with or without cooling, was investigated for reducing the activity of lipase and peroxidase of wheat bran. Lipid stability parameters (free fatty ac...

Buckwheat hulls (BWH) are a lignocellulosic material with valuable nutrient contents, especially rutin and dietary fibre, which are worth exploring from a food industry perspective. BWH are also a voluminous material that is difficult to grind to very fine particle sizes, which can be achieved under cryogenic conditions. Therefore, we investigated...

Cereal by‐products can negatively affect sensory properties and shelf life of foods if they are not pre‐processed in order to alter their physico‐chemical properties. Cryo‐grinding is an innovative method for processing cereal by‐products; therefore, we investigated the effect of adding cryo‐ground proso millet bran (10%) and buckwheat hulls (2%) o...

In this study, we designed high fiber cookie recipe without using additives by means of extrusion-based 3D printing. We aimed to relate printing quality and cookie physical properties with dough rheology and dietary fiber content depending on the flour (oat, rye, rice, and carob flour) and fat type (olive oil or butter). The flour choice influenced...

Wheat bran is a by‐product rich in bioactive compounds, but possess a strong polyphenol oxidase (PPO) activity, which can act undesirably on product quality. This study aimed to optimize the particle size (500, 255, 10 µm) of wheat bran and time and amplitude of high‐intensity ultrasound (HIU) treatment on the PPO activity, total phenolics, antioxi...

Research background: Carob is widely cultivated Mediterranean plant, but its flour is scarcely used in bread making. Previous studies investigated the quality of wheat bread with added carob flour showing discrepant results. This study aims to investigate the fermentation performance, antioxidant activity, rheological behaviour and baking applicat...

By-products of fruit processing, such as grapes and aronia pomace, are rich in fibre and polyphenols, and their application in bakery products could significantly improve nutritional value, bioactive potential and shelf life of final product. This research aimed at optimising wholemeal biscuit formulation with grape and aronia pomaces as partial su...

This study aimed to valorise the underutilised by-product of proso millet decortication. Millet bran was sieved into three fractions with substantially different nutritional profile. The fraction with diameter <500 μm had the highest nutrient density (14% protein, 26% starch, 36% dietary fibre, 9% fat, and 3 mg GAE/g phenolics (d.w.)) and was analy...

Acrolein is a toxic compound present in food. It can be formed by bacterial species isolated from sourdough or applied as sourdough starter cultures, such as Lactobacillus reuteri. To the best of our knowledge, the content of acrolein in sourdough bread has not yet been determined, neither has a method for its quantification in such a sample been p...

Millet is an unexploited cereal with potential in the food industry due to its nutritional value and resistance to harsh climate conditions. Nutritious millet byproducts have a potential application in the development of functional cereal products, but require processing in order to improve their physical and nutritional quality. Therefore, we inve...

The effects of high power ultrasound of 24 kHz and ultrasound bath of 24 kHz frequency on the textural and pasting properties of corn starch suspensions was examined. Suspensions were treated with different intensities and treatment times (15 min and 30 min) using an ultrasound probe set and bath. The treatments with high power ultrasound probes ca...

Driven by the bakery industry urge to satisfy consumer demand for fresh, diverse and high quality bakery products, we investigated the influence of barley sourdough and vacuum cooling on shelf life quality of partially baked bread stored in modified atmosphere packaging at ambient conditions. Barley sourdough was fermented with Lactobacillus reuter...

Market reports show an increasing interest for healthy biscuits, with omega-3 and lignan rich flaxseeds being highlighted as key ingredients. Usage of milled flaxseed in comparison to the whole seed might improve bioaccessibility of lignans and omega-3, but also accelerate lipid oxidation, thus diminishing the consumers’ acceptability. This researc...

Purpose: Cookies were not generally viewed as functional contributors to well-being as they are primarily perceived as confectionery products. The purpose was to evaluate the potential of flaxseed-enriched cookies as carriers of lignans and omega-3 fatty acids – functional compounds that are lacking in the Western diet. Design/methodology/approach...

Cookies are widespread confectionary cereal based product. Recently it was recognized that cookies can be easily transformed into nutritionally valuable functional product, while retaining the taste. However, this type of functional product can live on the market only if consumers adopt it. Therefore we investigated purchase habits of Croatian cons...

A need for food that contributes to individual nutrition and health status, and also to the sustainability of the planet, is rising as a consequence of consumer’s awareness of foods nutritional value and origin. This behaviour is mostly expressed through the preference toward organically grown and wholesome food. Science to some extent supports thi...

Background: Bread can be a good source of nutrients as well as non-nutrient compounds. This study was designed to assess the effect of adding of sourdough and whey proteins to wholemeal (WM) bread produced by bake-off technology on chemical composition and bioavailability of proteins, calcium, phosphorus, magnesium and iron content in Wistar rats....

Partially baked frozen (PBF) process prolongs bread shelf life, but diminishes its volume and crumb texture. Therefore, we investigated the possibility of using sourdough for the quality improvement in PBF wholewheat bread. Sourdough was fermented with either Lactobacillus plantarum, Lb. brevis or Leuconostoc mesenteroides mixed with yeast Candida...

Many attempts have been made to increase the nutritional value of bread by adding dietary fibre. However, fibre enrichment is usually associated with various technological problems. The aim of this study was to optimise the composition of a blend of inulin, pectin and guar gum to enrich the fibre content of partially baked frozen bread without impa...

Gluten-free bread often has low nutritive value, high glycemic index (GI) and short shelf-life. The aim of this research was to investigate the influence of sourdough addition on GI, quality parameters and firming kinetics of gluten-free bread produced by partially baked frozen technology. Sourdough was fermented with a commercial starter of Lactob...

Since 1980s, several methods for the determination of lignans in food samples have been developed depending on the types of lignans and foods analysed, but mostly on flaxseed as a reference food. In this work, specific steps in flaxseed preparation for lignan secoisolariciresinol analysis by gas chromatography-mass spectrometry method were examined...

Different enzymes and other proteins are used to improve the quality of gluten-free breads, but their combinations and relative amounts need to be optimised to reduce product cost and improve overall consumer acceptability. This paper aimed to investigate the feasibility of using extruded flours (rice, potato, corn, buckwheat) in combination with v...

Whole grain cereals are an important source of bioavailable lignans, the group of compounds with potential anti-cancerogenic, antioxidant, anti-proliferative, pro-apoptotic, and antiangiogenic properties. The aim of this work was to develop a sensitive method for determination of wheat bran lignans. The analysis of lignans secoisolariciresinol, hyd...

Different lactic acid bacteria starters were used to prepare sourdough to make partially-baked frozen wholemeal wheat bread. The sourdough was prepared with a pure culture of Lactobacillus plantarum or with commercial starters containing Lactobacillus brevis combined with Saccharomyces cerevisiae var. chevalieri (LV4), Lactobacillus fermentum (PL1)...

Z. (2010): Texture and pasting properties of ultrasonically treated corn starch. Czech J. Food Sci., 28: 83–93. The effects of high power ultrasound of 24 kHz and ultrasound bath of 24 kHz frequency on the textural and pasting properties of corn starch suspensions was examined. Suspensions were treated with different intensities and treat-ment time...

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 cul...

In order to obtain high protein bread, enrichment of wheat flour with defatted soybean flour (DSF) was investigated. For laboratory bread making, the following were added to wheat flour: 30 or 40 % (w/w flour) extruded blend of corn meal (CM) and DSF prepared in two ratios (w/w) 75 % CM / 25 % DSF (blend 1) and 62.5 % CM / 37.5 % DSF (blend 2). All...

To obtain a high protein bread, wheat flour was enriched with defatted soybean flour (DSF) by adding a 30 or 40% (w/w flour) extruded blend of corn meal (CM) and DSF prepared in two ratios (w/w): 75% CM/25% DSF (blend 1) and 62.5% CM/37.5% DSF (blend 2). All bread samples had high protein content (>14 g/100 g dry matter), high protein digestibility...

The objective of this work was the optimization of extrusion process for the production of extruded cornmeal (ECM) that may be used in the production of corn bread by a direct procedure. The extrusion process variables, barrel temperature, Et (111–159C), moisture content, Mc (12.10–24.77%) and screw speed, Ss (160–460 rpm), were considered and thei...

Bread quality index was established using the instrumental analysis of bread parameters that influence the consumers’ acceptability. The instrumental methods that describe bread appearance, structure and texture have been chosen in order to enable the identification and quantification of main discrepancies of wheat bread produced by different proce...

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 investi...

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 grain...