Katarina Jurcic

Katarina Jurcic

*This is an algorithmically generated author record based on publicly available information.

Katarina Jurcic has a total of 14 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    An Integrated Screening Study of Polyphenol Recovery from Olive Mill Wastewater Using Cationic Starch-Assisted Clarification and Adsorption Resin Purification

    by Nina Knezovic, Ajka Pribisalic, Barbara Soldo, Ivica Ljubenkov, Roberta Frleta Matas, Sanja Luetic, Katarina Jurcic, Mladenka Sarolic, Davorka Sutlovic, Zlatka Knezovic

    Olive mill wastewater (OMW) is an environmentally problematic effluent but also a rich source of antioxidant phenolic compounds. This study evaluated an integrated recovery approach combining cationic starch clarification and adsorption resin purification for obtaining phenolic-rich fractions from Dalmatian OMW. A pooled OMW sample was characterized for conventional wastewater parameters and total phenolic content (TPC), clarified with four commercial cationic starches, and subsequently processed using Seplite LXA84, Seplite LXA88, Seplite LXA816, and Amberlite XAD4 adsorption resins. PrimePHASE 2545 at 1000 mg active substance L−1 provided the most favorable balance between matrix removal and phenolic retention, reducing suspended solids and organic load while preserving approximately 92% of the initial TPC. In the preliminary resin screening, Seplite LXA84 produced the most favorable ethanol eluate, with the highest phenolic recovery and strong antioxidant activity, particularly in FRAP and ORAC assays. HPLC profiling confirmed hydroxytyrosol as the dominant recovered phenolic compound, accompanied by tyrosol and selected phenolic acids. These findings support a two-stage OMW valorization approach in which cationic starch pretreatment improves the suitability of OMW for column processing, while resin adsorption produces phenolic-rich fractions with antioxidant activity that may serve as candidates for further purification, characterization, and application-oriented research.

  • Open Access

    From Waste to Resource: Extraction and Characterization of Polyphenols from Dalmatian Olive Mill Wastewater

    by Nina Knezovic, Ajka Pribisalic, Katarina Jurcic, Ivica Ljubenkov, Barbara Soldo, Danijela Skroza, Mladenka Sarolic, Sanja Luetic, Davorka Sutlovic, Zlatka Knezovic

    Background: Olive cultivation and olive oil production are key agricultural sectors in the Dalmatia region, where numerous oil mills operate. Analyses have shown that extra virgin olive oils (EVOO) produced in this area contain respectable amounts of polyphenols, which contribute to superior oil quality due to their antioxidant properties. During processing, hydrophilic phenolic compounds predominantly transfer into olive mill wastewater (OMW), making it a concentrated source of valuable bioactive molecules. The antioxidant, anti-inflammatory, and photoprotective effects of these polyphenols are highly relevant for cosmetic and pharmaceutical use. Methods: A total of 186 OMW samples were collected from oil mills in the Split-Dalmatia County across three production seasons (2023–2025). Total polyphenol content (TPC) was measured spectrophotometrically, while polyphenol composition was determined by High Performance Liquid Chromatography (HPLC). Antioxidant activity was evaluated using hydrogen atom transfer (HAT; 2,2-diphenyl-1-picrylhydrazyl) (DPPH), electron transfer (ET; ferric reducing antioxidant power) (FRAP), and oxygen radical absorbance capacity assay (ORAC). Results: The obtained results indicated high total polyphenols concentrations, with values ranging from 111.8 to 6717.2 mg of gallic acid equivalents per L of OMW (mg GAe L−1). In the vast majority of analyzed samples, hydroxytyrosol was the predominant phenol compound. The antioxidant activity of the samples was high.


  • Open Access

    Nitrates and Nitrites in Leafy Vegetables: The Influence of Culinary Processing on Concentration Levels and Possible Impact on Health

    by Sanja Luetic, Zlatka Knezovic, Katarina Jurcic, Marina Luetic Perasovic, Davorka Sutlovic

    Vegetables, as an important source of vitamins and minerals, are highly recommended in a healthy diet. At the same time, vegetables can contain elevated amounts of nitrates and nitrites, which are the possible nitrosating agents responsible for the formation of carcinogenic nitrosamines. In young children, they can cause methemoglobinemia. Determining the level of nitrates and nitrites, as well as the possible reduction in their concentrations during culinary processing, is especially important for the diet of young children, who are introduced to leafy vegetables during the first year. For some types of vegetables that are often found in the diet, maximum permissible concentrations have not yet been established. Our goal was to estimate the reduction factors of nitrates and nitrites and suggest the best ways to properly prepare foods. For this purpose, samples of Swiss chard, spinach, and white cabbage were collected from the market to determine the nitrate and nitrite content. Vegetable samples were subjected to culinary preparations: soaking, cooking, and a combination of soaking and cooking. Quantitative and qualitative determination of nitrates and nitrites in vegetables was carried out on high-performance liquid chromatography (HPLC) equipped with a diode array detector (DAD). The obtained results showed that the highest nitrate concentrations were in Swiss chard samples, followed by spinach, and the lowest in white cabbage samples. The impact of culinary preparation was highest on spinach samples. Considering the average nitrate concentrations achieved after cooking or soaking and cooking, there was no risk of exceeding the ADI limit. However, the ADI values would be exceeded at the maximum nitrate concentrations.


  • Open Access

    Artificial Sweeteners in Food Products: Concentration Analysis, Label Practices, and Cumulative Intake Assessment in Croatia

    by Zlatka Knezovic, Branka Jurcevic Zidar, Ajka Pribisalic, Sanja Luetic, Katarina Jurcic, Nina Knezovic, Davorka Sutlovic

    Background/Objectives: Artificial sweeteners (ASs) are food additives used to impart sweetness to various food products. Common sweeteners used individually or in combination include acesulfame-K, aspartame, cyclamate, saccharin, sucralose, and neotame. While traditionally considered harmless, emerging research suggest potential health implications. This study aims to analyze commonly consumed food products in Croatia for ASs presence, quantify four ASs, and estimate daily intake of ASs. Additionally, product labeling was assessed for compliance with Regulation 1169/2011 on food information to consumers. Methods: This study assessed the presence of acesulfame-K, aspartame, cyclamate, and saccharin dihydrate in 121 frequently consumed food products from the Croatian market using a high-performance liquid chromatography method. Based on obtained concentrations, data from a parallel consumption study, and existing literature on acceptable daily intake (ADI), we assessed exposure to ASs. Results: ASs were found in a substantial proportion of analyzed products, with multiple sweeteners often present in a single product. Specifically, ASs were detected in 74% of carbonated drinks, 54% of fruit juices, 86% of energy drinks, 70% of high-protein milk products, and 66% of chewing gums. Hypothetical consumption scenarios demonstrated that children, due to their low body mass, are at the highest risk of exceeding ADI values. Conclusions: The widespread presence of ASs in food products raises concerns about excessive intake, particularly among children who frequently consume soft drinks, instant beverages, and protein drinks. These findings highlight the need for further research into cumulative ASs exposure and its potential health effects, as well as the importance of public health strategies to regulate ASs consumption.


  • Open Access

    Consumer Perceptions of Artificial Sweeteners in Food Products, Consumption Frequency, and Body Mass Index: A Multivariate Analysis

    by Branka Jurcevic Zidar, Zlatka Knezovic, Ajka Pribisalic, Sanja Luetic, Katarina Jurcic, Nina Knezovic, Davorka Sutlovic

    Background/Objectives: Artificial sweeteners are commonly used food additives that provide sweetness without calories. Once considered harmless due to their lack of metabolism, recent studies suggest that they may have unintended effects, potentially stimulating appetite and increasing food intake, leading to weight gain. This study aimed to assess consumer perceptions of artificial sweeteners in food, examine consumption frequencies of products containing them, and explore their potential influence on body mass index. Methods: A cross-sectional study was conducted using two voluntary and anonymous surveys administered via Google Forms. Results: The study included 649 participants: 324 parents of preschool and school-aged children and 325 university and secondary school students. A substantial proportion of parents (59.3%) recognized artificial sweeteners as common sugar substitutes in beverages like juices, soft drinks, and protein drinks. Awareness was notably higher among students (88.9%). While most participants held a negative attitude toward artificial sweeteners, their awareness and engagement with food label reading were low. Multivariate linear regression identified significant associations: Male gender (β = 1.17, p < 0.001) and older age (β = 0.42, p < 0.001) were associated with higher BMI. Additionally, participants who rarely or never consumed carbonated soft drinks had a lower BMI (β = −1.48, p = 0.039), while those who occasionally consumed snacks had a higher BMI (β = 0.51, p = 0.039). Conclusions: This research underscores the urgent need for public health initiatives addressing misconceptions, raising food label reading practices, while encouraging healthier consumption habits through educational campaigns. Additionally, the study’s insights will help assess the potential cumulative health impacts of artificial sweetener intake.


  • Open Access

    Intake of Artificial Sweeteners through Soft Drinks in the Preschool- and School-Aged Population

    by Branka Jurcevic Zidar, Sanja Luetic, Katarina Jurcic, Zlatka Knezovic, Davorka Sutlovic

    One of the main public health issues that has recently been observed in a greater number of children is being overweight. The cause certainly lies in the decreasing physical activity of children, but mostly in their eating habits. Soft drinks are recognized as the most significant contributor to body overweight due to high sugar content; thus, as a result of numerous campaigns, part of the sugar is replaced by artificial sweeteners (ASs). Despite their advantage due to their low caloric value, WHO recommends that they should not be used to achieve weight control or as prevention for reducing the risk of non-communicable diseases, as there is no evidence of their effectiveness. Apart from beverages, artificial sweetener combinations are also added to a variety of “low fat” and “high protein” food products, which are highly favored especially among the young population. Therefore, it is necessary to take care of the cumulative intake. The conducted study included a survey of 323 parents of children aged 1–14 years, as well as an analysis of the AS content in the products most often consumed by the respondents. The results of the survey show that a large part of children (40%) aged 3–14 often consume soft drinks. Different products (soft drinks, juices/nectars, syrups) were sampled based on the respondents’ responses, and an analysis showed that 54% of them contained one or more ASs. In addition, the survey indicated parents’ lack of information about the presence of AS in products, as 51% of parents declared that they do not read the declarations of the products they buy. It is necessary to persist in consumer education and changes in dietary preferences and habits, especially among children.


  • Open Access

    Leafy Vegetable Nitrite and Nitrate Content: Potential Health Effects

    by Sanja Luetic, Zlatka Knezovic, Katarina Jurcic, Zrinka Majic, Ksenija Tripkovic, Davorka Sutlovic

    The aim of this research was to determine the concentrations of nitrates and nitrites in different types of vegetables that are commonly represented in the diet of the inhabitants of Split and Dalmatian County. Therefore, using the method of random selection, there were 96 samples of different vegetables. The determination of the nitrate and nitrite concentrations was carried out by high-pressure liquid chromatography (HPLC) with a diode array detector (DAD). The nitrate concentrations in the range 2.1–4526.3 mg kg−1 were found in 92.7% of the analyzed samples. The highest nitrate values were found in rucola (Eruca sativa L.) followed by Swiss chard (Beta vulgaris L.). In 36.5% of the leafy vegetables intended for consumption without prior heat treatment, nitrite was found in the range of 3.3–537.9 mg kg−1. The high levels of nitrite in the vegetables intended for fresh consumption and the high nitrate values in Swiss chard indicate the need to establish maximum nitrite limits in vegetables, as well as the broadening of legal nitrate limits to wide varieties of vegetables.