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Scientific research should be one of the key drivers of the knowledge-based economy in the future. The need for effective communication of research and the promotion of science becomes very important. Thus, FINS repository aims to disseminate to a wider audience some of the important scientific work being undertaken in FINS and in other collaborating research institutions.

FINS repository is a digital service that collects, preserves and distributes scientific outputs of the researchers from the Institute of Food Technology in Novi Sad. It has been established to provide open, online access to the community, free of all restrictions on access, granted through the use of Creative Commons licenses.

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Institute of Food Technology
FINS

Recent Submissions

Characterization and in vitro bioaccessibility of rapeseed protein isolates: a comparison of alkaline and DES extraction
(Sciknowledge Education, 2026) Đermanović, Branislava; Marić, Aleksandar; Sedlar, Tea; Vujetić, Jelena; Dragojlović, Danka; Jovanov, Pavle; Šarić, Bojana
1. Introduction – The global shift towards sustainable protein sources has intensified interest in valorising edible oil by products as food grade ingredients. Rapeseed proteins are nutritionally attractive due to their well-balanced essential amino acid (EAA) profile [1]. Conventional alkaline extraction (pH 9–12) offers high recovery, yet it may promote cruciferin denaturation, napin losses, and colour deterioration driven by phenolic oxidation [2]. Green alternatives, such as deep eutectic solvents (DES), have emerged as promising media due to their low toxicity and the ease with which their properties can be tailored through chemical composition [3]. The main aim of this study was to compare the nutritional quality and in vitro digestibility of rapeseed protein isolates obtained by conventional alkaline extraction (AE-12) and by a choline chloride:urea DES system (DES-ChCl:U). 2. Experimental - Protein isolates were obtained from defatted rapeseed cake by alkaline extraction at pH 12 (AE-12) and with choline chloride:urea DES (1:2, 10% water; pH 7.60 at 60 °C). Amino acid composition was determined by ion-exchange chromatography, while in vitro digestibility and molecular-weight distribution before and after digestion were evaluated using the INFOGEST protocol and lab-on-a-chip capillary electrophoresis, respectively. 3. Results and Discussion - The nutritional value of the obtained isolates was assessed through analysis of their amino acid (AA) composition and their susceptibility to enzymatic hydrolysis. A particularly notable finding was the high content of sulfur-containing amino acids (methionine and cystine) in the DES1 isolate, exceeding 3%, which fully meets the FAO/WHO nutritional requirements for adults [2]. Among the essential amino acids (EAA), leucine was highest in DES-ChCl:U (6.39 g/100 g), whereas lysine reached its maximum in AE-12 (5.09 g/100 g). This high proportion of essential amino acids, with an EAA/NEAA ratio of 0.59, makes the isolate nutritionally superior to many other plant sources, such as legumes [1]. The high nutritional potential was further confirmed by in vitro digestion performed according to the INFOGEST protocol. Although both isolates showed high digestibility, DES-ChCl:U exhibited a distinct digestion profile, indicating a more extensive conversion of proteins into smaller, absorbable components. By the end of the intestinal phase, the proportion of fractions below 10 kDa in the DES-ChCl:U isolate reached 89.77%, suggesting an almost complete conversion of proteins into bioavailable peptides and free amino acids. This digestion efficiency is directly linked to the excellent solubility of the DES-ChCl:U isolate across a wide pH range (gastric and intestinal conditions), enabling proteolytic enzymes to access peptide bonds more readily. In contrast to the AE-12 isolate, which shows signs of structural fragmentation due to extreme pH, the DES-ChCl:U system preserves more native cruciferin oligomers (145 kDa) prior to digestion, which are then efficiently broken down during digestion. Overall, these findings confirm that the use of choline based DES systems not only preserves the nutritional integrity of rapeseed proteins but also ensures their maximal utilization in the body. 4. Conclusions - The DES-ChCl:U system represents a sustainable and efficient alternative to alkaline extraction. Although it offers a lower yield, the resulting isolate is of superior purity and nutritional quality, with a well-balanced amino acid profile and excellent digestibility. These characteristics make DES-ChCl:U extracted rapeseed proteins highly suitable for the development of functional food products.
Sustainable deep eutectic solvent extraction: isolation, structural characterisation and application of rapeseed proteins in food systems
(Sciknowledge Education, 2026) Marić, Aleksandar; Đermanović, Branislava; Tomić, Damjana; Dragojlović, Danka; Sedlar, Tea; Šarić, Bojana; Jovanov, Pavle
1. Introduction – The development of sustainable plant protein systems requires not only alternative biomass sources but also a detailed understanding of structure˗function relationships governing their behaviour in complex food matrices. Rapeseed cake, a major by-product of edible oil production, represents an abundant and underutilised protein-rich resource with a favourable essential amino acid profile and high levels of sulphur-containing amino acids [1]. Valorisation of this side stream aligns with circular bioeconomy principles and waste-prevention strategies. However, conventional protein isolation from rapeseed cake relies on highly alkaline processing (pH ≥ 12), which enhances extraction efficiency but may induce irreversible conformational changes, protein fragmentation, and functional alterations that ultimately affect matrix interactions, aroma-binding capacity, and sensory performance in formulated foods [2]. From a green chemistry perspective, the replacement of chemically harsh extraction conditions with safer, tunable solvent systems is highly desirable. Deep eutectic solvents (DES) have emerged as promising green extraction media due to their low toxicity, biodegradability, negligible volatility, and capacity for rational solvent design through hydrogen-bond interactions [3]. Their compositional flexibility enables targeted modulation of solvent polarity, hydrogen-bonding capacity, and pH, allowing controlled extraction under reduced chemical severity while minimising structural disruption and preserving protein assemblies relevant for flavour-matrix interactions. 2. Experimental – In this study, protein isolates were obtained from defatted rapeseed cake using three extraction approaches: alkaline extraction at pH 12 and two deep eutectic solvent systems, choline chloride:urea (1:2 molar ratio, 10% water; pH 7.60) and betaine:citric acid (1:1 molar ratio, 20% water; pH 2.45). Extractions were performed at 60 °C with ultrasound assistance, followed by centrifugation, ethanol precipitation, washing, and freeze-drying. Protein yield and purity were determined, and structural properties were evaluated by FTIR spectroscopy together with amino acid and techno-functional analyses 3. Results and Discussion – Alkaline extraction achieved the highest protein recovery (36.9%), followed by DES2 (31.2%) and DES1 (23.2%). However, DES1 yielded the highest protein purity (95.8% on a dry matter basis), exceeding alkaline extraction (86.0%) and DES2 (70.3%). FTIR spectroscopy revealed pronounced conformational alterations and broader molecular weight distribution under alkaline conditions, whereas DES systems, particularly DES1, preserved higher-order protein assemblies such as cruciferin oligomers. Amino acid profiling confirmed a balanced composition across isolates, with enhanced preservation of sulphur-containing amino acids in DES-based systems. The improved structural preservation translated into favourable techno-functional properties, confirming the relevance of solvent-driven structure˗function relationships in plant protein systems. Importantly, the isolates were successfully incorporated into model food matrices, including omega-3-enriched pâté, crackers, and protein-enriched spreads. The results indicate that extraction-induced structural differences modulate matrix organisation and may influence flavour retention, release dynamics, and overall sensory perception, providing a physicochemical foundation for understanding protein-driven flavour behaviour in complex systems. 4. Conclusions – Deep eutectic solvents offer sustainable alternatives to harsh alkaline extraction for rapeseed protein isolation. DES systems, particularly choline chloride:urea, enabled high-purity protein recovery with improved structural preservation and favourable functional performance in food matrices. Beyond techno-functional attributes, maintaining higher-order protein organisation may contribute to controlled flavour interactions within complex matrices. This approach supports circular biomass valorisation while aligning with Green Chemistry principles of safer solvent design and reduced chemical severity, providing a sustainable platform for advanced plant protein integration with flavour-relevant functionality in food systems.
Towards targeted valorization of wine lees: comparative assessment of white and red wine by-products
(Sciknowledge Education, 2026) Tomić, Damjana; Marić, Aleksandar; Đermanović, Branislava; Dragojlović, Danka; Sedlar, Tea; Đorđević, Tatjana; Šarić, Bojana
1. Introduction – Wine lees are a heterogeneous by-product generated during wine production as a sedimentary residue formed after fermentation, storage, clarification, filtration, and centrifugation processes. They account for a significant proportion of winery waste, with global production exceeding one million tonnes annually [1]. Wine lees contain varying proportions of proteins, phenolic compounds, and other bioactive constituents, which may determine their suitability for different valorisation pathways [2]. Despite increasing interest in the circular utilisation of winery by-products, wine lees are often treated as a single waste stream, while compositional differences between white and red wine lees remain insufficiently explored. Therefore, this study aimed to comparatively assess the protein and phenolic potential of white and red wine lees obtained from the autochthonous grape varieties Grašac and Probus, respectively, and to evaluate their suitability for targeted valorisation approaches based on their compositional characteristics. 2. Experimental – Wine lees were characterised in terms of protein content, amino acid composition, phenolic composition, and antioxidant activity. DPPH, ABTS, and FRAP assays were used to evaluate antioxidant activity. The results were comparatively analysed to assess the suitability of each wine lees type for targeted valorisation. 3. Results and Discussion – The compositional analysis revealed pronounced differences between white and red wine lees. White wine lees contained approximately 35% more protein than red wine lees and exhibited a more favourable amino acid profile, including higher levels of most essential amino acids and a greater essential-to-non-essential amino acid ratio. These characteristics indicate the potential of white wine lees as a source of protein-rich ingredients for food and biotechnological applications. In contrast, red wine lees exhibited a markedly richer phenolic profile. Total phenolic content was more than four times higher, while flavonoid content was more than six times higher than that of white wine lees. Moreover, monomeric and polymeric anthocyanins were detected exclusively in red wine lees. The enhanced abundance of bioactive compounds was reflected in their antioxidant properties. Red wine lees demonstrated stronger radical scavenging activity in both DPPH and ABTS assays, as indicated by considerably lower IC50 values, and exhibited more than fourfold higher ferric reducing antioxidant power. Overall, the results demonstrate a clear compositional divergence between white and red wine lees, highlighting the influence of grape variety and winemaking practices on the nutritional and functional properties of these by-products. 4. Conclusions – White and red wine lees should not be regarded as a uniform by-product stream, as their distinct compositional profiles favour different valorisation pathways. White wine lees showed greater potential for the development of protein-rich ingredients, while red wine lees emerged as a promising source of phenolic compounds and natural antioxidants. Adopting composition-driven valorisation strategies may enhance resource efficiency, maximise the recovery of valuable compounds, and promote more sustainable utilisation of winery by-products.
ATR-FTIR spectroscopy as a green screening tool for sustainable wine less valorization
(Sciknowledge Education, 2026) Tomić, Damjana; Marić, Aleksandar; Đermanović, Branislava; Bojić, Milica; Sedlar, Tea; Vujetić, Jelena; Šarić, Bojana
1. Introduction – Wine lees are a heterogeneous by-product generated during wine production and represent a significant fraction of winery waste. Their composition includes proteins, polysaccharides, phenolic compounds, organic acids, minerals, and yeast-derived materials, making them a promising source of value-added compounds for sustainable valorisation strategies [1]. However, conventional characterisation of wine lees often requires multiple analytical techniques, extensive sample preparation, and the use of chemical reagents. Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy is a label-free, non-destructive technique that enables rapid analysis of complex biological matrices with minimal sample preparation [2]. As a solvent-free analytical approach, ATR-FTIR is consistent with the principles of green analytical chemistry and offers the potential for rapid screening of winery by-products. Therefore, the aim of this study was to evaluate the applicability of ATR-FTIR spectroscopy for the rapid characterisation of white and red wine lees obtained from the autochthonous grape varieties Grašac and Probus, respectively, and to assess its potential as a green screening tool for by-product valorisation. 2. Experimental – Wine lees obtained from the autochthonous grape varieties Grašac and Probus were analysed using ATR-FTIR spectroscopy. Spectra were recorded in the mid-infrared region and interpreted in relation to the chemical composition of the samples. The applicability of ATR-FTIR as a rapid and solvent-free screening tool for wine lees characterisation was evaluated. 3. Results and Discussion – ATR-FTIR spectra of white and red wine lees revealed characteristic absorption bands associated with proteins, polysaccharides, organic acids, and phenolic-rich fractions. Differences observed in the intensity and distribution of selected absorption regions reflected the distinct chemical composition of the analysed samples. White wine lees exhibited spectral features associated with protein-rich fractions, whereas red wine lees showed more pronounced signals associated with phenolic-rich fractions, reflecting their distinct compositional profiles. The absence of residual ethanol signals confirmed the effective removal of alcohol during sample processing, while the previously determined low sulphur dioxide content further supported the suitability of wine lees for subsequent valorisation processes. Overall, ATR-FTIR analysis enabled rapid discrimination between white and red wine lees and provided valuable information regarding their compositional characteristics without the need for extensive sample preparation or solvent consumption, highlighting its potential as a green analytical approach for the preliminary assessment and classification of winery by-products intended for further valorisation. 4. Conclusions – ATR-FTIR spectroscopy proved to be a rapid, non-destructive, and solvent-free technique for the characterisation of wine lees. The method enabled the rapid differentiation of white and red wine lees and provided compositional information relevant to their potential valorisation pathways. Due to its minimal sample preparation requirements and reduced use of chemical reagents, ATR-FTIR represents a promising green screening tool for the sustainable management and valorisation of winery by-products.
SUSTAINABLE EXTRACTION OF RAPESEED PROTEIN: COMPARISON OF DEEP EUTECTIC SOLVENTS AND ALKALINE EXTRACTION
(Faculty of Food Technology and Biotechnology, University of Zagreb, 2025) Marić, Aleksandar; Đermanović, Branislava; Sakač, Marijana; Tomić, Damjana; Dragojlović, Danka; Šarić, Bojana; Jovanov, Pavle
The growing global population and increasing food demand require sustainable protein sources, with rapeseed meal emerging as a promising alternative to meat. It contains over 40% protein with a favorable amino acid composition. Traditionally, protein isolation relies on alkaline extraction, but this method can lead to protein denaturation and reduced digestibility. Therefore, alternative methods such as enzymatic treatment, ultrasound-assisted extraction, and deep eutectic solvents (DESs) have been explored. DESs are eco-friendly and biodegradable solvents that enhance protein extraction efficiency while preserving the native structure and functionality of proteins. This study compares the efficiency of two DESs (ChCl:urea and betaine:citric acid) with conventional alkaline extraction at pH 12 for rapeseed protein isolation, focusing on yield and antinutrient content. The highest yield was achieved with ALK12 (36.9%), followed by DES2 (betaine:citric acid) at 31.3%, while DES1 (ChCl:urea) had the lowest yield (23.2%). Interestingly, despite its lower yield, DES1 provided the highest protein purity (95.8%), significantly surpassing ALK12 (86.0%) and DES2 (70.3%). These differences may be attributed to the physicochemical properties of the solvents, such as viscosity, polarity, and alkalinity, which influence protein solubilization, diffusion, and stability during extraction and precipitation. The antinutrient content varied depending on the extraction method. Isolates obtained with DESs contained approximately 1.4 times more phytic acid compared to the ALK12 isolate, likely due to pH conditions favoring its solubility. The total phenolic content in the ALK12 isolate was nearly three times higher than in DES2 and almost four times higher than in DES1, indicating enhanced polyphenol extraction under alkaline conditions. Similarly, tannin content in the ALK12 isolate was about 1.5 times higher than in the DES isolates. No glucosinolates were detected in any of the isolates. These findings suggest that DESs represent a sustainable alternative for rapeseed protein isolation, with acidic formulations offering a balance between extraction efficiency and retention of antinutritional compounds. While ALK12 achieved the highest yield, DESs provide environmental benefits and better protein structure preservation, making them promising candidates for advancing plant protein extraction technology.