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Strawberry tree fruit (Arbutus unedo L.) is an excellent source material for the production of functional foods. This is because of the valuable bioactive compounds abundant in this fruit, which are believed to have many health benefits. Therefore, the aim of this study was to investigate the possibility of using strawberry tree fruit in the production of 3D printed snacks through additive manufacturing. The influence of two different 3D printing (3DP) programs as well as the type (corn vs. wheat) and the level of added starch carrier (4, 6 and 8%) were analyzed. All samples were analyzed for water activity (aw), pH, mass fraction of bioactive compounds, pigments, and antioxidant capacity. The type of starch carrier had a statistically significant effect on aw, pH, total phenolic compounds, hydroxycinnamic acids, flavonols, monomeric anthocyanins, condensed tannins, total carotenoids, and antioxidant activity of the 3D- printed samples. The lower level of starch carrier (4 vs. 6 and 8%) had a positive effect on the stability of the analyzed bioactive compounds, pigments and antioxidant capacity. The type of 3DP program had a statistically significant effect on the mass fraction of flavonols, chlorophyll a and b, total carotenoids and on the antioxidant activity of the 3D printed samples. In conclusion, 3DP technology can be considered as promising in the field of development of innovative and functional strawberry tree fruit-based products.

The strawberry tree fruit (Arbutus unedo L.) has great potential for the development of functional products due to its high bioactive potential and health-promoting properties. The objective of this research was to investigate the potential of 3DP in the production of strawberry tree fruit- based functional foods. The formulation for 3DP was developed by separately adding different proportions (4, 6 and 8%) of wheat and corn starch. Two programs with different printing parameters: printing speed, ingredient flow speed, first-layer-nozzle height, and line thickness were tested for the printability of a strawberry tree fruit-based formulation. The final 3D printed product looked like a heart printed in three layers, in which total phenolic content (TPC), chlorophyll a (CHL A) and chlorophyll b (CHL B), carotenoids (CAR) and antioxidant capacity [2, 2- diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods] were determined spectrophotometrically. The starch type had a statistically significant effect on the content of all bioactive components and antioxidant capacity, except for two chlorophylls. The proportion of starch had a statistically significant effect on all observed components and antioxidant capacities. When starch content was increased, there was a decrease in TPC, pigments, and DPPH antioxidant capacity, which is in line with expectations, considering that blends with higher starch carrier content contained a lower amount of strawberry tree fruit, which is a source of TPC and pigments. The 3DP programs showed no statistically significant effect on TPC, while they showed a significant influence on pigments. A significant effect of the 3DP program on DPPH antioxidant capacity was not observed, while the FRAP method gave the opposite results. In conclusion, both starches are suitable as carrier materials and can be used for the preparation of 3DP products, and 3DP can be successfully used for the production of a strawberry tree fruit-based functional product.

Three-dimensional printing (3DP) technology, also known as additive technique, is a new method that provokes the great interest of researchers, industry and the public due to its various applications such as medicine, gastronomy, engineering, food industry, etc. The main feature of this technology is the addition of material layer-by-layer. This enables the production of complex product geometries that would be difficult or impossible to achieve using conventional production methods. 3DP technology has been the focus of much innovative research in the food sector in recent years. This technology enables the computerized production of 3D-molds of food products of various compositions, which stands out from many other emerging technologies due to numerous advantages, such as customized food design, personalized nutrition, simplification of the supply chain, and expansion of uses for available food materials. As far as the food sector is concerned, this technology offers a wide range of potential applications, from the production of food for the elderly and children, to the production of functional foods and confectionery, to use in space missions. One area of particular interest in the application of this technology is in the production of functional foods. With the aim of increasing the daily consumption of fruits and vegetables, this technology has good prospects for products with different food combinations with these raw materials, focusing not only on the rheological and sensory properties but also on the nutritional and bioactive aspects. Therefore, the aim of this work was to investigate the possibility of applying 3DP for the development of functional products based on strawberries. The influence of two different extrusion-based printing programs with the application of two different starch hydrocolloids (corn vs. wheat) in different proportions (10, 15 and 20%, w/w) on the stability of bioactive compounds (total phenols, hydroxycinnamic acids, flavonols, total flavonoids, anthocyanins and condensed tannins) and antioxidant capacity (DPPH and FRAP) were investigated. Results showed that the type of starch significantly modified all determined bioactive compounds, and antioxidant capacity of the 3DP products tested. The starch content and the type of printing program also had a significant effect on the majority of the components studied. For the preservation of the bioactive profile and antioxidant capacity of the 3DP product, a starch content of 15 % and printing program 2 were found to be the most suitable. In summary, the results obtained show that three- dimensional printing can be considered as a technology with high potential for the development of innovative and customized functional fruit products.

Strawberry fruit is rich in various bioactive compounds such as anthocyanins, phenolic acids and flavo- noids, and has many health-promoting properties. Due to its chemical composition and biological po- tential, this fruit can be considered as a functional food. In this study, the aqueous extract was prepared by ultrasonic extraction from a freeze-dried fresh strawberry fruit. The content of the polyphenolic compounds was measured spectrophotometrically. The cytotoxic and antioxidant effects of the extract on human cell lines (CAL 27, AGS, Caco-2, and HepG2) were performed using the Neutral Red and DCFH- DA methods, respectively. The DNA protective effect was tested on a plasmid model ΦX174 RF1 DNA using agarose gel electrophoresis. According to the results, strawberry extract contains the most procyanidins (64.35 ± 0.05 mg/100 g) and the least flavonols (3.98 ± 0.01 mg/100 g). It was shown that the recommended daily dose of polyphenols, calculated on 5 L of blood and the average weight of a human, had an antiproliferative effect only on the colorectal adenocarcinoma cell line (Caco-2), while it had no effect on the other cell lines tested, and no effect on the induction of free radicals. Moreover, the biologically active compounds in the extract have a dose-dependent protective effect on DNA and prevent the formation of hydroxyl radicals that would lead to the relaxing of supercoiled DNA. The cytotoxic effect of strawberry may be related to the antiproliferative properties of hydroxycinnamic acids, which are one of the most abundant com- ponents of the extract. The results of this work confirm the potential role of strawberry polyphenols against oxidative stress and represent a good basis for further research.

The omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are found primarily in seafood. The long-chain omega-3 fatty acids, EPA and DHA can be synthesized from alpha- lipoic acid (ALA), but due to low conversion efficiency, it is recommended to consume foods rich in EPA and DHA. Loss of balance of n-6 and n- 3 polyunsaturated fatty acids in the diet has been associated with the incidence of disease in modern civilization. Squids have lower contents of saturated fatty acids but higher contents of polyunsaturated fatty acids compared to ruminants. Also, it is known that the changes in fatty acids affect the product aroma. EPA and DHA reduce the nutritional value of fishery products because they are converted into compounds with lower molecular weight associated with off-flavors (e.g. aldehydes, ketones, alcohols). The aim of this study was to use fatty acid analysis as a potential method for determining quality changes and estimating shelf life of two types of squid samples (Loligo vulgaris) one immersed in acid whey and the other only under traditional chilling, both stored for 11 days at 4 ± 1oC. Here, n=48 individual squids that were caught in the Croatian Adriatic Sea. The fat contents of the samples were determined by the Soxlet method (HRN ISO 1443:1999). Fatty acid content and composition were determined in the samples by the gas chromatography method (HRN EN ISO 5508, 1999) using the Varian CP-3800 device, while triPlus autosampler was used for injecting. The results of DHA and EPA were compared with the results on each day of storage. Samples were analyzed post-mortem on days 2, 5, 9, and 11. The mantle length of the squid averaged to 14.5 ± 0.5 cm. On the last day of storage (day 11), the C20:5n3 content was 4% higher and the C22:6n3 content was 100% higher in the whey-treated samples. It was shown that fat content was one of the most important quality parameters. Therefore, the data suggested that immersion of squid mantles in acid whey may be beneficial storage technique that has the potential to protect polyunsaturated fatty acids.

Nowadays, consumers are increasingly looking for high-quality foods and food products that have positive impacts on health. Therefore, the demand for functional foods has also increased. Strawberry can be considered as a functional food due to its nutritional and biological composition. However, due to its short shelf life, it is usually consumed fresh, nevertheless, there is also growing interest for their juices. Juices are usually preserved by thermal technologies although the application of high-temperature treatments negatively affects the nutritional quality of the food. For this reason, the development and application of non-thermal processing technologies, such as a pulsed electric field (PEF), has attracted much attention. The aim of this study was to investigate the effects of PEF technology on soluble solids content (SSC), pH, and stability of polyphenols in strawberry juice during seven days of storage at 4 °C. Juice was prepared from strawberries (Fragaria x ananassa Duch.) cultivar 'Albion', whose fruits were harvested at 75 % (J1) and 100 % (J2) maturity. The parameters of the PEF treatment were: (i) electric field strength (40 and 50 kV), (ii) frequency (100 and 200 Hz), and (iii) treatment duration (3 and 6 min). All results were analyzed by multifactorial analysis of variance (p≤0.05). Total polyphenolic content (TPC) was determined by the Folin Ciocalteu spectrophotometric method. The control (untreated) samples of strawberry juice J2 had significantly higher SSC, significantly higher pH, and significantly lower TPC compared to the control samples of strawberry juice samples J1. Storage of the control samples of strawberry juice at a temperature of 4°C for seven days resulted in a significant decrease in SSC and pH, and a significant increase in TPC. Treated samples of strawberry juice J1 had significantly lower SSC and pH than treated samples of strawberry juice J2. Treated juice samples of both ripeness levels stored at 4°C for seven days had significantly lower SSC, while pH values were not significantly different from the first day of storage. The electric field strength of 50 kV proved to be the only statistically significant parameter of the PEF technology that led to a significant increase in TPC, as compared to the 40 kV strength. PEF- treated J1 samples had significantly higher TPC than J2. Regardless of maturity, storage of treated samples at a temperature of 4°C for seven days resulted in a statistically significant increase in TPC. In general, it can be concluded that PEF technology positively affects the stability of TPC in strawberry juices during seven days of storage at 4°C, and that strawberries with lower ripeness are also suitable for the production of functional fruit juices.

The effects of PEF technology on the content of anthocyanins (ANT), hydroxycinnamic acids (HCA) and flavonols (FL) in strawberry juices from the strawberry (Fragaria x ananassa Duch.) cultivar 'Albion' harvested at 75 % maturity (J1) and 100 % maturity (J2) and stored at +4 °C for 7 days were evaluated. The parameters of the PEF treatment were: (i) electric field strength (40 and 50 kV/cm), (ii) frequency (100 and 200 Hz), and (iii) treatment duration (3 and 6 min). All results were analyzed by multifactorial analysis of variance (p≤0.05). The untreated juice J2 had higher ANT, HCA and FL values than the untreated juice J1. After 7 days of storage at 4 °C, the control samples showed decreasing values of FL and increasing values of ANT and HCA. The treated juice samples of both maturity levels stored at 4 °C for seven days had significantly lower FL, while the values of ANT and HCA were significantly higher on the first day of storage. The electrical strength of 50 kV showed a statistically significant effect on the increase of ANT, HCA and FL content compared to the 40 kV strength. In contrast to the electrical strength, increasing the frequency from 100 Hz to 200 Hz resulted in a statistically significant decrease in ANT, HCA, and FL. Treatment duration did not show a statistically significant effect on ANT and HCA, with the exception of FL, where an increase in treatment duration resulted in a decrease in the levels of FL. PEF-treated J2 samples had significantly higher ANT, HCA and FL than J1. Regardless of maturity, storing treated samples at a temperature of 4 °C for seven days resulted in a statistically significant increase in ANT, HCA, and a decrease in FL. In general, it can be concluded that PEF technology positively affects the stability of ANT and HCA in strawberry juices during seven days of storage at 4 °C. Among the PEF process parameters, electric field strength and frequency had a statistically significant effect on the content of ANT, HCA and FL in the juices.

The Republic of Croatia has a long tradition in fruit growing due to its geographical position, climatic conditions and high quality of fruit crops. The autochthonous fruit varieties are characterized by good morphological/pomological properties, but their nutritional and biological potential is underestimated. The fruits of the strawberry tree (Arbutus unedo L.) are an underappreciated fruit species in Croatia, whose potential for cultivation and consumption has not yet been sufficiently utilized. Therefore, it can be considered as an excellent raw material for the production of functional foods, which are under increasing demand by consumers. The aim of this study was to investigate the chemical and biological value of strawberry tree fruit collected in October 2021 in island Mali Lošinj, Croatia. Among the chemical properties, soluble solids content (SSC), pH, total carbohydrates, lipids, crude protein, crude cellulose, crude energy and sugar content were determined. Among bioactive compounds, total phenolic content (TPC), total flavonoids (TF), anthocyanins (ANT), hydroxycinnamic acids (HCA), flavonols (FL) and condensed tannins (CT) were analyzed. The obtained results showed that strawberry fruit samples contained high SSC (38 %), pH 4.6, total carbohydrates 30, 28 g/100 g, lipids

The Republic of Croatia has a long tradition of fruit growing due to its geographical position, climatic conditions and high quality of fruit crops. Autochthonous fruit varieties are characterized by good morphological/pomological properties, but their nutritional and biological potential has been underestimated, as well as their ability to be processed into functional foods, which are in great demand on the market. The fruit of the strawberry tree (Arbutus unedo L.) is an underestimated fruit species in Croatia, and its cultivation and consumption potential has not yet been sufficiently exploited. This fruit is a rich source of health-promoting components such as vitamins, minerals, easily digestible sugars, fiber, and various bioactive compounds with functional value. Therefore, it can be considered as an excellent raw material for the production of functional foods, which are increasingly demanded by consumers. Functional nutrition has largely become the main direction for a healthy lifestyle and is therefore attracting great interest from consumers as well as the food industry, with the aim of improving human health and creating economic wealth in a sustainable way. The existing combination of information and communication solutions is likely to usher in the fourth industrial revolution in the near future, with a focus on additive manufacturing led by 3D printing technology (3DP) in the food industry. 3DP is an emerging digitized technology for producing three- dimensional objects from digital files created layer by layer. Recent advances have led to the ability to create more complex and multi- ingredient food products using 3DP with customized color, shape, flavor, texture, and nutritional content. Since 3DP of food products has great potential to improve the quality and utility of food products, the objective of this work was to investigate the effect of two printing programs with different printing speed, ingredient flow speed, first layer nozzle height and line thickness on the printability of a strawberry tree fruit-based formulation developed by adding different proportions (4, 6, and 8%) of wheat starch (WS) and corn starch (CS). In this study, an extruder-type 3D food printer (Natural Machines Foodini) was used to develop and investigate the applicability of 3DP for functional food production. All samples were analyzed for total phenols, hydroxycinnamic acids, flavonols, flavonoids, anthocyanins, condensed tannins, chlorophylls, and carotenoids, as well as antioxidant capacity (DPPH and FRAP). The type of starch and also the different amounts added played a crucial role in the stability of the bioactive compounds and the antioxidant capacity of the 3DP products. This study suggests that strawberry tree may be a valuable nutrient for the production of novel functional 3DP foods.

The strawberry tree (Arbutus unedo L.) is one of the most common species with fleshy fruits in the Mediterranean region [1]. In local agricultural communities, the mealy and sweetish but not very aromatic fruits are mainly used for the production of jams, marmalades and alcoholic beverages. Also, the chemical composition indicates that the fruits are a good source of minerals and have high content of phenols and antioxidant capacity [2]. The aim of our work was to investigate the antioxidant and cytotoxic potential of A. unedo fruits on human squamous cell carcinoma cell line (CAL 27), human gastric adenocarcinoma cell line (AGS), colorectal adenocarcinoma cell line (Caco-2) and hepatocellular carcinoma cell line (HepG2). Furthermore, the DNA-protective effect and antimicrobial activity against Escherichia coli were investigated. A concentration range of 0.01-100 mg/mL was used in the experiments, with 1 mg/mL and 10 mg/mL being the recommended daily dose of polyphenols based on human blood volume and average human weight, respectively. Strawberry tree fruits at the recommended daily doses had a proliferative effect on AGS and CAL 27 cells without recovery and with 24-hour cell recovery, respectively. In CAL 27 cells, antioxidant activity was shown during 24-hour cell recovery. In Caco-2 and HepG2 cells, A. unedo fruit was shown to induce reactive oxygen species (ROS). The concentrations tested showed no antimicrobial activity against E. coli, but a dose-dependent protective effect on DNA was demonstrated. Additionally, further studies on individual bioactive compounds from strawberry tree fruit are needed to provide more detailed information on their potential use.