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  • Open access
  • 37 Reads
Characterization of Volatile Fraction of Cretan PDO “Pefkothymaromelo” Honey Using SPME/GC-MS

Crete is a Greek island with a long tradition in the art of beekeeping. According to the commission implementing regulation (EU) 2017/1555 of 12 September 2017, Crete entered a new honey name in the register of protected designations of origin (PDO) called “Pefkothymaromelo Kritis”. This honey is a natural mixture of thyme honey with pine honey. In terms of physicochemical, microscopic, and organoleptic characteristics, “Pefkothymaromelo” is a combination of the above two types of honeys. Five PDO honey samples were used in this study, with the physicochemical parameters agreed with existing legislation. The volatile fraction was then isolated using the solid-phase micro-extraction (SPME) technique with a view to characterizing and comparing with thyme and pine honeys. For this purpose, a triple-phase divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber was used and the analysis was performed using a gas chromatograph coupled to a mass spectrometer (GC-MS). All peaks were identified with Wiley 275 mass spectra library, retention index (RI) using n-alkanes, and concentrations of the isolated compounds were calculated using internal standard (benzophenone) as mg kg-1 of honey. The identified components were 30, with three dominant volatiles including 3-methylbutanenitrile (3.82 mg kg-1); 2-phenylacetaldehyde (2.57 mg kg-1); and nonanal (1.30 mg kg-1). Characteristic compounds from both botanical sources were found in all the PDO honeys were analyzed. “Pefkothymaromelo Kritis” characterized with volatiles included in thyme honeys like benzaldehyde; 2-phenylacetaldehyde; 2-phenylethan-1-ol; 2-phenylacetonitrile; 5-isopropyl-2-methylphenol (carvacrol); 3-hydroxy-4-phenyl-2-butanone; and (Z)-3-hydroxy-4-phenylbut-3-en-2-one. Also, compounds found in pine honeys like undecane; nonanal; decanal; methyl nonanoate, and nonanoic acid were detected. Of particular interest is the fact that a significant concentration of the compound (E)-5-methyl-2-phenylhex-2-enal (0.22 mg kg-1) was detected in all PDO honeys. This compound, which according to previous reports has been detected in Greek thyme honey mainly from Crete, could potentially be an indicator of the botanical origin of “Pefkothymaromelo Kritis”. However, extensive research should be performed to reach safe conclusions.

  • Open access
  • 34 Reads
Muffin enriched with bioactive compounds from milk thistle by‐product: baking and physical–chemical properties, and sensory characteristics

Background: Muffins are sweet, high-calorie baked products whit a typical porous structure and high volume which confer a spongy texture. Because of this texture and good taste, these products are highly valued by consumers. But muffins have low nutritional value. Objective: The aim of this study was to develop the technology of muffins as a functional product with hepatoprotective activity using defatted milk thistle powder (DMTP). The addition of this dietary supplement was carried out by partial replacement of flour in the classic baking formulation. Methods: Physical-chemical and sensory analyses were performed to evaluate muffins either with or without defatted milk thistle powder. The moisture sorption isotherms of porous structure were determined by the gravimetric method on vacuum equipment with McBen quartz spring balances over 0.05-1.0 water activity range, and the data fitted to models to Guggenheim-Anderson-de Boer (GAB), Brunauer-Emmet-Teller (BET). Results: It has been established that the addition of milk thistle powder reduces baking, increases the drying out of products and increases the water-holding capacity, as well as increasing the volume of muffins and crumbs density. The microstructure of the muffin was examined using a moisture sorption isotherm. The moisture sorption isotherms of muffin samples presented a sigmoid shape and belong to type II of BET classification. The hysteresis loops of the samples are almost the same, which indicates similar structural data. The value of the monolayer according to BET models varied in the range 2.38–4.59 g H2O/100 g-1 of dried sample, showing a slight decreasing trend for muffin with DMTP. The GAB model accurately fits the adsorption isotherms in the water activity range from 0.05 to 0.9. The parameter K calculated by this model, which reflects the interaction between water molecules and absorbents in multilayers, turned out to be slightly higher for the sample with DMTP. The sensory results from consumer evaluation indicated that both samples are characterized by the traditional pleasant appearance of the muffin, without visible flaws, pleasant taste, and a good flour aroma. Conclusion: The result was a muffin with the same texture and sensory characteristics, but with a potential functional food.

  • Open access
  • 28 Reads
Effects of processing conditions of high hydrostatic pressure (HHP ) on gelling abilities and properties of inulin - soy protein hydrogels

The aim of the research was to determine the effect of processing conditions of high hydrostatic pressure (HHP ) on gelling abilities and properties of inulin - soy protein hydrogels The induced gels consisted of 20% inulin and 1% and 6% soy protein isolate. The pressure treatments were 150, 300 and 500 MPa for 5, 10 and 20 minutes. The obtained gels and the control sample (obtained under normal conditions of 0.1 MPa) were analyzed for ability to form gel structure (VGI), yield stress, texture and spreadability, microreological properties, stability and color parameters.

Based on the conducted research, it was found that inulin-protein hydrogels can be induced by the high hydrostatic pressure. It was also noticed that the use of high hydrostatic pressure in the case of hydrogels with a lower soy protein addition (1%) caused a decrease in the yield stress and texture parameters compared to the control sample, however, the observed changes were not found in the case of hydrogels containing a higher protein concentration (6%). Moreover, it was found that the use of lower pressure (150 MPa) for induction of protein-polysaccharide hydrogels resulted in obtaining gels with lower values of spreadability parameters compared to the control sample, while similar observations were not made for hydrogels induced by higher pressures (300 and 500 MPa). The use of high-pressure induction also extended the destabilization time of the tested hydrogels, and it was also found that the processing conditions did not change the color of the obtained hydrogels.

  • Open access
  • 69 Reads
Multistep process extraction of almond hull biomass with pulsed electric fields and supercritical CO2 to recover carbohydrates and biologically active compounds

This work reports a combined sequential extraction with pulsed electric field (PEF) and supercritical fluid extraction (SFE) using SC-CO2 in almond hull (AH) biomass, a recognized source of primary metabolites and bioactive products. Compared to traditional methods (maceration, percolation etc), this hybrid technique showed higher yields in total antioxidant capacity (TAC) and polyphenols content (TPC), being an enabling, sustainable and efficient approach for the recovery of these compounds. The liquid extracts obtained after both PEF and PEF + SFE treatments were analyzed by LC-MS, obtaining that the main polyphenols present were flavanols ((+,-)-catechin, (+,-)-epicatechin), flavonols (kaempferol and isorhamnetin) or flavons (luteolin, scutellarein, nepetin or 3-hydroxyphloretin), as well as others glycosylated derivatives such as kaempferol 3,7-O-diglucoside. Moreover, NMR analysis allowed to detect some freely accesible carbohydrates (glucose, fructose or sucrose), useful starting material for platform chemicals (levulinic acid or 5-hydroxymethylfurfural), or as additives in many foodstuffs. This analysis showed an interesting lipidic fraction obtained with SFE treatment as well. The post-extraction residual solid biomass was characterized by several techniques such as TGA, FT-IR and SEM. The latter showed the formation of surface pores after PEF treatment, as well as the compaction of fibers after SFE, proving the excellent extraction efficiency of this new hybrid technique.

  • Open access
  • 23 Reads

Cervical cancer is the fourth most common female malignancy worldwide and represents serious health problem, especially in less developed countries. Metastasis is an important issue in cancer therapy. Very often alternative medical approach, such as fungotherapy, has been applied on many cancer patients. Mushrooms have been found to produce a wide range of complex metabolites, some of which have pivotal biological activity. An edible and medicinal mushroom Laetiporus sulphureus (Bull.) Murrill is known to be prolific producer of phenolic compounds, polyketides, terpenes and steroids, with potential medicinal applications in the treatment of various diseases such as cancer. This study aimed to analyze effects of L. sulphureus on cervical cancer cell line (HeLa). Cells were seeded for nitroblue tetrazolium test (NBT) and Wound healing tests, and treated with ethanolic mushroom extract in two selected concentrations (10 and 50 µg/mL). Effects were tracked after 24 h and 72 h for NBT assay, while for Wound healing test effects were evaluated 24 h of treatment. Extract induced acute prooxidative effect on HeLa cells, while the level of superoxide anion radicals fell below the control values after a longer time of exposure to the treatment. Ethanol extract of L. sulphureus had an antimigratory potential 24 h after treatment when compared to untreated cells, with a higher concentration (50 µg/ml) having a slightly stronger antimigratory activity. Laetiporus sulphureus is a very important source of significant biological potential and should be reconsidered for development of promising anticancer therapies.

  • Open access
  • 39 Reads
3D Food printing: effect of apricot pulp concentration on texture analysis profile and image analysis in a gel cylinder.

Daily consumption of fruits and vegetables is protective against several chronic diseases, mainly due to their content in phytochemicals. On the other hand, consumers increasingly demand functional products that promote health. In this scenario, 3D printing plays an important role in developing customized food formulations. This technique produces three-dimensional food products of any shape and dimension, with desired flavors and nutritional compositions. This study aimed to evaluate the effect of apricot pulp content on the stability and printability of gels. Texture Profile Analysis (TPA) and image analysis after 3D printing were measured. Bovine gelatin gels (5%) were formulated with different concentrations of apricot pulp (30%, 50%, and 70%), and cylinders of 3 cm in diameter and 1 cm in height were printed. An increase in firmness of the printed gel was observed with the rise in the pulp concentration. Concerning image analysis, it was observed that as the concentration of apricot pulp in the samples increased, there was minor deformation of the height dimension. There were no significant differences (p > 0.05) in pieces for the cylinder area, and all presented a 12% area deformation. From the results obtained, it can be said that the 70% apricot pulp sample has the best texture profile and is the sample with the slightest deformation thanks to its higher fiber and sugar content, which help to maintain a better stabilization of the figure.

  • Open access
  • 29 Reads

Royal jelly (RJ) has been employed throughout history as natural product with multiple benefits for human wellbeing. In present days, it is mainly consumed as a functional food, active factor of daily supplements and other formulations because of its various beneficial biological activities. Apitherapy presents a complementary medical approach which imply application of bee products in various diseases, including cancer. RJ has been considered as important agent in apitherapeutic practice, especially when there are experimental studies proving its antimetastatic effects. Pivotal process underlying metastasis is acquisition of migratory potential, which is why the present report aimed to investigate the effects of RJ (sampled from Serbia) on migration of colorectal cancer cells (HCT-116) and explain the possible cellular mechanism involved in cancer cell motility. Therefore, we employed Transwell assay to determine migration of HCT-116 cells and expression of proteins responsible for motility of these cells (E- and N-cadherin) was assessed by immunofluorescent method. Experiments were done 24 h after treatment with two selected noncytotoxic RJ concentrations (10 and 100 µg/mL). Transwell results showed suppression of HCT-116 migratory activity by RJ, which was probably the result of enhanced expression of antimigratory protein E-cadherin, as well as significantly suppressed expression of promigratory marker N-cadherin. These results should not be neglected and further additional research necessary for elucidation of this significant antimigratory potential of Serbian RJ will be certainly carried out.

  • Open access
  • 93 Reads
Microwaving expansion kinetics of corn third-generation extruded pellets under different moisture content

The third-generation extruded pellets are formed via extrusion at high moisture content and moderate temperature. The combination of nonexpanding extrusion and microwave expansion is referred to as the production of third-generation snacks allowing the preservation of thermally sensitive ingredients. In this study, a Brabender Kompakt extruder KE 19/25 was used to get corn third-generation pellets with three moisture content mixtures (25, 30, and 35 %). These pellets were subjected to microwave expansion at eight microwave application times (between 10 and 90 s). The drying curves were fitted to three mathematical models (Page, Logarithmic, and Midilli and Kucuk). The model's coefficients were determined by non-linear regression analysis, and the models were compared based on their coefficient of determination (R2). Root means square error (RMSE) was calculated between experimental and predicted moisture ratios. The Page model best fits the experimental data, closely followed by the Midilli and Kucuk model. The constant drying k showed an inversely proportional trend to the moisture content of the mixtures for the Page model, which could be related to the diffusion coefficient. Due to microwaves' high heating velocity, the constants were higher than the unit. The variables evaluated at extruded pellets were appearance, sectional expansion index (SEI), and volumetric expansion index (VEI). The evolution of expansion indexes during the microwave process strongly depends on moisture content. Pellets with 35 % water content showed the lower SEI and VEI values, and pellets with 30% water content followed this behavior closely. In contrast, pellets with 25 % water content exhibited a higher expansion index in all the application times evaluated. According to the results of drying curves, expansion indexes, and appearance, the recommended expansion time with 25, 30, and 35 % moisture content for mixtures is 50, 60, and 60-75 s, respectively.

  • Open access
  • 42 Reads
Quality assessment of black currant, strawberry and cranberry seeds’ lipid fraction

Proper management of waste generated during food production and processing is currently one of major and urgent challenges for the food industry. Berry seeds are believed to be a source of bioactive substances, that could be reused in food and cosmetic production, what is in agreement with the UE politics of circular economy and sustainable development. The aim of this study was to extract oils from black currant, strawberry and cranberry seeds and to determine the quality of the obtained oils. The following parameters were determined: fatty acid composition by gas chromatography, distribution of fatty acids between sn-2 and sn-1,3 positions of triacylglycerols by enzymatic hydrolysis, oxidative stability of fat by pressure differential scanning calorimetry and melting characteristics by differential scanning calorimetry. Oils were extracted with the yield of 5.71%, 11.62% and 22.74% in the case of black currant, strawberry and cranberry seeds, respectively. Based on the obtained results, it can be stated that studied oils were a rich source of polyunsaturated fatty acids, especially linoleic and alpha-linolenic acids. Linoleic acid was mainly present in the internal position of triacylglycerol molecules, whereas saturated fatty acids usually occupied the external positions of triacylglycerols. Black currant and strawberries seed oils were characterized by short oxidation induction times, which proves their low oxidative stability. Melting curves for black currant and strawberry seed oils were of similar shape characterized by one endothermic event, indicating the presence of low-melting triacylglycerol fractions containing polyunsaturated fatty acids. The shape of DSC curve for cranberry seed oil differed from the shape of the melting curves for blackcurrant and strawberry seed oils, and indicated two endothermic transitions proving the presence of low-melting fractions containing polyunsaturated fatty acids and medium-melting fractions rich in monounsaturated fatty acids. The shape of the curves corresponds to the analysis of the fatty acid composition. On the basis of the conducted analyzes, it can be concluded that cranberry seed oil is characterized by the highest quality parameters among the analyzed oils: it can be a source of both polyunsaturated and monounsaturated fatty acids; the distribution of fatty acids at the internal and external positions of the triacylglycerols is nutritionally favorable. This oil is also characterized by the highest resistance to oxidative processes.

  • Open access
  • 124 Reads
Ultrasound-assisted extraction of bioactive compounds from black currant and chokeberry pomaces.

Constantly growing amounts of food wastes encourages to find new solutions to recover valuable components. Fruit industry by-products such as pomaces obtained after juice pressing are a source of bioactive compounds e.g., polyphenols, which are known as anti-oxidative molecules. The process of bioactive compounds extraction may be however harmful to environment and energy-consuming. In the following study sonication was used to improve the extraction efficiency and decrease energy and organic solvents consumption. Black currant and chokeberry pomaces obtained as by-products of juice pressing were dried. Bioactive extracts were collected in ultrasound-assisted process applying different parameters of ultrasound amplitude and time of sonication and using water as an extractant. Total polyphenol content of extracts was determined in Folin-Ciocalteu assay and antioxidant capacity of them was determined in ABTS study. Values of total polyphenol content were significantly higher when sonication was applied, reaching over 1.7-fold higher value of polyphenol content in chokeberry extract when 80% amplitude and 10 min time of ultrasound treatment were implemented, comparing to control. According to the literature main groups of polyphenols found in chokeberry pomace are anthocyanins followed by phenolic acids and flavonols and black currant pomace consists mainly of anthocyanins. Differences in antioxidant capacity values were also significant reaching maximum level of 0.27 μmol Trolox equivalent/ml of chokeberry extract and 0.33 μmol Trolox equivalent/ml of black currant extract. Both highest results were noted when 80% amplitude and 10 min time of ultrasound treatment were applied. Alternative extraction methods accelerate the extraction process and let obtain bioactive compounds-rich extracts from berry fruit by-products.