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In this study freeze-drying and oven-drying (at 50 and 65 °C) were applied for the preparation of dried pumpkin waste. The effect of drying methods on physical properties (moisture content, water activity, hygroscopicity, water solubility, bulk and tapped density, flowability and colour), content of bioactive compounds (carotenoids and phenolics) and antioxidant activity were investigated. Also, the influence of one-year storage at –20 °C on the bioactive compounds content and the antioxidant activity of dried pumpkin waste was examined. Results indicated that drying method showed a significant impact on the investigated characteristics. Bioactive compounds content and antioxidant activity by DPPH test of freeze-dried were higher than of oven-dried pumpkin waste, while higher antioxidant activity in reducing power assay was determined by oven-dried pumpkin waste. An artificial neural network model was developed, for the anticipation of antioxidant activity according to bioactive compounds content (phenolics and carotenoids), in oven-dried (at 50 and 65 °C) and in freeze-dried pumpkin waste after one-year storage. These models showed good prediction properties (the r2 value during training cycle for output variables was 0.999). It was demonstrated that pumpkin waste is potentially an important source of bioactive compounds, which can be used after extraction in suitable forms in the development of functional food products.

The application of bioactive antioxidant compounds is limited because of their instability. To overcome this drawback, different protection systems including encapsulation have been developed. In this study, for the stabilisation of bioactive compounds (carotenoids and phenolics) extracted from tomato waste, encapsulation with carbohydrate (inulin and gum arabica) and protein (soy protein and pea protein) wall materials by freeze drying method was applied. Content of bioactive compounds and antioxidant properties (determined by DPPH, reducing power and β-carotene bleaching assay) of encapsulates before and after in vitro digestion was investigated. Also, in obtained encapsulates carotenoid stability during storage at ambient (25 ± 5 °C) light and dark conditions for four weeks was assessed. The results indicated that release behavior of bioactive compounds and antioxidant activity after digestion of encapsulates varied according to the type of wall material. Protein carriers showed better ability to preserve phenolic compounds through in vitro gastrointestinal digestion in comparison to carbohydrate wall materials. Pea protein showed best carrier properties for delivery of carotenoids, while differently to other used carriers, gum arabica showed minor ability to release carotenoids after in vitro gastrointestinal digestion. During storage higher content of carotenoids was preserved in encapsulates prepared with carbohydrate carriers. All encapsulates retained higher amount of carotenoids under dark conditions. The results of this study showed that assessment of the behavior of encapsulates during digestion and storage is necessary in order of selection appropriate delivery system of bioactive compounds in powder form which can be used as ingredient in functional food products.

Utilization of carotenoids as a nutraceutical ingredients or natural colorants within foods is currently limited due to their instability. Encapsulation is one of the prominent means used to improve carotenoid stability. In this study the content of bioactive compounds (lycopene, β-carotene and phenolics) and antioxidant activity (DPPH, ABTS, superoxide anion and reducing power test) were investigated in the tomato waste extract. Based on the obtained results, tomato waste showed high contents of lycopene (13.72 mg/100 g DW), β-carotene (12.36 mg/100 g DW) and phenolic compounds (203.33 mg/100 g DW). Also, high values of antioxidant activity were determined in all applied tests. To protect extracted sensitive carotenoid compounds (lycopene and β-carotene) tomato waste extract was encapsulated with various encapsulating materials (soy protein, pea protein, inulin and gum arabica) by freeze drying method. The influence of applying different encapsulating materials on the encapsulation efficiency of carotenoids (lycopene and β-carotene) was studied. Also, obtained encapsulates were characterized in terms of water activity, moisture content, hygroscopicity, flowability, density ratios and particles size. Encapsulate on the basis of gum arabic showed highest encapsulation efficiency of β-carotene (53.47%), while encapsulate prepared with soy protein as encapsulating material showed highest encapsulation efficiency of lycopene (51.44%). The results of this study support the need for preparation of encapsulates with different encapsulating material and evaluation of their characteristics with the aim of development powder forms suitable for supplementation and food fortification.

Carrot is an important root vegetable rich in bioactive compounds like carotenoids and polyphenols with appreciable levels of several other functional components having significant health-promoting properties. Utilization of carotenoids is limited due to their instability. Encapsulation is one of the alternatives used to improve carotenoid stability. The objectives of this study were to optimize the extraction and encapsulation of carotenoids from carrot. Freeze-dried carrots were extracted by conventional solvent extraction (CSE) using four solvents, i.e. ethanol, acetone, ethyl acetate, and hexane. Although CSE using hexane and ethyl acetate resulted in highest carotenoid contents (18.27 and 15.73 mg β-carotene/100 g), acetone and ethanol at a solid to solvent ratio 1:10 w/v with slightly lower carotenoid contents (14.52 and 11.45 mg β-carotene/100 g) were chosen for further studies due to their higher food compatibility and higher polyphenol content (88.86 and 66.21 mg GAE/100 g) than with lower solid to solvent ratio (1:5 w/v). Ethanol and acetone carrot extracts were encapsulated using different carriers by a freeze-drying method in order to obtain the optimum encapsulate with the highest carotenoid encapsulation efficiency (EE). Encapsulation using the maltodextrin, whey and soy protein as a wall material yielded an EE of carotenoids ranging from 41.95% to 100%. The encapsulated β-carotene content was evaluated during two months of storage at ambient temperature under light and dark conditions. Generally, the retention of carotenoids was significantly higher in dark conditions, where maximum retention (65.94-87.32%) occurred in the samples encapsulated in maltodextrin and soy protein. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 31044]

Sprouts of cereals have received significant attention as functional food due to their nutritional and functional value. Consumption of sprouts has become increasingly popular among people interested in improving and maintaining their health status by changing dietary habits. Cereal grains contain several classes of phytochemicals, i.e. phenolics, chlorophylls, and carotenoids. However, their nutritional and chemical profile is altered and improved during germination. The purpose of this study was to find the best ratio of the powdered wheat (WS), oat (OS) and barley (BS) sprouts for designing the cereal sprout mixture (CSM) with the highest total phenolic content (TPh) and antioxidant capacity (AC), using Simplex-Centroid experimental design and response surface methodology (RSM). Single- and multi-response optimizations showed that OS did not contribute to TPh or AC values of CSM and, therefore, was not included in any of the compositions of the optimized CSM. Single-response optimizations showed that the highest TPh was found for CSM containing 82% BS and 18% WS, while the best AC was found for pure BS. The predicted ratio of cereal sprout powders in CSM obtained by multi-response optimization was: 96% BS and 4% WS. This mixture possessed the highest predicted TPh and AC (372.32 mg GAE/100 g, 549.99 μmol TE/100 g, respectively), which was confirmed to be in accordance with the experimental values. Based on the results obtained in this study, a designed CSM is proposed as a convenient ingredient of functional food products, dietary supplements and nutraceuticals.

Samples of three types of honey: polyfloral (PH), linden (LH) and acacia (AH,) without and with addition of dried cherries (40%) were analyzed before and after three months of storage. The total phenol (TPh), flavonoid (TFd) and anthocyanin (TAn) contents, antioxidant activities and sensory properties of honeys with and without the addition of dry cherries were evaluated. TPh and TFd increased with addition of dried cherries to the honey, while enriched honeys showed high TAn. The LH sample with dried cherries showed the highest anthocyanins content (41.41mgCGE/100g). The antioxidant activity increased with addition of dried cherries in honey in the DPPH• test and reducing power. The PH and enriched PH exibited the best antiradical activity compared to LH and AH. The EC50 DPPH values were: 23.81 for PH and 24.19 mg/mL for PH, while the EC50 DPPH were: 1.16 mg/mL for PH40 and 1.18 mg/mL for PH40s. RP0.5 values were: 57.00 mg/mL for PH40 and 56.00 mg/ml for PH40s, while RP0.5 were: 15.05 mg/mL for PH40 and 15.18 mg/mL for PH40s. The statistical analysis showed that TPh, TFd and TAn, and antioxidant activity of honeys and enriched honeys showed significant correlation. Sensory analysis of honey with dried cherries, before and after storage, indicated very good sensory characteristics.

The main chemical composition, i.e. the total content of bioactive compounds (phenolics 2209.86 ± 70.32 mg GAE/100g FDR, flavonoids 831.87 ± 12.61 mg R/100g FDR and anthocyanins 144.55 ± 0.39 mg CGE/100g FDR), in freeze-dried raspberry (FDR) was evaluated spectrophotometrically. Vitamin C content was determined by HPLC analysis (88.81 ± 4.38 mg vit C/100g FDR). Antioxidant activities of FDR extract were evaluated spectrophotometrically on stable 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals and by electron spin resonance spectroscopy (ESR) method on hydroxyl radicals (•OH). EC50 values were evaluated. EC50 DPPH• was 0.127 ± 0.013 mg/ml, while EC50 •OH was 1.366 ± 0.026 mg/ml. Antiproliferative activity of the FDR extract was evaluated in vitro in three human cell lines by colorimetric sulphorhodamine B (SRB) assay. The most pronounced effects were obtained in the breast adenocarcinoma cell line (MCF7). EC50 value was 395.07 ± 96.38 μg/ml. Antimicrobial activity was determined by disk diffusion method. The FDR extract produced a clear inhibition zone (without visible colonies) only toward Staphylococcus aureus. The minimal inhibitory (MIC) and minimal bactericidal (MBC) concentrations of FDR extract were evaluated. The values MIC were in the range of 4.7 - 100 mg/ml, and of MBC in the range of 6.3 - > 100 mg/ml.[ Projekat Ministarstva nauke Republike Srbije, br. TR 31044]

Dried apricot was extracted using two different solvents: 80% ethanol and hexane. The contents of total phenolics, flavonoids and anthocyanins were determined in ethanol apricot extract (EAE), while the carotenoid content was determined in hexane apricot extracts (HAE) by spectrophotometric method. The detected amounts of bioactive compounds in dried apricot were: phenolics 498.13 ± 12.04 mg GAE/100g DA, flavonoids 218.45 ± 14.14 mg R/100g DA and anthocyanins 3.08 ± 0.40 mg CGE/100g DA. In dried apricot the β-carotene was present in the amount of 0.56 ± 0.03 mg/100g DA. Some individual phenolic compounds in EAE were determined by HPLC analysis and the most dominant compound was gallic acid (35.02 ± 1.65 mg/100g DA). Free radical scavenging activities of EAE and HAE were tested spectrophotometrically using stable DPPH radicals and reducing power method. The EC50 value for EAE was 2.05 ± 0.06 mg/ml and for HAE was 6.28 ± 0.01 mg/ml. The RP0.5 values determined by reducing power method were 6.11 ± 0.01 mg/ml for EAE and 62.04 ± 0.03 mg/ml for HAE. The results indicate that dried apricot can be a valuable source of natural antioxidants and can be used as a functional food ingredient in the food industry.

Objective: Goji fruit extracts, methanol (MGE) and hexane (HGE), were subjected to evaluation as potential source of phenolic antioxidants and antiradical activity.Methods: Some phenolic compounds (gallic, protocatechuic, vanillic, chlorogenic, coumaric, caffeic and ferulic acid and catechin and rutin), vitamin C and carotenoids were identified and quantified by HPLC. Antioxidant activity was tested by measuring ability to scavenge DPPH and hydroxyl radicals. Also, reducing power of goji fruit extracts was determined.Results: HPLC analysis results showed predominance of gallic acid (40.44 mg/g g.f). Vitamin C content in MGE was 716.91 mg vitC/100 g g.f. IC50DPPH· varied from 26.64 μmolTEAC/g for HGE to 62.15 μmolTEAC/g for MGE, while RP0.5 values varied from 952.23 μmolTEAC/g for MGE to 1360.48 mg/mL for HGE. IC50·OH for MGE was 1844.01 μmolTEAC/g.Conclusions: Our results support the use of goji fruits as rich sources of phytochemicals for further utilization in the food industry as supplements and functional food ingredients. [ABSTRACT FROM AUTHOR]

The production of high-quality freeze-dried raspberry was studied by response surface method. Two independent variables, temperature (X1) and time (X2) were determined as the most important factors affecting the final product quality estimated by the responses: total phenol (Y1), total anthocyanin (Y2), vitamin C (Y3) and total bioactive compounds (Y4) content. A two-factor central composite design was used for freeze-drying experiments. The second order polynomial models obtained were found to be significant (p < 0.05) for all responses. The statistical analysis of experimental data indicated that only the quadratic time variable (X22) had significant (p < 0.05) effect on all responses. The optimal conditions for all responses combined were found to be -31 ºC and 35 h. The experimental values of all responses obtained under optimal conditions were in good agreement with predicted values, which enables the use of the proposed mathematical models for optimization of investigated process. [ABSTRACT FROM AUTHOR]

Kombucha is a fermented tea beverage which is traditionally prepared by fermenting sweetened black or green tea (Camellia sinensis L.) with symbiotic consortium of bacteria and yeasts (SCOBY). In this study, lemon balm (Melissa officinalis L.) was used as the only nitrogen source for kombucha fermentation. During the seven-day fermentation process, pH value, titratable acidity (TA), total phenolic content, phenolic compounds, and antioxidant activity against hydroxyl (OH) and 1,1-diphenyl-2-picrylhydrazil (DPPH) radicals were measured to detect the connection between the fermentation time and antioxidant and antibacterial activities of lemon balm kombucha. Antibacterial activity of finished beverages with optimum acidity (TA=4--4.5 g/L), the value which is confirmed by long-time kombucha consumers, and enhanced acidity (TA=8.12 g/L) was tested against eleven wild bacterial strains. The results showed that lemon balm could be successfully used as an alternative to C. sinensis L. for kombucha fermentation. Total phenolic content and antioxidant activity against DPPH radicals of lemon balm fermentation broth were higher than those of traditional kombucha. Rosmarinic acid is the main phenolic compound of the lemon balm-based kombucha that probably provides biological activity of the beverage. Judging from the EC50 values, kombucha beverages exhibited higher antioxidant activities compared with C. sinensis L. and M. officinalis L. infusions, which can probably be ascribed to SCOBY metabolites. Lemon balm kombucha with both optimum and enhanced acidity showed antibacterial activity, which can be primarily ascribed to acetic acid, but also to some other tea components and SCOBY metabolites. [ABSTRACT FROM AUTHOR]