Christina G. Drosou

Dr. Christina G. Drosou


Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
21 December 2016 in Drying Technology
Verified
Journal Article
Closed access
CDChristina G. Drosou
Christina G. Drosou
MKMagdalini K. Krokida
Magdalini K. Krokida
CBCostas G. Biliaderis
Costas G. Biliaderis
Spray drying and electrohydrodynamic processes, namely, electrospinning and electrospraying, are the most promising encapsulation technologies for entrapping and effectively delivering bioactive compounds. Encapsulation is used by the food industry to incorporate such compounds into different food matrices, protect them from adverse environmental conditions, and thereby increase the product shelf life and maintain the health-promoting properties of the composite formulation. This review provides a succinct discussion on the potential of food ingredient-based applications of spray drying and electrohydrodynamic processes on encapsulation as well as the principles and the parameters that affect the structure–morphology of the carrier matrix and the encapsulation efficiency of the process.

19 June 2024 in Foods
Verified
Journal Article
Open access
PDF file
CDChristina G. Drosou
Christina G. Drosou
Magdalini KrokidaMagdalini Krokida
Magdalini Krokida
The encapsulation of β-carotene was investigated using pullulan and whey protein isolate (WPI) as a composite matrix at a weight ratio of 20:80, employing both spray-drying and freeze-drying techniques. The influence of processing parameters such as the concentration of wall material, flow rate, and inlet temperature for SP encapsulants, as well as wall-material concentration for FZ encapsulants, was examined in terms of encapsulation efficiency (EE). The morphology, structural characterization, moisture sorption isotherms, and thermal properties of the resulting encapsulants at optimum conditions were determined. Their stability was investigated under various levels of water activity, temperature conditions, and exposure to UV–Vis irradiation. β-carotene was efficiently encapsulated within SP and FZ structures, resulting in EE of approximately 85% and 70%, respectively. The degradation kinetics of β-carotene in both structures followed a first-order reaction model, with the highest rate constants (0.0128 day−1 for SP and 0.165 day−1 for FZ) occurring at an intermediate water-activity level (aw = 0.53) across all storage temperatures. The photostability tests showed that SP encapsulants extended β-carotene’s half-life to 336.02 h, compared with 102.44 h for FZ encapsulants, under UV–Vis irradiation. These findings highlight the potential of SP encapsulants for applications in functional foods, pharmaceuticals, and carotenoid supplements.

6 December 2024 in Molecules
Verified
Journal Article
Open access
PDF file
KLKonstantina Theodora Laina
Konstantina Theodora Laina
CDChristina G. Drosou
Christina G. Drosou
Chrysanthos StergiopoulosChrysanthos Stergiopoulos
Chrysanthos Stergiopoulos
PEPanagiota Eleni
Panagiota Eleni
Magdalini KrokidaMagdalini Krokida
Magdalini Krokida
This study presents the synergistic application of ultrasound- and microwave-assisted extraction (UAE–MAE) as a novel and efficient method for recovering bioactive compounds from the medicinal plants oregano, rosemary, Hypericum perforatum, and chamomile. Extraction parameters, including microwave (MW) power, ultrasound (US) power, and extraction time, were optimized using the response surface methodology (RSM), with ethanol as the solvent. Extracts were evaluated for total phenolic content (TPC) via the Folin–Ciocalteu method and antioxidant activity (IC50) using the DPPH assay. High-performance liquid chromatography with diode array detection (HPLC–DAD) identified the main bioactive compounds contributing to their antioxidant and therapeutic potential. The optimized UAE–MAE conditions enhanced phenolic recovery and antioxidant potential across all plants. Notably, Hypericum perforatum exhibited the highest TPC (53.7 mg GAE/g) and strongest antioxidant activity (IC50 29.8 mg extract/g) under 200 W MW, 450 W US, and 12 min, yielding 14.5%. Rosemary achieved the highest yield (23.36%) with a TPC of 26.35 mg GAE/g and an IC50 of 40.75 mg extract/g at 200 W MW, 700 W US, and 8 min. Oregano’s optimal conditions (500 W MW, 700 W US, 12 min) produced a TPC of 34.99 mg GAE/g and an IC50 of 50.31 mg extract/g. Chamomile extracts demonstrated lower phenolic content and antioxidant activity but achieved significant yields under 500 W MW, 700 W US, and 5 min. This study highlights UAE–MAE’s superior efficiency, showcasing its potential to maximize phenolic recovery sustainably, making it a promising technique for industrial and therapeutic applications.

20 April 2025 in Foods
Verified
Journal Article
Open access
PDF file
KLKonstantina Theodora Laina
Konstantina Theodora Laina
CDChristina G. Drosou
Christina G. Drosou
GFGeorgia Frakolaki
Georgia Frakolaki
Magdalini KrokidaMagdalini Krokida
Magdalini Krokida
The aim of this study was to develop a functional yogurt enriched with encapsulated probiotics with viable cell counts exceeding 107 CFU/g while preserving sensory quality, thereby enhancing health benefits and potentially preventing intestinal barrier dysfunction. Lacticaseibacillus rhamnosus LGG® was encapsulated in prebiotic-based matrices for enhanced stability, bioavailability, and controlled release under gastrointestinal conditions. Two encapsulation methods were investigated—the innovative electrohydrodynamic processing (electrospraying) method and conventional freeze drying. The encapsulation matrices were composed of inulin and whey protein isolate. Encapsulation efficiency was determined via microbiological analysis, and the encapsulated structures were characterized using scanning electron microscopy. The efficacy of the encapsulated probiotics was further assessed through exposure to gastrointestinal conditions. Electrosprayed LGG® provided the highest survival rates, up to 76%. Storage stability was evaluated at 4 °C for 105 days and after incorporation in commercial yogurt for 60 days. The sensory characteristics of the different yogurt products were also evaluated. The final products presented acceptable sensory features and final viable counts of 1.6–1.8 × 107 CFU/g. The denser structure of electrosprayed LGG® led to even higher protection. The findings highlight the potential of encapsulation—particularly electrospraying—in developing functional foods with improved probiotic delivery systems, paving the way for health-oriented dairy products.

29 June 2024 in Potato Research
Verified
Journal Article
Closed access
PDF file
ZTZoi Tsakiri-Mantzorou
Zoi Tsakiri-Mantzorou
CDChristina G. Drosou
Christina G. Drosou
AMAlexandra Mari
Alexandra Mari
MSMarina Stramarkou
Marina Stramarkou
KLKonstantina Theodora Laina
Konstantina Theodora Laina
MKMagdalini Krokida
Magdalini Krokida

26 August 2024 in Foods
Verified
Journal Article
Open access
PDF file
CDChristina G. Drosou
Christina G. Drosou
Magdalini KrokidaMagdalini Krokida
Magdalini Krokida
This study developed functional white chocolate enriched with free (WC-F) and encapsulated β-carotene using whey protein isolate (WPI) and pullulan (PUL) blends through spray drying (WC-SP), freeze drying (WC-LP), and coaxial electrospinning (WC-EL). The thermal properties, rheological properties, hardness, and color of the chocolates were evaluated, and the stability of β-carotene was monitored over 4 months at 25 °C. No significant differences were found in melting profile temperatures among samples; however, WC-LP and WC-EL exhibited higher melting energies (30.88 J/g and 16.00 J/g) compared to the control (12.42 J/g). WC-F and WC-SP showed rheological behaviors similar to those of the control, while WC-LP and WC-EL displayed altered flow characteristics. Hardness was unaffected in WC-F and WC-SP (7.77 N/mm2 and 9.36 N/mm2), increased slightly in WC-LP (10.28 N/mm2), and decreased significantly in WC-EL (5.89 N/mm2). Over storage, melting point, rheological parameters, and hardness increased slightly, while color parameters decreased. β-carotene degradation followed a first-order reaction model, with degradation rate constants (k) of 0.0066 day−1 for WC-SP, 0.0094 day−1 for WC-LP, and 0.0080 day−1 for WC-EL, compared to 0.0164 day−1 for WC-F. WC-SP provided the best β-carotene retention, extending the half-life period by 2 times compared to WC-F (126.04 days vs. 61.95 days). Practical implications: The findings suggest that WC-SP, with its superior β-carotene stability, is particularly suitable for the development of functional confectionery products with extended shelf life, offering potential benefits in industrial applications where product stability is crucial. Future research directions: Further studies could explore the incorporation of additional bioactive compounds in white chocolate using similar encapsulation methods, as well as consumer acceptance and sensory evaluation of these enriched products.