Naslov
Bioactive and sensory profiling of green tea extracts and their stabilization by microencapsulation in different biopolymer-based hydrogel microparticles

Autori
Belscak-Cvitanovic, Ana ; Busic, Arijana ; Vojvodic, Aleksandra ; Dordevic, Verica ; Komes, Drazenka ; Bugarski, Branko ; Nedovic, Viktor

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of abstracts of the Third International Congress on Cocoa, Coffee and Tea / - , 2015

Skup
Third International Congress on Cocoa, Coffee and Tea (CoCoTea 2015)

Mjesto i datum
Aveiro, Portugal, 22.06.2015. - 24.06.2015

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Caffeine; Green tea; Electrostatic extrusion; Microencapsulation

Sažetak
In this study, knowledge on the extraction efficiency and bioactive profile of green tea was extended to sensory preference and microencapsulation in alginate-based microparticles, with the aim of achieving encapsulated nutraceutical dosage forms. Different extraction procedures consisted of repeated combined conventional and ultrasonic extractions) of green tea were employed and the obtained extracts compared based on their bioactive and sensory profiling. The concentration of green tea extract that exerted the most potent antioxidative activity was encapsulated using different formulations of alginate, chitosan, pectin, xanthan gum and hydroxypropylmethyl cellulose (HPMC) by electrostatic extrusion. Temperature revealed to be the determining factor for the extraction of green tea. Repeated conventional extraction at 80°C provided the optimal extract composition, exhibiting 5282 mg GAE/L of total polyphenols, 1112 mg/L of epigallocatechin gallate and 319 mg/L of caffeine. Higher correlation between the total polyphenols and tannins content with bitterness and astringency intensity of green tea extracts was observed, than with the caffeine content, indicating that polyphenolic compounds are the main contributors to the sensory properties of green tea extracts. Among the evaluated delivery formulations for green tea bioactive compounds, HPMC hydrogels blended with pectin (1:1 ratio) provided the highest encapsulation efficiency of polyphenolic antioxidants (up to 87%), although their controlled release was not improved (majority of polyphenolic compounds released during 10-15 min). Microparticles composed of alginate and 20% of alternative carriers (pectin, HPMC) exhibited the best morphological properties, while the formulations comprising xanthan were the most unhomogenous. HPMC-pectin microparticles exhibited the largest particle size (< 1300 μm) and alginate-modified starch the smallest (650 μm). The obtained results provide a complete approach to the obtention of green tea extract with confirmed antioxidative properties and its encapsulation in innovatively modified supports of nutraceutical importance.

Izvorni jezik
Engleski

Znanstvena područja
Prehrambena tehnologija

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