Efficiency Assessment of Natural Biopolymers as Encapsulants of Green Tea (Camellia sinensis L.) Bioactive Compounds by Spray Drying

Abstract

In this study a bottom-up approach of designing functional ingredients from green tea extract is proposed by a systematic investigation of 12 different natural biopolymers and their efficiency as carrier materials of green tea bioactive compounds by spray drying at low temperature (130°C). Screening of carriers revealed that inulin and whey proteins provide the highest product yields (67.04 and 65.18 %, respectively) and, accompanied with pectin, also the highest total polyphenols (67.5-82.2 %) and flavan-3-ols (93.7-75.9 %) loading capacity. Up to 162 mg/g of (−)−epigallocatechin gallate (EGCG) was achieved, while low-caffeine contents (<5 mg/g) indicated the potential of obtaining lowcaffeine functional ingredients. Employing alginate, carageenan and gums (acacia gum and xanthan) enabled the best colour preservation and highest chlorophyll content. Reconstituted green tea microencapsulates comprising modified starch, inulin or carageenan exhibited the lowest bitterness and astringency and the highest green tea flavour intensity as the most favourable sensory properties. An artificial neural network (ANN) designed based on the experimentally obtained results revealed hydrocolloid gums as the best encapsulants for achieving good physical properties, high EGCG contents and prolonged dissolution/release profiles while pectin, inulin and modified starch as the optimal ones in terms of the product yields, loading capacities and sensory properties. This indicates that a formulation comprising a combination of all of those biopolymers would provide potentially functional ingredients with encapsulated green tea phytochemicals, retained colour and improved sensory properties.

The Effect of Low-Temperature Spray Drying with Dehumidified Air on Phenolic Compounds, Antioxidant Activity, and Aroma Compounds of Rapeseed Honey Powders

“…It was not observed in M-based powders, and can suggest better properties of N as protective agent for phenolic compounds. In the work presented by Belščak-Cvitanović et al (2015), inulin was also effective microencapsulant, enabling significantly higher product yield obtained by spray drying, when compared to plain spray-dried green tea extract.…”

Antioxidant and Antimicrobial Activities of (‐)‐Epigallocatechin‐3‐gallate (EGCG) and its Potential to Preserve the Quality and Safety of Foods

“…Belscak‐Cvitanovic et al. () tested the role of 12 different natural biopolymers such as inulin, whey proteins, pea proteins, pectin, AG, carrageenan, acacia gum, xanthan gum, locust bean gum, guar gum, modified starch, and oligofructose on bitterness, astringency, and flavor intensity of spray‐dried GTE (0.5% w/v). Panelists were given a caffeine solution (as the standard for bitterness) and tannic acid solution (the standard for astringency) at 0 to 500 mg/L for 2 weeks.…”

Microencapsulation of anthocyanin-rich black soybean coat extract by spray drying using maltodextrin, gum Arabic and skimmed milk powder

“…The main advantages of spray drying over the other encapsulation techniques are simplicity, continuity, cost-and time-effectivness, availability and applicability, even for the drying of sensitive compounds since the atomization of the liquid mixture lasts extremely shortly. However, spray drying do not provides uniform conditions into drying chamber and easy control of particle size, as well as drying of highly viscous solutions (Nedović et al 2013, Belščak-Cvitanović et al 2015.…”

“…Maltodextrin (MD) and gum Arabic (GA) have been frequently used as carrier materials for microencapsulation of different juices, infusions extracts and various functional byproducts via spray drying (de Souza et al 2015, Santiago-Adame et al 2015, Laokuldilok and Kanha 2015, 2016Cano-Chauca et al 2005, Belščak-Cvitanović et al 2015, Diaz et al 2015, Daza et al 2016.…”