Fabrication of Spray-Dried Microcapsules Containing Noni Juice Using Blends of Maltodextrin and Gum Acacia: Physicochemical Properties of Powders and Bioaccessibility of Bioactives during In Vitro Digestion.

Chuang Zhang,Peter Swedlund,Yang Shan,Siew Young Quek,Yukiharu Ogawa,Siew Lin Ada Khoo

doi:10.3390/foods9091316

Abstract

Microencapsulation of fermented noni juice (FNJ) into powder format could protect bioactive compounds, reduce the unpleasant odour and improve the acceptability for consumers. Blends of maltodextrin (MD) and gum acacia (GA) were used to achieve spray-drying microencapsulation of noni juice at different blending ratios. The physicochemical properties including microstructure, moisture content, water activity, particle size, bulk/tapped density, dissolution rate, ATR-FTIR and the bioaccessibility of bioactive compounds in powders during in vitro digestion were examined. Results showed that blends produced with more GA produced microcapsules with lower moisture content, water activity and bulk/tapped density, but slower powder dissolution. The ATR-FTIR results suggested that there were no significant chemical interactions between the core material and carrier or between the MD and GA in the blend powders. The spray-dried noni juice powder produced using the blends with higher ratio of GA to MD showed a better protection on the bioactive compounds, resulting in a higher bioaccessibility of powders during in vitro digestion. This study provides insights into microencapsulation of noni juice using blends of MD and GA and examines the physicochemical properties and bioaccessibilities of spray-dried powders as affected by the selected carriers.

Highlights

Morinda citrifolia L. (Noni) has been used for centuries as a medicinal plant, with reported therapeutic effects in the prevention or treatment of dyslipidaemia, diabetes, inflammation and cancer [1]
This is consistent with the study on microencapsulation of grape polyphenol using MD and gum acacia (GA) as carriers conducted by Tolun et al [29]
The total phenolic content (TPC) in P73 and P91 dropped to 82–86%, and the lowest retention of TPC was found in fermented noni juice (FNJ) (~74%)

Summary

Introduction

Morinda citrifolia L. (Noni) has been used for centuries as a medicinal plant, with reported therapeutic effects in the prevention or treatment of dyslipidaemia, diabetes, inflammation and cancer [1]. Spray-drying microencapsulation of fruit juice is an efficient method used in preserving and delivering sensitive materials [4], and its application on noni juice has been studied [5,6]. These studies have examined the physicochemical properties (moisture content, particle size, tapped bulk density and hygroscopicity, etc.) and functionalities of noni juice microcapsules produced by systems with one hydrocolloid, either maltodextrin (MD, 10–13 and 17–20 DE (dextrose equivalent)) or gum acacia (GA), and elucidated the advantages of using MD (10–13 DE) or GA as carriers for microencapsulation

Objectives

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Results

Conclusion