Minimising variation in aspalathin content of aqueous green rooibos extract: optimising extraction and identifying critical material attributes

Abstract

By setting raw material specifications in terms of AC, as well as applying practical optimum extraction conditions, 160 g kg extract with an AC ≥ 80 g kg could be consistently achieved from green rooibos plant material. © 2017 Society of Chemical Industry.

Model development for predicting in vitro bio-capacity of green rooibos extract based on composition for application as screening tool in quality control

“…Following a quality-by-design (QbD) approach, process parameters for producing a hot water extract of green rooibos containing at least 80 g kg −1 aspalathin were established 11 as the first step toward extracts with a guaranteed in vitro biocapacity. Hot water extraction was selected in favour of other extraction solvents as it represents the most common solvent for the production of food grade extracts of rooibos.…”

“…A QbD approach shifts the focus from quality assurance through testing to quality control (QC) by process understanding. 12 Miller et al 11 also identified critical material attributes that would impact on the aspalathin content of the extract, which addressed to some extent one of the key issues that handicaps implementation of QbD for herbal products, i.e. quality variation of the herbal raw material.…”

Hydrodistillation condition adjustment for different material particle sizes: a method to increase batch‐to‐batch quality consistency

“…Plant materials are usually pulverised before extraction, as the particle size can impact on the extraction yields (Taralkar et al, 2016;Chen et al, 2017;Jovanovic et al, 2017). The extraction from plant materials of varying particle sizes will give rise to the batch-to-batch variation of the contents of bioactive compounds in the extracts, which is one of the challenges for producing standardised extracts (Miller et al, 2017). the required range of particle size for extraction), and the batch-to-batch consistency of the particle size cannot be ensured.…”

“…In the production of many foods, dietary supplements and herbal medicines, the extraction of bioactive compounds from plant materials is usually the first process (Teng & Choi, 2013;Gong et al, 2015;Shang et al, 2016;Xu et al, 2016;Chanioti & Tzia, 2017;Miller et al, 2017). Plant materials are usually pulverised before extraction, as the particle size can impact on the extraction yields (Taralkar et al, 2016;Chen et al, 2017;Jovanovic et al, 2017).…”

“…For the particles larger than the specification, the pulverising process needs to be conducted again, while there is a lack of methods to handle the particles smaller than the specification. The extraction from plant materials of varying particle sizes will give rise to the batch-to-batch variation of the contents of bioactive compounds in the extracts, which is one of the challenges for producing standardised extracts (Miller et al, 2017). To ensure the batch-to-batch consistency of the extracts, a method to adjust the extraction process for different particle sizes is needed.…”