Checklist for choosing a plant extract

UK-based Quest Nutra Pharma Group has advised looking beyond application to the plant source, extraction process, quality, and value

Photo as seen on Quest Nutra Pharma website

Quest Nutra Pharma has provided an insight into what to be aware of when looking to buy a plant extract.

The UK-based group says you, of course, have to consider the application you will be applying the extract to, but also the source, extraction process, quality, and value.

Understanding your application

There are multiple reasons for buying plant extracts. One of the principal uses is to flavour hot and cold beverages such as tea or gin; alternatively, they can be used as active substances in medicines, such as cough and cold syrups, and as natural ingredients for cosmetic products.

Understanding the nature of the application and what the key quality attributes are required is clearly of primary importance when buying plant extracts. For example, a herb such as Arnica is extracted for functional reasons. Therefore, assurance over the efficacy of the Arnica product is critical.

The herb must comply with the specific quality standards as set down in the European Pharmacopoeia. On the other hand, when buying plant extracts to flavour a premium gin, their aroma and flavour profile is what matters.

Consider the source

Considering a plant extract, a plant has many different parts to it and may be grown in different ways and in different environments as well as extracted at different times, producing markedly different results.

For example, the simple juniper berry, which is the cornerstone of all gins, grows in the US, UK, Europe, Japan and parts of Asia. Moreover, there are multiple sub-species of juniper and the sensory components in juniper varies depending on their stage of maturity at harvesting.

Therefore, it is not enough to simply buy juniper berries. Buyers must understand the origin and specifics of the raw material.

The extraction process

Plant extracts are prepared in a variety of different ways. They may be prepared by extracting the herb with solvents including water, alcohol (usually ethanol or methanol) or a mixture of alcohol and water. These extracts may then be available in different forms listed in order of increasing strength: tinctures, liquid extracts, soft extracts and dry extracts.

Hydro alcoholic solvent extraction is a general method and will extract a wide range of constituents from the herb. If the desired actives are more fat soluble high strength alcoholic extracts are appropriate whereas if water-soluble components are required water-based extracts are suitable.

Most extracts used in medicinal applications are prepared by solvent extraction and their selection should be based on the levels of active constituent present relative to the end-use application.

Another consideration to be made here are the characteristics of the finished product. The plant extract should be compatible with the finished product matrix and compatibility will be governed by the water content and nature of the excipients making the bulk finished product.

On the other hand, for providing concentrated flavours, essential oils are the appropriate form of extract to be used. Most essential oils are extracted through the use of steam distillation and/or hydrodistillation. Although on a large scale steam distillation may be costly the essential oil fractions are very concentrated so only small doses are required for flavouring.

Understanding these processes and how they affect the plant extract that you wish to purchase is important as it can have a significant impact on your final product.

Testing botanical products

It is recommended that buyers of plant extracts, particularly for medicinal applications, carry out their own rigorous quality assessments. There are third party laboratories that can carry out a variety of checks including chromatography tests to verify the identification and quality of the product that is being bought.

Other quality attributes that should be monitored when buying from a new supplier is microbiological control, which looks for harmful bacteria or other micro-organisms present in the product and additionally pesticide and heavy metal content.

Plant extract manufacturers themselves should also be able to provide certifications to show that their product adheres to required standards.

Buying on value, not just price

As can be seen, there are many opportunities for unscrupulous plant extract manufacturers to manipulate products in order to undercut pricing. These are just some of the questions you can and should ask when you need to purchase plant extracts as ingredients for your final product.


N.B This article was written by Quest Nutra Pharma Group. Link to the original article on the company's website here

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