Spring 2002 Issue — Getting the Best from Beta-Carotene:
Selecting the Right Source for Maximum Vitamin Delivery and a 'Natural' Label

Jeanet Gerritsen and Freek Crum

DSM Food Specialties, Nutritional Ingredients

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Introduction

Left: Pro-vitamin A activity, eradication of harmful free radicals and attractiveness as a natural colourant render beta-carotene indispensable in a wide range of food, drinks and supplements.

Manufacturers keen to formulate foods, beverages and dietary supplements incorporating beta-carotene - widely appreciated as a vitamin A precursor, antioxidant and colourant - face the dual challenge of creating tempting end-products while ensuring sufficient benefit from nutraceutical ingredients. Vitamin A bio-availability from beta-carotene varies widely depending on the origin. Manufacturers must therefore ensure they choose the right source of this vital ingredient. With consumers becoming increasingly conscious of daily recommended intakes, maximising the potential for vitamin A is a major marketing advantage. This article examines how natural beta-carotene sources coupled with specialist processing can deliver required vitamin A potency with a 'natural' label in appealing end-products.

Compound	Microgram/IU	IU/mg	RE/mg
All-trans retinol (vitamin A)	0.3	3,333	1,000
All-trans beta-carotene	1.8	1,666	167
Other pro-vitamin A carotenoids (eg alpha-carotene; gamma-carotene)	3.6	833	83

Table 1. International Units (IU) and Retinol Equivalents (RE)

Functions of beta-carotene

The controlled conversion of beta-carotene into vitamin A makes it the preferred source for this vitamin. The human body derives vitamin A from beta-carotene on an 'as required' basis, minimising any toxicological concern regarding overdosing - a potential issue with pure vitamin A. Beta-carotene is also well known as an antioxidant, helping to protect healthy cells from free radical damage which may play a role in degenerative diseases such as cancer, heart disease and stroke. As a colourant, it creates attractive hues of yellow and orange with wide reaching 'health' associations.

Beta-carotene occurs naturally in many brightly coloured foods such as carrots, spinach and red peppers, but manufacturers looking to harness its positive effects need to establish more efficient and reliable sources and delivery systems.

Selecting the source

Beta-carotene is one of more than 600 naturally occurring carotenoids. Of these, about 50 are known to have pro-vitamin A activity and approximately 20 are found in the average western diet.

Carotenoids can be obtained from three different sources:

1. Plants such as carrots, palm oil and algae. This is a relatively expensive source, however, and does not deliver the most effective form of beta-carotene in terms of vitamin A conversion.
2. Chemical synthesis through a process developed in the 1950s to create b-ionone- based beta-carotene from acetone. The result is pro-vitamin A beta-carotene but it is a chemical product and cannot be labelled as 'natural'.
3. Biosynthesis from micro-organisms. A more recently perfected process, this option enables beta-carotene with a high conversion rate to vitamin A to be obtained from natural origins.

Of the naturally occurring micro-organisms, Blakeslea trispora-derived beta-carotene has been found to yield a very efficient source of vitamin A while also supporting a natural label declaration. DSM Nutritional Ingredients derives its CaroPure® range from this source and has increased the micro-organism's beta-carotene productivity through classical strain selection.

Beside beta-carotene, Blakeslea trispora produces approximately 2.5% other mixed carotenoids - proof of its natural origins of Caro-Pure®. These include gamma-carotene, beta-zeacarotene and citroxanthin together with approximately ten other carotenoids in low concentrations.

So why does Blakeslea trispora deliver such efficient pro-vitamin A carotenoids? The answer lies in its carotenoid profile.

Structures for strength

The beta-carotene molecule appears in two different geometric forms: trans-isomer and cis-isomer with all-trans beta-carotene yielding the highest rate of conversion to vitamin A (100% based on weight). The all-trans structure is defined as one unsubstituted beta-ionone ring, attached to the intact conjugated isoprenoid side chain containing at least 11 carbon atoms. The pro-vitamin A activity of cis-isomers is approximately 50% lower than that of all-trans beta-carotene. The CaroPure® range of beta-carotene from DSM contains the highest proportion of trans-isomers of any natural beta-carotene, providing unrivalled pro-vitamin A potency.Fig 1 shows the Trans and cis configuration of carotenoids.

Fig 1. The trans and cis configuration of carotenoids.

Cutting costs

With 98% trans-isomers and 2% cis-isomers, synthetic beta-carotene has a very high conversion rate to vitamin A but loses favour because it cannot be labelled as 'all natural' or 'contains no artificial colours'. DSM Nutritional Ingredients' CaroPure® range of natural beta-carotene products contains 94% trans, the highest IU level per gram of any available natural beta-carotene product. One molecule of CaroPure® beta-carotene converts to two molecules of vitamin A in the body. This high conversion rate compared with other natural beta-carotenes means fewer kilograms of beta-carotene are needed in formulations. For supplement manufacturers this could mean considerable cost savings since less beta-carotene is needed for the same label claim. It also opens up opportunities to cater for the growing trend towards multi-vitamin solutions.

Processing for success

Production takes part in three stages: fermentation, extraction and crystallisation. The Blakeslea trispora is cultivated in large-scale fermentors using raw materials of vegetable origin. The beta-carotene is then extracted from the biomass and processed into a pure beta-carotene crystal. The process used by DSM ensures the beta-carotene supplied is safe for use in dietary supplements and foods and is consistent with a 'natural' marketing approach. It can be labelled as E160a(ii) in compliance with EU directives on colour, meets FCC and USP purity standards and is FDA listed as a GRAS nutrient and dietary supplement.

Keep it all in

For the dietary supplement manufacturer, confidence in a consistent product is a very important aspect. If beta-carotene leaks from the tablet is becomes exposed on the surface, resulting in oxidation and content loss. Tablets also appear less attractive and appealing. Key here is the micro-encapsulation technique perfected by DSM which determines beadlet quality. DSM beadlets are resistant to high pressures during tabletting and do not show signs of leaking or extrusion. SIgnificant cost savings can be made as manufacturers do not need to add contingency levels of beta-carotene to compensate for potential losses.

Summary

The positive effects of beta-carotene are undisputed. Pro-vitamin A activity, eradication of harmful free radicals and attractiveness as a natural colourant render it indispensable in a wide range of food, drinks and supplements. Available from a variety of natural sources, beta-carotene is most effective as an all-trans isomer which provides the highest conversion rate to vitamin A. Manufacturers keen to ensure maximum vitamin A potential with a 'healthy' label now have the option of a 96% trans, natural source beta-carotene available from DSM in beadlet, oil suspension, crystal and CWS form for use in tablets, (soft gel) capsules, as a colourant and for nutritional applications. For the first time, beta-carotene is available with both a high conversion rate to vitamin A (due to its 'trans' form) plus origins and processing compatible with natural marketing claims.

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