Printer friendly versionQuarter 3 2001 Editorial
The editorial aims to bring to your attention the key features in each quarter and focuses on what is happening in the hydrocolloids world in terms of technology and development. It aims to point out potential threats and potential opportunities for your business.
This issue we start with a threat to the carrageenan business. Once again there is a publication in the medical literature that claims that carrageenan can cause cancer. This was promptly seized upon by the UK press and soon found its way into the popular newspaper the Daily mail published in the UK (reproduced on page7). This is nothing new and is an oft repeated claim by medical academics. In fact this new scare is not even based on new work but rather is from a couple of review articles published by Dr Joanne Tobacman from the University of Iowa. Dr Tobacman talks about the cancer causing properties of degraded carrageenan and states that in her view nothing has been done about this possible risk despite it being identified in the 1970's. However it would seem that Dr Tobacman does not give due credit to the work done on the stability of carrageenan during processing carried out by Leatherhead Food Research Association and the in depth toxicological work only recently completed on behalf of JECFA. To say 'nothing was ever done' is simply not true, there was significant work carried out and as a result carrageenan was awarded a recommended daily intake of 'not specified' as recognition of its perceived safety in use.
An area that seems to be gaining significant attention is the use of a gelatin replacement in capsules. In this issue alone there are two patents on new compounds for capsules, one from Warner Lambert and the other from the Suheng Capsule company Ltd. With the ongoing problems with gelatin it is only a matter of time until gelatin is replaced in these 'health product' types of areas.Although the various scares on gelatin come and go there is still an underlying trend away from gelatin. The prime candidates worth looking at for gelatin replacement in capsules would undoubtedly be the same products as could be used in wine gums. What type of products should we be looking for? Well the high concentration would force a high level of aggregation and potentially force a lot of gums out of solution. So gums with a good solubility in high sugar systems are essential such as pectins, carrageenans (but probably not kappa), agar and any of the low molecular weight gums. Guar as theoretical potential as it weakly aggregates in solution and at the right molecular weight may just self aggregate enough to form a gel in a very high solids system.Unfortunately guar has the problem of having a strong odour and is highly coloured when concentrated. This can be got around by enzyme treating in solution to break it down to oligomers and filtering through a carbon bed.....the trick will be to control the break down to get exactly the size you want!
A US patent was published which may have some general applicability across the hydrocolloids world.US 20010025101 describes the use of a modified flash dry grinder that uses injected steam. The system is claimed to produce a fine mesh product (20 μ) with very little oversize. The claim was for cellulose ethers it may only work because of their unusual thermal properties. However if it turns out to be generally applicable then it could be very valuable as fine milling any hydrocolloids extremely time consuming and hence expensive. The problem with hydrocolloids is their lack of brittleness. A particle in a mill simply bounces around getting hot and degrading rather than actually milling. One solution is to use cryogenic milling which not only reduces degradation but can also increase throughput, the disadvantage is the capital outlay needed for nitrogen storage and you cannot use all mills cryogenically as the mill body may end up as brittle as the hydrocolloid!
An article in Carbohydrate Polymers (Carbohydrate Polymers, Jul. 2001) discusses the use of an inactivated enzyme mixed with a pectin to effectively give a delayed set gelation system. This could be beneficial in a variety of polysaccharide system apart from pectin. Other possible combinations could be an alginate with a C5 epimerase enzyme or a galactomannan with a galactosidase enzyme. On the latter it could be a method of utilising fenugreek galactomannan which generally has such a high galactose level that it does not interact with other gums. On the down side there would be a need for a pure and concentrated form of the enzyme which generally means it has to be expressed from a GMO. Also if the enzyme reaction is not halted the polysaccharide could find itself rendered so available for crosslinking that it becomes completely insoluble and drops out of solution.
Another article in a later edition of Carbohydrate Polymers (Carbohydrate Polymers, Aug. 2001)related the gel strength of a gel has measured by the SAG method to the elastic modulus (G'). This potentially opens up the possibility of correlating a range of gel techniques thus eliminating the requirement for an endless series of different types of gel testers. Within the hydrocolloids field gel strengths are routinely measured by oscillation (G'), using a Steven's type texture analyser,using a FIRA jelly tester, using a Neocurd jelly tester, or using the SAG method. Add to this the proliferation of test methods for each piece of equipment and we have a very chaotic state of affairs. Unfortunately the goal of finding a unifying formula to link various method is probably naïve. The SAG method and elastic modulus can be linked because they are both essentially measurements of a system under rest conditions. Another good candidate for this type of correlation would be the gelatin bloom strength test which also essentially measures the elastic modulus. Many of the other techniques measure the gel by some form of dynamic, destructive test where the rate of movement is critical to the test result thus rendering correlation significantly more difficult.
An article in Food Chemistry (Food Chemistry, Aug. 2001) describes the use of new infra red techniques for measuring polysaccharide ester contents quickly and accurately. Most peoples memories of infra red analysis was spending ages grinding up nujol mulls or making KBr discs only to get a poor spectrum dominated by the water peaks in their damp samples. However Infra red is a much more useful technique these days and reflectance techniques overcomes many of the problems of sample preparation that used to exist. The technique should be useful for a range of modified polysaccharides such as the pectin described but also amidated pectins, propylene glycol alginate and maybe hydroypropyl guar and modified cellulosics. In fact the technique is used to monitor the deacetylated of konjac mannan in another paper (Biopolymers, Jul. 2001).
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