Hydrocolloids - Andrew Hoefler

Hydrocolloids - Andrew Hoefler

• Title: Hydrocolloids
• Author: Andrew Hoefler
• Price: Euro 69 ($69)
• ISBN: 1-891127-38-1
• Copyright: 2004
• Published: Eagan Press

Summary

 A good book for people with little or no experience of hydrocolloids looking for a broad and basic understanding of the subject with plenty of practical recipes to get them started. Essentially a good shot at producing a practical and pragmatic introduction to using hydrocolloids in foods with better content and presentation than other books that have attempted to fill this slot.

The book is basic and tends towards reducing each topic down to a few elementary facts that you need to know and some useful information to get you started. Sometimes the simplification is extreme but this book is only one hundred pages long and attempts to cover a huge area in a very small book so that is to be expected. Its well presented with plenty of illustrations, useful reference and troubleshooting tables, excellent starter recipes and is very easy to read (a rare achievement for a book on hydrocolloids!).

This is not a book for the hard bitten hydrocolloid scientist. I would argue that some of the book is technically not correct but including a full and comprehensive explanation of certain topics would probably not be justified in the context. Full time hydrocolloids scientists will learn little from this book, full time food scientists having to deal with hydrocolloids will find it very useful.

Details

The book is divided into eight chapters. The first four are all about hydrocolloids and the last four are more application focussed.

The first chapter is very short and covers the absolute basics of what a hydrocolloid is, what it does and how the differences in structures affect some of the properties. This is a useful chapter for someone with no experience in hydrocolloids whatsoever.

The second chapter gives a quick half to one page introduction of each of the most common gums. Each paragraph covers where the gum come from, how it is processed, what the structure is and some of the basic properties. At first I was rather surprised with this chapter as some of the information, particularly on processing, was simplified to the point of being quite misleading about what really happens. But we have to consider the audience, a food technologist doesn't need or even want five pages on processing details and a short sentence giving a rough idea of how the product is made is adequate and appropriate in this case. I was disappointed in some of the comments, for instance to see a comment about how standardisation of gums like carrageenan is necessary to ensure consistency of product. This is a story the industry likes to perpetuate to justify diluting its products, I am sure it was necessary forty years ago but products today are very consistent and its about time these myths were debunked rather than perpetuated. Also the section on konjac completely missed out one of the key functionalities of konjac, its superb synergy with xanthan and carrageenan. However other gums such as HPMC and PGA, which are often ignored, where covered.

Chapter three is all about function. The chapter devotes a considerable amount of time to practical advice on dissolution which will be very useful for those who have little experience of hydrocolloids and is time well spent. Another useful inclusion is a simple table giving some comparative properties of different gums in various environments which will be useful for the novice to decide where to start in a project. The rest of the chapter covers assorted generic properties of different gums including some synergies and the effect of uniformity of substitution. The final paragraph attempts to cover the cost of hydrocolloids, unfortunately this is almost impossible to simplify in a meaningful way and the paragraph ends up telling the reader very little and could easily have been dropped.

Chapter four is very practical and covers various testing methods and some basic rheology. I thought this was well presented, nicely illustrated with copious photographs of the often idiosyncratic gel testing equipment found in the industry. It also explained the basics of rheology in a very easy manner. Rheology is often a scary subject for people and many rheology books do not help by diving straight into mathematics, a guaranteed method of ensuring most readers never reach chapter two! The chapter also provides a section on understanding specifications. I would have liked it to be pointed out that although you might buy a gelling hydrocolloid and it might have a certain specification based on gel strength you cannot take it for granted that the same hydrocolloid from another manufacturer with the same gel strength will work in your product. Product functionality is so much more complex than what is laid out in specifications and at best they help ensure some degree of lot to lot consistency and at worst they are so broad as to be utterly meaningless.

Chapter five is all about choosing the right hydrocolloid for a particular job. This is always a difficult job and the simple tables and decision trees help to point inexperienced people in the right direction. A final paragraph touches briefly on nutrition and mentions the use of gum arabic as a source of soluble fibre. More could have mentioned here as dietary fibre is a growing area for hydrocolloids and there is a range of products apart from gum arabic including inulin, depolymerised guar and larch gum that deserve a mention.

The following chapters start getting down to end use specific areas. The first is dairy products. The chapter rapidly covers a wide range of products with a nice selection of starter recipes for many of the products. I particularly appreciated the fact that the recipes are all vendor neutral. Many of the recommendations are very traditional rather than being the latest or best offering for a product but then these are very much starter recipes. I liked the troubleshooting guide at the back of the chapter and it would be a good place for a young technician to start whose product has some hideous defect.

Chapter seven continues with a mixed chapter on processed fruit, confectionery and beverages. The chapter follows the same layout as the dairy chapter with good, vendor neutral starter recipes and a trouble shooting table at the end.

Chapter eight is a miscellaneous applications chapter, along the same lines as the previous two but picking up other applications including processed meats, syrups, baked goods and salad dressings.