Stevioside: Technology, Applications and Health by Sirshendu De, Sourav Mondal, and Survrajit Banerjee. Chichester, United Kingdom: John Wiley & Sons, Ltd.; 2013. Hardcover, 240 pages. ISBN: 978-1-118-35066-9. $199.95.

Sweeteners derived from Stevia rebaudiana (Asteraceae) have been of much interest due to several widespread approvals in the last decade. According to the preface, the book Stevioside: Technology, Applications and Health “covers the state of the art of stevioside extraction with an emphasis on membrane technology.... [T]he book also presents an account of the history, medicinal values, and other applications in some detail.” The authors are a chemical engineering professor, Sirshendu De, PhD, who has considerable experience in membrane filtration technology, and two graduate students, Sourav Mondal and Suvrajit Banerjee.

As one may expect based on the experience of the authors, the book focuses on membrane filtration of stevia extracts; in fact, six of the 10 chapters are dedicated to this topic. The other chapters include an overview on stevia, a review of biological effects, applications, and extraction processes other than those using filtration. As a text on lab-scale filtration of stevia, this book does provide a detailed review. At times, Stevioside reads more as a journal article in this regard, giving details such as which company provided the membranes used. Due to the sparse citations in these sections, it would seem that great swaths of the filtration chapters are excised from a few manuscripts.

While the text shows evidence of scientific authority on membrane filtration technology, the background on stevia is a bit outdated. For example, in the “list of all the chemical constituents of S. rebaudiana” provided in this book, except for the pigments mentioned, the most recent reference given is from 1988. Consequently, the aforementioned table names only eight ent-kaurane diterpenoids from S. rebaudiana, while a recent review by Ceunen and Geuns lists 35.¹

A continual issue with the text is the stated focus on stevioside. In truth, the text alternates focus among stevia extract, steviol glycosides in general, and stevioside specifically. On occasion, it seems that these terms are used interchangeably or that stevioside is forced into the text. For example, the statement is made that “stevioside and Stevia extract can be used for the treatment of diabetic patients,” referencing an article by Renwick and Molinary from 2010.² The cited review article does not mention any studies involving purified stevioside; however, a human study with rebaudioside A and a rat study with stevia extract are discussed briefly. This is a common theme in the chapter covering health benefits of steviol glycosides, where claimed biological effects are overstated relative to the cited work — most frequently manifested by representing in vitro or animal studies as activity in humans.

Unfortunately, there are several instances of this text making bold claims in the absence of any references. The text sometimes reads as a polemic against the use of organic solvents in stevia refining. Water-based extraction techniques are touted as “health friendly” and using “no chemicals,” while solvents are called “toxic chemicals which may be deleterious to health.” Perhaps the most egregious example is that calcium chloride is called a “toxic chemical.” According to the US Food and Drug Administration’s Select Committee on GRAS Substances, there is “no evidence in the available information on calcium acetate, calcium chloride, calcium gluconate, and calcium phytate that demonstrates, or suggests reasonable grounds to suspect, a hazard to the public when they are used at levels that are now current or that might reasonably be expected in the future.”³ Additionally, stevia is touted as “the world’s only natural [no calorie] sweetener,” a statement inconsistent with the substantial literature on natural high potency sweeteners in general; and the growing use of monk fruit (Siraitia grosvenorii, Cucurbitaceae, syn. Momordica grosvenorii)-based sweeteners in particular.

Overall, as a source of information on membrane filtration techniques possible for the preparation of refined stevia extracts, this text is satisfactory. However, given the bias against other extraction techniques and the reliance on laboratory scale equipment, the “state of the art of stevioside extraction” is not fully covered. This book could be used as a reference for those wishing to learn more about membrane filtration of stevia extract, and functions quite well as a collection of membrane filtration experiments on stevia extract with theoretical background. However, those wishing to learn about stevia-based sweeteners or stevioside should look elsewhere.

—Joshua N. Fletcher, PhD Research Scientist Tate and Lyle PLC Hoffman Estates, Illinois

References

1. Ceunen S, Geuns JMC. Steviol glycosides: chemical diversity, metabolism, and function. J Nat Prod. 2013;76:1201-1228.
2. Renwick AG, Molinary SV. Sweet-taste receptors, low-energy sweeteners, glucose absorption and insulin release. Br J Nutr. 2010;104:1415-1420.
3. Database of Select Committee on GRAS Substances (SCOGS) Reviews. Calcium chloride. US Food and Drug Administration website. Available at: www.accessdata.fda.gov/scripts/fcn/fcnDetailNavigation.cfm?rpt=scogslisting&id=47. Accessed August 18, 2014. Accessed August 29, 2014.