PIERA PERICU*, TAKENORI KASHIMURA
*Corresponding author
Personal Care, Health & Biosciences, IFF, Oegstgeest, the Netherlands

Abstract

Rheological properties play an important role in beauty and personal care formulations. Natural polymers have long been used as rheology, sensory, and texture modifiers. Guar gum is a natural polymer extracted from the endosperm of the Guar bean. It is commonly used as a rheology modifier in the food industry. In this article, we discuss its rheological behaviour and application as a thickener in different types of cosmetic formulations. We also investigate how the synergistic combination of Guar gum and Xanthan gum results in enhanced viscosity. The wide pH range and cationic components compatibility, together with its unique sensory profile, make the underused guar gum a very promising ingredient for the thickening of various beauty and personal-care products.

INTRODUCTION
Rheology modifiers are essential ingredients used in formulating beauty and personal care products.
They alter the rheological behaviour of a finished product to deliver technical and application benefits, including enhanced sensorial and texture properties that improve the consumer experience.

The correlation between rheology modification and aesthetics has been the object of complex studies for decades (1, 2), with the multidisciplinary science of rheology playing a fundamental role in determining key parameters that govern product behaviour. Besides deepening the understanding of such mechanisms and behaviours, the results of these studies show that human touch – specifically via the fingerstips – remains one of the most sophisticated and multi-functional sensory instruments that consumers use to decide which products they like and would repurchase (3).

The term ‘rheology’, originating from the Greek words rhéō (“flow”) and logia (“study of”), was invented by Eugene C. Bingham in the 1920s and is the study of the deformation and flow of matter (4).