CASPAR VAN LEEUWEN, PATRICK ZWAMBORN,
WILLEM VAN RIJSWIJK
Center For Testmaterials BV. Stoomloggerweg 11,
3133 KT Vlaardingen, The Netherlands

Abstract

In recent years, new enzyme generations have been introduced to the detergent market. Fatty stains are always interesting since they are consumer-relevant.
To help remove these fatty stains, improved Lipases have been developed and introduced.
Recently we have received an increasing number of enquiries about the fat and the dye levels used in our range of Commercial Testmaterials. The current fat and dye levels in the Commercial Testmaterials are concentrations determined in earlier studies based on previous generations of Lipase enzymes. In the past, the Lipase effect on testmaterials was relatively low, so it was quite difficult to determine what would be the optimum levels of fats and dyes in our testmaterials. The new Lipase might yield more measurable effects on testmaterials. This would enable us to investigate more fully the effects of fat levels and dye levels on testmaterials’ sensitivity to Lipase, and thus allows to offer an improved range of testmaterials to our customers.
For publication reason this article is intentionally split into three different papers. Part one addresses the method, dye information, results and conclusions of research hypotheses 1 and 2 (The new generation of Lipase is one of the enzymes to consider when it comes to improved wash performance; . Fatty stains are more responsive to Lipase activity when they are washed with powder detergent than with liquid detergent.) Part two considers hypothesis 3 and 4 (Fatty stains on knitted cotton are more responsive to Lipase activity than fatty stains on woven cotton; Reduced dye levels in testmaterials lead to a better Dynamic Range).
Part three revolves around the remaining results and conclusions regarding hypothesis 5 and 6. (Reduced fat levels in testmaterials lead to a better Dynamic Range;. Different groups of fatty stains react differently to Lipase activity).

INTRODUCTION

This research investigates the responsiveness of testmaterials to the new generation of Lipase enzymes. It also explores several "recipe" changes which might improve responsiveness to Lipase.

A range of Standardized Testmaterials and Circular Stains was selected on the basis of previous research results and knowledge gained from many years of experience. A total of 74 testmaterials were examined, including 23 readily available Commercial Testmaterials and 51 new Experimental Testmaterials which were specially developed for this research.

These testmaterials comprise five groups of comparable fatty stains which are both common in reality and often used as testmaterials. The research was thus able to investigate which Standardized Testmaterials and Circular Stains had the best Lipase responsiveness within these five groups:

• Vegetable Oils/Fats
• Butter Fat
• Beef Fat
• Lard
• Lipstick

Responsiveness to Lipase was quantified by measuring the ? Reflectance (?R) at 460nm for (a) no, (b) low, (c) medium and (d) high dosages of Lipase, tested at 25°C both with powder referen ...