However, most of the available analytical methods index the damage to the cuticle,
while the damage to the inner mass (cortex), particularly at the molecular level, remains largely not investigated. From this angle, the positron method utilizes positronium as its de- fect probe, which due to its small size (2 Å) and penetrability can directly characterize the microstructural damage to the cortex re- gion. This special feature of PALS technique, exploited in this study, could be the basis for an important and unique method of product testing and evaluation in the cosmetic industry.