Guerra et al. (2011) suggested that, compared to other fruit of similar shape and size, peppers have a high surface area/weight ratio (SA/FW) because the fruit are hollow. Moreover, microscopic observations (Fig. 5) showed that pepper skin, in comparison to apple skin, is non-uniform and porous. Material coatings resulted in surface alignment and smoothing. The coatings adhered well to the external skin surface forming an additional protective layer.