Development of biohybrid materials based on a synthetic nanoclay and chlorophylls from agri-food waste

Cucumber peel has high amounts of chlorophylls (Chl), a natural pigment with potential application as a food colorant. However, the valorization of this agri-food waste has been little explored. The present work aims to study the adsorption process of Chl from cucumber peel juices using a nanoclay (Laponite®, Lap), as well as to characterize some physicochemical of the organoclay based on Chl and Lap after the adsorption process, and to evaluate the thermal stability. Chl from acidified juice (pH = 1) were completely recovered using Lap at 20 °C. After Chl adsorption, the organoclay had a yellow color and amorphous structure. X-ray diffractograms suggest that Chl were adsorbed between the Lap layers. Yellow color in the biohybrid material (BH) suggests the pheophytinization of Clh in acid pH. The BH color remained stable at different temperatures and it could be used as a colorant in food and nonfood applications. The current research reports new information about the valorization and application of Chl from cucumber peel for the food sector.