Valorisation and sensory evaluation of natural colorants for a sustainable food supply

Abstract

The study explored the potential of several typical Tunisian food plants as sources of natural colorings, focusing on sustainability and ecology. Five common fruits and vegetables were studied: spinach, beetroot, red cabbage, carrot, and turmeric. Their deep pigments, affected by pH, were examined. Red cabbage was found to be the richest in condensed tannins, while turmeric contained the highest levels of anthocyanins. These natural colorings were then incorporated into the formulation of two bakery products, one sweet and the other savory, to give an attractive appearance and stimulate the appetite, as the food industry commonly does with synthetic colorings. Additionally, orange and lemon peels were upcycled by extracting essential oils for analysis. The primary findings indicate that these essential oils are complicated blends of many substances, with monoterpenes and sesquiterpenes being the most prevalent. The last part of this project required using gluten-free flour to make two food products (zouza and ravioli dough), substituting fructose for sucrose, and adding other colorings that had been produced and tested. We also improved the flavor by adding essential oils. Sensory research with sixty unsuspecting panelists revealed that our items were well-liked by all. The result of a very successful initiative is the packaging for these goods and the market research that went into it.