Citrus peels, often regarded as waste products in the food industry, hold significant potential for valorization due to their rich composition of bioactive compounds. The valorization process involves transforming these underutilized by-products into valuable ingredients for various applications, including functional foods, cosmetics, and pharmaceuticals.

This study focuses on the valorization of citrus peels from oranges and lemons to develop functional food products. We conducted a comparative study by incorporating citrus peel powder and carotenoids extracted from these peels into shortbread biscuits, comparing them to synthetic colorants. Our physicochemical analyses revealed that incorporating peel powder enhances the nutritional quality of the biscuits, increasing their content of polyphenols, flavonoids, tannins, and carotenoids. Our results indicated that the biscuit enriched with orange peel powder has a pH of 6.635, DPPH antioxidant activity of 92.59%, and carotenoid content of 1344.76 mg/ml.

Additionally, this research highlights the importance of citrus peels as natural sources of antioxidants, contributing to better human health. The findings also indicate significant potential for creating functional beverages from these by-products, which could reduce agro-industrial waste and promote sustainable resource use. Overall, these efforts pave the way for future research on optimizing processing methods and valorizing citrus peels, with positive implications for both the agro-industry and public health.