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Worldwide, approaches inspired by the Circular Economy model have been increasing steadily, generating new business opportunities such as the recovery of high‐added value molecules (e.g., pigments) from vegetable food waste that may be applied as food additives (e.g., colorants). Indeed, food waste is a global problem that does not seem to be decreasing, leading to economic, environmental, and social issues. Moreover, synthetic dyes have been associated with adverse effects on human health, encouraging research to explore much safer, natural, and eco‐friendly pigments. This state‐of‐the‐art review gives a brief overview of the regulatory aspects concerning food waste, Circular Economy, and natural versus synthetic colorants. We have critically reviewed the recent advances in pigment recovery from vegetable food waste bringing back the green/unconventional extraction methods. Among them, enzyme‐assisted extraction as a depth feature technique is highlighted, given that it allows the recovery of pigments in a mild, selective, efficient, and sustainable way. Furthermore, the stability issue of the different natural colorants has been critically discussed in relation to the extraction and application conditions. Several and tailored stabilization methods have been described and reported for each pigment although additional research is necessary on their long‐lasting stabilization and utilization in food matrices. Practical Application This review focuses on the main types of natural pigments in vegetable food waste, their legislative framework, extraction technologies and strategies to improve the stability , as well as their possible applications.

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In this paper, we describe the development of an efficient enzyme immobilization procedure based on the activation of epoxy carriers with glucosamine. This approach aims at both creating a hydrophilic microenvironment surrounding the biocatalyst and introducing a spacer bearing an aldehyde group for covalent attachment. First, the immobilization study was carried out using penicillin G acylase (PGA) from Escherichia coli as a model enzyme. PGA immobilized on glucosamine activated supports has been compared with enzyme derivatives obtained by direct immobilization on the same non-modified carriers, in the synthesis of different 3′-functionalized cephalosporins. The derivatives prepared by immobilization of PGA on the glucosamine-carriers performed better than those prepared using the unmodified carriers (i.e., 90% versus 79% cefazolin conversion). The same immobilization method has been then applied to the immobilization of two other hydrolases (neutral protease from Bacillus subtilis, PN, and bromelain from pineapple stem, BR) and one transferase (γ-glutamyl transpeptidase from Bacillus subtilis, GGT). Immobilized PN and BR have been exploited in the synthesis of modified nucleosides and in a bench-scale packed-bed reactor for the protein stabilization of a Sauvignon blanc wine, respectively. In addition, in these cases, the new enzyme derivatives provided improved results compared to those previously described.