Review Insights on the Demand for Natural Pigments and Their Recovery by Emerging Microwave-Assisted Extraction (MAE)

Abstract

The current trend of shifting to food naturalness has prompted food industries to switch from synthetic to natural colorants. Concurrently, there is a spike in interest concerning the extraction of pigments from natural sources using non-conventional extraction techniques as the latter are environmental-friendly and sustainable compared to traditional methods. Microwave-assisted extraction (MAE) is one of the emerging technologies that has been reported to be effective in the recovery of bioactive compounds from a plethora of natural sources because of its ability to expeditiously heat the extraction matrix, leading to rapid product recovery. This review focuses on the voluminous demand for natural colorants, their limitations, and potential food applications. Also, this review emphasizes the underlying principle and mechanism of MAE, as well as studies that unveil the efficacy and suitability of the technique for the recovery of pigments. Hence, given that natural pigments are susceptible to natural degradation, MAE is a promising technology for enhanced pigment yield and stability. In addition, recent trends such as technology integration and novel extraction solvents have considerably widened the scope and versatility of MAE as a greener extraction method. Furthermore, when coupled with MAE, waste valorization and further exploration of novel pigment sources (such as algae and other microorganisms) present thrust areas of research concerning the global sustainable development goals (SDGs).