Green Extraction Approaches for Carotenoids and Esters: Characterization of Native Composition from Orange Peel

Abstract

Orange peel is a by-product produced in large amounts that acts as a source of natural pigments such as carotenoids. Xanthophylls, the main carotenoid class found in citrus fruit, can be present in its free form or esterified with fatty acids, forming esters. This esterification modifies the compound’s chemical properties, affecting their bioavailability in the human body, and making it important to characterize the native carotenoid composition of food matrices. We aimed to evaluate the non-saponified carotenoid extracts of orange peel (cv. Pera) obtained using alternative green approaches: extraction with ionic liquid (IL), analyzed by high performance liquid chromatography coupled to a diode array detector with atmospheric pressure chemical ionization and mass spectrometry HPLC-DAD-APCI-MS, and supercritical fluid extraction (SFE), followed by supercritical fluid chromatography with atmospheric pressure chemical ionization and triple quadrupole mass spectrometry detection (SFC-APCI/QqQ/MS) in an online system. Both alternative green methods were successfully applied, allowing the total identification of five free carotenoids, one apocarotenoid, seven monoesters, and 11 diesters in the extract obtained with IL and analyzed by HPLC-DAD-APCI-MS, and nine free carotenoids, six carotenoids esters, 19 apocarotenoids, and eight apo-esters with the SFE-SFC-APCI/QqQ/MS approach, including several free apocarotenoids and apocarotenoid esters identified for the first time in oranges, and particularly in the Pera variety, which could be used as a fruit authenticity parameter.

Bioactive Compounds of Citrus Fruits: A Review of Composition and Health Benefits of Carotenoids, Flavonoids, Limonoids, and Terpenes

“…A significant amount of research has been conducted to recover the commercially vital compounds from citrus fruit pomace [ 60 , 61 , 62 ]. Citrus peel is a rich source of essential oils [ 63 ], carotenoids [ 64 , 65 , 66 ], pectin [ 67 , 68 ], flavonoids [ 69 , 70 , 71 ], and several other bioactive components with excellent antioxidant [ 69 ] and health-promoting potential [ 62 , 72 , 73 , 74 ]. Among the flavonoids, hesperidin, naringin, rutin, and neohesperidin are the major flavonoids found in the peel of citrus fruits [ 71 , 74 ], with especially high amounts in mandarins, which exhibit high antioxidant potency [ 71 ].…”

Red Propolis as a Source of Antimicrobial Phytochemicals: Extraction Using High-Performance Alternative Solvents

“…The extraction processes using hydrophobic IL [C 6 mim]Cl proved to be selective for more hydrophobic flavonoids (medicarpin). Thus, the higher hydrophobicity of the IL implies the extraction of the most hydrophobic components of the biomass because of the π–π, n–π, and hydrophobic bonds ( de Souza Mesquita et al, 2019 ; Murador et al, 2019b ).…”

“…The non-volatile and flammability suggest that these compounds are an essential alternative in developing new extractive processes ( Nam et al, 2015 ). Ionic liquid, for example, can assume several properties, it has been applied to obtain several molecules with different polarities, such as carotenoids (hydrophobic compounds; Xiao et al, 2018 ; de Souza Mesquita et al, 2019 , 2020a , b ; Murador et al, 2019a , b ), as well as flavanones (hydrophilic compounds), depending on the ionic composition ( Xiao et al, 2018 ). Another advantage of IL is the possibility to recycle and reuse, thus contributing to a low carbon footprint in the process ( de Souza Mesquita et al, 2019 , 2020a , b ).…”

Current Panorama, Practice Gaps, and Recommendations to Accelerate the Transition to a Circular Bioeconomy in Latin America and the Caribbean

“…On the innovation to reduce the use of toxic chemicals, one can point out the extraction of carotenoids from orange peel (waste from the orange juice manufacturing process) through a process without the use of toxic components (which are part of standard practices) [68].…”