Citrus Peel Flours: From Residues to Bioactive Ingredients for Food Applications

Area of Science:

• Food Science
• Nutritional Biochemistry
• Sustainable Agriculture

Background:

• Citrus fruit consumption generates significant peel waste, posing environmental and economic challenges.
• Valorization of citrus peel bioresidues is crucial for sustainable agri-food systems and circular economy initiatives.

Purpose of the Study:

• To characterize the nutritional, chemical, and bioactive properties of orange, tangerine, lime, and lemon peel flours.
• To evaluate the potential of these flours as functional food ingredients.
• To assess the application of lime flour in a food model for improved preservation.

Main Methods:

• Proximate composition, organic acids, phenolic compounds, fatty acids, and free sugars analysis of citrus peel flours.
• Evaluation of antioxidant, antimicrobial, antiproliferative, and nitric oxide inhibitory activities of flour extracts.
• Incorporation of lime flour into a traditional muffin cake (Madalenas) at 10% and 20% levels to assess its impact on product preservation.

Main Results:

• Lime flour exhibited the highest protein, ash, dietary fiber, and total phenolic content, with hesperidin as the predominant compound.
• Lime flour extracts demonstrated significant antioxidant, antimicrobial, antiproliferative, and nitric oxide inhibitory activities.
• Incorporating lime flour into muffins improved product preservation compared to control and synthetic preservative formulations.

Conclusions:

• Citrus peel flours, particularly lime flour, possess valuable nutritional and bioactive properties, making them suitable as natural functional ingredients.
• Lime flour shows significant potential for enhancing food preservation and can serve as a sustainable alternative in food formulations.
• These findings support the valorization of citrus peel waste, contributing to waste reduction and circular economy principles in the agri-food sector.