Reuse of food residues: Development and characterization of tangerine peel flour (Citrus reticulata)

Abstract

Many studies have been using fruit by-products (seeds, pomace, and peels) for the production of flours in order to sustainably take advantage of these parts that are usually neglected. The current study aimed to elaborate flour from the tangerine peel (TPF) and evaluate its properties such as physical-chemical, microbiological, phenolic compounds, and antioxidant activity. Moisture, carbohydrates, proteins, lipids, total minerals, and fibers were analyzed. The carried out microbiological analyzes were of molds, yeasts, Escherichia coli, Bacillus cereus and Salmonella spp. All analyzes were determined according to official methods. The flour showed moisture content within the values established by the current standard (6.86%), and low water activity (0.484). The microbiological results were in accordance with the criteria established by Brazilian legislation in the three evaluated times (0, 30, and 90 days). FCT showed a high content of dietary fiber (47.17%), total phenolic compounds (1389.99 mg GAE 100 g^-1), and antioxidant activity (DPPH: 12.054.37 µM trolox g^-1, ABTS: 84.62 µM trolox g^-1 and FRAP: 151.68 µM ferrous sulfate g^-1). It’s concluded that tangerine peel flour had a nutrient content that makes it possible to use it in food products since it has a high content of dietary fiber and phenolic compounds with antioxidant activity and has been shown to be safe from microbiological requirements throughout the study period.