Full utilization of the yellow passion fruit peel: Chemical characterization and valorization to reduce biomass waste

The yellow passion fruit is a well-known fruit worldwide and Brazil is one of its largest producers, mainly of the juice generated from the pulp. This production feeds thousands of people every year and contributes to a significant portion of the country's economic movement. Regarding this production, large amounts of waste are generated from the disposal of passion fruit peels, which causes serious environmental problems. The objective of the present study was to chemically characterize the yellow passion fruit peel before (flour) and after (residue) pectin extraction. Acid extraction of pectin, acid hydrolysis of flour and analysis by high-performance liquid chromatography (HPLC) were carried out to obtain the chemical content of the yellow passion fruit peel. The results showed that the mass balance of yellow passion fruit flour is close to 100% and has significant amounts of cellulose and hemicellulose (around 50% and 20% respectively), which can be used for several purposes. Furthermore, the residue generated (after pectin extraction) also presents cellulose (13%) and hemicellulose (1%), confirming the excellent nutritional value of the whole biomass. Additionally, the amount of pectin found in the present work places the yellow passion fruit as an important source of this polysaccharide and directs it to the industrial use of compounds that require a gelling structure in the composition of the product. Therefore, the present study represents an important starting point for the use of the chemical content of yellow passion fruit residues to produce several compounds of industrial interest, as well as the minimization of the environmental damage that occurs with the disposal of the peels.