Valorização sustentável da casca da pitaia (hylocereus undatus) via extração e hidrólise em água subcrítica para recuperar produtos de alto valor agregado

Author(s)

Vanessa Cosme Ferreira

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos
• Defense date: 2024-08-05

Examining board members

Tânia Forster Carneiro; Mauro Donizati Berni; Aline Priscilla Gomes da Silva

• Advisor: Leda Maria Saragiotto Colpini; Tânia Forster Carneiro

Abstract

The pitaya ("Hylocereus" spp.) is a fruit with great potential for the production of foods such as jam, yogurt, and wine. However, up to 40% of the fruit becomes by-products during agro-industrial processing. Reusing these residues is an alternative to minimize the negative environmental effects, as well as to promote economic gains, since many of these residues can be used as sustainable raw material for the production of high-value-added compounds. The objective of this study was to evaluate the use of a semi-continuous high-pressure hydrothermal process for the recovery of value-added products from pitaya peel. The experimental assay used the hydrothermal process at a pressure of 15 MPa, a water flow rate of 2 mL/min, and temperatures ranging from 40 to 210 °C. A bibliometric analysis was carried out of studies over the last 22 years to identify the areas and studies carried out on pitaya. The results of the review and bibliometric analysis show gaps in research progress, trends, and perspectives on the application of pitaya by-products for the recovery of value-added products using sustainable processes. The main research field identified was the extraction of bioactive compounds, with betacyanin being the major bioactive compound extracted from pitaya, followed by anthocyanins, flavonoids, and flavones. The results also indicate that pitaya and its by-products have applications as dyes, and there is a trend in the use of sustainable extraction techniques (microwaves, ultrasound, pressurized liquids, and supercritical fluids) for the valorization of pitaya peel. The results of the experiment with the hydrothermal process show that extraction temperatures between 40 and 80 °C promoted the recovery of betacyanin (1.52 mg/g), malic acid (25.6 mg/g), and citric acid (25.98 mg/g). The main phenolic compounds obtained were p-coumaric acid (17.95 µg/mL), protocatechuic acid (11.43 µg/mL), and piperonylic acid (9.27 µg/mL). Hydrolysis temperatures between 150 and 210 °C produced sugars, while temperatures above 180 °C generated Maillard reaction products, increasing the total phenolic compounds and antioxidant activity of the hydrolysates. It is concluded that the semi-continuous high-pressure hydrothermal process proves to be a promising and sustainable approach for the recovery of valuable compounds from pitaya peel, supporting the circular economy in the agro-food industry (AU)

• FAPESP's process: 22/02305-2 - Evaluation of subcritical water hydrolysis in an automated reactor with in-line analysis of compounds with higher added value from pitaya peels (Hylocereus undatus)
• Grantee: Vanessa Cosme Ferreira
• Support Opportunities: Scholarships in Brazil - Master