Solubilization of Phenols and Sugars from Raspberry Extrudate by Hydrothermal Treatments

Juan Cubero-Cardoso,Fernando G Fermoso,Ángeles Trujillo-Reyes,Denys Villa-Gomez,Guillermo Rodríguez-Gutiérrez,Rafael Borja,Patricia Marín-Ayllón,Antonio Serrano

doi:10.3390/pr8070842

Juan Cubero-Cardoso, Fernando G Fermoso + Show 6 more

Open Access

https://doi.org/10.3390/pr8070842

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Abstract

Raspberry extrudate residue has bioactive compounds in its matrix that are considered high-added value compounds. In the present study, different hydrothermal treatments were carried out using different operational systems, temperatures and times to solubilize raspberry extrudate in order to obtain these bioactive compounds (i.e., sugars and phenolic compounds). Hydrothermal treatment conditions were assessed in the range of 60 °C to 210 °C, with increments of 30 °C. The hydrothermal treatment at 210 °C for 5 min with direct steam and decompression was the most efficient process based on the solubilization of sugars and phenols, as well as on the antioxidant capacity of the products recovered in the liquid phase after treatment. Under these conditions, the concentration of soluble phenols was more than double the concentration in the raw raspberry extrudate, with more than 5000 mg phenols per kilogram of raspberry extrudate. The obtained values demonstrate the potential of applying this treatment for recovering valuable bioactive compounds from raspberry extrudate.

Highlights

Up to 870,000 tons of raspberries are produced worldwide every year
The high antioxidant capacity of raspberries is related to the presence of major groups of bioactive compounds such as ellagitannins and anthocyanins, while phenolic acids and flavonoids are the minor phenolic constituents [5]
The main objective of this work was to evaluate the hydrothermal treatment using a wide range of temperatures (60–210 ◦ C), to find the optimal conditions for the recovery of high added-value compounds such as phenols from raspberry extrudate

Summary

Introduction

Up to 870,000 tons of raspberries are produced worldwide every year. In Spain, more than43,000 tons of raspberries were produced in 2018 [1]. Several components of raspberries have been found to provide potential health benefits, including cardiovascular, antihypertensive, antioxidant, antiproliferative, and antidiabetic effects [2,3]. The high antioxidant capacity of raspberries is related to the presence of major groups of bioactive compounds such as ellagitannins and anthocyanins, while phenolic acids and flavonoids are the minor phenolic constituents [5]. In addition to their antioxidant capacity, anthocyanins are responsible for the characteristic red color of the raspberry [6]. Raspberries contain a high amount of Processes 2020, 8, 842; doi:10.3390/pr8070842 www.mdpi.com/journal/processes

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