Solubilization of Phenols and Sugars from Raspberry Extrudate by Hydrothermal Treatments

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.

Acid Hydrothermal Amendment of Grape Wine Pomace: Enhancement of Phenol and Carbohydrate Co-Solubilization

“…Conversely, for an acid concentration of 5% (v/v), the phenols increased from 554 ± 42 to 1621 ± 102 mg GA/kg GP when the operational temperature was increased from 65 to 95 °C. A similar behavior was described by Cubero-Cardoso et al [24], who reported an increase of around 53% in the total phenols content in the liquid fraction obtained after the hydrothermal The model relating the total soluble phenols to the experimental factors was obtained using Equation (1), where A, B, and C denote time, sulfuric acid, and temperature, respectively (see Supplementary Material, Table S1):…”

“…These values are markedly lower than the inhibition limit described for some bioprocesses such as anaerobic digestion, wherein concentrations of around 2.0 g/L of furfural and HMF are required for the full inhibition of microbial activity [34]. The low concentrations of furfural and HMF observed in the present research are expected since their generation is clearly related to the severity of the treatment applied and, especially, temperatures above 120 • C [24].…”

“…Most of the phenolic compounds in GP are concentrated in the seeds, which means that solubilization is the best method to achieve higher recovery of bioactive compounds [8,21]. Hydrothermal treatments have been widely proposed as a cost-effective option for the solubilization of lignocellulosic substrates [22,23]; however, the application of excessively severe conditions during hydrothermal treatment would entail the degradation of a fraction of the bioactive compounds and sugars in the substrate as well as the appearance of undesirable compounds such as furfural or hydroxymethylfurfural (HMF) [22,24]. These compounds have been reported to be biological inhibitors and thus would hinder the further valorization of the substrate after the recovery of bioactive compounds [25].…”

Effect of acidification and thermal treatment on quality characteristics of high‐moisture laver ( Porphyra spp.)

“…In particular, the content in H group varied greatly, ranging from 71.49 mg/g (at 0 min) to 247.05 mg/g (at 20 min). Cubero‐Cardoso et al (2020) found that during hydrothermal treatment, macromolecules depolymerized at low temperature (below150°C), hemicellulose depolymerized at medium temperature (150–180°C), and shortly thereafter, cellulose and lignin. Therefore, the increase of soluble sugar might be a result of the decomposition of insoluble polysaccharide macromolecules into soluble substances during thermal treatment.…”

Exploring the Biochemical Methane Potential of Wholesale Market Waste from Jordan and Tunisia for a Future Scale-Up of Anaerobic Digestion in Amman and Sfax

“…Total COD was measured on the wet material using the methods described by Trujillo-Reyes et al [19]. To analyze the extractable fraction of the waste mixtures, the method described by Cubero-Cardoso et al [20] was applied, being widely used Lab 3 (Laboratory of wastewater management and treatment technologies, Democritus University of Thrace, Greece)…”