Different green extraction technologies for soluble dietary fibre extraction from orange by‐product

Abstract

The aim of this work was to extract soluble dietary fibre from orange by-product, by testing four different green (non-contaminant, solvent free) extraction technologies: hot water (HW), extrusion + hot water (EHW), jet cooker (JC) and jet cooker + hot water (JCHW). Starting from orange pomace, the treatments were assayed and sample was separated in soluble and insoluble fractions. The processing and analysis of the soluble fraction was continued, through subsequent spray drying until obtaining a soluble fibre-enriched powder. Powders were analysed: dietary fibre, sugar profile and bioactive characterisation (total polyphenol content, antioxidant capacity). Through the application of these green technologies, it was possible to obtain a functional ingredient with soluble dietary fibre from orange by-product. EHW was the treatment that yielded the highest amount of soluble dietary fibre, the lowest content of glucose, sucrose and fructose, and the highest polyphenol content and antioxidant capacity.

Sorption Isotherms, Glass Transition and Bioactive Compounds of Ingredients Enriched with Soluble Fibre from Orange Pomace

“…Orange fibre powders were obtained according to Perez-Pirotto et al (2022) [ 18 ]. Four different treatments (hot water extraction—HW; extrusion + hot water extraction—EHW; jet cooker—JC; jet cooker + hot water extraction—JCHW) were assayed on orange pomace to obtain a soluble fibre-enriched powder.…”

“…Powders were kept in laminated bags at room temperature until use. The composition of these powders has been previously studied by Perez-Pirotto et al (2022) [ 18 ]. Briefly, results per 100 g of dry sample were: total dietary fibre (TDF) 9.48 ± 0.45 g in HW, 20.20 ± 3.69 g in EHW, 10.25 ± 0.89 g in JC and 13.03 ± 1.8 in JCHW; total sugars content 64.15 ± 0.2 g in HW, 46.15 ± 0.05 g in EHW, 64.24 ± 0.13 g in JC and 60.37 ± 0.31 g in JCHW.…”

“…Polyphenol content was determined by Folin–Ciocalteu method, as described by [ 18 ]. Briefly, 1.0 mL of extract was mixed with 6 mL of distilled water and 0.5 mL of Folin–Ciocalteu reagent.…”

“…Some of the assayed technologies are high hydrostatic pressures [ 12 ], steam explosion [ 13 ] and ultrasound-assisted extraction [ 14 ]. Work has been also been carried out with extrusion, hot water and steam use through the use of jet cooking [ 15 , 16 , 17 , 18 , 19 ]. After treatments, soluble fibre can be extracted and dried to obtain a powder ingredient that can be used in the formulation of other foods [ 18 ].…”

“…Work has been also been carried out with extrusion, hot water and steam use through the use of jet cooking [ 15 , 16 , 17 , 18 , 19 ]. After treatments, soluble fibre can be extracted and dried to obtain a powder ingredient that can be used in the formulation of other foods [ 18 ].…”