Effect of pulsed electric fields pretreatment on juice expression and quality of chicory

The Impact of Thermal and Electrical Pretreatments and Antibrowning Solution on the Chlorogenic and Dicaffeoylquinic Acid Extraction Yield from Endive Roots

Forced endive roots (FERs) contain beneficial antioxidant compounds such as chlorogenic acid (5-CQA) and dicaffeoylquinic acids (diCQAs). This study compared the extraction yields of 5-CQA and diCQAs using a biomass pressing method with various pretreatments, including pulsed electric field (PEF) and microwave (MW), against the solid-liquid extraction method (water, 90 °C, 30 min). The results indicated that the MW pretreatment achieved the highest yields, extracting 28 ± 2% of 5-CQA and 13 ± 1% of diCQAs, surpassing the solid-liquid method. Furthermore, the oxidative degradation of CQAs was studied, and it appeared that this reaction was enhanced by PEF pretreatment. An antibrowning solution (ABS) was successfully tested to reduce this oxidation and protect CQAs. An extraction process utilizing MW and PEF pretreatments combined with an ABS solution achieved yields of 65 ± 1% for diCQAs and 80 ± 5% for 5-CQA, significantly outperforming the solid-liquid extraction method.

Comparative analysis of extraction technologies for plant extracts and absolutes

Plant extracts and absolutes have high application value in several industries such as medicine, food, and fragrance. Especially in the field of fragrance, while there is expensive, they are prized by perfumers and provide a rich and lasting aroma. Owing to advancements in extraction technology, their yields have increased and their ingredients have become richer. However, no extraction technology is universal and each extraction technology has its own distinct advantages and disadvantages. Therefore, this review systematically characterizes the extraction technologies for plant extracts and absolutes, including traditional extraction technologies, such as maceration, percolation, reflux, and Soxhlet extraction, and green extraction technologies, such as microwave-assisted, ultrasonic-assisted, pressurized liquid, and supercritical fluid extractions. These extraction technologies are analyzed and compared in terms of their principles, advantages and disadvantages, improvement solutions, and applications. In addition, this review summarizes and compares new green extraction solvents and discusses the practical applications of these advanced extraction methods and solvents from different perspectives.

Pulsed Electric Field-Assisted Extraction of Inulin from Ecuadorian Cabuya (Agave americana)

Inulin is a carbohydrate that belongs to fructans; due to its health benefits, it is widely used in the food and pharmaceutical industries. In this research, cabuya (Agave americana) was employed to obtain inulin by pulsed electric field-assisted extraction (PEFAE) and FTIR analysis confirmed its presence. The influence of PEFAE operating parameters, namely, electric field strength (1, 3 and 5 kV/cm), pulse duration (0.1, 0.2 and 0.5 ms), number of pulses (10,000, 20,000 and 40,000) and work cycle (20, 50 and 80%) on the permeabilization index and energy expenditure were tested. Also, once the operating conditions for PEFAE were set, the temperature for conventional extraction (CE) and PEFAE were defined by comparing extraction kinetics. The cabuya meristem slices were exposed to PEFAE to obtain extracts that were quantified, purified and concentrated. The inulin was isolated by fractional precipitation with ethanol to be characterized. The highest permeabilization index and the lowest energy consumption were reached at 5 kV/cm, 0.5 ms, 10,000 pulses and 20%. The same extraction yield and approximately the same amount of inulin were obtained by PEFAE at 60 °C compared to CE at 80 °C. Despite, the lower amount of inulin obtained by PEFAE in comparison to CE, its quality was better because it is mainly constituted of inulin of high average polymerization degree with more than 38 fructose units. In addition, TGA analyses showed that inulin obtained by PEFAE has a lower thermal degradation rate than the obtained by CE and to the standard.

Electrodialysis Tartrate Stabilization of Wine Materials: Fouling and a New Approach to the Cleaning of Aliphatic Anion-Exchange Membranes

Electrodialysis (ED) is an attractive method of tartrate stabilization of wine due to its rapidity and reagentlessness. At the same time, fouling of ion-exchange membranes by the components of wine materials is still an unsolved problem. The effect of ethanol, polyphenols (mainly anthocyanins and proanthocyanidins) and saccharides (fructose) on the fouling of aliphatic ion-exchange membranes CJMA-6 and CJMC-5 (manufactured by Hefei Chemjoy Polymer Materials Co. Ltd., Hefei, China) was analyzed using model solutions. It was shown that the mechanism and consequences of fouling are different in the absence of an electric field and during electrodialysis. In particular, a layer of colloidal particles is deposited on the surface of the CJMA-6 anion-exchange membrane in underlimiting current modes. Its thickness increases with increasing current density, apparently due to the implementation of a trap mechanism involving tartaric acid anions, as well as protons, which are products of water splitting and "acid dissociation". A successful attempt was made to clean CJMA-6 in operando by pumping a water-alcohol solution of KCl through the desalination compartment and changing electric field direction. It has been established that such a cleaning process suppresses the subsequent biofouling of ion-exchange membranes. In addition, selective recovery of polyphenols with high antioxidant activity is possible.