Rapid Solid-Liquid Dynamic Extraction (RSLDE): a New Rapid and Greener Method for Extracting Two Steviol Glycosides (Stevioside and Rebaudioside A) from Stevia Leaves

Abstract

Stevioside and rebaudioside A are the main diterpene glycosides present in the leaves of the Stevia rebaudiana plant, which is used in the production of foods and low-calorie beverages. The difficulties associated with their extraction and purification are currently a problem for the food processing industries. The objective of this study was to develop an effective and economically viable method to obtain a high-quality product while trying to overcome the disadvantages derived from the conventional transformation processes. For this reason, extractions were carried out using a conventional maceration (CM) and a cyclically pressurized extraction known as rapid solid-liquid dynamic extraction (RSLDE) by the Naviglio extractor (NE). After only 20 min of extraction using the NE, a quantity of rebaudioside A and stevioside equal to 1197.8 and 413.6 mg/L was obtained, respectively, while for the CM, the optimum time was 90 min. From the results, it can be stated that the extraction process by NE and its subsequent purification developed in this study is a simple, economical, environmentally friendly method for producing steviol glycosides. Therefore, this method constitutes a valid alternative to conventional extraction by reducing the extraction time and the consumption of toxic solvents and favouring the use of the extracted metabolites as food additives and/or nutraceuticals. As an added value and of local interest, the experiment was carried out on stevia leaves from the Benevento area (Italy), where a high content of rebaudioside A was observed, which exhibits a sweet taste compared to stevioside, which has a significant bitter aftertaste.

Fatty Acids from Paracentrotus lividus Sea Urchin Shells Obtained via Rapid Solid Liquid Dynamic Extraction (RSLDE)

“…The extracts analyzed in the present work were obtained by rapid solid liquid dynamic extraction (RSLDE), a convenient extractive technique which is easy to implement on the base of automated devices and does not require special expertise [12][13][14]. Contrary to previous studies conducted on red (Strongylocentrotus franciscanus) and green (S. droebachiensis) sea urchins using different hard strategies to obtain extracts [39,40], RSLDE allowed us to investigate the composition of shells without using a high volume of acidic solvents.…”

“…The aim of this study is to obtain extracts of P. lividus shells using the rapid solid liquid dynamic extraction (RSLDE) implemented via Naviglio Extractor®, as this technique has already successfully applied in the pharmaceutical, cosmetic, herbal, food and beverage fields [9][10][11][12][13][14][15]. Here we present our results on the qualitative and quantitative analysis via gas chromatography-mass spectrometry (GC-MS) of lipophilic components of the crude extract.…”

Allium ursinum and Allium oschaninii against Klebsiella pneumoniae and Candida albicans Mono- and Polymicrobic Biofilms in In Vitro Static and Dynamic Models

“…The initial concentration of 500 µg/mL was then diluted with sterile distilled water to get concentrations of 5-250 µg/mL, for subsequent uses [30,31].…”

Chemical Composition and Antioxidant Activity of Thyme, Hemp and Coriander Extracts: A Comparison Study of Maceration, Soxhlet, UAE and RSLDE Techniques

“…Scientific literature presents several works about RSLDE comparison with other extraction techniques. However, few records of this comparison are aimed at food preservation [ 16 , 17 , 18 , 19 ]. The present work focuses on the comparison of different conventional and unconventional extraction techniques (maceration, Soxhlet, UAE, and RSLDE), to obtain extracts suitable for food preservation.…”