Optimization and comparison of non-conventional extraction technologies for Citrus paradisi L. peels: a valorization approach

Abstract

The phenolics from grapefruit peel were obtained by ultrasound assisted extraction (UAE) and enzyme-assisted extraction (EAE). Extraction parameters were optimized using response surface methodology to maximize the yield of total phenolic content (TPC) and total flavonoid content (TFC). The optimized extracts from UAE and EAE were then compared with conventional solvent extraction for their TPC, TFC, antioxidant activity and phenolic composition. The best optimized conditions for UAE was obtained at 33.12 min extraction time, 71.11% amplitude and a solvent-solid (SS) ratio of 39.63 mL/g. The optimized parameters for EAE were 4.81 h extraction time, 0.9% enzyme concentration and 40 mL/g SS ratio. Similar values of experimental and predicted TPC and TFC at optimized conditions indicates the suitability of the quadratic model in optimizing the extraction parameters. Further characterization of extracts suggested EAE as most efficient process in extracting bioactive compounds.

Chemical Composition and Biological Activities of Extracts from Pomelo Peel By-Products under Enzyme and Ultrasound-Assisted Extractions

“…Total phenolic, total flavonoid, naringin, and hesperidin contents of the extracts from pomelo peels were significantly affected by extraction techniques, in which the enzyme treatment had a higher impact than the ultrasound treatment. Nishad et al [13] also reported that EAE was more effective than UAE in extracting bioactive compounds of Citrus paradisi L. peels, similar to the results of this study. e more effective action of enzyme in releasing flavonoid compounds than ultrasonic wave might be due to the selective breakdown of the cell walls by enzyme compared to the random breakdown of cell walls by ultrasound.…”

“…e previous study also reported that the enzymes were used to disrupt the pectin-cellulose complex in citrus peel and released higher flavonoids (naringin) in the extracts [19]. Nishad et al [13] found that the optimized conditions for enzyme-assisted extraction of grapefruit peel were as follows: enzyme concentration of 0.9%, solvent-solid ratio of 40 ml/g, and extraction time of 4.81 h. In this study, the optimal extraction conditions were as follows: enzyme concentration of 2%, water-solid ratio of 40 ml/g, incubation temperature of 50°C, and extraction time of 60 min.…”

“…Likewise, the ultrasound-assisted extraction (UAE) method has been widely used because of its higher extraction efficiency with shorter extraction time compared to traditional methods [12]. Until now, most of the studies on extraction of bioactive compounds from citrus peels used either EAE or UAE technique only [13]. erefore, the objective of this study is to investigate the effects of combined ultrasound and enzyme treatment and vice versa on total flavonoids, naringin, and hesperidin concentration, antioxidant capacity, and antimicrobial activities of extracts from peels of different pomelo species.…”

High Biological Value Compounds Extraction from Citrus Waste with Non-Conventional Methods

“…On the other hand, the range of hesperidin content extract by UAE from grapefruit peel (0.62–1.09 mg/g) samples is consistent with the hesperidin content (0.71 mg/g) reported by Wu et al [ 58 ] from grapefruit peel treated by an ultrasound bath. However, the highest concentration of phenolic compounds, extracted from grapefruit peel ( Citrus paradisi L.) by UAE was published by Nishad et al [ 59 ]. They obtained 2116.71 mg GAE/100 g of TPC and 276.53 mg QE/100 g of TF and observed that TPC was affected ( p < 0.05) mainly by amplitude, simple-solvent ratio, and their interaction.…”

Optimization of Espresso Spent Ground Coffee Waste Extract Preparation and the Influence of its Chemical Composition as an Eco-friendly Corrosion Inhibitor for Carbon Steel in Acid Medium

“…Solid-liquid extraction is the most widely used procedure for the extraction of organic substances in botanical materials due to its easy use, efficiency, and wide range of applicability. 18,19 Different organic solvents and their combination, as well as the combination of organic solvents and water, may be applied. Other factors such as pH, temperature, sample mass, and extraction time may be studied, as well as sequential steps in order to maximize the extraction.…”