Impact of extraction parameters and their optimization on the nutraceuticals and antioxidant properties of aqueous extract mulberry leaf

Abstract

An investigation into the efficient use of water as a solvent and the influence of extraction temperature, extraction time, water to leaf powder ratio, particle size, and extraction cycle on the nutraceutical and antioxidant profile of aqueous mulberry leaf extract were conducted using a single-factor experiment approach. All the assessed extracting parameters showed a significant effect on the nutraceutical compounds and antioxidant properties. The optimum extraction conditions were as follows: extraction temperature of 70°C, extraction time of 40 min, water to leaf powder ratio of 40:1 ml/g, particle size of 25 µm, and two extraction cycles. Based on these optimal conditions, chlorogenic acid (62.10 mg/g), caffeic acid (32.21 mg/g), kaempferol-7-O-glucoside (19.30 mg/g), quercetin-3-rutinose (15.69 mg/g), quercetin-3-O-glucoside (32.38 mg/g), kaempferol-3-(6-rhamnosylglucoside) (42.52 mg/g), quercetin-3-(6-malonylglucoside) (65.19 mg/g), kaempferol-3-glucoside (66.27 mg/g), kaempferol-3-(6-malonylglucoside) (50.18 mg/g), 1-deoxynojirimycin (15.58 mg/g), and gamma-aminobutyric acid (5.05 mg/g) were obtained. The optimal aqueous extract had high antioxidant properties of 2,2-azino-bis-3ethylbenzothiazoline-6-sulfonic acid (39.98 mM/g), cupric ion reducing capacity (58.93 mM/g), 1,1-diphenyl-2-picrylhydrazyl (101.33 mM/g), and ferric reducing antioxidant power capacity (233.77 mM/g) of dried mulberry leaf extract.

Optimization of the Extraction of Bioactive Compounds from Walnut (Juglans major 209 x Juglans regia) Leaves: Antioxidant Capacity and Phenolic Profile

“…On the other hand, the extract FRAP antioxidant activity increased with decreasing the S/L ratio in the whole range analyzed. These results were in agreement with previous research on the extraction of phenolic compounds from various plant materials [7,16,17] and can be explained by analyzing the concentration gradient of phenolics between walnut leaves and the solvent. The lower the S/L ratio, the greater the concentration gradient and consequently the extraction rate.…”

“…Finally, 120 min was the selected time to favor the extraction yield, as its influence on antioxidant properties was almost negligible. Longer extraction times were not proposed since the effects were the same as those previously indicated for high temperatures [17].…”

“…Concerning extraction temperature, a temperature rise of up to 75 • C increased the extraction yield as the extraction process was favored by temperature as the solubility of phenolic compounds and the mass transfer rate were enhanced [22]. Moreover, FRAP, DPPH, and ABTS antioxidant activity of the extracts also increased with increasing extraction temperature to 75 • C. However, greater extraction temperatures were not recommended as oxidation, epimerization, and degradation of phenolic compounds was promoted [17] with the consequent decrease of the extract antioxidant activity. Therefore, 75 • C was selected as the optimum temperature.…”

Carrier Effects on the Chemical and Physical Properties of Freeze-Dried Encapsulated Mulberry Leaf Extract Powder

“…The extraction of nutraceutical compounds was conducted following the methodology described by Tchabo et al 16 using a two-step extraction. Concisely, the fresh leaf was lyophilized (48 h, -60 °C, 0.02 mbar, FD-1A-50, Boyikang Laboratory Instruments, Beijing, China) and powdered using a jet miller (0101S Jet-O-Mizer Milling, Fluid Energy Processing and Equipment Company, Telford, USA).…”

Vegetable Additives in Food Packaging Polymeric Materials

“…These polyphenols could be incorporated [234] within a film or coating applied to the food [235], which could release the antioxidant into the product or act on its surface, limiting the oxidative reactions of food components [236]. Aromatic herbs containing polyphenols have been traditionally used as healthy food ingredients [237][238][239][240] obtained through an aqueous extraction [241,242] process.…”