Incorporation of white tea extract in nano‐liposomes: optimization, characterization, and stability

Abstract

BACKGROUND: In the present study, an extraction method affected by sonication intensity (40%, 70% and 100%), sonication time (5, 10 and 15 min) and different solvents (ethanol, methanol and a combination of ethanol/methanol) was optimized to extract the white tea with the greatest polyphenolic compounds using a response surface methodology. To prepare the nano-liposomal vesicles, phospholipids and cholesterol in various proportions (60:0, 40:20, 30:30 and 20:40) were applied based on thin-film hydration and ultrasound method. The nano-capsules enriched in bioactive compounds were examined through particle characteristics, encapsulation efficiency, morphological analysis, thermal properties and Fourier transform infrared spectroscopy. RESULTS:The observations showed that the extraction yield highly depended on the type of solvent with varying permeability, sonication time and power. The highest total phenolic content (68.38 mg GA g -1 ) and free radical scavenging activity (77.65%) were observed for the following optimal conditions: 70% for sonication intensity, 15 min for sonication time and methanol as solvent. Characteristics of nanoliposomes within a compositional ratio of lecithin/cholesterol (40:20) and with a zeta potential of −56 ± 0.01 mV, as well as white tea extract (WTE) samples with an average particle diameter of 82.20 ± 0.08, microencapsulation efficiency of 76.5% ± 0.081, polydispersity index of 0.06 ± 0.02 and span value of 0.69 ± 0.03. are used as the optimal formulation for microencapsulation of antioxidant WTE. The results demonstrated an increment in thermal stability of liposomal WTE samples compared to other samples. CONCLUSION:The findings of the present study indicated that nano-liposomes comprise an effective technology for coating the WTE, as well as to increasing its stability and thermal properties.

Processing Technologies for the Extraction of Value-Added Bioactive Compounds from Tea

“…The optimum conditions for temperature included a range of 28 – 60 °C [ 39 , 131 , 134 , 137 , 141 , 142 , 146 – 148 ], power in the range 50–461W [ 39 , 131 , 140 ] and frequency in the range of 20 kHz—40 kHz [ 39 , 122 , 134 , 148 ]. Sonication time for optimized conditions varied from as low as 10 s to as high as 120 min [ 39 , 122 , 131 , 134 , 137 , 140 – 142 , 146 – 149 ]. UAE is efficient at lower temperatures (60 °C), thereby minimizing thermal damage and maintaining the organoleptic characteristics of tea [ 39 ].…”

“…Most of the research work was on green tea leaves [121,[134][135][136][137][138][139][140][141][142][143] and Black tea [31, [136][137][138]143]. In addition, research has been carried out to extract bioactive from tea infusions [39], matte leaves [144,145], tea solids [146][147][148], tea seeds [131], yellow tea [122], white tea [136,137,149], and Oolong tea [136,137]. Solvents used for the extraction process were dependent on the targeted bioactive compounds for the process.…”

“…Solvents used for the extraction process were dependent on the targeted bioactive compounds for the process. Water remained the most used solvent for extraction [31,121,122,138,142,143,[146][147][148] followed by methanol [138,143,144,148,149], ethanol [122,138,142,147,149], hexane [131,144], and acetone [147]. Sometimes solvents like water/acetone and methanol/ethanol were used in combination for better yields.…”

A comprehensive review of nano-delivery system for tea polyphenols: Construction, applications, and challenges

“…The experimental results showed that all three encapsulation systems had high encapsulation efficiency (>97 %) and slow release effect, and could mitigate the degradation of EGCG to make it have high stability performance, and EGCG-loaded nano-liposomes as well as alginate and chitosan particles containing EGCG nano-liposomes had the ability to stabilize EGCG. Ahmadi ( Ahmadi et al, 2022 ) to improve the insolubility of white TPs and some special odors that limit the application of white TPs, researchers prepared TPs nano-liposomes to increase the bioavailability and stability of TPs, to protect them from degradation by internal and external factors and to retard chemical reactions. The extraction conditions of polyphenols in white tea were optimized, and the effects of liposomes on the encapsulation of white TPs were explored by optimizing different ratios of phospholipids and cholesterol as wall materials encapsulated in nano-liposomes, and the liposome particle characteristics, encapsulation efficiency, morphology, interaction and thermal properties were analyzed.…”

Synthesis and application of near-infrared dyes based on sulfur-substituted dicyanomethylene-4H-chromene and diarylethene

“…Synthesis of S-DCM-1O@PEG, S-DCM-2O@PEG, S-DCM-3O@PEG, and S-DCM-4O@PEG All nanomaterials were prepared by the thin film hydration sonication method. [38][39][40] Taking S-DCM-1O@PEG as an example, mPEG 2000 -DSPE : S-DCM-1O (2 : 1, m/m) was prepared and dissolved in tetrahydrofuran. The solution was quickly added to the ultrasonic water (10 mL).…”