| As a kind of naturally occurring benzoquinone, coenzyme Q10 (CoQ10) is the only endogenous lipophilic antioxidant with positive impact on anti-fatigue, antioxidation and improving body immunity. However the application of this nutrient has been restricted which is attributed to the low aqueous solubility and oral bioavailability of CoQ10. Nanoliposomal delivery system is a possible route that is helpful to solve the aforementioned problems of lipophilic nutrients such as CoQ10. Due to its water solubility and dramatic bioavailability, CoQ10 nanoliposomes could be used as one kind of nutrient in sports drink. Furthermore, CoQ10 proliposomes can be got by lyophilisation in order to achieve long-term stability. The storage stability of CoQ10 nanoliposomes fortified sports drink was investigated and the parameters of ultra-high pressure processing (UHP) were optimized. Furthermore, its anti-fatigue effect had been evalued. Cryoprotectants, parameters such as bilayer composition, freezing rate and temperature, primary and secondary freeze-drying protocol had also been investigated in order to get CoQ10 proliposomes with long-term stability.The storage stability of CoQ10 nanoliposomes fortified sports drink had been evaluated. Furthermore, response surface methodology (RSM) was employed. The optimum process parameters were obtained as follows: pressure 394 MPa and pressure holding time 8.44 min with the temperature at 20～25℃. The sports drink after UHP were less than 10 cfu /mL by colony-counting method. The z-average diameter of CoQ10 nanoliposomes was lower than 100 nm. The encapsulation efficiency of CoQ10 was above 90%. The retention ratio of CoQ10 kept above 90% during 6 months at 4℃.Then anti-fatigue effect of CoQ10 nanoliposomes fortified sports drink was evalued in mice. Compared with the control group, CoQ10 nanoliposomes fortified sports drink prolonged the swimming time, increased the accumulation amount of hepatic glycogen, and decreased the level of serum urea nitrogen and LA. The SOD activity in nanoliposome group significantly increased and the concentrations of MDA decreased. The CoQ10 concentration in liver of nanoliposome group increased to be 5.56±0.90μg/g, which was significantly higher (P<0.05) than that of the control group. The results indicated that CoQ10 nanoliposomes fortified sports drink could improve sporting endurance and delay fatigue by improving the oral bioavailability of CoQ10. Exogenous CoQ10 was accumulated in the liver by passive targeting with nanoliposomal delivery systems.To enhance the stability of coenzyme Q10 liposomes, freeze-drying method was used to prepare coenzyme Q10 proliposomes. The optimum process parameters of freeze-drying were obtained as follows: pre-freezing at -70℃for 24h, primary drying-30℃22h,-10℃10h,-4℃5h and secondary drying at 25℃for 3h( rate 1.5℃/min). Then sucrose, trehalose, mannitol and lactose were selected as cryoprotectants. The particle morphology, the size range and encapsulation efficiency of coenzyme Q10 liposomes before freeze-drying and after rehydration were studied. The weight ratios of the optimized formulation were trehalose/egg lecithin (4:1), trehalose 20% (w/v). The best formulation consisted of CoQ10/ egg yolk phospholipid/ cholesterol/Tween 80 (0.47:2.5:0.4:1.8, w/w) with phosphate buffer solution (pH 7.4, 0.01 mol/L) as hydration media.CoQ10 proliposomes formed an cake with uniformity and well redispersion in water. It maintained stable in desiccator at normal temperature for 6 months. After rehydration, the encapsulation efficiency of CoQ10 liposomes was above 85% and the z-average diameter almost kept about 255 nm during 24 h. The analysis of FTIR spectrum showed that the hydrogen bond between trehalose and lipid headgroups formed in the dry state."Water replacement hypothesis"is more suitable for the cryoprotective mechanism of EPC-trehalose system.
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