Application of biopolymers for improving the glass transition temperature of hairtail fish meat.

BACKGROUND: Glass transition temperature (Tg ) and food moisture content are closely related, especially in foods with a high moisture content, such as surimi products. In order to improve storage condition and maintain food quality, the influence of six biopolymers on the Tg of hairtail fish meat paste was investigated by differential scanning colorimetry. RESULTS: Samples were stored at -8 °C (>Tg ), -14 °C (Tg ) and -18 °C (

Preparation and characterization of nanoliposomes entrapping medium-chain fatty acids and vitamin C by lyophilization.

The complex nanoliposomes encapsulating both a hydrophilic drug vitamin C (vit C) and hydrophobic drug medium-chain fatty acids (MCFAs) was prepared by combining double emulsion method with dynamic high pressure microfluidization. The complex nanoliposomes was further freeze-dried under -86 °C for 48 h with sucrose at the sucrose/lipids ratio of 2:1(w/w) in order to enhance its stability. The freeze-dried complex nanoliposomes under the suitable conditions exhibited high entrapment efficiency of MCFAs (44.26 ± 3.34)%, relatively high entrapment efficiency of vit C (62.25 ± 3.43)%, low average size diameter (110.4 ± 7.28) nm and good storage stability at 4 °C for 60 days with slight changes in mean particle diameter and drug entrapment efficiencies. The results of transmission electron microscopy of freeze-dried complex nanoliposomes also showed that the freeze-dried samples with sucrose were stable without great increase in their particle sizes and without destroying their spherical shape. The results indicated that sucrose presented well protection effects in MCFAs-vit C complex nanoliposomes, suggesting the possibility of further usage in commercial liposomes.

Medium-chain fatty acid nanoliposomes suppress body fat accumulation in mice.

Medium-chain fatty acids (MCFA) are widely used in diets for patients with obesity. To develop a delivery system for suppressing dietary fat accumulation into adipose tissue, MCFA were encapsulated in nanoliposomes (NL), which can overcome the drawbacks of MCFA and keep their properties unchanged. In the present study, crude liposomes were first produced by the thin-layer dispersion method, and then dynamic high-pressure microfluidisation (DHPM) and DHPM combined with freeze-thawing methods were used to prepare MCFA NL (NL-1 and NL-2, respectively). NL-1 exhibited smaller average size (77.6 (SD 4.3) nm), higher zeta potential (- 40.8 (SD 1.7) mV) and entrapment efficiency (73.3 (SD 16.1) %) and better stability, while NL-2 showed narrower distribution (polydispersion index 0.193 (SD 0.016)). The body fat reduction property of NL-1 and NL-2 were evaluated by short-term (2 weeks) and long-term (6 weeks) experiments of mice. In contrast to the MCFA group, the NL groups had overcome the poor palatability of MCFA because the normal diet of mice was maintained. The body fat and total cholesterol (TCH) of NL-1 (1.54 (SD 0.30) g, P = 0.039 and 2.33 (SD 0.44) mmol/l, P = 0.021, respectively) and NL-2 (1.58 (SD 0.69) g, P = 0.041 and 2.29 (SD 0.38) mmol/l, P = 0.015, respectively) significantly decreased when compared with the control group (2.11 (SD 0.82) g and 2.99 (SD 0.48) mmol/l, respectively). The TAG concentration of the NL-1 group (0.55 (SD 0.14) mmol/l) was remarkably lower (P = 0.045) than the control group (0.94 (SD 0.37) mmol/l). No significant difference in weight and fat gain, TCH and TAG was detected between the MCFA NL and MCFA groups. Therefore, MCFA NL could be potential nutritional candidates for obesity to suppress body fat accumulation.

Preparation and evaluation of easy energy supply property of medium-chain fatty acids liposomes.

To develop an easy-energy-supply agent, medium-chain fatty acids (MCFAs) liposomes were prepared by thin-layer dispersion, freeze-thawing and dynamic high pressure microfluidization (DHPM)-freeze-thawing methods. Results showed that MCFAs nanoliposomes obtained by the novel method (DHPM-freeze-thawing) exhibited a smaller size (72.6 ± 4.9 nm), narrower size distribution (PDI = 0.175 ± 0.005), higher zeta potential (-41.27 ± 1.16 mV) and entrapment efficiency (45.9 ± 6.0%) compared to the other two methods. In the weight-loaded swimming test of the mice, the high-dose group of MCFAs nanoliposomes indicated a significantly longer swimming time (105 ± 31 min, p < 0.05), a lower serum urea nitrogen (839.5 ± 111.9 mg/L, p < 0.05) and blood lactic acid (5.7 ± 1.0 mmol/L, p ≤ 0.001), and a higher hepatic glycogen (15.0 ± 3.6 mg/g, p ≤ 0.001) than those of the control group (53 ± 13 min, 1153.6 ± 102.5 mg/L, 12.5 ± 1.9 mmol/L and 8.8 ± 3.3 mg/g, respectively). However, no significant difference was found between the high-dose group and MCFAs group. The results suggested that MCFAs nanoliposomes could be used as a potential easy-energy-supply agent.

Carboxymethyl chitosan coated medium-chain fatty acid nanoliposomes: structure, composition, stability and in vitro release investigation.

Medium-chain fatty acids (MCFAs) have been proven as an easy energy source and active ingredient to prevent obesity and other metabolic disorders. However, the inherent hydrophobic nature of MCFAs causes poor aqueous solubility and dissolution in the gastrointestinal (GI) tract, thus limiting their applications in aqueous foods. To address these issues, a nutraceutical carrier system was developed by coating nanoliposomes with carboxymethyl chitosan (CMCS) through a series of well-designed processes, including thin-film hydration, dynamic high pressure microfluidization (DHPM) and surface modification. Electron microscopy investigation reveals an obvious morphology evolution from the uncoated nanoliposomes (UC-LPs) to the final CMCS coated nanoliposomes (CMCS-LPs). Together with the FTIR results, it confirms the successful coating of CMCS. More importantly, the resultant CMCS-LPs have a more negatively charged surface with a ζ-potential value of around -18.5 mV, which helps to increase the stability by avoiding severe particle aggregation. Owing to the above benefits, the encapsulated MCFAs can be safely retained in a long storage period of 90 days at 4 °C and the new carrier system also exhibits a more sustained release of MCFAs in the GI fluid.

Preparation and characterization of medium-chain fatty acid liposomes by lyophilization.

In this study, medium-chain fatty acid (MCFA) liposomes were prepared by the film ultrasonic dispersion, modified ethanol injection, and reverse-phase evaporate methods. The results indicated that the liposomes prepared by the thin-film ultrasonic dispersion method had a high entrapment efficiency of 82.7% and a good distribution in size diameters. The MCFA liposomes were freeze-dried and the optimal preparation conditions of freeze-drying were as follows: The cryoprotectants were mannitol and sucrose (1:1 w/w), the hydrated medium was distilled water, and the freeze-drying time was 48 hours. Under these conditions, the freeze-dried MCFA liposomes had a perfect appearance, a small particle size, and high encapsulation efficiency. The mean diameters were 251.1 and 265.3 nm, and the encapsulation efficiencies were 80.5 and 79.2% for freshly prepared and reconstituted liposomes, respectively.

Medium-chain fatty acid nanoliposomes for easy energy supply.

OBJECTIVE: Developing a nanoliposome delivery system for an easy energy supply of medium-chain fatty acids (MCFAs) to improve oral doses and bioavailability. METHODS: Bangham's method and high-pressure microfluidization were used to prepare MCFA liposomes. The easy energy-supply property of MCFA nanoliposomes was estimated by the anti-fatigue experiments of mice including a weight-loaded swimming test and its corresponding parameters (serum urea nitrogen, blood lactic acid, and hepatic glycogen). For comparison, nanoliposomes without MCFAs and MCFAs not entrapped in nanoliposomes were used throughout. RESULTS: Compared with crude MCFA liposomes according to Bangham's method, the MCFA nanoliposomes made by high-pressure microfluidization exhibited great advantages in their characteristics, with a small average diameter (76.2 ± 34.7 nm), narrow size distribution (polydispersity index 0.207), high ζ-potential (-50.51 mV), great entrapment efficiency (70.5%) and drug loading (9.4%), and good stability. The high-dose group and the MCFA group (680 mg/kg) showed a longer weight-loaded swimming time (104 ± 29 min, P = 0.087, and 108 ± 11 min, P = 0.047, respectively) and significantly higher hepatic glycogen (16.40 ± 1.45 mg/g, P < 0.001 and 17.27 ± 2.13 mg/g, P < 0.001, respectively) than the control group (59 ± 11 min and 8.79 ± 2.76 mg/g, respectively). Moreover, serum urea nitrogen (891.5 ± 113.4 mg/L, P = 0.024, and 876.6 ± 70.8 mg/L, P = 0.015, respectively) and blood lactic acid (6.05 ± 1.40 mmol/L, P = 0.001, and 5.95 ± 1.27 mmol/L, P < 0.001, respectively) in the high-dose group and the group with an equivalent MCFA dose were significantly lower than those in the control group (1153.6 ± 102.5 mg/L and 12.53 ± 1.86 mmol/L, respectively). CONCLUSION: Similar to MCFAs, MCFA nanoliposomes prepared by high-pressure microfluidization showed a strong easy energy-supply property, which suggested that MCFA nanoliposomes could be a potential drug candidate for an easy energy supply.