Process optimization of microencapsulation of curcumin in γ-polyglutamic acid using response surface methodology.

The aim of this study was to develop an optimal microencapsulation method for an oil-soluble component (curcumin) using γ-PGA. The results show that Span80 significantly enhances the encapsulation efficiency (EE) of γ-Na(+)-PGA microcapsules. Therefore, the effects of γ-Na(+)-PGA, curcumin and Span80 concentration on EE of γ-Na(+)-PGA microcapsules were studied by means of response surface methodology (RSM). It was found that the optimal microencapsulation process is achieved by using γ-Na(+)-PGA 6.05%, curcumin 15.97% and Span80 0.61% with a high EE% (74.47 ± 0.20%). Furthermore, the models explain 98% of the variability in the responses. γ-Na(+)-PGA seems to be a good carrier for the encapsulation of curcumin. In conclusion, this simple and versatile approach can potentially be applied to the microencapsulation of various oil-soluble components for food applications.

Optimization of ultrasonic-assisted extraction of cordycepin from Cordyceps militaris using orthogonal experimental design.

This study reports on the optimization of the extraction conditions of cordycepin from Cordyceps militaris by using ultrasonication. For this purpose, the orthogonal experimental design was used to investigate the effects of factors on the ultrasonic-assisted extraction (UAE). Four factors: extraction time (min), ethanol concentration (%), extraction temperature (°C) and extraction frequency (kHz), were studied. The results showed that the highest cordycepin yield of 7.04 mg/g (86.98% ± 0.23%) was obtained with an extraction time of 60 min, ethanol concentration of 50%, extraction temperature of 65 °C and extraction frequency of 56 kHz. It was found that the cordycepin extraction yield increased with the effect of ultrasonication during the extraction process. Therefore, UAE can be used as an alternative to conventional immersion extraction with respect to the recovery of cordycepin from C. militaris, with the advantages of shorter extraction time and reduced solvent consumption.

Anti-diabetic effect of a traditional Chinese medicine formula.

An anti-diabetic TCM formula consisting of Schizandra chinensis Baill. (SC), Coptis chinensis (CC), Psidium guajava L. leaves (PG) and Morus alba L. leaves (MA) was developed based on its α-glucosidase, DPP-4 and AGE inhibitory activities in vitro using response surface methodology (RSM). Then, the in vivo study was carried out to confirm the anti-diabetic function of the formula. RSM results showed that the optimum anti-diabetic TCM formula is the combination SC (3000 µg mL(-1)), CC (80 µg mL(-1)), PG (374.56 µg mL(-1)) and MA (480 µg mL(-1)). For the in vivo study, insulin resistant mice were induced by high-fat/high-sucrose (HF/HS) feeding for 6 weeks. Administration of the developed formula significantly decreased non-fasting blood glucose in the HF/HS diet mice. Moreover, the formula decreased blood glucose levels in the insulin tolerance test. These results indicated that the anti-diabetic mechanism of the formula might be due to decreased insulin resistance. The serum fructosamine level in the high dose group was significantly lower than the HF/HS and normal control groups, indicating that the formula could improve middle term glucose levels and reduce the risk of complications. The contents of berberine and 1-deoxynojirimycin in the formula were 4.7 ± 0.4 and 77.1 ± 1.1 µg mL(-1), respectively. These two compounds can be used as indicators for quality control during production.

Efficient hydrolysis of tuna oil by a surfactant-coated lipase in a two-phase system.

A surfactant-coated lipase (SCL) prepared by mixing Candida rugosa lipase with emulsifier in ethanol was used to hydrolyze tuna oil in a two-phase aqueous-organic system. Both enzyme (SCL) and substrate (tuna oil) were soluble in the organic phase, and the hydrolysis could occur with water molecules from the aqueous phase. This hydrolysis could promptly proceed compared to that catalyzed by native lipases which only occurred at the interface between the two phases. Michaelis-Menten kinetics in the two-phase reactions showed that the K(m) value of the SCL was half that of the native lipase, while the maximum velocity (V(max)) was 11.5 times higher. The hydrolysis method resulted in enrichment of n-3 polyunsaturated fatty acid (n-3 PUFA) content in glyceride mixtures from 26.4% to 49.8% and DHA from 19.1% to 38.9%. The SCL acted as an efficient hydrolytic catalyst for tuna oil.