The use of dietary ingredients is gaining much significance as a practical approach to the reduction of the risk of a number of diseases. Epidemiological evidence has linked the habitual consumption of tea with reduced risk of cardiovascular disorders and cancer. Polyphenols appear to play an important role in the potential health benefits associated with tea. With growing interests on the positive health attributes of tea, the present review covers relevant findings on many therapeutic properties of tea. Types of tea, the polyphenols, and their nutraceutical implications, as well as adverse effects and course of action together with bioavailability form the essence of coverage in this review.

No abstract

The purpose of this study was to determine the physicochemical properties of lutein microcapsules. Nine types of lutein microcapsules were prepared in order to determine their encapsulation efficiency and yield. Results show that lutein microcapsules with maltodextrin M040 and sucrose at the weight ratio of 3:1 (designated as M040:1) had the highest encapsulation efficiency (90.1%) among the lutein microcapsules, as well as a higher encapsulation yield (90.4%). The onset glass transition temperatures (Tgi ) and the surface dents of the lutein microcapsules decreased as the dextrose equivalent value of maltodextrin and the weight ratio of sucrose increased. Enthalpy relaxation experiments were conducted for the lutein microcapsules M040:1 at (Tgi - 5) , (Tgi - 10), and (Tgi - 15) °C, and the obtained data were fitted to the Kohlrausch-Williams-Watts model. Results show that the mean relaxation time (τ) (316 h) of M040:1 lutein microcapsules aged at (Tgi - 15) °C was greater than the τ (161 h) at (Tgi - 10) °C and τ (60.5 h) at (Tgi - 5) °C. Effects of temperature and oxygen transmission rates for package film on the storage stability of M040:1 lutein microcapsules were also investigated. Findings show that rates of lutein degradation and color change increased by an order of magnitude as storage temperature (4 to 97 °C) and oxygen transmission rate of the package film (0.018 to 62.8 cc/m(2) day) increased. These results suggest that lutein is highly unstable and susceptible to thermal and oxidative degradations. However, microencapsulation with appropriate wall materials of higher relaxation time and high oxygen barrier packaging can increase the storage life.

No abstract

In this study, we developed a fluorescence method to quantify oxygen barrier properties for wall materials used in microencapsulation of oxygen‐sensitive compounds. We used a reversible, oxygen quenching dye, tris (4,7‐diphenyl‐1, 10‐phenanthroline) ruthenium(II) dichloride complex, as a marker to monitor oxygen transport across spray‐dried and freeze‐dried Hi‐cap100 and maltodextrin microspheres. We fit the rate of oxygen transport to Fick's second law and extrapolated an effective oxygen diffusion coefficient Deff. Results show that the Deff for spray‐dried maltodextrin and Hi‐cap100 formulations were in the range of 6.46 × 10−15 to 7.45 × 10−15 m2/s and 16.0 × 10−15 to 22.4 × 10−15 m2/s, respectively. Results also show an increasing trend in thiobarbituric acid reactive substances reaction rate constants, with an increasing Deff for each formulation. Additionally, freeze‐dried maltodextrin formulations had significantly higher Deff (31.1 × 10−15 to 36.0 × 10−15 m2/s) compared to spray‐dried matrices due to a more porous morphology. This new method provides a framework for the in situ estimation of Deff for wall materials in microspheres. Potential applications include the design and selection of wall materials for maximum oxidative stability of encapsulated ingredients. Practical Application Currently, the selection of wall materials used in microencapsulation of lipids takes a trial‐and‐error approach, which can be time consuming and prone to error. In this study, we developed a new methodology to directly assess the oxygen barrier properties of wall materials in microspheres. This method can be used by food scientists to screen wall materials in order to optimize the oxidative stability of encapsulated lipids.