Li Liang

Microencapsulation is a process of building a functional barrier between the core and wall material to avoid chemical and physical reactions and to maintain the biological, functional, and physicochemical properties of core materials. Microencapsulation of marine, vegetable, and essential oils has been conducted and commercialized by employing different methods including emulsification, spray-drying, coaxial electrospray system, freeze-drying, coacervation, in situ polymerization, melt-extrusion, supercritical fluid technology, and fluidized-bed-coating. Spray-drying and coacervation are the most commonly used techniques for the microencapsulation of oils. The choice of an appropriate microencapsulation technique and wall material depends upon the end use of the product and the processing conditions involved. Microencapsulation has the ability to enhance the oxidative stability, thermostability, shelf-life, and biological activity of oils. In addition, it can also be helpful in controlling the volatility and release properties of essential oils. Microencapsulated marine, vegetable, and essential oils have found broad applications in various fields. This review describes the recognized benefits and functional properties of various oils, microencapsulation techniques, and application of encapsulated oils in various food, pharmaceutical, and even textile products. Moreover, this review may provide information to researchers working in the field of food, pharmacy, agronomy, engineering, and nutrition who are interested in microencapsulation of oils.

Beta-lactoglobulin (beta-LG), the major whey protein in the milk of ruminants, has a high affinity for a wide range of compounds. Resveratrol (3,5,4'-trihydroxystilbene), a natural polyphenolic compound found in grapes and red wine, exhibits many physiological effects associated with health benefits. In this study, the interaction of resveratrol with beta-LG was investigated using circular dichroism, fluorescence and UV-vis absorbance. Self-association of resveratrol possibly occurs at high concentrations. Resveratrol interacts with beta-LG to form 1:1 complexes. Resveratrol is bound to the surface of the protein because beta-LG-bound polyphenol is in a weaker hydrophobic environment relative to 75% ethanol. The binding constant for the resveratrol-beta-LG interaction is between 10(4) and 10(6) M (-1), as determined by protein or polyphenol fluorescence. The beta-LG-resveratrol interaction may compete with self-association of both the polyphenol and the protein. It has no apparent influence on beta-LG secondary structure but partially disrupts tertiary structure. Complexing with beta-LG provides a slight increase in the photostability of resveratrol and a significant increase in its hydrosolubility.

The L-enantiomer of ascorbic acid is commonly known as vitamin C. It is an indispensable nutrient and plays a key role in retaining the physiological process of humans and animals. L-gulonolactone oxidase, the key enzyme for the de novo synthesis of ascorbic acid, is lacking in some mammals including humans. The functionality of ascorbic acid has prompted the development of foods fortified with this vitamin. As a natural antioxidant, it is expected to protect the sensory and nutritional characteristics of the food. It is thus important to know the degradation of ascorbic acid in the food matrix and its interaction with coexisting components. The biggest challenge in the utilization of ascorbic acid is maintaining its stability and improving its delivery to the active site. The review also includes the current strategies for stabilizing ascorbic acid and the commercial applications of ascorbic acid.