Licorice and rosemary contain a number of natural phenolic compounds which have a strong antibacterial and antioxidant activity. Ulleungdo stonecrop (US, scientific name: Sedum takesimense Nakai), indigenous island, is also known as a good antibiotic agent and skin whitening agent and is regarded as a promising materials in cosmetics field. Although the antibacterial activity of each material have been reported, little is known about the effect of using them together. Therefore, the purpose of this study was to investigate the synergistic effect on antibacterial activity when licorice and rosemary extract and US were used together. Since licorice and rosemary are lipid soluble materials and US is water soluble material, oil in water (O/W) emulsion system was used for this study. To manufacture O/W emulsions containing three kinds materials, first licorice and rosemary extracts and US was dispersed in soy bean oil and phosphate buffer (pH7) respectively. Decaglyceryl laurate was used as an emulsifier. There was slight decrease (-0.09~-0.46 Δlog) in the number of bacteria when O/W emulsion containing 300ppm of each licorice and rosemary extracts was mixed into B.subtilis. However, adding US (2,700ppm) into aqueous phase caused the rapid decrease in the amount of bacteria to -1.71 ~ -2.96 Δlog which were much higher decrement than US only in normal emulsion (-1.64 Δlog). In particular, there was a noticeable synergistic effect when rosemary extract and US was used together. The results obtained from this study could provide useful information for utilizing licorice and rosemary extracts and US as functional materials in the food and cosmetic areas.

Retinol is a type of vitamin A that helps the skin's epidermal cells maintain their original function and plays an important role in visual acuity. However, retinol cannot simply be incorporated into foods in its pure form because of limited solubility and chemical instability. In this study, retinol was encapsulated within lipid droplets of oil-in-water (O/W) emulsion and the photo stability of retinol loaded in O/W emulsion was examined. O/W emulsions containing retinol were prepared using Tween 20, Decaglycerine myristate and WPI, respectively, at different oil concentrations (0.1, 0.5, 1.0, 2.0, and 4.0 wt%). Photo stability of retinol was determined by measuring retention rate (%) of retinol loaded in O/W emulsions after exposure to UV light for 24 h and compared to that of retinol dissolved in ethanol. The retinol retention rate was higher for O/W emulsions than retinol in ethanol and the retention rate increased as the oil concentration of emulsions increased, which might be attributed to the opaqueness of emulsions. As the oil concentration of emulsions increased, the turbidity of emulsions also increased. In terms of the type of emulsifier, decaglycerine myristate-stabilized emulsion had the highest retinol retentions rate than other emulsifier-stabilized emulsions after exposure to UV light. This study provides important information for designing effective emulsion-based delivery systems for improving the stability of retinol.

A variety of rice cultivars have been developed and their usages are being expanded to develop value added products in relation to their physicochemical properties. Cyclodextrin (CD), commonly produced from potato starch, is widely used in food and pharmaceutical industries. So far, few studies have been reported on the CD production from rice starches. In this study, the physicochemical properties of various rice starches were investigated and their substrate performance were evaluated for the CD production using cyclodextrin-glucanotransferase (CGTase). Starches of 5 Korean rice cultivars, Dodamssal (DD), Ilpummi (IP), Saegoami (SG), Sintoheukmi (SH), and Geonganghongmi (GH) were isolated by alkaline extraction method. The amylose content of DD and SG was ~66% and ~30%, respectively, while the others ranged from ~18% to ~23%. A similar amylopectin branch chain length distribution was observed in SH, GH, and IP, showing higher content of middle chains B1. SG showed higher content of the short chains A and lower content of the long chains B3+ than SH, GH, and IP, whereas DD showed opposite trends. RVA pasting properties showed the lowest values of peak viscosity, breakdown, and final viscosity in DD. The X-ray diffraction pattern of DD was the typical B-type pattern, whereas the others showed A-type patterns. Most starches had typical polygonal granular shapes, whereas DD showed round shape as revealed by SEM. In order to produce CD, starches were treated with isoamylase, CGTase and glucoamylase in a sequential order. DD showed the highest CD yield of 83% and GH showed the lowest CD yield of 70%. Based on this study, it can be concluded that the starches with high amylose contents tend to show low peak viscosity, high pasting temperature, and high CD production yield.