The objective of this study was to evaluate size-different chitosan nanoparticles as a CO2 indicator. CO2 gas is dissolved to form H2CO3 which makes the solution acidic. Chitosan is acid soluble and its appearance (turbidity) changes depending on pH in aqueous solution. Two size-different chitosan nanoparticles were fabricated by ionic gelation between chitosan (0.30 and 0.50%, w/v) and 0.07% sodium tripolyphosphate (TPP) solution. The sizes of chitosan nanoparticles were 630.77 and 1194.87 nm, respectively. To investigate the effect of chitosan nanoparticles as CO2 indicator, the initial pH of chitosan nanoparticle suspension was adjusted to 8.0. Thereafter, 100% CO2 gas was injected into the chitosan nanoparticle suspension, and the changes of pH and absorbance (600 nm of absorption wavelength) of the suspension over time were measured for 28 min. Absorbance at the appearance transition and its corresponding time was calculated using logistic function (R2> 0.99).As a result, pH of chitosan nanoparticle suspension decreased rapidly under CO2 gas injection for 10 min and finally reached around 6.0. In addition, there was significant difference in appearance transition time which was6.62 and 12.45 min for small- and large-sized chitosan nanoparticle suspensions, respectively. This study suggests that chitosan nanoparticle suspension might be useful as a food quality indicator for CO2 emitting foods such as fermented foods.

Excessive nitrate content in drinking groundwater is one of the sources of nitrate-nitrogen that threatens humanhealth all over the world. Nitrate-nitrogen reduction technology is categorized into membrane filtration, electro-dial-ysis, ion exchange, adsorption, chemical methods, and biological methods according to the principle of eliminationfrom water. In particular, an adsorption technique is the most popular and common process because of its cost effec-tiveness, convenience, and effective adsorption. In this review, the application of conventional adsorbents used toreduce nitrate-nitrogen from drinking water is discussed and novel technologies on nitrate-nitrogen removal are intro-duced. Furthermore, the recent development of novel nitrate-nitrogen adsorbents from biopolymers such as chitosanand agricultural and industrial byproducts is reviewed.

Wheat is a major food source for a large proportion of the worldwide population. Wheat production is hampered by drought, cold and various diseases. Wheat germplasms contain various characteristics such as high yield, low plant height, resistance to diverse diseases and good seed quality. In this study, we evaluated agronomic traits of wheat germplasms collected from the National Plant Germplasm System (NPGS) for application of the breeding program. Total 221 wheat lines contain cultivars and landraces were provided by NPGS and USDA-ARS. The germplasms were evaluated quantitative and qualitative agronomic properties in Korea university research farm. The agronomic traits of the germplasms in each region were analysed using statistical analysis. The most of germplasms were geographically originated from America continent. The germplasms average heading date showed on May 10. The average heading date of Africa germplasms was 6 days earlier than Europe germplasms. The germplasms average plant height and spike length showed 81.7 cm and 8.6 cm, respectively. The germplasms of Europe showed 21.7 cm taller than average plant height of America continent and the germplasms of Africa showed the smallest plant height comparing with other continents. The germplasms of Asia showed taller spikere length than that of other continents. Seed color in germplasm comprises white, red and purple seed color, 24%, 75%, 1%, respectively. In addition, about 39% of the germplasms indicated lodging resistant. These results could be useful for improvement of wheat breeding program.