<p>Black tiger shrimps (<em>Penaeus monodon</em>) wereharvested andstored at 0⁰Cfor study. The quality index method (QIM) was developed to evaluate the freshness of black tiger shrimp, and was presented in this study. The terms used to describe all the changes related to the texture, color, and odor are carefully chosen. The development of a QIM scheme included three main steps:A preliminary scheme to evaluate all the changes of attributes related to quality – Final QIM scheme and training – Validation of QIM scheme and comparison estimate the remaining shelf life and actual shelf life. The results show that shelf life of black tiger shrimp in the ice storage is 8 days. Quality score involving attributes decreases during the storage timeand have a correlation close to the linear regression equation. The scheme validation quality of black tiger shrimp by QIM method allows the estimation of the remaining shelf life.</p>

The green tea leaves were extracted and spray‐dried to make powder. The polyphenol in green tea is known for its antioxidant and antimicrobial activities. This study investigated the application of green tea extraction powder as a preservative in sponge cake. Our green tea extract powder contained a total polyphenol content of 322.6 mg GAE/g and EGCG content of 11.4%. Green tea extract powder was added to sponge cakes at concentrations of 0.5, 1.0, 1.5, and 2.0% (w/w wheat flour mass). The sponge cakes were tested for some properties including total polyphenol content, antioxidant activity, peroxide value, sensory acceptance, and microbial quantity. As a result, the sponge cake with 1.0% green tea extract powder obtained the best quality with low peroxide value and good microbial quality. Also, the addition of green tea extract powder kept good‐quality sponge cakes for 14 days when they were stored at room temperature in sealed packaging. Practical applications Green tea extract powder rich in polyphenols had not only high antioxidant activity but also microbial inhibitory properties. Therefore, green tea extract powder could function as a natural and healthy additive, replacing chemical synthetic additives to preserve fresh sponge cakes.

Streptococcus mutans is the primary etiological agent of human dental caries. The well-known extraordinary ability of S. mutans to adapt and survive the environment of human mouth is highly acidogenicity and strong exopolysaccharide (EPS) production, a skeleton of dental plaque (biofilm). In this research, the total biofilm biomass, as well as the contents of protein, intracellular polysaccharide (IPS), alkaline soluble polysaccharide (ASP), water soluble polysaccharide (WSP) in the biofilm treated with 150 M α-mangostin was reduced ca. 40% compared to those of the control in ethanol as the vehicle. Two important glycosyltranferases B and C, responsible for biofilm formation by S. mutans, showed to be very sensitive to α-mangostin. Under the treatment condition, biofilm structure was clearly changed. Non-uniform and bigger microcolonies were found in the treated biofilms. Effects of α-mangostin on expression of the virulent genes and the detailed changes in biofilm structure are now under examination. The results showed that the -mangostin is a new and potential anti-biofilm agent of S. mutans UA159.

<p>Black tiger shrimps (<em>Penaeus monodon</em>) wereharvested andstored at 0⁰Cfor study. The quality index method (QIM) was developed to evaluate the freshness of black tiger shrimp, and was presented in this study. The terms used to describe all the changes related to the texture, color, and odor are carefully chosen. The development of a QIM scheme included three main steps:A preliminary scheme to evaluate all the changes of attributes related to quality – Final QIM scheme and training – Validation of QIM scheme and comparison estimate the remaining shelf life and actual shelf life. The results show that shelf life of black tiger shrimp in the ice storage is 8 days. Quality score involving attributes decreases during the storage timeand have a correlation close to the linear regression equation. The scheme validation quality of black tiger shrimp by QIM method allows the estimation of the remaining shelf life.</p>