Vibrio parahaemolyticus is one of the leading foodborne pathogens causing seafood contamination. Here, 22 V. parahaemolyticus strains were analyzed for biofilm formation to determine whether there is a correlation between biofilm formation and quorum sensing (QS), swimming motility, or hydrophobicity. The results indicate that the biofilm formation ability of V. parahaemolyticus is positively correlated with cell surface hydrophobicity, autoinducer (AI-2) production, and protease activity. Field emission scanning electron microscopy (FESEM) showed that strong-biofilm-forming strains established thick 3-D structures, whereas poor-biofilm-forming strains produced thin inconsistent biofilms. In addition, the distribution of the genes encoding pandemic clone factors, type VI secretion systems (T6SS), biofilm functions, and the type I pilus in the V. parahaemolyticus seafood isolates were examined. Biofilm-associated genes were present in almost all the strains, irrespective of other phenotypes. These results indicate that biofilm formation on/in seafood may constitute a major factor in the dissemination of V. parahaemolyticus and the ensuing diseases.

Since chemical sanitizing treatments such as chlorine showed ineffectiveness to reduce microorganisms loaded on berry surface (Beuchat and others 2001, Sapers 2001), hot water treatment on fresh blueberries could maximize microbial reduction with acceptable quality of fresh blueberries.

The aim of this research was to develop a two-step technique to prepare biodiesel from waste palm oil (WPO) with high free fatty acid content. The developed process consists of esterification and transesterification steps. Response surface methodology (RSM) was applied for investigating the experimental design for esterification step. Design of experiment was performed by application of 5-levels-3-factors central composite design in order to study the optimum condition for decreasing FFA in WPO. The WPO with low FFA was further experimented in transesterification step to obtain fatty acid methyl ester (FAME). The investigated results showed that the WPO containing 48.62%wt of high FFA. The optimum condition of esterification step was 28 moles of methanol to FFA in WPO molar ratio, 5.5% sulfuric acid concentration in 90 min of reaction time and 60 °C of reaction temperature. After transesterification step, WPO biodiesel gave methyl ester content at 84.05% according to EN 14103 method. The properties of WPO methyl ester meet the standards of Thailand community biodiesel that can be used as fuel in agricultural machine.

Abstract. Enzyme utilization today constitutes an important and essential part of processes used by the modern food industries. The objective of this research was to investigate the enzymatic skinning of catfish nuggets optimized by response surface methodology to remove the peritoneal membrane of nuggets. The effect of enzyme concentration, temperature, and time was carried out using central composite design. The response surface methodology found out that the optimized process conditions for good skinning and maximum yield were the following: (a) any enzyme concentration, temperature 42°C, time 12 min; (b) 0.15% enzyme concentration, temperature 35°C and time 12 min. This finding is important for maximize enzyme utilization on manufacture processes used by the catfish industries.