ABSTRACT. The flood is a well-known phenomenon in the Vietnamese Mekong River Delta (MRD). Although people have experienced the impact of floods for years, some adapt well, but others are vulnerable to floods. Resilience to floods is a useful concept to study the capacity of rural households to cope with, adapt to, and benefit from floods. Knowledge of the resilience of households to floods can help disaster risk managers to design policies for living with floods. Most researchers attempt to define the concept of resilience; very little research operationalizes it in the real context of "living with floods". We employ a subjective well-being approach to measure households' resilience to floods. Items that related to households' capacity to cope with, adapt to, and benefit from floods were developed using both a five-point Likert scale and dichotomous responses. A factor analysis using a standardized form of data was employed to identify underlying factors that explain different properties of households' resilience to floods. Three properties of households' resilience to floods were found: (1) households' confidence in securing food, income, health, and evacuation during floods and recovery after floods; (2) households' confidence in securing their homes not being affected by a large flood event such as the 2000 flood; (3) households' interests in learning and practicing new flood-based farming practices that are fully adapted to floods for improving household income during the flood season. The findings assist in designing adaptive measures to cope with future flooding in the MRD.

Cashew apple (Anacardium occidentale) is considered as a by-product of the cashew processing industry. Efficient utilization of this material source contributes to valorization of cashew and reduces the burden of agricultural waste placed on the environment. This study investigated the effects of various blanching conditions on the total tannins, the ascorbic content and the phenolic contents of cashew apples. The three parameters including blanching temperature, blanching duration and salt concentration of the blanching solution were considered. It was found that optimal blanching conditions (heating at 70°C, NaCl concentration at 1% within 2 mins) resulted in cashew apples with vitamin C content and tannin retention rate of about 78.125% and 45% compared to those of the fresh samples, respectively. The cashew apple texture seemed to be insensitive to the heating process, however, the colors (mainly red gamuts of carotenoids) were lost during blanching.

In this study, we focused on water quality in an urban canal and the Mekong River in the city of Can Tho, a central municipality of the Mekong Delta region, southern Vietnam. Water temperature, pH, electrical conductivity, BOD5, CODCr, Na(+), Cl(-), NH4 (+)-N, SO4 (2-)-S, NO3 (-)-N, and NO2 (-)-N for both canal and river, and tide level of the urban canal, were monitored once per month from May 2010 to April 2012. The urban canal is subject to severe anthropogenic contamination, owing to poor sewage treatment. In general, water quality in the canal exhibited strong tidal variation, poorer at lower tides and better at higher tides. Some anomalies were observed, with degraded water quality under some high-tide conditions. These were associated with flow from the upstream residential area. Therefore, it was concluded that water quality in the urban canal changed with a balance between dilution effects and extent of contaminant supply, both driven by tidal fluctuations in the Mekong River.

The isolation of acid-soluble collagen (ASC) from by-products of snakehead fish (Channa striata), including skin and the mixture of skin and scale, has been investigated. The recovery yield of fish skin ASC (13.6%) was higher than ASC from fish skin and scale (12.09%). Both ASCs were identified as type I collagen and showed maximal solubility at pH 2. Collagen samples from the mixture of skin and scale had higher imino acid content (226 residues/1000 residues) and lower wavenumber in the amide I and amide III region (1642 and 1203 cm−1, respectively) than the fish skin ASC (the imino acid content was 220 residues/1000 residues and the wavenumber in the amide I and amide III were 1663 and 1206 cm−1, respectively. The difference scanning calorimeter (DSC) showed higher thermal stability in ASC from the mixture of skin and scale (Td of 35.78 °C) than fish skin ASC (34.21 °C). From the result, the denaturation temperature of ASC had a close relationship with the content of imino acid as well as with the degradation of α-helix in amide I and III. These results suggest that collagen could be obtained effectively from snakehead fish by-products and has potential as a realistic alternative to mammalian collagens.

The utilization of three important freshwater fish skins including tra catfish (Pangasianodon hypophthalmus), clown knifefish (Chitala ornata), and tilapia (Oreochromis niloticus) in Mekong Delta Region, Vietnam for acid‐soluble collagen (ASC) extraction was investigated. From the SDS‐PAGE profile, ASCs can be identified as type I collagen (consisting of two different α‐ chains and β component in protein pattern).The solubility among individual collagens was highest at pH 1–2, depending on fish species. FTIR spectra showed a close relationship between the lowest wavelength number in amide I and amide III regions and the stabilization of the triple‐helical structure in ASC from clown knifefish. ASC from clown knifefish skin had highest ASC yield and contained highest amino acid content as well as the highest denaturation temperature (33.09°C) in comparison with ASCs from tra catfish and tilapia skin. Practical applications Acid‐soluble collagen (ASC) from three important fish skins in the Mekong Delta Region, Vietnam was characterized. ASC from clown knifefish skin showed the highest of extraction yield and denaturation temperature. The thermal stability of ASC from clown knifefish skin not only related to the content of imino acid but is also had the correlation with the transition of α‐helix in amide I and III.