A comprehensive study in efficacy of Vietnamese herbal extracts on whiteleg shrimp (<em>Penaeus vannamei</em>) against <em>Vibrio parahaemolyticus</em> causing acute hepatopancreatic necrosis disease (AHPND)

Traditional Vietnamese herbal species were examined for their antimicrobial activity and disease resistance in whiteleg shrimp. In-vitro screening, the extracts of ten herbs were conducted to test the inhibition ability against Vibrio parahaemolyticus, causing acute hepatopancreatic necrosis disease. The results showed that five out of ten herbal species, including Pithecellobium dulce, Melaleuca leucadendron, Eucalyptus globulus, Mimosa pirga, and Hibiscus sabdariffa displayed potent antibacterial activity. Besides, three types of extracts of H. sabdariffa, E. globulus, and M. pirga were coated to the pellet feed at a concentration of 1%. After 30 days of feeding, the whiteleg shrimp (Penaeus vannamei) were challenged by V. parahaemolyticus through immersion. The growth performance (such as growth rate in length and weight, survival rate), hematological parameters of total hemocytes (THC), hyaline hemocytes (HC), and granulocytes (GC), and hepatopancreas recovery under the treatments with herbal extracts of the whiteleg shrimp were significantly enhanced as compared with the control (without herbal extract). The mortality and the bacterial density in the hepatopancreas of shrimp decreased. Specifically, the mortality of shrimp in the treatment supplemented with the methanol extract of H. sabdariffa was the lowest, followed by M. pirga and E. globulus. The experimental results also indicated that H. sabdariffa, E. globulus, and M. pirga could improve immune parameters and disease resistance; therefore, they should be employed in sustainable shrimp, practical farming

Rapid integrated assessment of food safety and nutrition related to pork consumption of regular consumers and mothers with young children in Vietnam

Pork is the most common and widely consumed meat product in Vietnam. The study aimed to assess nutrition and food safety risks and opportunities associated with pork value chains in Vietnam. Twenty-nine focus group discussions (FGD) were conducted in Hung Yen and Nghe An provinces with 164 participants who were both regular pork consumers and mothers with young children. In each province, three districts were selected, and in each district we selected one commune. To assess the quality of pork, we took 30 swab samples of pig carcasses at slaughterhouses, 90 pork samples at slaughterhouses and markets and analysed all samples for total bacterial count (TBC), coliforms, water holding capacity and pH. The results showed that pork was the main livestock product consumed and women are responsible for buying and preparing food for daily meals. Pork was the main animal sourced food (ASF) for Vietnamese consumers, for 50–60% of ASF. There was little knowledge of zoonotic diseases. The findings suggest further studies to address consumers’ concern on chemical contamination. Most market pork samples were not within the allowable range of limits standards of Vietnam for bacterial contamination: 90% of samples were above the official permissible limit for TBC and 98% did not meet standards for coliforms. Fifty percent of samples had acceptable pH but only 5% had acceptable water holding capacity. There were no significant differences in pork quality between intensifying Hung Yen and traditional Nghe An provinces, although there was a tendency for samples from Hung Yen to have better compliance. This rapid assessment revealed considerable interest and knowledge on pork nutrition and safety and found some behavioural but few quality and safety differences between traditional and intensifying systems. This indicated marketed pork is of low quality and safety, and a lack of support to consumers in making good choices

Risk assessment of Salmonella in pork in Hanoi, Vietnam

Quantitative Microbial Risk Assessment (QMRA) was used to assess the health risk of pork meat contaminated by Salmonella spp. in Hanoi, Vietnam. A total of 72 pork samples were collected from 4 formal markets in Long Bien District, Hanoi. Salmonella spp. was analyzed by the Most Probable Number (MPN) method. A survey consisting of self-administered structured questionnaires was conducted in 210 households to determine the consumption of pork and examine cooking and eating habits. A health risk assessment was performed for 4 scenarios of cross-contamination of Salmonella spp. including contamination from raw meat to cooked food via i) hands, ii) knife, iii) cutting board, and iv) full cross-contamination. The results showed that Salmonella spp. was detected in 25% of pork samples (18/72). The concentration of Salmonella spp. varied from 100 to 27,500 per 25 grams of pork (mean: 673 per 25 grams). Pork consumption, a component of exposure assessment, was estimated by amount and frequency. The mean amount of pork consumption was estimated at 86.1 grams per person per day; mean frequency of pork consumption was 219 days per person per year. Infection risk of Salmonella spp. was from 2.1×10-4 to 4.9×10-4 by single exposure (per consumption). The annual risk was from 4.3×10-2 to 9.5×10-2. Although this study considered only one stage of exposure in the “farm to fork” chain, the findings showed that this stage is critical and represents a potential health risk for consumers. Appropriate practices for pork meat preparation and consumption at the household level need to me targeted as risk management measures

Health risk assessments of Salmonella spp. in pork in Hanoi, Vietnam

Quantitative Microbial Risk Assessment (QMRA) was used to assess health risk of pork meat contaminated by Salmonella spp. in Hanoi, Vietnam. A total 72 pork samples were collected from 4 formal markets in Long Bien district, Hanoi. Salmonella spp. was analyzed by the MPN method. A survey with 210 households was conducted to determine the consumption of pork and examine cooking and eating habit using self-administered structured questionnaires. The health risk assessment was done for 4 scenarios of cross-contamination of Salmonella spp. from raw meat to cooked food through hands, knife, cutting board and full cross-contamination. Results showed that Salmonella spp. was detected in 25% of pork samples (18/72). Concentration of Salmonella spp. varied from 100 to 27,500 per 25 grams of pork (mean: 673 per 25 grams). Average amount of pork consumption was 86.1 grams/person/day and pork meat was eaten 219 day/per person/year. Infection risk of Salmonella spp. was from 2.1×10-4 to 4.9×10-4 by single exposure (per consumption). The annual risk was from 4.3×10-2 to 9.5×10-2. Although this study considered only one stage of consumption within the “farm to table” chain, the findings showed this stage is critical and represents health risk for consumers. Appropriate practices for preparation and consumption of pork meat at the household level needs to me targeted as risk management measures

Application and policy implication of quantitative microbial risk assessment in developing countries

The development of QMRA and its application are seen mainly in developed countries whereas they are still at an early stage in developing countries. However there is a good potential that QMRA can be used more extensively in training and research and to set the standard of water quality and food safety in developing countries. This presentation highlights how training and research on QMRA have been done in Vietnam. As little trainings on risk assessment in general and no training on QMRA were available in Vietnam, we developed a training course of QMRA by gathering existing QMRA trainings, contextualizing and adapting them to the local context. The resulting course teaches participants about the concept of risk analysis, the steps of a QMRA, and how to implement these steps as well as risk communication and management. A first one-week training course was successfully organized. Risk related to wastewater reuse in agriculture and food safety was assessed using QMRA in Vietnam, Thailand and Ivory Coast. Diverse scenarios of exposure to wastewater when working with wastewater for agriculture and consumption of pork meat have been studied to quantify health risk. The results showed that water and vegetables were heavily contaminated with pathogens and risk was high in tested scenarios and largely exceeded the acceptable level set by WHO. Results identified the most critical points where risk is important and intervention can be focused. Findings can serve to improve policy and practices on waste reuse. QMRA training course has been recognised by health staff, lecturers, researchers, and policymakers at the MOH as a useful tool that provides scientific evidence for decision-making and risk management. Thus a book on QMRA was published in Vietnamese with support of MOH and WHO. University has adapted the health risk assessment course for undergraduate and graduate public health students. Other initiatives are going on to increase QMRA research activities

Screening for pancreatic lipase inhibitors: evaluating assay conditions using p-nitrophenyl palmitate as substrate

Current in vitro pancreatic lipase inhibitor screenings are based on previous spectrophotometric lipase assays. Nevertheless, they are with little evaluation of assay conditions. This study focuses on the impacts of experimental factors on enzyme activity in the assay with p-nitrophenyl palmitate as substrate by monitoring their effects on the hydrolysis rates. On the results, experimental conditions for lipase inhibitory assay were proposed. Notably, 5 mM sodium deoxycholate as emulsifier not only maintains the assay homogeneity but also enhances lipase activity. Organic co-solvents to dissolve organic inhibitors including DMSO, EtOH, MeOH, IPA, AcCN [0–30% (v/v)] was found well tolerated by the enzyme. With 10% (v/v) glycerol, lipase solutions can be stored at –20°C for up to one month without significant loss of activity. The results reported here provide researchers the assay condition sets in which most inhibitors can be dissolved, and lipase activity is not severely affected. This could accelerate the rational development of novel lipase inhibitors

Advanced Fabrication and Application of Pineapple Aerogels from Agricultural Waste

10.1080/10667857.2019.1688537Materials Technology3511-12807-81

Developing technologies for giant grouper (Epinephelus lanceolatus) aquaculture in Vietnam, the Philippines and Australia

This project established a sustainable aquaculture industry for giant grouper in Vietnam and the Philippines through the development of captive breeding and larval-rearing techniques. Captive breeding innovations and larval-rearing techniques, developed through a collaborative Fisheries project, are sustaining the aquaculture industry for giant grouper in Vietnam and the Philippines. Groupers are vital to the live reef food-fish trade in South-East Asia, and the giant grouper is a high-value, fast-growing species with significant aquaculture potential. Establishing a sustainable giant grouper aquaculture industry is a high priority for the region, but research is hampered by the high level of investment required to hold and maintain giant grouper broodstock. Lack of commercial production is also due to limited knowledge about the giant grouper’s maturation and spawning behaviour, and low larval survival