http://tvhdh.vnio.org.vn:8080/xmlui/handle/123456789/18689 Wed, 16 Sep 2026 02:44:31 GMT 2026-09-16T02:44:31Z http://tvhdh.vnio.org.vn:8080/xmlui/handle/123456789/21848 Chemical and Photochemical Profiles of Selected Vietnamese Fruit By-Products Le, Xuan Son; Nguyen, Duy Nhut; Nguyen, Dinh Thuat; Nguyen, Van Long; Nguyen, Duy Linh; Dang, Thi Thanh Truyen; Dang, Xuan Cuong Aims: This study characterized the chemical, mineral, and photochemical properties of underutilized tropical fruit by-products in Vietnam—banana pseudostems, dragon fruit peels, and durian husks—to assess their potential in biomaterials, nutraceuticals, and circular agriculture. Study design: Experimental cross-sectional compositional analysis with international benchmarking. Place and Duration of Study: Ho Chi Minh University of Industry and Trade, Vietnam. Samples were collected from U Minh Thượng (An Giang), Bình Thuận, and Đắk Lắk. Methodology: Freeze-dried and ground samples were analyzed for proximate composition, minerals, polyphenols, carotenoids, and betalains using AOAC methods, HPLC–DAD, and UV– Vis/fluorescence spectroscopy. All analyses were performed in triplicate (n = 3). Results: Banana pseudostems were rich in cellulose (38.4%) and hemicellulose (22.5%), highlighting their suitability as lignocellulosic feedstocks. Dragon fruit peels contained betalains (2.45 ± 0.12 mg/g DW) and polyphenols (12.4 mg GAE/g DW), confirming strong antioxidant and pigment potential. Ri6 durian husks exhibited distinct carotenoid and phenolic acid profiles, with elevated calcium (355 mg/100 g DW) and phosphorus (138 mg/100 g DW). Photochemical assays revealed UV-absorbing activity of banana phenolics, photolability of dragon fruit betalains, and stability of durian carotenoids. Comparative analysis with India, Thailand, and Malaysia confirmed Vietnamese samples fall within global ranges while demonstrating cultivar-specific advantages. Conclusion: These findings highlight Vietnamese banana pseudostems, dragon fruit peels, and Ri6 durian husks as promising agro-industrial by-products. Their valorization into bioplastics, natural pigments, nutraceuticals, and compost aligns with circular bioeconomy goals and supports sustainable resource utilization. Wed, 01 Jan 2025 00:00:00 GMT http://tvhdh.vnio.org.vn:8080/xmlui/handle/123456789/21848 2025-01-01T00:00:00Z http://tvhdh.vnio.org.vn:8080/xmlui/handle/123456789/21846 The first report on the marine snail Phos senticosus (Linnaeus, 1758) causing a tetrodotoxin poisoning in Viet Nam Dao, Viet Ha; Le, Ho Khanh Hy; Bui, Quang Nghi; Phan, Bao Vy; Nguyen, Phuong Anh; Doan, Thi Thiet; Phan, Minh Thu; Nobuhisa, Kajino; Kwang-Sik, Choi; Nguyen, Dang Duc; Pham, Xuan Ky The neurotoxic poisonings that result in death with fatalities caused by consumption of Nassarius snails have been reported in Viet Nam but the causative toxin has only been identified in a small number of cases. A poisoning incident by eating marine snails happened in Binh Thuan Province, Viet Nam in March 2021. The leftover food from the incident, 29 snail specimens, later were identified as all Phos senticosus (Linnaeus, 1758) were collected for identification of causative toxin. At 60.7 ± 126.5 µg/g, anh-TTX was detected in the most dominant level, followed by tetrodotoxin (TTX) (46.0 ± 107.6 µg/g) and 4-epiTTX (23.3 ± 24.3 µg/g) by hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) analysis. Overall toxicity was assessed to be 229 ± 526 MU/g in the snail specimens that responded mostly to TTX due to its strong potency. All specimens were reported as toxic in toxicity range of 10–2,672 MU/g, which is comparable to what was found in some other Nassarius species in Taiwan and Viet Nam. Of 29 specimens, 75.8% showed toxicity in the range of 10–100 MU/g, 17.3% indicated toxicity in the range of 100––1,000 MU/g, whereas 6.9% displayed toxicity that was exceptionally high (> 1,000 MU/g). The data demonstrates that TTX is accountable for this poisoning incident. Notebly, it is the first report on TTX in P. senticosus causing the seafood poisoning in Viet Nam, highlighting the threat this species poses to human consumption. As a result, there ought to be a more severe warning about its potential cause of poisoning. Thu, 01 Jan 2026 00:00:00 GMT http://tvhdh.vnio.org.vn:8080/xmlui/handle/123456789/21846 2026-01-01T00:00:00Z http://tvhdh.vnio.org.vn:8080/xmlui/handle/123456789/21809 Fish Assemblage Structure and Biodiversity in the Han and Cu De Rivers, Central Vietnam Nguyen, Tuong Vi; Phan, Minh Thu; Le, Thi Thu Thao Estuarine ecosystems are among the most biodiverse yet increasingly threatened environments worldwide, particularly in tropical coastal regions where river and marine systems interact. This study investigated the structure, species composition, and seasonal variation of fish assemblages in the Han and Cu De Rivers in Da Nang City, central Vietnam. Field surveys were conducted during the rainy season (September–December 2024) and dry season (March–June 2025) at major fish landing sites and aquatic product collection points along the two river basins. A total of 957 specimens were collected and analyzed using standard morphological taxonomy, and community patterns were analyzed using Bray–Curtis similarity and Principal Component Analysis (PCA). Overall, 166 fish species belonging to 122 genera, 64 families, and 21 orders were recorded. Species richness differed between rivers, with 109 species in the Han River and 99 in the Cu De River, and only 42 shared species, indicating clear spatial differentiation. The Han River assemblage was dominated by estuarine and marine-associated taxa (e.g., Acanthuriformes and Carangiformes), whereas the Cu De River was characterized by freshwater taxa, particularly Cypriniformes (28.3%). Seasonal variation was pronounced, with 121 species recorded in the dry season compared to 75 in the rainy season. These findings demonstrate that the study area functions as an estuarine transition zone with strong environmental gradients shaping fish communities. The results provide essential baseline data for biodiversity conservation and fisheries management, while highlighting the importance of hydrological connectivity and seasonal dynamics in coastal river ecosystems. Wed, 01 Jan 2025 00:00:00 GMT http://tvhdh.vnio.org.vn:8080/xmlui/handle/123456789/21809 2025-01-01T00:00:00Z http://tvhdh.vnio.org.vn:8080/xmlui/handle/123456789/21808 Utilization and Management Implications of Bale-Bale Fishing Gear for Flying Fish Eggs (Exocoetidae) Tuapetel, Friesland; Hukubun, Ronald D.; Apituley, Yolanda M.T.N.; Tran, Cong Thinh; Rauf, Syahril A. Flying fish (Exocoetidae) represent an important marine resource inthe Aru Islands, Eastern Indonesia, where their eggs have long been harvestedusing traditional bale-bale gear. However, recent increases in exploitation byandon fishers from Sulawesi have placed growing ecological strain on theresource and raised the risk of social tensions. This study investigates thedynamics of the flying fish egg fishery, evolving harvesting practices, and themanagement challenges associated with bale-bale use. Data were gatheredthrough field observations, structured interviews (2021–2023), participatorymapping, and policy review. The results show that 80% of the fishers aremigrants who operate between 2 and 200 nautical miles offshore, using gear thatranges from simple rafts to double-deck configurations. The overlap of fishingzones between local and andon fishers has intensified competition, leading to asignificant reduction in egg catch. Furthermore, centralized fisheries governancehas limited the effectiveness of local enforcement. Unregulated harvesting posesa serious threat to recruitment in flying fish populations, drawing parallels tochallenges observed in lobster seed collection. To mitigate these risks, the studyrecommends standardizing gear, restricting bale-bale use to a maximum of 85units per vessel, prohibiting double-deck rafts, enforcing stricter licensing andquota systems for migrant fleets, and enhancing coordination between differentlevels of government. A collaborative management framework rooted inscientific data is vital for safeguarding the long-term sustainability of the flyingfish egg fishery in Maluku waters. Wed, 01 Jan 2025 00:00:00 GMT http://tvhdh.vnio.org.vn:8080/xmlui/handle/123456789/21808 2025-01-01T00:00:00Z http://tvhdh.vnio.org.vn:8080/xmlui/handle/123456789/21807 Geo-chemical fractionations of phosphorus in sediments of Thuy Trieu lagoon and Cam Ranh Bay, Vietnam Le, Hung Phu; Pham, Hong Ngoc; Le, Trong Dung; Vo, Tran Tuan Linh; Tran, Van Binh; Ho, Van The The geochemical fractions of phosphorus (P) and its bioavailability in sediments of Thuy Trieu Lagoon and Cam Ranh Bay were investigated. Twenty-four surface sediment samples were collected in the dry season (Jun 2024) and the rainy season (Oct 2024). A sequential extraction procedure was applied to identify the phosphorus (P) fractions in sediments, including Exchangeable P (Ex-P), iron-bound P (Fe-P), aluminum-bound P (Al-P), calcium-bound P (Ca-P), and residual P (Res-P). Total P (TP) ranged from 214.9 to 2365.2 μg·g¡1 , and the Ca-P fraction was the dominant chemical form in sediments. Based on the results of Pearson correlation and principal component analysis, this study suggests that the terrestrial organic matter was the main source for shaping the distribution of P fractions in sediments. Meanwhile, the Ca-P fraction was likely formed through co-precipitation with calcite and other minerals in the sediments. The bioavailable P fraction constituted a small proportion of the total sedimentary P, accounting for 7.6—45.5 % in sediments of Cam Ranh Bay. Wed, 01 Jan 2025 00:00:00 GMT http://tvhdh.vnio.org.vn:8080/xmlui/handle/123456789/21807 2025-01-01T00:00:00Z