Piyanut Sridonpai

Selenium (Se) speciation in seafood is a key determinant of its nutritional value. However, limited data exist on the influence of common cooking methods on Se chemical forms. This study investigated Se speciation in commonly consumed Thai seafood prepared by different cooking methods, namely, fresh (control), boiling, frying, and grilling, using HPLC–ICP–QQQ–MS. Across all samples, Se was predominantly present in organic forms, with selenomethionine (SeMet) identified as the major species, followed by selenocystine (SeCys₂), while inorganic forms (Se(IV) and Se(VI)) were generally below the limit of quantification. Indo-Pacific horseshoe crab (eggs) consistently presented significantly higher SeMet concentrations than all other seafood species across all cooking methods (p < 0.05). In addition, frying and grilling resulted in higher apparent SeMet concentrations compared to fresh and boiled samples in several species (p < 0.05). This increase should be interpreted as a concentration effect associated with moisture loss during high-temperature cooking, rather than a true chemical formation of SeMet. SeCys₂ concentrations varied across species and cooking conditions, with significantly higher levels found in certain crustaceans, such as banana prawn and musk crab, particularly after boiling (p < 0.05). Extraction yields ranged from 77% to 94%, indicating high analytical recovery. Overall, cooking methods influenced the concentration of Se species but did not substantially alter their chemical forms. These findings suggest that commonly consumed Thai seafood is a rich source of bioavailable Se, particularly in the form of SeMet. Further research is warranted to characterize minor Se species and assess their nutritional implications.

Selenium (Se) is a vital element for human health and seafood represents one of its major dietary sources. Nevertheless, information regarding the bioaccessibility of Se from seafood commonly consumed in Thailand remains scarce. To address this limitation, the present study evaluated in vitro Se bioaccessibility using the equilibrium dialyzability approach. Ten seafood species frequently selected by Thai consumers were investigated to determine total Se concentrations following different culinary treatments, namely fresh, boiling, frying, and grilling. For thermally processed samples, gastrointestinal digestion was simulated in vitro through enzymatic digestion prior to bioaccessibility assessment using the equilibrium dialyzability method. Inductively coupled plasma triple quadrupole mass spectrometry (ICP-QQQ-MS) was used to precisely quantify the total and dialyzable Se fractions. The effects of seafood species and cooking methods were evaluated statistically using two-way analysis of variance and the Tukey’s honestly significant difference (HSD) test for post hoc comparisons. The findings showed that, across the majority of cooking techniques, Indo-Pacific horseshoe crab eggs consistently showed considerably greater Se contents than other seafood (p < 0.05). Moreover, Se bioaccessibility in Indo-Pacific horseshoe crab eggs (81.1–88.3%) was markedly greater than that observed in other seafood items, including musk crab, blue crab, oysters, and wedge shell, regardless of cooking method (p < 0.05). No statistically significant differences in Se bioaccessibility were observed among boiling, frying, and grilling (p > 0.05), indicating that thermal processing did not adversely affect Se availability. Overall, the seafood species examined in this study, irrespective of preparation method, contained substantial Se levels with high bioaccessibility, underscoring their nutritional value and supporting dietary recommendations that promote balanced consumption of marine foods.

This study evaluates the risk of toxic heavy metal exposure in 20 commonly consumed seafood species from Thailand, focusing on arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb). Seafood is nutritionally valuable but may accumulate harmful metals due to environmental contamination from industrial, agricultural, and medical sources. Samples were collected from markets in Chonburi, prepared through boiling, frying, and grilling, and analyzed using ICP-MS/MS. Most toxic metal levels were within Thai regulatory limits; however, Wedge shell and Musk crab showed arsenic concentrations exceeding permissible levels. Risk assessment employed hazard quotient and margin of exposure calculations using consumption data stratified by age and cooking methods. Results demonstrated that arsenic presents the highest risk, particularly for children aged 0–5.9 years, with Wedge shell and Musk crab posing significant concerns. Cadmium and mercury generally posed low or no risk across samples, except for isolated high-level cadmium exposure in Wedge shell and occasional mercury concerns. Lead, based on the margin of exposure assessment, showed significant health risk for eater only group. The study concludes that although arsenic contamination in certain seafood species requires careful monitoring and public awareness, other toxic metals—particularly cadmium, mercury, and lead—currently present minimal health risks. Routine surveillance of seafood contaminants is essential to safeguard consumer health, particularly among vulnerable groups.

Selenium (Se) is an important trace element in our body; however, food composition data remain limited due to analytical challenges and interferences. Seafood, abundant in Thailand, is recognized as a rich source of Se. This study aimed to expand knowledge on Se content in seafood prepared using traditional Thai cooking methods. Twenty seafood species were selected and prepared by boiling, frying, and grilling. Inductively Coupled Plasma–Triple Quadrupole–Mass Spectrometry (ICP-MS/MS) was used to analyze total Se contents in selected seafood species. Results revealed significant variation in Se content across species and cooking methods. The Indo-Pacific horseshoe crab showed the highest Se concentration, with fried samples reaching 193.9 μg/100 g. Se concentrations were in the range of 8.6–155.5 μg/100 g (fresh), 14.3–106.6 μg/100 g (boiled), 17.3–193.9 μg/100 g (fried), and 7.3–160.1 μg/100 g (grilled). Results found significant effects of species and cooking method on Se content (p < 0.05). Fried seafood exhibited the highest estimated marginal mean Se concentration (a 78.8 μg/100 g edible portion), significantly higher than other methods. True retention (%TR) of Se ranged from 40.4% to 100%, depending on species and method. Bigfin reef squid, wedge shell, and silver pomfret showed the highest %TR (100%), while splendid squid exhibited the lowest (52.5%). Significant interaction effects on %TR were also observed (p < 0.05). Fried seafood had the highest mean %TR (88.8%), followed by grilled (82.1%) and boiled (79.7%). These findings highlight the effects of both species and cooking method on Se retention, emphasizing the nutritional value of selected seafood in preserving bioavailable Se after cooking.

This study identified the levels of arsenic, cadmium, mercury, and lead in 15 species of commonly consumed fish in Thailand (7 freshwater species, 8 marine species), as well as the risk of these toxic elements for consumers. Inductively coupled plasma mass spectrometry (ICP-MS-MS) was used to identify toxic elements, while an exposure assessment was conducted by applying consumption amounts from the national food consumption survey to the toxic element contents in the fish samples. The results showed that the fish contained arsenic ranging from less than the limit of detection (LOD) to 8.51 mg/kg fresh weight (FW), cadmium ranging from the LOD to 0.04 mg/kg FW, and mercury ranging from the limit of quantitation (LOQ) to 0.38 mg/kg FW. Lead was found in small amounts (<LOQ) when compared to the Codex and Thailand’s standards. Only grouper had a higher mercury content (0.55 mg/kg FW) than that of the Codex standard, but it was lower than the notification requirement of Thailand’s Ministry of Public Health. Based on the estimated daily intake scenario, the consumption of most fish species posed a low risk of concern in terms of cadmium and lead. A high risk of concern was found for arsenic exposure, with the exception of long, non-scaly fish (catfish and dory). Marine fish, with the exception of Indo-Pacific mackerel, also posed a high risk of mercury exposure, but only in the case of a high mercury content, high consumption, or both. For a high arsenic content with high consumption or both, children aged 0–5.9 years were at a high risk of concern. Food safety authorities should regularly monitor the levels of toxic element contamination in high-risk food products.

This study examined the effect and stability of ultraviolet B (UV-B) irradiation and subsequent cooking on vitamin D content in commonly consumed mushrooms in Thailand. Eight varieties of mushrooms were exposed to two-sided UV-B lamps for up to 3 h in a patented cabinet, followed by vitamin D content analysis. Thereafter, the four mushroom varieties with the highest vitamin D content were exposed to UV irradiation, cooked, and analyzed for various forms of vitamin D using LC-MS-MS. The results showed that vitamin D2 in all varieties of mushrooms significantly increased (p < 0.05) after UV-B irradiation according to the exposure time. The highest level of vitamin D2 was found in enokitake mushrooms. In addition, 25-OH D2 and vitamin D4 contents increased after UV-B irradiation in enokitake mushrooms. The vitamin D2 true retention in all cooked mushrooms ranged from 53 to 89% and was highest in stir-fried mushrooms. With economic investment, the two-sided UV-B cabinet has the potential to increase the vitamin D content in commercial mushroom production.

This study investigated the vitamin D level of nine species of cultivated mushrooms and three species of wild mushrooms commonly consumed in Thailand and the effect of cooking on their vitamin D content. Cultivated mushrooms were obtained from three wholesale markets, while wild mushrooms were collected from three trails in a conservation area. Mushrooms from each source were separated into four groups: raw, boiled, stir-fried, and grilled. Different forms of vitamin D were analyzed using liquid chromatography with tandem mass spectrometry (LC-MS/MS). The analyzed method demonstrated good linearity, accuracy, and precision, as well as being low in the limit of detection and limit of quantitation. Results showed that vitamin D2 and ergosterol (provitamin D2) were the major forms of vitamin D found in the mushrooms. Both raw cultivated and wild mushrooms had wide ranging ergosterol contents (7713–17,273 μg/100 g edible portion, EP). Lung oyster mushroom and termite mushroom contained high levels of vitamin D2 (15.88 ± 7.31 and 7.15 ± 0.67 μg/100 g EP, respectively), while other mushroom species had negligible amounts (0.06 to 2.31 μg per 100 g EP). True retention (TR) levels of vitamin D2 after boiling, stir-frying, and grilling were not significantly different (p > 0.05) (with estimated marginal means ± standard error 64.0 ± 2.3%, 58.8 ± 2.3%, and 64.7 ± 3.6% TR, respectively). Consuming cooked lung oyster mushrooms, in particular, along with regular exposure to sunlight should be promoted to reduce the incidence of vitamin D deficiency.

Selenium (Se), abundantly obtained in fish, is a crucial trace element for human health. Since there are no data on Se bioaccessibility from commonly consumed fish in Thailand, this study assessed the in vitro bioaccessibility of Se using the equilibrium dialyzability method. The five fish species most commonly consumed in Thailand were selected to determine total Se content using several preparation methods (fresh, boiling, and frying). Equilibrium dialyzability was used to perform in vitro bioaccessibility using enzymatic treatment to simulate gastrointestinal digestion for all boiled and fried fish as well as measuring Se using inductively coupled plasma triple quadrupole mass spectrometry (ICP-QQQ-MS). Two-way ANOVA with interaction followed by Tukey’s honestly significant difference (HSD) post hoc test revealed that boiled Indo-Pacific Spanish mackerel, longtail tuna, and short-bodied mackerel were significantly higher in Se content than striped snakehead and giant sea perch (p < 0.05). For fried fish, longtail tuna showed the highest Se content (262.4 µg/100 g of product) and was significantly different compared to the other fish (p < 0.05, estimated marginal means was 43.8–115.6 µg/100 g of product). Se bioaccessibilities from striped snakehead (70.0%) and Indo-Pacific Spanish mackerel (64.6%) were significantly higher than for longtail tuna (p < 0.05). No significant difference in bioaccessibility was found in terms of preparation method (i.e., boiling and frying). In conclusion, the fish included in this study, either boiled or fried, have high Se content and are good sources of Se due to high bioaccessibility.

Although fish are good sources of selenium (Se), an essential trace element for the human body, very limited data exist on Se content in commonly consumed fish in Thailand. Consequently, this study investigated selenium content and the effect of cooking among 10 fish species (5 freshwater and 5 marine) most-commonly consumed by the Thai people. The fish were purchased from three representative wholesale markets within or nearby to Bangkok. All fish species were prepared to determine their edible portions (EP) and moisture contents. Total Se in fresh, boiled, and fried fish were analysed using Inductively Coupled Plasma-Triple Quadrupole-Mass Spectrometry (ICP-QQQ-MS). In general, higher levels of Se were found in marine fish (37.1–198.5 µg/100 g EP in fresh fish, 48.0–154.4 µg/100 g EP in boiled fish, and 52.9–262.4 µg/100 g EP in fried fish) compared to freshwater fish (6.9–29.4 µg/100 g EP in fresh fish, 10.1–26.5 µg/100 g EP in boiled fish, and 13.7–43.8 µg/100 g EP in fried fish). While Longtail tuna showed significantly higher Se content than other fish (p < 0.05), boiled Longtail tuna had significantly lower true retention of Se than the other fish (p < 0.05). Most fish species retained a high level of selenium (ranged 64.1–100.0% true retention in boiling and frying). Longtail tuna, Short-bodied mackerel, Indo-pacific Spanish mackerel, Nile tilapia, and red Nile tilapia–cooked by boiling and frying–are recommended for consumption as excellent sources of selenium.

This study determined vitamin D content in commonly consumed fish in Thailand and the effects of different cooking methods on vitamin D retention. Five species of freshwater fish and four species of marine fish were purchased from three representative markets. All of the fish were individually prepared according to common household practices. Vitamin D2 and D3 were determined using the HPLC standard method (AOAC method 995.05). The results indicated that vitamin D3 was the only detectable form of vitamin D in the fish. Vitamin D content of raw freshwater fish ranged from 2.42 to 48.5 µg per 100 g edible portion (EP), which was higher than that of raw marine fish (2.94 to 4.69 µg per 100 g EP). Common silver barb, Red Nile tilapia, and Nile tilapia (freshwater fish living in the limnetic zone) contained high levels of vitamin D (48.5 ± 26.5, 31.0 ± 7.7, and 19.8 ± 3.5 µg per 100 g EP, respectively). Boiled fish (except for Common silver barb), fried fish (except for Striped snakehead, Walking catfish, and Common silver barb), and grilled fish (except for Common silver barb, Giant sea perch, and Short-bodied mackerel) retained high levels of vitamin D, which were not significantly different (p > 0.05) from raw fish. Common silver barb, Red Nile tilapia, and Nile tilapia—cooked by boiling, frying, and grilling—are recommended for consumption as excellent sources of vitamin D.