Level of heavy metals in marine ecosystem has been intensively studied during recent years as these hazardous substances could be accumulated in the biota. Generally, the presence of contaminants in fish is a result of human activities such as industrial and agricultural wastes. In this study, the marine fish and shellfish from the Straits of Malacca were analyzed using Inductively Coupled Plasma Optical Emission Spectrophotometer (ICP-OES) and Flow Injection Mercury System (FIMS) for Cd, As and Pb and Hg, respectively. The Straits of Malacca is one of the busiest shipping routes in the world that make the level of heavy metals potentially high besides the various industrial activities along the west region of Peninsular Malaysia. The range of heavy metals in samples were 1.0-3-6.5-3 µg/ g wet sample for Hg, 0.5-2-47-2 µg/ g wet sample for Cd, 0.01-0.39 µg/ g wet sample for Pb and 0.14-6.57 µg/ g wet sample for As. Most part of the values was below the permitted limit set by FAO/WHO 2004 as well as Food Act 1983 and Food Regulations 1985. Therefore it can be generalized that fish and shellfish from the Straits of Malacca are safe to consume in terms of these heavy metals concentrationand do not constitute a risk for human health.
Cockle (Anadara granosa) meat wash water precipitate was hydrolyzed using bromelain. Experiments were carried out to determine optimum conditions for temperature, enzyme concentration and hydrolysis time using response surface methodology (RSM) based on a central composite rotatable design (CCRD) to obtain the highest value of nitrogen content (NC) and degree of hydrolysis (DH). Results revealed that the optimum conditions for temperature, enzyme concentration and hydrolysis time were 33.7°C, 1.45% (E/S) and 28.42 hrs, respectively. At the optimum condition, hydrolysis of cockle meat wash water precipitate using bromelain resulted in a NC of 0.6% and DH of 48%. The NC and DH were significantly influenced by temperature, enzyme concentration and hydrolysis time. When the bromelain concentration, hydrolysis time and temperature were increased, the values of NC and DH also increased. The hydrolysate produced contained flavor compounds found in clam and oyster which were 3-methylbutanol and 1-pentanol. The compound 3-MCPD was not found in the hydrolysate.
A total of sixty V. parahaemolyticus strains isolated from local cockles (Anadara granosa) were investigated by their antibiotic resistance patterns and plasmid profiles. The isolates showed multiple resistances towards most of the antibiotics tested. All strains of V. parahaemolyticus isolated harbored 1-3 plasmids, with sizes ranging from 2.7 to 54 kb. All V. parahaemolyticus strains showed high multiple antibiotics in frequencies of 0.58 – 0.94 indicating that the strains were derived from high-risk sources. In addition, no particular plasmid profile was predictive of a particular pattern of antibiotic susceptibility. These findings are essential because of the suggested involvement of seafood especially shellfish and environment in transmission of this pathogen to human. Thus, indicating that seafood may be a source of food- acquired antibiotic resistant bacteria to consumer.
The total lipid contents and the concentration of eicosapentaenoic (EPA) and docosahexaenoic
(DHA) fatty acid of fourteen selected marine, three freshwater fish species, four shellfish species and two selected canned fish species of East Coast of Peninsular Malaysia were determined. The fat content of all samples ranged from 1.01 % to 15.83 % with silver catfish reported to have the highest value. Most of the fish had fat amounts lower than 10% of their total weight. In general, DHA concentrations (50.50-165.21 µg/g) were significantly higher than EPA (11.12-55.38 µg/g) in all of the fish species analyzed. Among all marine fish species, the sixbar grouper recorded the highest concentration of DHA (165.21 µg/g) while barramundi had the highest concentration of EPA (55.38 µg/g). In conclusion, all fish and shellfish species are considered a good source of EPA and DHA, representing a very valuable essential nutrient for maintenance of human health.
The study was conducted to determine the mineral contents of 20 species of marine fish and 4 species of shellfish from the west coast of Peninsular Malaysia.Overall, the contents of micro minerals in all samples were below the permissible limits; except for oyster; with copper slightly higher than the limit set by FAO/WHO (1984), but below the limit set by Malaysian Food Regulations (1985); and zinc content higher than the limit set by Malaysian Food Regulations (1985), but below the limit set by FAO/WHO (1984). Meanwhile for macro minerals, most samples contained comparable sodium contents, significantly lower of potassium contents, higher calcium contents, and extremely higher of magnesium contents compared to the common ranges reported in the literatures. All samples were good sources of micro and macro minerals and could provide multi-health benefits if consumed in recommended amounts.
Aimed of this study was to determine the presence of Vibrio cholerae in cockles (Anadara granosa)
from different coasts in Malaysia and to measure the biosafety of V. cholerae in raw cockles at wet market in Malaysia using the polymerase chain reaction (PCR) in combination with the most probable number (MPN) method. A total of 100 samples from 4 different wet markets in the West and East were examined for the presence of V. cholerae. The prevalence of V. cholerae between the two coasts was not significant different. In fact, the 74% of samples from West coast area was found positive while the 69% for samples collected in the East coast. West coast samples showed a prevalence of 60% for the wet market A=, 64% for B=, 88% for C= and 84% for the market D); East coast samples showed the same percentage with 72% for the wet markets E, F and H, followed by wet market G with 60%.With the MPN-PCR method, using 80 samples of raw cockles obtained from 4 wet markets, the occurrence of V. cholerae detected was of 95%. The frequency of V. cholerae in raw cockles obtained from wet market I and L was higher (100%) compared to other wet market (Wet market B=, 90%; Wet market C=, 95%).The density of V. cholerae detected in all samples ranged from 24000 MPN/g, but most of the samples (24 samples) were in category >24000 MPN/g concentration. V. cholerae was present in raw cockles in higher number. Hence, these results demonstrate the presence of pathogenic V.cholerae in cockles harvested and reveal the potential risk of illness associated with their consumption. This study will be the first biosafety assessment of V. choleare in raw cockles in Malaysia and it will provide significant insights about Malaysian scenario.
Vibrio parahaemolyticus is prevalent in tropical marine environment in all seasons and can cause seafood-borne gastroenteritis. A total of 251 suspected isolates were tested including 60 from frozen shrimp, 50 from cultured live shrimp, 67 from sediments of culture ponds and 74 from water were subjected to polymerase chain reaction (PCR) targeting the toxR gene for confirmation as V. parahaemolyticus. Of the 128 toxR positive isolates, 15% of the isolates from culture environment (from live shrimp, sediments and water) and 7% of frozen shrimp samples were positive for the tdh and trh genes. Since urease production could be a marker of trh but not tdh in V. parahaemolyticus, a total of 189 of the 251 suspected V. parahaemolyticus isolates were tested for urease production and 41% of the isolates were found to be positive for urease production. However not all urease positive strains of V. parahaemolyticus were positive for either tdh or trh genes. Detection of virulent strains in shrimp culture environment in Malaysia suggests a probable risk for health of people consuming raw shrimp.
Vibrio parahaemolyticus is a main foodborne disease in seafood and generally seafood is
easily deteriorates in quality of color and flavor. In this study, clove (Syzygium aromaticum)
extract shows potent antibacterial activity against growth of antibiotics resistant Vibrio
parahaemolyticus on seafood samples (cockles and shrimps). Vibrio parahaemolyticus was
artificial contaminates on the samples with 106 CFU/ml. The samples were treated with different
concentration of cloves extract with 10 mg/ml which are 0.5%, 5% and 10% concentration
from methanol food grade extraction in 0 hr, 5 min, 10 min, 15 min, 30 min, 60 min and
120 min. Tab water and deionized water were selected as a negative control. As a result, the
amount of 10 % cloves managed to mitigates the number of V. parahaemolyticus on seafood
samples in 5 minutes and 15 min on both samples. Therefore, our results signify the fact that
cloves can be apply as natural sanitizer which could meet consumer demands for safe and
traditionally consumed either raw without any undesirable effect when applied in the seafood
system industries.
DNA damaging effect of the salted and fermented food products (salted fishes, dried shrimps and shrimp pastes) collected from three different locations in Malacca namely Pantai Puteri, Batang Tiga and Kelemak on the DNA of the Chang liver cells were evaluated via Alkaline Comet Assay. Treatment at 62.5 mg/ml following 24 hours of incubation was used based on the preliminary cytotoxicity data. Percentage of damage to the DNA was calculated using software for scoring based on the tail moment and tail intensity (severity of the DNA damage). Hydrogen peroxide was used as positive control at 0.1 mM following 30 minutes of incubation in 4 C. The results showed that the methanol extracts of shrimp pastes and salted fish from Pantai Puteri, exhibited a higher DNA damage (shrimp pastes - TM - 8.33 ± 2.19; TI - 31.67 ± 5.84, salted fishes - TM - 2.25 ± 0.86; TI - 9.25 ± 1.55) and were expressed as (shrimp pastes) 56.66 ± 8.74% of DNA damage and methanol salted fish extracts from the same location showed 13.00 ± 2.84% of the DNA damage on Chang liver cells compared to the other extracts. Values for methanol extract of shrimp pastes from Pantai Puteri were comparable to the positive control - Hydrogen peroxide (TM- 9.50 ± 1.50; TI - 30.50 ± 2.50). On the other hand, aqueous salted fishes extract from Pantai Puteri (TM - 1.33 ± 0.42; TI - 8.67 ± 2.42) and shrimp pastes extracts from Kelemak (methanol extract - TM -1.75 ± 0.15; TI -7.50 ± 0.50, aqueous extract - TM - 1.00 ± 0.00; TI - 5.00 ± 0.00) showed slightly high value for tail moment and tail intensity as compared to negative control (TM - 0.29 ± 0.05; TI - 2.50 ± 0.29). Values for methanol extracts of shrimp pastes from Pantai Puteri were comparable to the positive control (TM- 9.50 ± 1.50; TI - 30.50 ± 2.50). In conclusion, our results demonstrate genotoxic damage induced by few salted and fermented food extracts in Chang liver cell.
Harmful algal blooms (HABs) events have been increasingly reported in the country, not only of the frequency and severity of the events, but also involved more species than previously known. In this paper, a decadal review of HABs events in Malaysia is summarized. Bloom events caused by harmful dinoflagellate species including the shellfish poisoning events were highlighted. Paralytic shellfish poisoning (PSP) is no longer restricted to Sabah coasts and Pyrodnium bahamense. Bloom of Alexandrium minutum was reported for the first time in the Peninsula with six persons hospitalized including one casualty after consuming the contaminated benthic clams. Algal blooms that are associated with incidence of massive fish kills have been reported from both east and west coasts of the Peninsula in conjunction to finfish mariculture loses. The culprits of these bloom events have been identified as the dinoflagellates, Cochlodinium polykrikoides, Neoceratium furca, Prorocentrum minimum, Noctiluca scintillans and a raphidophyte, Chatonella ovata. In this paper, some of these HABs species were characterized morphologically and genetically, including their toxicity. Therefore, with the increase of coastal utilization and eutrophication, prevention, management and mitigation strategies, such as site selection, moving pens, clay spraying should be adopted to minimize the impact of these natural events.
This study was conducted to determine the proximate composition and energetic value of selected marine fish and shellfish from the West Coast of Peninsular Malaysia. This study has included 20 species of fish (10 pelagic fish and 10 demersal fish) and 4 species of shellfish. For pelagic fish, Longtail shad (terubuk) was found to contain significantly lower moisture (59.31+0.00%), but significantly higher fat content (23.15+0.00%) compared to other fish species. For demersal fish, moisture and ash contents ranged between 74-82%, and 0.9-2.1%, respectively. Long-tailed butterfly ray contained the highest protein (22.22+1.24%) compared to other fish studied. The highest fat content of demersal fish was in Moonfish at 6.89+2.76%. For shellfish, prawn contained the highest protein (19.12+1.44%). The fat content of shellfish ranged between 1-2%. Oyster contained significantly higher carbohydrate at 6.45+0.00%, compared to other shellfish. Longtail shad contained the highest energetic value of 13.34 kJ g-1 of all samples. These values are useful references for consumers in order to choose fish and shellfish based on their nutritional contents.
The concentrations of cadmium, copper, zinc and lead, in the total soft tissues of green-lipped mussel Perna viridis of a wide range of sizes (2-11 cm), were determined from a population at Pasir Panjang. The metal contents (μg per individual) and concentrations (μg per g) of cadmium, lead, copper and zinc were studied in P. viridis to find the relationships with body sizes. Smaller and younger mussels showed higher concentrations (μg per g) of Cd, Pb and Zn than the larger and older ones. The results of the present study showed that the plotting of the metal content, against dry body flesh weight on a double logarithmic basis, gave good positive straight lines; this observation is in agreement with Boyden’s formula (1977). This indicated that P. viridis showed a different physiological strategy for each metal being studied, which is related to age.
The recurrent environmental and economic issues associated with the diminution of fossil fuels are the main impetus towards the conversion of agriculture, aquaculture and shellfish biomass and the wastes into alternative commodities in a sustainable approach. In this review, the recent progress on recovering and processing these biomass and waste feedstocks to produce a variety of value-added products via various valorisation technologies, including hydrolysis, extraction, pyrolysis, and chemical modifications are presented, analysed, and discussed. These technologies have gained widespread attention among researchers, industrialists and decision makers alike to provide markets with bio-based chemicals and materials at viable prices, leading to less emissions of CO2 and sustainable management of these resources. In order to echo the thriving research, development and innovation, bioresources and biomass from various origins were reviewed including agro-industrial, herbaceous, aquaculture, shellfish bioresources and microorganisms that possess a high content of starch, cellulose, lignin, lipid and chitin. Additionally, a variety of technologies and processes enabling the conversion of such highly available bioresources is thoroughly analysed, with a special focus on recent studies on designing, optimising and even innovating new processes to produce biochemicals and biomaterials. Despite all these efforts, there is still a need to determine the more cost-effective and efficient technologies to produce bio-based commodities.
The shrimp paste called belacan is a traditional umami taste condiment extensively used in Malaysia that is rich in glutamate and 5'-nucleotides. The aim of this study was to determine the concentration of glutamate and 5'-nucleotides of various types of foods prepared with belacan and to measure their sensory attributes. The concentration of free glutamic acid found in different brands of belacan was 180-530mg/100g and in local dishes 601-4207mg/100g. The total amount of 5'-nucleotides in belacan samples ranged from 0.85 to 42.25μg/g. A Quantitative Descriptive Analysis (QDA) using a list of 17 sensory attributes showed a good correlation between belacan concentration in the final food and a range of positive sensory attributes, except for bitter, sweet, sour taste and astringency. Belacan also contains bitter, sweet and sour compounds that change the positive attributes of belacan at higher concentrations. The highest aroma attributes were linked to nasi goreng belacan (belacan fried rice) while the highest flavour attributes were found in sambal belacan. There was a 32 folds significant increase of umami attributes with the addition of belacan to final foods. The optimum amount of belacan was 0.45% for asam pedas (tamarind flavoured dish with belacan), 18% for sambal belacan (chilli belacan), 1.5-2.5% for kangkong goreng belacan (stir fried water convolous with belacan), and 2% for nasi goreng belacan.
This is the first report in which a marine mollusc, Oliva vidua fulminans (olives), generally not known to be poisonous, was responsible for death in five children after consuming boiled olives with tamarind. The onset of symptoms was rapid 10 to 20 min after consumption of the olives. Signs and symptoms included nausea, vomiting, abdominal pain, tingling sensation around the lips, numbness around the mouth, drowsiness, lethargy and generalized weakness with paraesthesia in the limbs. The five deaths occurred within 3 to 4 hours after eating the poisoned olives and resulted from respiratory failure. Left-over olives from the affected household and freshly collected live olives had a toxicity of 14,200 mouse units (M.U.) and 15,000 M.U. per 100 g meat respectively. No other common chemical poison and organophosphorus insecticides were detected. The neurotoxic agent was acid and heat stable and was toxic at pH less than 4. Its action was similar to that of paralytic shellfish poisoning which was caused by toxins from certain dinoflagellates.
Species of the benthic dinoflagellate Gambierdiscus produce polyether neurotoxins that caused ciguatera fish/shellfish poisoning in human. The toxins enter marine food webs by foraging of herbivores on the biotic substrates like macroalgae that host the toxic dinoflagellates. Interaction of Gambierdiscus and their macroalgal substrate hosts is believed to shape the tendency of substrate preferences and habitat specialization. This was supported by studies that manifested epiphytic preferences and behaviors in Gambierdiscus species toward different macroalgal hosts. To further examine the supposition, a laboratory-based experimental study was conducted to examine the growth, epiphytic behaviors and host preferences of three Gambierdiscus species towards four macroalgal hosts over a culture period of 40 days. The dinoflagellates Gambierdiscus balechii, G. caribaeus, and a new ribotype, herein designated as Gambierdiscus type 7 were initially identified based on the thecal morphology and molecular characterization. Our results showed that Gambierdiscus species tested in this study exhibited higher growth rates in the presence of macroalgal hosts. Growth responses and attachment behaviors, however, differed among different species and strains of Gambierdiscus over different macroalgal substrate hosts. Cells of Gambierdiscus mostly attached to substrate hosts at the beginning of the experiments but detached at the later time. Localized Gambierdiscus-host interactions, as demonstrated in this study, could help to better inform efforts of sampling and monitoring of this benthic toxic dinoflagellate.
Several of the coastal zones in Sabah, Malaysia, are isolated and inaccessible. This study aimed to review the published literature on the health status of the coastal communities in Sabah. The following four main health issues were found: (i) malaria, (ii) tuberculosis (TB), (iii) seafood poisoning, and (iv) antenatal problems. Factors associated with the risk of acquiring malarial infection in the studied coastal area were advanced age, male sex, farming as an occupation, history of travel outside the village, and rainy seasons. TB infection was primarily observed in adult men. Seafood poisoning was significantly common in Sabah. Studies have reported that tetrodotoxin and paralytic shellfish poisoning were commonly reported (30-60 cases annually). Several pregnant women in the coastal community had insufficient knowledge of the national antenatal care programme. Nonetheless, 99% of them received antenatal care at public healthcare facilities with 92% of them undergoing safe delivery. Nevertheless, a majority of the pregnant women had iodine deficiency due to low iodised salt intake. Findings from this review highlighted that the coastal communities in Sabah are experiencing significant health problems. Specific attention is required to significantly enhance the health and well-being of the individuals living in the coastal communities in Sabah.