A good temperature management, such as precooling and cold storage, can delay deterioration of fresh produce. In this study, different forced-air precooling times were applied on Musa AAA Berangan to investigate the influence of forced-air precooling time on the changes of quality attributes and consumer acceptance. The banana was subjected to forced-air precooling treatment (5 ± 1°C) for 0, 14, 50, and 120 min and then stored in a cold room (13 ± 1°C) for 2 weeks. Then, all the fruits were transferred to a ripening room (25 ± 2°C) and initiated to ripen with ethylene gas. Quality attributes analyses and sensory evaluations were conducted when the fruits reached maturity index 5. Quality parameters, such as soluble solids concentration, titratable acidity, pulp firmness, and peel colour, showed no significant differences when fruits were precooled at different times. Blackening of peel as a result of chilling injury occurred in fruits treated with forced-air precooling for 50 and 120 min. This blackening significantly influenced consumer acceptance, although it did not affect the pulp colour and taste.
Foodborne pathogens have become a constant threat to the consumer and food industry.
Reduce efficacy of antibiotics with emergence of resistant bacteria has limited the opportunities
for controlling pathogenic bacteria in food commodities and treating foodborne infections.
Bacteriophages can be a promising alternative for alleviate the risk of transmitting pathogenic
bacteria via food commodities. Therefore, this research was conducted to find distribution of
bacteriophages in diverse niches in order to identify suitable sources for isolating bacteriophages
to use controlling foodborne pathogens. Firstly bacterial strains were screened for lysogenic and
selected suitable host bacterial strains were used for isolating and determining bacteriophage titer
in fresh raw food and environmental samples. Eighteen different lytic bacteriophages effective
against Campylobacter, S. aureus, L. monocytogenes and E. coli were isolated from this study.
Bacteriophages titer was determined within range of 102
to 1010 PFU/mL and bacteriophages
were most frequently isolated from chicken (60%) samples. The isolated bacteriophages could
be potential candidates for controlling foodborne diseases.
Street food is popular in Asia due to its availability, low price and good taste. The safety of
street food has been always questionable due to its poor handling which probably leads to
microbial contamination. The objective of this study was to determine the surviving quantities
of V. parahaemolyticus under various conditions in street-vended food, namely satar and otakotak
after anticipated cross-contamination to support policy and regulatory documents. The
satar and otak-otak were prepared from minced and unminced fish flesh, respectively, together
with other ingredients. Each satar and otak-otak were prepared with 0, 0.5, 1.5 and 3% of
sodium chloride (NaCl), respectively. V. parahaemolyticus inoculum at approximately 8.66 log
CFU/ml were inoculated into the samples and incubated for up to 6 h. Samples were taken at 0,
1, 3 and 6 h for enumeration of V. parahaemolyticus using spread plate method on Thiosulphate
Citrate Bile Salts Sucrose (TCBS) agar. For control samples, V. parahaemolyticus was not
immediately inactivated in distilled water even though significant better survivability was
observed in Phosphate Buffer Saline (PBS). The numbers of V. parahaemolyticus was found
to decrease by varying amounts based on the salt content and duration of holding. However,
significant amounts survived to indicate potential risk.
Ultra high temperature (UHT) treated milk products and formula milk are known to be
frequently contaminated with Bacillus cereus. Presence of B. cereus in these milk products is
of particular concern considering the majority of consumers are infants and children. Possible
sources of contamination are contaminated raw milk, cross-contamination during processing,
under-processing and mishandling of milk products. This study was conducted to detect the
presence of B. cereus in both formula milk (n=12) and UHT milk (n=20) sold in selected retail
markets. The approach consisted of enumerating by MPN/g followed by PCR assay aimed
at detecting gyrB gene in B. cereus, that encode for the subunit B protein of DNA gyrase
(topoisomerase type II). Contamination level of B. cereus in both types of samples examined
ranged from < 3 to > 1100 MPN/g. The contamination level of B. cereus was found to be
highest in full cream UHT milk (> 1100 MPN/g) and formula milk (> 1100 MPN/g). The PCR
analysis showed that 41.7% (5/12) formula milk and 30% (6/20) UHT milk samples were
detected with B. cereus, respectively. This is the first report of such study demonstrating the
presence of B. cereus in formula milk from Malaysia. Therefore, constant surveillance of these
milk products would reduce the potential risk of B. cereus-linked outbreaks.
Listeria monocytogenes is a gram positive, facultative intracellular pathogen with the capacity to cause
food poisoning outbreaks as well as severe illness in vulnerable human population groups. It can cause a rare but serious disease called listeriosis with high fatality rates (20–30%) compared with other foodborne microbial pathogens. Although Listeria monocytogenes is infective to all human population groups, it is more likely to cause severe problems among pregnant women, immunocompromised individuals, the elderly and neonates. There are a variety of phenotyphic and genotyphic methods for the detection of Listeria monocytogenes in foods. Recent technological advances have increased the ability of scientists to detect Listeria monocytogenes. The purpose of this review is to discuss molecular characteristics of the Listeria monocytogenes pathogen, standard detection methods of this pathogen in foods based on culture methods, confirmation of species and subtyping based on phenotypic and genotyphic methods.
Little is known on the biosafety level of Vibrio spp. in freshwater fish in Malaysia. The purpose of this study was to investigate the prevalence and concentration of Vibrio spp. and V. parahaemolyticus in
freshwater fish using the Most Probable Number-Polymerase Chain Reaction (MPN-PCR) method. The study was conducted on 150 samples from two types of freshwater fish commonly sold at hypermarkets, i.e. Pangasius hypophthalmus (catfish) and Oreochromis sp. (red tilapia). Sampling was done on the flesh, intestinal tract and gills of each fish. The prevalence of Vibrio spp. and V. parahaemolyticus was found to be 98.67% and 24% respectively with higher percentages detected in samples from the gills followed by the intestinal tract and flesh. Vibrio spp. was detected in almost all red tilapia and catfish samples. V. parahaemolyticus was detected in 25% of the catfish samples compared to 22.6% of red tilapia fish. The density of Vibrio spp. and V. parahaemolyticus in the samples ranged from 0 to 1.1x107 MPN/g. Although the maximum value was 1.1x107 MPN/g, most samples had microbial loads ranging from 0 to >104 MPN/g. The outcome on the biosafety assessment of Vibrio spp. and V. parahaemolyticus in freshwater fish indicates another potential source of food safety issues to consumers.
The organic foods’ market is becoming one of the rapidly growing sections in agricultural economies in the world. During the last two decades, food-borne outbreaks associated with fresh produce have rapidly increased. E. coli O57:H7, the caustic agent of acute hemorrhagic diarrhea and abdominal cramps, is mainly associated with meat and poultry product outbreaks but frequent outbreaks linked to the consumption of vegetables have been reported. The aim of this study was to investigate prevalence of E. coli O157:H7 in some organic foods. A total of 230 organic food samples including four-winged bean, tomato, white radish, red cabbage, chinese cabbage, lettuce, cucumber and chicken form retailed groceries and supermarkets in Malaysia were investigated. Low prevalence of E. coli O157:H7 was detected in organic vegetables and chickens. The estimated quantity of E. coli O157:H7 in all samples ranged from 2400 MPN/g. The overall MPN/g estimate of E. coli O157:H7 in the samples from organic groceries was higher than supermarket with the maximum of >2400 MPN/g. Most of the samples from supermarket showed a minimum of
Listeria monocytogenes (L. monocytogenes) is a serious food-borne pathogen for immunocompromised individuals. L. monocytogenes is capable of producing biofilm on the surface of food processing lines and instruments. The biofilm transfers contamination to food products and impose risk to public health. Transfers contamination to food products, and impose risk hazard to public health. The aim of this study was to investigate biofilm producing ability of L. monocytogenes isolates. Microtitre assay was used to measure the amount of biofilm production by ten L. monocytogenes isolates from minced chicken / meat, sausages and burgers. Results showed that all 10 L. monocytogenes isolates were able to form biofilm after 24 h at 20˚C on polystyrene surface (the common surface in food industries). Some strains were capable of forming biofilm more than the others. All strains showed a slight raise in the quantities of attached cells over 48 and 72 h. L. monocytogenes strains isolated from minced chicken, minced meat and burgers were better biofilm-producers comparing to the strains isolated from sausages.
E. coli O157:H7 is associated with life threatening diseases such as hemorrhagic colitis (HC), hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). Raw milk is considered a high risk food as it is highly nutritious and serves as an ideal medium for bacterial growth. The aim of this study was to investigate the prevalence of E. coli O157:H7 in raw cow, goat and buffalo milk samples. MPN-PCR method targeting the major virulence rfbE gene and fliCH7gene of E. coli O157:H7 was used. Total of 177 raw milk samples were collected from local dairy farms in the state of Selangor, Malaysia. The highest prevalence of E. coli O157:H7 was found in raw cow milk (18.75%). E. coli O157:H7 was detected in 7.32% and 3.57% of raw goat and buffalo milk, respectively. The estimated quantity of E. coli O157:H7 in raw cow, goat and buffalo milk ranged from
Nowadays, the incidence rate of foodborne disease has increased and become one of the global burdens affecting all individual ages in South East Asia region. Foodborne disease is responsible for mortality and morbidity worldwide thus affecting socio-economic and quality of life. Major causes of foodborne hazards diseases include diarrheal and invasive infectious disease agent, helminthes and chemicals. However, in developing countries, data and record is insufficient with poor surveillance systems leading to incomplete information on the real burden of foodborne disease. The introduction of Actor Network Theory (ANT) as tools for assessing and analyzing the food safety issues has drawn attention from various researcher as it is proven to be able to point out and identify the human and non human actors which is directly and contingently involved. The interaction between the actors such as a worker in an organization, student in school, and peoples in public provide information that can be used to minimize the risk of foodborne disease. The ultimate use of ANT is it helps the researcher to draw a framework of the source of contamination, agent responsible, factors involved, and idea to control the spread.
The prevalence of Salmonella in chicken and beef sold in retails outlets in Malaysia was
determined by analysing 312 raw beef and chicken meat samples including their processed
products. Samples purchased from supermarkets, butcher shops and wet market, which being
classified into raw, minced and processed chicken and beef. A total of 86 (27.6%) samples were
found positive for Salmonella spp., with chicken meat samples (40.4%) showed greater presence
compared to beef (15.4%). Highest presence of Salmonella were detected from wet market
samples (35.4%), followed by supermarket (26.9%) and butcher shop (21.3%). The prevalence
of Salmonella were higher in unpacked chicken meat (84.8%), followed by unpacked beef
(27.8%). Salmonella serovars were identified as S. Enteritidis, S. Hadar, S. Dublin, S. Anatum,
S. Stanley, S. Gallinarum, S. Choleraesuis and S. Typhimurium. Detection of 8 Salmonella
serovars showed possibilities of cross contamination in various sources either at slaughtering
house, processing plant or until storage at retails level. Improper cooking method on meats and
hygiene practices prior to consume should be avoided in order to ensure food safety before
ingestion.
Bacteriophages are the viruses of bacteria and are widely distributed in the biosphere, exhibiting
dramatic manifestations both in liquid cultures and on solid media. In this study, bacteriophages
were isolated from different types of food (beef, chicken meats, cucumber, lettuce, clam,
cockles and shrimp) and sewage samples using 6 reference pathogen strains (Salmonella
Enteritidis, Salmonella Typhimurium, Campylobacter jejuni, Vibrio parahaemolyticus, Listeria
monocytogenes and Escherichia coli). A total of 29 bacteriophage isolates were obtained and
further examined for titer via agar overlay assay. The titers were determined within the range
of 108
to 1011 PFU/mL. Our results showed that diverse of bacteriophages are naturally present
in a variety of foods.
Listeriosis and salmonellosis are the major foodborne illnesses worldwide. Over the last decade,
increasing reports about the antibiotic resistance of Listeria monocytogenes and Salmonella from diverse sources have prompted public health concerns, especially in developing countries with over reliance or misuse of antibiotic drugs in the treatment of humans and animals. In this study, antibiotic susceptibility profiles of 58 L. monocytogenes and 12 Salmonella Enteritidis strains from vegetable farms and retail markets in Malaysia were testedby the standard disk diffusion method. Listeria monocytogenes isolates were found to exhibit 100% resistance to penicillin G. Also, high resistance patterns were observed for meropenem (70.7%) and rifampicin (41.4%). The multiple antibiotic resistance (MAR) index of L. monocytogenes isolates ranged from 0.11 to 0.56. Besides, the antibiogram results revealed that multidrugresistant (MDR) S. Enteritidis were detected and all the S. Enteritidis isolates demonstrated resistance to at least four antibiotics. Ampicillin, amoxicillin, and trimethoprim failed to inhibit all the S. Enteritidis strains. Salmonella Enteritidis isolates also displayed high resistance to nalidixic acid (75.0%), trimethoprim-sulfamethoxazole (75.0%), and chloramphenicol (66.7%). Findings in this study indicated that vegetables could be potential sources of multidrug resistance of L. monocytogenes and S. Enteritidis, which can be a serious issue and a major concern for public health. Thus, there is a great need for surveillance programs in Malaysia to continuously monitor the antibiotic resistance profiles of important pathogens.
Salmonellosis is an important public health problem and causes large economic losses in the poultry industry. The emergence of molecular technology has opened various possibilities for constructing tailor-made proteins, particularly protein E from bacteriophage PhiX174 for the
production of bacterial ghosts (BGs) applied in vaccines purposes. In the present study, the plamdaPRcI-Elysis plasmid carrying the PhiX174 lysis gene E and thermo-sensitive lamda PR-cl857 regulatory system was constructed. Two Salmonella Enteritidis (SE-2 and SE- 4) and one Salmonella Typhimurium (ST-4) isolates were able to uptake the lysis plasmid via electrotransformation. Generation of ghosts was enhanced by increasing the incubation temperature up to 42˚C. Cell viability of SE-2, SE-4 and ST-4 decreased ranging in log 2.7 to log 4.1 cycles after lysis induction. Moreover, SE-2 and SE-4 exhibited the earliest reduction of CFU after 3 h of incubation. Our results may provide a promising avenue for the development of Salmonella BGs vaccines.
The diversity of specific bacteria taxa, such as the actinomycetes, has not been reported from the Antarctic island of Barrientos. The diversity of actinomycetes was estimated with two different strategies that use PCR-denaturing gradient gel electrophoresis. First, a PCR was applied, using a group-specific primer that allows selective amplification of actinomycete sequences. Second, a nested-PCR approach was used that allows the estimation of the relative abundance of actinomycetes within the bacterial community. Molecular identification, which was based on 16S rDNA sequence analysis, revealed eight genera of actinomycetes, Actinobacterium, Actinomyces, an uncultured Actinomycete, Streptomyces, Leifsonia, Frankineae, Rhodococcus, and Mycobacterium. The uncultured Actinomyces sp and Rhodococcus sp appear to be the prominent genera of actinomycetes in Barrientos Island soil. PCR-denaturing gradient gel electrophoresis patterns were used to look for correlations between actinomycete abundance and environmental characteristics, such as type of rookery and vegetation. There was a significant positive correlation between type of rookery and abundance of actinomycetes; soil samples collected from active chinstrap penguin rookeries had the highest actinomycete abundance. Vegetation type, such as moss, which could provide a microhabitat for bacteria, did not correlate significantly with actinomycete abundance.
The effect of 18 different chemicals, which included acidic compounds (sulfuric acid, chloridric acid, phosphoric acid, benzoic acid, citric acid, acetic acid), alkaline compounds (ammonia, sodium bicarbonate, sodium hydroxide, potassium hydroxide, calcium hydroxide), salts (acetate ammonium, sodium bisulfite, sodium hydrosulfite, sodium chloride, sodium sulfate) and oxidising agents (hydrogen peroxide, sodium hypochlorite), on the reduction of aflatoxins B(1), B(2), G(1) and G(2) and ochratoxin A (OTA) was investigated in black and white pepper. OTA and aflatoxins were determined using HPLC after immunoaffinity column clean-up. Almost all of the applied chemicals showed a significant degree of reduction on mycotoxins (p < 0.05). The lowest and highest reduction of aflatoxin B(1), which is the most dangerous aflatoxin, was 20.5% ± 2.7% using benzoic acid and 54.5% ± 2.7% using sodium hydroxide. There was no significant difference between black and white peppers (p < 0.05).
Escherichia coli O157:H7 is a major food-borne pathogen that has resulted in numerous
outbreaks around the world. Widespread distribution of the organism in various ecological
niches impedes the control measures. This study aimed to detect and quantify E. coli O157:H7
in beef sold in wet markets and hypermarkets in Malaysia and to determine the risk of E. coli
O157:H7 infection linked to consumption of beef. The rfbO157 and flicH7 primers targeted on
somatic antigen (O157) and flagellar antigen (H7) respectively of E. coli O157:H7 was used for
the MPN-PCR method. A total of 99 beef samples were collected from local wet markets and
hypermarkets. The highest E. coli O157:H7 contamination rate was observed in beef samples
collected from wet markets (89.50%), whereas the contamination rate in hyper market A and B
were compratively low (35.35 and 20% respectively). However, the microbial load was highest
in the beef samples from hypermarket A (1100 MPN/g) while E. coli O157:H7 bacterial load
in beef samples from hypermarket B and wet market ranged from 3 to 93 MPN/g and 3 to 240
MPN/g, respectively. Using the Quantitative Microbial Risk Assessment (QMRA) approach
the risk was estimated incorporating the findings of the prevalence study and predictions
based on home storage, cooking and consumption patterns. Three different exposure pathways
were investigated to estimate the risk associated with contaminated beef and Monte Carlo
simulation was used to determine the level of uncertainty. The developed model predicated that
consumption of contaminated beef can be accountable for 1.83E+06 E. coli O157:H7 cases per
year in Malaysia. The reliability of the model, data gaps and further research needs, is discussed.
Through continuous improvement Quantitative Microbial Risk Assessment provides valuable
insight into controlling and prevention strategies.
Cross contamination is one of the most important contributing factors in foodborne illness
originating in household environments. The objective of this research was to determine the
transfer between naturally contaminated chicken liver and leg to cutting board, hand glove,
knife and cucumber, during slicing. The microorganism tested was Campylobacter jejuni and
the results showed that the pathogen transferred to all utensils, at different transfer rate, despite
the low level of the naturally contaminating pathogen. With unknown concentration bacteria in
the naturally contaminated samples, a proportion of the utensils were still contaminated with C.
jejuni and not surprisingly, when the sample were contaminated with higher concentrations of
the pathogen, a higher proportion of the utensils had detectable C. jejuni cells present, though
in many cases cross contamination seems to be a random event. Transfer of the naturally
contaminating C. jejuni from the chicken liver and leg to the utensils were
The safety level of microwaved foods remains at vague as this subject was less addressed
scientifically. A study was initiated to address the matter by investigating on the
survivability of Salmonella and Shiga-toxigenic Escherichia coli (STEC) O157 in
microwave heated ready-to-eat (RTE) foods using the Most Probable Number coupled
Polymerase Chain Reaction (MPN-PCR) technique. A total of 329 samples of various
ready-to-eat (RTE) convenience meals were collected around Wilayah Persekutuan Kuala
Lumpur and Selangor regions. Salmonella was positively identified in 66 samples (20.1%,
This goal of this study was to investigate the presence of Vibrio cholerae in street food,
namely satar and otak-otak, using Loop-Mediated Isothermal Amplification (LAMP),
multiplex Polymerase Chain Reaction (mPCR) and conventional plating on Thiosulphate
Citrate Bile-Salt Sucrose (TCBS) agar methods. A total of 78 satar and 35 otak-otak were
purchased from different districts of Terengganu (Besut, Setiu, Kuala Terengganu and
Kemaman). V. cholerae was found in satar with LAMP (10.3%), mPCR (10.3%) and
plating (0%). No V. cholerae was found in otak-otak using the three methods. This might
be due to V. cholerae able to survive in satar after grilling due to its thickness which may
contribute to undercooking. This study concluded that low presence of V. cholerae in satar
and otak-otak can be detected by molecular methods but not the conventional plating
method. LAMP assay is a useful tool for rapid detection of pathogens in food due to its
simplicity, highly sensitive and visual interpretation capability. Though the prevalence of
V. cholerae was low in the samples, proper handling of this food will help in reducing the
risk of acquiring infection from V. cholerae in contaminated samples.