Vibrio cholerae still represents a significant threat to human health worldwide despite the advances in hygiene, consumer knowledge, food treatment and food processing. In Malaysia, statistics in year 2009 have shown that among the food and water borne diseases, food poisoning has the highest incidence rate of 36.17 per 100,000 populations and with a mortality rate of 0.01 per 100,000 populations. In this study, 22 seafood samples comprising of fish, squid, crustacean and mollusks purchased from wet market and supermarket were analyzed. The Most Probable Number (MPN) and real time PCR was used to enumerate the Vibrio cholerae in seafood sample. The results showed that MPN-real time PCR of the samples from wet market had a maximum of >1100 MPN/g compare to 93 MPN/g enumerated from the MPN plate. The MPN-real time PCR in the samples from supermarket indicated 290 MPN/g as compared to 240 MPN/g enumerated from the MPN plate. The standard curves showed that there was a good linear correlation between the Ct values. The minimum level of detection of Vibrio cholerae standard DNA at targeted gene was 3 x 10-5 ng/μl.
Modified atmosphere packaging (MAP) has become a popular method for packaging foods as it can extend the shelf life of food with minimal quality defect. Oxygen, nitrogen and carbon dioxide are the common gases used in MAP, Oxygen and carbon dioxide inclusive as only these two gaseous have the preservative effects on the packed food product. Their effect on microbial changes of any food product throughout storage period is highly depend on type of the product and packaging materials, appropriate gas composition, storage temperature, the ratio between gas and product volume, and hygienic manner during processing and packaging. MAP with highest percentage of carbon dioxide is proven to be more effective than vacuum packaging in inhibiting the growth of spoilage and pathogenic bacteria in many fishery products. This article reviews the consequences of MAP towards microbial changes in fishery products.
The demand for novel antimicrobial agents from natural resources has been increased worldwide for food conservation purpose. In this study antimicrobial activity of musk lime, key lime and lemon were evaluated against various food borne pathogens and spoilage bacteria using disc diffusion test. Type of extraction solvent and concentration level significantly influenced the antibacterial activity of all the extracts. Ethanol extracts of musk lime, key lime and lemon exhibited significant broadest inhibitory activity at 100% concentration level (pure extract) compared to water and juice extracts. 100% ethanol extracts of musk lime (39.7 mm), key lime (26.7 mm) and lemon (32.0 mm) exhibited the largest diameter of inhibition zone (DIZ) against Aeromonas veronii. 100% water extracts of musk lime (25.3 mm), key lime juice extract (23.3 mm) and water extracts of lemon (23.7 mm) was most effective against food spoilage bacteria, A. veronii. The prominent results of the antimicrobial activity from lime, key lime and lemon extracts may attribute them as potential natural food preservatives and could be used in pharmaceuticals field.
The effect of microwave heating and conventional heating towards the physicochemical and
functional properties of corn and rice flour with 30% moisture content in water suspension at
temperature of 50°C and 60°C were investigated. Conventional heat treatment was carried out
at 50°C and 60°C respectively by direct heating the moisture treated flour. Microwave heating
treatment was carried out by using domestic microwave oven at 50°C and 60°C respectively.
The amylose content, particle size diameter, and gelatinization temperature are increasing in
microwave and conventional heat treated corn and rice flour. Decreasing of pasting temperature,
swelling power and solubility of all the heat-treated starches compared to control were detected.
X-ray diffraction pattern of all control and heat treated corn and rice flour exhibit typical A-type
pattern. Scanning Electron Microscopy (SEM) has revealed the heat treated corn and rice flour
showed rougher surface, porous granules and rupture granules. There are no significance effect
of temperature differences on corn and rice flour carried out at 50°C and 60°C. Evidently,
microwave heating was effective to alter the physicochemical and functional properties of corn
and rice flour.
Broiler part samples (80 fresh and 80 chilled) were examined for the prevalence and numbers of C. jejuni and C. coli by employing most-probable-number (MPN) and polymerase chain reaction (PCR) techniques. The prevalence of the bacteria was high where C. jejuni was detected in 92.5% fresh and 53.8% chilled samples while C. coli in 80.0% fresh and 56.3% chilled. The number of these bacteria in the positive fresh and chilled samples was from 3 to more than 2400 MPN/g and from 3 to 290 MPN/g, respectively. Antibiotic resistance test (using Kirby-Bauer disc diffusion method) on 10 C. jejuni and 13 C. coli isolates toward ampicillin, tobramycin, enrofloxacin, ciprofloxacin, tetracycline, cephalothin, gentamicin and norfloxacin revealed high resistance toward all antibiotics (20.0% - 100.0%). All isolates were resistant to at least two antibiotics. This study highlights the potential of multidrug-resistant C. jejuni and C. coli transmission to humans through fresh and chilled broiler parts. Consecutive studies with bigger sample sizes and covering all over Malaysia are warranted in future.
Studies indicate that bacterial cross-contamination occurs during food preparation where bacteria can retent on the food contact surfaces and cause illness. The study evaluated the adherence of Campylobacter spp. to cutting boards, blades of knives and hands after cutting chilled, raw broiler parts (thighs + drumsticks, wings and livers). The adherence to cucumber cuts that were cut using the unwashed boards and knives was also analyzed. Generally, utensils have higher mean of Campylobacter spp. retained to them (1.4-223.3 MPN/ml rinse) than hands (0.7-43.4 MPN/ml rinse); however, Mann-Whitney U test showed no significant differences in the bacterial numbers found among the different surfaces. The transfer rates of Campylobacter spp. from utensils to cucumber cuts varied from 0% to more than 100%. The bacteria detected could be from the utensils and cucumber contamination before purchase or due to other factors where further investigation is required. The possibility is there for Campylobacter to spread to contact surfaces during chilled broiler handling; therefore, utensils and hands involved should be washed thoroughly especially before ready-to-eat food preparation.
Vitamin D supplementation appears to be potential for reducing risks of cancer, cardiovascular disease, and other chronic diseases, existing evidence on its benefits and risks is inadequate and debatable. Questions remain as to whether supplementation of Vitamin D playing any role in the above mentioned diseases. In the absence of compelling evidence for benefit, taking supplement is producing any risk or not. While sorting the various positive and negative claims for Vitamin D, it attracts an urgent need for further research and review on reports to answer fundamental questions about the risks and benefits of supplementation. There still remains a great need to advance our understanding regarding the effectiveness of Vitamin D. This review gives an overview on disputes of Vitamin D supplementation that is convincing and interventional regarding burning issues of Vitamin D therapy. Beyond its use to prevent osteomalacia or rickets, the evidence for other health effects of vitamin D supplementation in the general inhabitants is conflicting. It is a well known predictability that any effective substance also has unwanted side effects, so clear cut evidence regarding the safety is required before supplementing Vitamin D for pathological conditions and other health benefits.
Starch blend films made from sago and mung bean were prepared by casting with glycerol as the plasticizer and subsequently exposed to ultraviolet (UV) irradiation for 2 h. The films were characterized by thickness, moisture sorption isotherms, X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy. All films produced were colorless while incorporation of glycerol resulted in more flexible and manageable films. Moisture sorption isotherms for all films showed sigmoidal shape and the control films showed slightly higher curve than treated films. While for X-ray analysis, the control and treated films for all formulations showed similar pattern, however for treated films showed more crystalline character. UV radiation showed affect on X-ray diffraction and sorption isotherms; however the UV radiation did not affect the spectra pattern of FTIR.
This study was undertaken to characterize the antibiotic resistance and randomly amplified polymorphic DNA (RAPD) profiles of Vibrio parahaemolyticus isolates from raw vegetable samples. A total of 46 isolates of V. parahaemolyticus recovered from raw vegetables samples and were confirmed by PCR were analyzed in this study. Most of the isolates were resistant to nalidixic acid (93.48%) and were the least resistant towards imipinem (4.35%). The MAR index results also demonstrated high individual and multiple resistances to antibiotics among the isolates. From the RAPD analysis, the size for RAPD fragments generated ranged from 250 bp to 1,500 bp, with most of the strains contained three major gene fragments of 350, 1,000 and 1,350 bp. The RAPD profiles revealed a high level of DNA sequence diversity within the isolates. Antibiotic resistance and RAPD proved to be effective tools in characterizing and differentiating the V. parahaemolyticus strains.
Salmonella enterica is one of the major causes of bacterial foodborne infection. The aims of this study were to determine the antibiotic resistance and the genetic diversity of Salmonella enterica isolated from street foods and clinical samples and to understand the correlation between the prevalence of serovars and genotypes with their source (street food and clinical samples) and geographic origin (Negeri Sembilan, Malacca and Selangor in Peninsular Malaysia). The enterobacterial repetitive intergenic consensus (ERIC) PCR analysis distinguished the Salmonella isolates into 19 ERIC types, with one untypable isolate. Dendrograms were specifically constructed for the S. Biafra and S. Typhi isolates. Identical or very similar ERIC types among the S. Biafra isolates from street food samples indicate transmission of the S. Biafra among the street foods, as well as possible cross-contamination of the street foods. In addition, the identical or very similar ERIC types among the S. Typhi isolates from human samples examined suggest possible similarity in their source of infection. All the twenty four isolates were resistant to rifampin and none were resistant to cefuroxime. Most isolates displayed multiple resistances. Dendrogram of antibiotic resistances produced six clusters, with similarity levels between 18.8% and 100%. Generally, street food and clinical isolates tend to cluster apart. Dendrogram to cluster the antibiotic groups showed that they could be grouped according to classes based on mode of inhibition. The findings suggest that street food contaminated with drug-resistant Salmonella enterica can be an important factor in the continuous emergence of antibiotic resistant Salmonella enterica.
Food labeling in accordance with Novel Food Regulation has been enforced in the European Community since 1997 with a series of updated legislations namely, EC/258/97, EC/1139/98, EC/49/2000, EC/50/2000 and EC/1829/2003. Guidelines and labeling regulations for the use of GMOs materials in food and feed products has also been introduced in Malaysia and Vietnam. Therefore, the demand for the establishment and development of a robust and rapid operation procedure for GMO detection has increased recently in both countries. The procedure of GMO detection emphasizes not only on detection tests but also on confirmation assays. This study employed PCR technology for detection and direct DNA sequencing for confirmation procedures respectively. The results demonstrated for the first time the presence of GM plants with glyphosate-resistant trait led by the control of P35S promoter and NOS terminator in either Malaysian or Vietnamese feed with high frequency (20 positive samples out of 24 analyzed samples). The P35S promoter, EPSPS gene and NOS terminator sequences obtained showed some mutations on single-stranded and double-stranded targeted sequences caused by single nucleotide insertion or single nucleotide changes. These results reinforce the need for development of detection procedures to comply with food/feed labeling system.
The ability to detect the presence of transgenes in crop-derived foods depends on the quantity and quality of DNA obtained from a product to be analyzed. The efficiency of DNA extraction protocols differs due to the nature of each food product. In this paper, we described two main DNA extraction protocols and their modifications that have been applied and evaluated for DNA extraction from raw and processed food as well as animal feed. The yield and quality for five categories of food and feed samples namely, raw soybean, raw maize, animal feed, smooth tofu and soymilk are discussed. The statistical interaction analyses showed that the cetyltrimethyl ammonium bromide (CTAB) method was proven to be the best method to extract DNA from raw soybean, maize and animal feed samples which not only obtained high DNA yield of 32.7, 28.4 and 33.4 ng DNA/mg sample respectively, but also produced high quality DNA with the absorbance A260/A280 ratio of 1.9, 1.9 and 2.0, respectively. These DNA were suitable for PCR amplification which produced a 164 bp DNA fragment of the lectin gene from soybean, and a 277 bp DNA fragment of the zein gene from maize. In the processed food category, the Wizard isolation method was found to be the best for the extraction of DNA from smooth tofu and soymilk with the yield of 13.2 and 3.4 ng DNA/mg sample, and the quality of the DNA at the absorbance A260/A280 ratio ranged from 1.9 to 1.7. These DNA were successfully amplified using primers specific to the lectin gene of soybean.
Presence of Norovirus in food can cause viral gasteroenteritis. Recently, lots of reports relating to Norovirus in food have been published. Special attention must be paid to the raw foods as they are not subjected to further heat treatment. In this study, pegaga, kesum, tauge and ulam raja (popular salad vegetables in Malaysia) were investigated for Norovirus. A total of 32 samples from each type of salad vegetables were purchased from local market and analyzed using One-step RT-PCR (Reverse Transcriptase-Polymerase Chain Reaction) for both genogroups namely Norovirus Genogroup I and Genogroup II. Results showed that tauge had the highest contamination with Norovirus Genogroup I (15.6%) comparing to pegaga (9.4%), kesum (12.5%)
and ulam raja (0%). Samples were free from Norovirus Genogroup II. The study showed that raw vegetables are high-risk foods and can be contaminated with Norovirus.
Piper nigrum, commonly known as black pepper, is one of the most important spice crops
with high demand by the world market. However, diseases like foot rot and stem blight
cause by Phytophthora capsici have become the important production constraints in black
pepper industry. The frequent application of toxic fungicides to counter the diseases in pepper
plantations has raised certain environmental issues. In order to mitigate the use of fungicides,
biological approach to control P. capsici has been suggested. In this study, endophytic bacteria
were isolated from six P. nigrum roots and screened for in vitro antagonistic activity against P.
capsici through dual culture, mycelial growth, spore germination and double plate assay. The
antagonism testing involved the secretion of volatile and diffusible bioactive compounds by
the endophytic bacteria. Out of 19 isolates tested, two isolates DB(2)7 and SB(2)6 produced
volatile bioactive compounds and these two isolates showed highest antagonism against P.
capsici mycelia with the percentage of inhibition up to 47.63% and 43.33%, respectively.
Diffusible compounds from isolates DB(2)7, DB(2)9 and SB(2)6 produced clear zones in spore
germination test with radii measurements of 10.0-17.0 mm. Three isolates with promising
antifungal activity were further characterised through 16S rDNA sequencing. The analysis
of their sequences via National Center for Biotechnology Information (NCBI) suggests close
identity towards Enterobacter cancerogenus, Enterobacter cloacae and Enterobacter asburiae.
This research study demonstrated that these endophytic bacteria isolates are potentially to be
used as biocontrol agent in pepper cultivation.
This study aimed to compare the antioxidant content and antioxidant capacity of pulp and peel of two varieties of pomelo fruit (Tambun White and Tambun Pink). Antioxidants including total phenolic content, total flavonoid content and ascorbic acid content were determined using Folin-Ciocalteu reagent assay, aluminium chloride colorimetric assay and AOAC method, respectively. Antioxidant capacity of pomelo pulp and peel was measured using ferric reducing antioxidant potential and trolox equivalent antioxidant capacity assays. The peels of both pomelo fruits had higher antioxidant content and capacity than their pulps. Moreover, the white variety of pomelo had higher antioxidant content and capacity compared to the pink counterpart. Trolox equivalent antioxidant capacity of the samples was positively high correlated with total phenolic content (r = 0.978) and total flavonoid content (r = 0.959), except for ascorbic acid. Therefore, pomelo peel from white variety possessed higher antioxidant properties and it is potentially rich sources of natural antioxidants.
The objectives of this study were predicting the transmission and survival of L. monocytogenes in cooked ham during supply chain. Cooked ham are frequently contaminated with L. monocytogenes during postprocessing steps through contact on surface of processing, handling, packaging equipment. Transfer rate of L. monocytogenes on static and dynamic condition in various surface type was investigated. The prevalence and level of L. monocytogenes in cooked ham at plant as well as the prevalence of unsatisfactory processing at retail were studied. A Monte Carlo simulation model was created by using @risk. The simulation predicted that the prevalence was 11.76 % with 90% confidence interval of 2% to 25% and estimated level was -4.02 log CFU/cm2. It was estimated to be occurred on slicing step at plant. Our results suggest that, the prevalence and level of L. monocytogenes can be reduced by Good Handling Process application and/or HACCP application.
The in vitro bioaccessibility of calcium, iron and zinc of breads added with different bread
spreads was determined. The mineral contents were assessed by flame atomic absorption
spectrophotometer and expressed in fresh weight (mg/100 g). For the mineral bioaccessibility
determination, in vitro gastrointestinal digestion was applied. Among the bread samples, calcium
content of wholemeal bread with chocolate hazelnut spread ranked the highest (159.96±0.869
mg/100 g). For iron, white bread with chocolate hazelnut spread (6.92±0.411 mg/100 g) showed
highest iron content while for zinc, white bread with peanut butter was the highest (1.82±0.015
mg/100 g). For calcium bioaccessibility, white bread with orange marmalade ranked the
highest (39.33±4.865%) while wholemeal bread with peanut butter (14.70±0.265%) showed
the lowest. The application of orange marmalade spread onto wholemeal bread increased the
iron bioaccessibility significantly (9.73±1.387%). The acidic properties attributed by organic
acids found in orange marmalade may favour both calcium and iron absorption. The zinc
bioaccessibility of white bread alone remained the highest (20.63±3.536%) while wholemeal
bread added with peanut butter (5.90±1.137%) showed the lowest. Overall, the addition of
bread spreads particularly peanut butter and chocolate hazelnut spread had increased mineral
contents of the bread samples. However, the presence of mineral enhancers (organic acids) and
inhibitors (phytate and polyphenols) played some significant role in influencing the mineral
bioaccessibility.
Different probiotic strains are incorporated into cultured-milk drinks by respective manufacturers with the common aim of providing health benefits to the consumers. Four common cultured-milk products (brands N, S, V and Y) were evaluated for their quality of probiotic strains used, based on the susceptibility of the probiotics to various pH levels simulated to mimic the gastrointestinal system. Results showed that brands Y and V have higher initial probiotic inoculum compared to brands N and S although probiotics from brands N and S were more tolerant to pH 3. Generally, all probiotic strains preferred higher pH with highest viability of Lactobacillus spp., Bifidobacterium spp., and Streptococcus thermophilus observed at pH 8.1. Our study also discovered that among the four brands tested, brand V contained probiotic strains which are most likely to remain viable after passage through the gastrointestinal system.
The study aimed to isolate and elucidate the chemical compounds that are found in banana
(Musa balbisiana cv. Saba) inflorescences. Banana inflorescence buds were extracted using
methanol and the resulted methanolic extract was partitioned using chloroform, ethyl acetate
and butanol against deionized water. The chloroform partition was further separated into
fractions using column chromatography assisted by thin layer chromatography. The structure
elucidation was performed using nuclear magnetic resonance spectrometry (NMR). Three
triterpenes were isolated namely 31-norcyclolaudenone (1), cycloartenol (2) and (24R)-4a,24-
trimethyl-5a-cholesta-8,25(27)-dien-3b-ol (3). This is the first report on the isolation of these
triterpenes from Musa balbisiana inflorescence. The discovery of new triterpenes from banana
inflorescence should be further explored to open a new perspective that banana by-products
might serve as new source of natural products for food and pharmaceutical applications.
Media components such as wheat flour, MgSO4 and particle size were screened by Placket Burman design (PBD) while the operating range was fixed by one-factor-at-a-time method (OFAT), primarily for the enrichment of cassava peels as animal feed. Optimization of the selected media components was carried out using Face–Centered Central Composite Design (FCCCD) of the Response Surface Methodology (RSM) and the responses were measured in term of protein and lignin contents. Statistical analysis of the result showed that the quadratic term of wheat flour and the interaction between wheat flour and particle size were highly significant (P