Simultaneous determination of multi-mycotoxins in palm kernel cake (PKC) using liquid chromatography-tandem mass spectrometry (LC-MS/MS)

Palm kernel cake (PKC) is a useful source of protein and energy for livestock. Recently, it has been used as an ingredient in poultry feed. Mycotoxin contamination of PKC due to inappropriate handling during production and storage has increased public concern about economic losses and health risks for poultry and humans. This concern has accentuated the need for the evaluation of mycotoxins in PKC. Furthermore, a method for quantifying mycotoxins in PKC has so far not been established. The aims of this study were therefore (1) to develop a method for the simultaneous determination of mycotoxins in PKC and (2) to validate and verify the method. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method using an electrospray ionisation interface (ESI) in both positive- and negative-ion modes was developed for the simultaneous determination of aflatoxins (AFB1, AFB2, AFG1 and AFG2), ochratoxin A (OTA), zearalenone (ZEA), deoxynivalenol (DON), fumonisins (FB1 and FB2), T-2 and HT-2 toxin in PKC. An optimum method using a 0.2 ml min–1 flow rate, 0.2% formic acid in aqueous phase, 10% organic phase at the beginning and 90% organic phase at the end of the gradient was achieved. The extraction of mycotoxins was performed using a solvent mixture of acetonitrile–water–formic acid (79:20:1, v/v) without further clean-up. The mean recoveries of mycotoxins in spiked PKC samples ranged from 81% to 112%. Limits of detection (LODs) and limits of quantification (LOQs) for mycotoxin standards and PKC samples ranged from 0.02 to 17.5 μg kg−1 and from 0.06 to 58.0 μg kg−1, respectively. Finally, the newly developed method was successfully applied to PKC samples. The results illustrated the fact that the method is efficient and accurate for the simultaneous multi-mycotoxin determination in PKC, which can be ideal for routine analysis

Microbiological quality of food contact surfaces (spoons) at selected restaurants in Klang Valley, Malaysia

Food borne diseases increase worldwide and contamination of food contact surfaces serves as one of the reasons for their occurrence. The aim of this study was to determine the microbiological quality of spoons at selected restaurants in Klang Valley, Malaysia. Five restaurants were selected therein for the study. They were respectively labelled A, B, C, D and E. A total of 150 cleaned spoons (30 spoons from each restaurants) that were ready to be used by customers at the restaurants were examined. Total plate counts (CFU/cm2) of the spoons were determined; the presumptive and confirmatory tests for the presence of Escherichia coli on the spoons were also conducted. The samples were collected by surface swabbing. The result showed that restaurant C and B had the highest and lowest total plate counts (TPC), respectively. Samples from 3 of the 5 selected restaurants (restaurants C, D and E) showed positive results for the presence of E. coli mainly due to poor dishware cleansing. On the contrary, negative results for the presence of E. coli at restaurant A and B were associated with the advance cleaning procedure, which used more hygienic method with dishwashers

Assessment of food handler's knowledge, attitude and practices on food hygiene in Serdang, Selangor

This paper reported a research on food hygiene knowledge, attitude and practices of food handlers from restaurants in Serdang, Selangor. A total of 200 questionnaires were distributed among the food handlers at food premises selected using convenience sampling technique. The findings from this study showed that food hygiene knowledge related to hand washing procedure (72.50%), temperature control of food and microbial (66.0%) were lacking among the food handlers. Attitude towards learning more about food hygiene and sanitation has the lowest rating (M= $.55), which suggest food handler may not perceive this as important to them. Respondents reported the lowest practices for hand washing before using glove (M= 3.92), which demonstrated that food handlers in Serdang might be lack of knowledge regarding the correct use of glove. This study provided data about the current knowledge, attitudes and practices of food handlers from restaurants operations. The results showed that further continuous effort should be invested in food hygiene education and enforcement for food handlers from commercial foodservices such as restaurants

Effectiveness of different cleanup sorbents for the determination of avermectins in fish by liquid chromatography tandem mass spectrometry.

An effectiveness and comparative study of cleanup sorbents used in dispersive solid phase extraction (DSPE) for the determination of avermectins, including emamectin (EMA), abamectin (ABA), doramectin (DOR), moxidectin (MOX), and ivermectin (IVE), was performed. Three different types of cleanup sorbents, alumina (Al), primary and secondary amine (PSA) and octadecyl (C18), were used to remove the matrix interference in fish samples. Homogenised fish samples were extracted with acetonitrile, magnesium sulphate anhydrous and sodium chloride. The cleanup sorbents were separately applied to the supernatant during the DSPE procedure; the mixtures were shaken and centrifuged, and the supernatant was dried. The extracts were reconstituted with acetonitrile/water and quantified by liquid chromatography tandem mass spectrometry with electrospray ionisation in the positive mode with two product ions that were monitored by selected reaction monitoring. The performance of each cleanup sorbent was observed for its accuracy and precision in a spiked blank sample at a concentration of 5 μg kg−1. The combination of the cleanup sorbents PSA and C18 was found to be the most effective in the cleanup of the fish samples. In the validation tests, the detection limit was in the range of 0.3 μg kg−1 to 0.4 μg kg−1, and the quantitation limit for all avermectins was 1 μg kg−1 in the linearity range of 1–15 μg kg−1. The recoveries of avermectins were 91.9–102.5%, with a relative standard deviation lower than 19%

Characterization of fungi from palm kernel cake (PKC) and the effect of storage temperature on fungi growth

The widespread contamination of animal feed with mycotoxin is not a new issue worldwide. Apart from economic loss, mycotoxin can have adverse health effects on humans due to the carcinogenicity, teratogenicity and mutagenicity potential of the toxins. Palm kernel cake (PKC) is the largest animal feed production in Malaysia. PKC is a by-product of palm kernel oil processing and it has been exported as animal feed. The purpose of this study was to isolate and characterise toxigenic fungi cultured in three different media, Dichloran Rose Bengal Chloramphenicol (DRBC) Agar, Dichloran 18% Glycerol (DG18) Agar and Malt Extract Agar (MEA), derived from PKC that is stored under three different temperatures, 4°C, 25°C and 60°C. Identification of fungi was carried out based on macroscopy and microscopy as well as molecular identification. Four mycotoxigenic fungi were found: Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus and Penicilium citrinum. In order to characterise polymorphism of the isolates, RAPD assay was performed using OPA 3 as the primer. The software resulted in a constructed dendrogram that revealed the percentage of similarities between the typable isolates (A. fumigatus, A. niger and P. citrinum) within range from 20% to 80%. The effect of storage temperature on the strains' enumeration is reported in this work. The distributing strains are influenced by the storage temperature of the PKC matrices. The findings clearly show that Aspergillus species profused at 25°C PKC storage, while it was restricted at low and high temperature

Anti-diabetic Activity and Microbial Quality of Ready-to-Serve Momordica charantia (MC) Drink

Diabetes mellitus has a high prevalence in Malaysia and is expected to rise in the future due to lifestyle changes. Thus, consumers are turning to alternative methods in the prevention and cure of the disease. The Momordica charantia has been studied for its anti-diabetic activity both in vitro and in vivo and is shown to be effective in inhibiting glucose absorption. Therefore, the MC is used as a main ingredient in the development of health beverages to offer alternatives for patients or the health conscious. The microbial quality of the product is examined to ensure the safety of the product and to find methods to enhance its shelf life

Reverse Transcriptase PCR detection of Hepatitis A virus (HAV) in cultured and wild shellfish from the Peninsular of Malaysia

Hepatitis A is a liver infection caused by the hepatitis A virus (HAV). Outbreaks of hepatitis A have been linked to the consumption of both raw and cooked shellfish. These outbreaks could induce a public confidence problem over shellfish safety and may result in important economic losses for the seafood industry. The work presented in this study investigated the presence of HAV in shellfish from Peninsular Malaysia. A total of 365 of cultured and wild shellfish from 36 sampling locations located throughout Peninsular Malaysia were examined using a commercial nucleic acid extraction and reverse transcription -polymerase chain reaction (RT-PCR) kit. HAV was not detected in almost all of the shellfish samples examined. Only one cockle sample from Changkat, Seberang Perai was positive for HAV. The results suggest the absence of HAV or very low amount of HAV viral particles in most of the shellfish examined

In vitro antimicrobial activity of musk lime, key lime and lemon extracts against food related pathogenic and spoilage bacteria

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

Quality changes of stabilizer-free natural peanut butter during storage

The storage stability of preservative-free peanut butter was evaluated for changes in physicochemical quality including moisture content and water activity, microbiological properties, oxidative stability and textural quality in terms of spreadability and firmness. The study was conducted for 16 weeks at storage temperature of 10, 25 and 35 °C on natural and pure peanut butter produced from two varieties of peanuts, the Virginia and Spanish TMV-2 varieties of China and India origin, respectively. The peanuts were ground using a high speed grinder for 2.5 and 3.0 min to produce peanut butter without addition of other ingredient. The natural peanut butter exhibited stability and had acceptable microbial count during storage. Storage at 10 °C gave similar textural quality with commercial product until week 8 and without appreciable loss in oxidative stability until week 12. At higher storage temperatures of 25 and 35 °C, oxidative stability was shortened to 4 weeks of storage. Among the factors of storage temperature and time, grinding time and peanut variety, storage temperature had the most significant effects on quality changes of natural peanut butter

Antimicrobial resistance of Escherichia coli and Staphylococcus aureus isolated from food handler's hands

The aim of this study was to determine the antimicrobial resistance of Escherichia coli and Staphylococcus aureus isolates from food handlers' hands at primary schools in Hulu Langat district, Selangor (Malaysia). Disc diffusion methods were used to examine the antimicrobial resistance of the bacteria by using ten types of antibiotic discs with different concentrations. The results show that the prevalence of S. aureus (65.88–74.12%) was far higher than the prevalence of E. coli (9.41–14.12%). The percentage isolates of E. coli that were resistant to the antibiotics was 85.71% Penicillin and Chloramphenicol, 57.14% Sulfamethoxazole-Trimethoprim, Ampicillin and Trimethoprim, 28.57% Kanamycin and Tetracycline and 14.29% Ciprofloxacin. All of the isolates had shown susceptible to Gentamicin and Nitrofurantoin. For S. aureus, the percentage isolates that were resistant to the antibiotics was 72.30% Ampicillin, 53.38% Penicillin, 4.73% Nitrofurantoin,1.35% Chloramphenicol and Trimethoprim and 0.68% Kanamycin and Tetracycline. None of the isolates had shown resistant to Ciprofloxacin, Sulfamethoxazole-Trimethoprim and Gentamicin. Multidrug resistant Escherichia coli represented a high percentage (85.71%) of the total positive strains revived whereas multidrug resistant S. aureus strains were only 5.41% of the total positive strains. The existence of multidrug resistant bacteria is quite worrying as they may pose serious threat to the patients. Hence, the microbiological quality of food handlers' hands from foodservice operations should be maintained in a good condition to reduce the existence of multidrug resistance bacteria