Vibrio parahaemolyticus is a gram negative bacterium and causes gastrointestinal illness in humans. In this study, twenty five out of fifty cockle samples from Padang, Indonesia produced purple colonies when they were grown on selective medium, CHROMagarTM Vibrio. Specific–PCR for toxR gene detection gave positive results in which a band with 368 base pairs size appeared on the gel for all the isolates that confirmed the presence of V. parahaemolyticus. In the virulence properties test, all the isolates showed negative results for tdh and trh genes detection. The results indicate that the isolates under this study do not contain virulence properties that correlate to the ability of infection and diseases, which means that they are nonpathogenic.
This study aims to determine the combined effects of hydrolysis time, temperature, pH and ratio of enzyme to substrate on the degree of hydrolysis (DH) of silver catfish frame using Response Surface Methodology. The proximate compositions of silver catfish frame and silver catfish hydrolysate powder were determined as well. The effects of independent factors were described using a three-level factors Face Centered Central Composite design. The suggested hydrolysis conditions for obtaining the optimum DH using Alcalase® were – temperature of 55oC, hydrolysis time of 163 min, pH of substrate at 9.45 and an enzyme concentration of 2.0%. The generated model showed a quadratic fit with experimental data. Proximate analyses revealed that silver catfish frame contained 25.02% protein, 68.21% fat and 7.08% ash. While silver catfish frame hydrolysate powder contained 65.05% protein, 32.92% fat and 0.86% ash. The protein recovery in silver catfish frame hydrolysate was as high as 71.6%.
This study aimed to determine the biofilm formation ability by Salmonella Typhi on cucumber, mango and guava surface, as well as to determine the relationship between time contact and biofilm formation. Crystal violet assay was performed to quantify the biofilm formation based on the value of optical density at 570 nm of the destaining crystal violet at the specific interval time. The result showed that the attachment of the bacterial cells on the fresh produce surface increased with the contact time. The readings of OD570at time 12 h for cucumber, mango and guava surfaces were 0.824, 0.683 and 0.598, respectively, indicating that the biofilm formation by Salmonella Typhi on different fresh produce surface varied with time. Since the result showed that Salmonella Typhi formed biofilm on fresh produce surfaces, hygienic practice from farm to fork including handling, processing, distribution and storage of the fresh produce should be of concern.
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.
Food-borne diseases have always been a major concern to the consumers, food safety authorities and food industries. Hylocereus spp or Pitaya peels are normally treated as wastes and will be discarded during processing. In this study, the antibacterial activity of ethanol, chloroform and hexane extracts from Hylocereus polyrhizus (red flesh pitaya) and Hylocereus undatus (white flesh pitaya) peels against nine pathogens was evaluated using disc diffusion method and broth micro-dilution method. Result from disc diffusion method showed that chloroform extracts from H. polyrhizus and H. undatus peel were found to exhibit good antibacterial activity where almost all the pathogens studied were successfully inhibited. Result of the minimum inhibitory concentration (MIC) showed that all extracts inhibit the growth of bacteria in the range of 1.25-10.00 mg/mL for all bacteria while their minimum bacteriacidal concentrations (MBC) indicated double of the MICs concentration except for B. cereus, L. monocytogenes and C. jejuni. Even though there is no clear trend indicating which bacteria were sensitive most to the extract, it can be concluded that chloroform extract of both H. polyrhizusand H. undatus peel showed the most potent antibacterial activity. Thus, these findings could be used further to understand the antibacterial property of the peel of pitaya fruits.
Chili shrimp paste (CSP) is a favorite condiment in Southeast Asia. Microbial spoilage makes CSP unsuitable for consumption within several days. Thermal treatment was applied to produce microbiologically safe CSP. The effect of heating process on physicochemical and sensorial properties of CSP was studied. Heating at the optimum condition (21.6 min, 80 ˚C) has been shown effective and reliable in controlling microorganisms in CSP. Complete inactivation of peroxidase activities could not be accomplished at the optimal point, and significant reduction of the total phenolic and capsaicinoids contents was observed. Sensorial evaluation indicated that thermally processed CSP was less preferred by panelists when compared to freshly prepared samples of dry weight respectively.
Two high protein wheat flour samples of Red Horse (RH) and Bake with Yen (BY) were examined for predominant Lactobacillus spp. in fermented liquid sourdough. The identification of Lactobacillus spp. was based on biochemical tests of catalase test, gas carbon dioxide production, arginine test, the ability to grow at temperature of 15°C and 45°C and carbohydrate fermentation using API50CH kit. Those strains were identified as Lactobacillus spp. and confirmed using polymerase chain reaction (PCR) of 16S rRNA partial sequencing analysis. In the present study, we successfully isolated and identified the Lactobacillus plantarum and L. fermentum which were predominant bacteria in liquid sourdough of the sample RH and BY brand, respectively.
The objective of this research is recovery of squalene from palm fatty acid distillate (PFAD) using supercritical fluid extraction (SFE). The extraction process was performed by using the SFE and recovered squalene was analyzed from total lipid extracts using HPLC. A central composite design was used to study the effect of SFE variables namely pressure (X₁) from 200 to 400 bar and temperature (X₂) from 40 to 60⁰C on the total lipid extracts (Y₁) and squalene concentration (Y₂) and optimize the SFE conditions. The nonlinear regression equations were significantly (p < 0.05) fitted for both responses with high R₂ (> 0.965), which had no indication of lack of fit. The results indicated that a combined pressure (200 bar) and temperature (50⁰C) was predicted to provide the optimum region in terms of total lipid extracts (13.84 ± 0.52%) and squalene concentration (418.31 ± 18.40 ppm) studied.
Not many attempts have been made in previous studies to understand consumers’ socio-demographic characteristics and their awareness towards organic rice. Knowledge towards organic rice among consumers is fundamental to induce demand and market for organic rice. This study seeks to understand consumers’ awareness towards organic rice in Malaysia. The survey is exploratory in nature and was conducted at major supermarkets in Klang Valley. Data were analysed using descriptive analysis and chi-square analysis using cross-classification techniques, and correlation to determine their relationship, strength and direction of their relationship. The findings showed majority of the respondents (85.6%) have some level of awareness towards organic rice, while only 64.7% planned to consume organic rice in the future. This indicates that awareness of consumers towards organic rice does not necessarily translate to their planning to consume organic rice. Thus, achieving awareness and understanding the linkage between awareness and consumption is fundamental to impacting demand and market for organic rice. The study also showed that the younger respondents have more concern towards organic rice. These findings if well responded to, would definitely have positive implications for the Malaysian organic rice industry.
The aim of this study was to assess the most probable number-polymerase chain reaction (MPNPCR) technique for detection of Listeria monocytogenes in salad vegetables in comparison with reference EN ISO 11290-2 and Food Drug Administration Bacteriological Analytical Manual method using artificial and naturally contaminated samples. Based on recovery of L. monocytogenes from artificially contaminated samples, MPN-PCR showed a moderate correlation (R=0.67) between spiking concentration and microbial levels which was better than the FDA-BAM method (R=0.642) and ISO 11290-2:1998 method (R=0.655). With naturally contaminated samples, it was found that L. monocytogenes was detected in 25% of the vegetable samples using MPN-PCR; 15% of the samples by the FDA-BAM method and 8% of samples using ISO 11290-2:1998 method. Overall, MPN-PCR was found to be a rapid and reliable method that could facilitate the enumeration of L. monocytogenes in vegetables.
This study was performed to enumerate the total viable cell count of probiotic in five brands (A to E) of commercially cultured milk drinks that are available in the Malaysian market as well as to test their tolerance to various pH and bile concentrations by simulating the human gastrointestinal pH and bile concentration. The acid tolerance test was studied under pH 1.5 and 3.0 with 7.2 as control. The cell count for the acid tolerance test was obtained at an interval of 0, 1.5 and 3 hours respectively and was plated onto duplicate MRS agars to be incubated at 37°C for 48 hours. All cells recovered after 3 hours of pH treatment were selected for bile tolerance test in MRS broth containing bile concentrations of 0% (control), 0.3% and 2.0% and cell counts were recorded after 24 hours of incubation. The probiotic strains in products A, B, C & D met the suggested initial count of 106 CFU/ml with brand C recording the highest at 9.19 ± 0.14 log CFU/ml. Strains in product A, B & C showed good tolerance to pH 3.0 and 7.2 recording a count of >106 CFU/ml after 3 hours with a range of 6.60 – 9.04 log CFU/ml. The higher bile concentrations resulted in lower growth of strains in all the brands. Upon pH 1.5 treatment, only brand C recorded growth in all bile concentrations. After pH 3.0 treatment, all brands except brand E met the requirement of survival at 0.3% bile concentration. Results showed probiotics in product A, B & C met the initial count requirement, and exhibited good acid and bile tolerance therefore being a potentially good source of probiotic.
Pineapple (Ananas comosus), Bromeliaceae family, is a fruit grows in tropical countries including Malaysia. This fruit has several pharmacological benefits due to the presence of high concentration of bromelain (cysteine proteases). Condition of elevated temperature will induce deformation of enzyme and result in loss of activity. Sulfhydryl groups in cysteine proteases are readily to be oxidized and might account for the denaturation of bromelain at elevated temperature. Polyphenol from ethanolic cashew leave extract could be complexed with bromelain to stabilize the enzymatic activity. In thermal stability test, the heat damage effect on bromelain was ten times reduced after complexing with cashew extract. The enzymatic activity of free bromelain decreased gradually from 25 o C to 95 o C. Complexed bromelain was stable in activity to heating up to 85 o C. Bromelainpolyphenol complex showed a good heat resistance. The result revealed that polyphenol could protect bromelain in pineapple juice from heat denaturation.
This research was carried out to determine the fructooligosaccharides content in local honey samples, namely the wild Malaysian Tualang honey and common wild honey obtained from Tapah, Perak and a commercial Tualang honey. Local wild honeys were found to contain a higher concentration of fructooligosaccharides (FOS) compared to the commercial Tualang honey. The FOS quantified from local wild honeys was inulobiose, kestose and nystose. Nystoses were found at a very low amount in the commercial Tualang honey. The effects of honey on the growth of Bifidobacterium longum BB 536 were investigated. Both wild and commercial honey samples including FOS standard were found to support the growth of B. longum. The pH value of the skim milk + honey inoculated with the probiotic strain decreases as expected. Addition of honey was found to support the growth of B. longum BB 536.
Studies have been carried out to determine the chemical (soluble solid content) and physical (firmness) parameters of locally grown Cavendish banana by near infrared (NIR) spectroscopy. NIR spectra in the wavelength region of 680-2500 nm were obtained from a total of 408 Cavendish bananas of different ripeness indices. Chemometrics using multiple linear regression (MLR) was applied to develop calibration models for prediction of firmness and soluble solid content (SSC) of Cavendish banana. Results showed that NIR spectroscopy had the feasibility for non-destructive determination of the quality of Cavendish banana. The coefficient of determination (R2) for firmness and SSC calibration models at different ripeness indices ranged from 0.78 to 0.86 and 0.75 to 0.96, respectively. The calibration models were validated using independent sets of data and prediction models developed with the root mean square error of prediction (RMSEP) ranged from 0.01 to 0.26 kgf and 0.039 to 0.788 Brix for firmness and SSC, respectively. The multi-index models showed considerable robustness but higher prediction error with RMSEP of 0.336 kgf for firmness and 0.937% Brix for SSC compared to index specific model.
Pathogenic Vibrio parahaemolyticus is one of the leading causes of bacterial gastroenteritis in many countries. Among the strains examined, 36 RAPD-types were found when amplified with primers OPA8 and OPA10. The analysis shows the majority of V. parahaemolyticus isolates originated from seafood were branched into four major clusters at 18.2%, 20.7% 34% and 3.4% similarity levels. This suggests that there is potential for a single strain to be distributed widely within a population and there also potential for multiple contaminating strains of different clonal lineages to be present within the same population. Optimum temperature (37ºC) was the highest and stable formation of biofilm. The total percentage of biofilm formation at 37ºC was 33.33% for each of weak, moderate and strong biofilm producers. Room temperature produces 61.1% of weak biofilm producer, while 13. 89% for moderate biofilm producers and produce 25% of strong biofilm. While a total of 91.67% weak biofilm producers at 4ºC and 8:33% for room temperature and no growth of strong biofilm. Upon analysis, strong biofilm was tracked from the largest group at 37°C and room temperature which produce 27.27% of strong biofilm producer respectively. Interestingly, they are derived from cockles.
Unripe and ripe kundang fruits (Bouea macrophylla Griffith) is either consumed fresh or is cooked in Malaysia. In this study composition of unripe and ripe fruits (proximate, amino acids profile, minerals and heavy metal contents) were evaluated. Results obtained showed unripe kundang fruit to possess higher moisture, ash, crude lipid, crude fiber and crude protein contents than the ripe fruits. With regard to amino acid contents, unripe fruits had higher content of essential amino acids. The unripe and ripe fruits were found to be rich in essential minerals with potassium (K) to be in abundance. Heavy metals such as cadmium, nickel, mercury, lead and arsenic, were detected in trace amounts (< 5.0 mg/kg) in both unripe and ripe fruits. Through this investigation, it is concluded that both unripe and ripe fruits to posses’ adequate amount of nutritionally important compounds beneficial to human health and can be explored for commercial purposes.
Raw goat milk is recognized as one kind of nutritious food owed to its originality and
medicinal values. This study aimed to evaluate the physico-chemical and microbiological
qualities of locally produced raw goat milk prior any processing steps during storage. Milk
samples passed organoleptic test and C.O.B. test were mostly (88.89 %) failed in alcohol test.
AOAC Official method of oven drying method, Kjeldahl method and Soxhlet method were
performed in physico-chemical analysis where results obtained were partially in lined with
reported literature due to subjective factors of breeds, geographical areas and feeds. The locally
produced raw goat milk’s compositions are high in water content and low in fat percentage.
Initial total plate count, coliform count and proteolytic count tested were 3.44 log cfu/ml, 1.87
log cfu/ml and 1.97 log cfu/ml, respectively. Storage time showed significant effect on the
bacterial counts (p>0.05) of milk samples. Shelf-life of milk samples were kept up to 12 hours
under ambient temperature (3.95 log cfu/ml) had not exceeded the standard limit. The shelflife
of the milk samples were extended up to 16 days storage under refrigerated temperature
of 4°C. The microbiological quality of the milk samples showed a significant bacteriological
growth upon prolonged storage and high initial coliform count indicates possible poor hygienic
practices at farm level.
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 xamined. 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.
‘Nasi kandar’ is defined as boiled white rice placed inside a wooden basket and carried on the shoulder using a pole. The rice is served with a variety of pairing dishes that are usually fried, curried or boiled. The tradition of carrying rice and pairing dishes on the shoulder began to die out in the 20th century as seller resorted to a more conventional way of selling ‘nasi kandar’. The ‘nasi kandar’ business in Malaysia has evolved from being sold as a street food into a multi-million dollar franchise business rivalling the fast food business. It is available 24 hours and enjoyed by Malaysians from all walks of life. This study aims to compare ‘nasi kandar’ eating pattern among patrons in the Klang Valley and Penang. Three hundred sets of questionnaires were answered and collected. Data from the questionnaires were analyzed in PASW 18.0 using descriptive statistics and chi-square test for association. Klang Valley patrons (72%) would consume ‘nasi kandar’ once a week. More than half (53.3%) of the patrons from Penang consumed ‘nasi kandar’ more than twice a week. A significant relationship exists between patron’s region and frequency of ‘nasi kandar’ consumption where p = <0.0001 and r = 0.277. A significant but moderate relationship between patron’s region and consumption of ‘nasi kandar’ during breakfast (p = <0.001, r = 0.250), lunch (p = <0.0001, r = 264) and dinner (p = <0.0001, r = 0.336). Patrons in Penang consumed ‘nasi kandar’ more often than their Klang Valley counterparts. Klang Valley patrons were more particular than Penang patrons when it comes to cleanliness, menu pricing, friendly service, air-condition and separate smoking area. Klang Valley patrons tend to consume more chicken based dishes while Penang patrons tend to consume more meat, fish, and squid based dishes.
Pitaya peel (Hylocereus polyrhizus), which consists approximately 22% of the whole fruit weight, is discarded during processing. Physico-chemical properties of the discarded pitaya peel were determined in
order to evaluate its potential for recovery of any value-added materials. The moisture content of the peel was approximately 92.7% and it was low in total soluble solids, protein, ash and fat content. Betacyanin pigment (150.46 ± 2.19 mg/100 g) and pectin (10.8%) were high in the peel. Glucose, maltose and fructose were detected in the peel but not sucrose and galactose. The peel also had very high insoluble and soluble dietary fibre which had exhibited a good ratio of insoluble dietary fibre to soluble dietary fibre (3.8: 1.0).