Microbiological and Chemical Quality of Keropok Lekor during Processing And Storage

Keropok lekor is an important fish product in Malaysia. The customers’ demands for keropok lekor have been increasing. This study was conducted to analyze the microbiological and chemical quality of keropok lekor in every stage of its processing, namely mincing, mixing, kneading, boiling and cooling. Subsequently, this study was also undertaken in an attempt to determine the effectiveness of post processing treatment on keropok lekor in order to prolong its shelf life. The method used to analyze the microbiological quality is known as the direct plate counts for the total plate counts (TPC), psychrotrophic, yeasts and molds, mesophilic sporeformer, Staphylococcus aureus, total coliform and fecal coliform counts. Simple biochemical test was carried out to identify the presumptive bacteria present in keropok lekor processing. Chemical quality was analyzed on the total volatile bases (TVB) and trimethylamine (TMA), using Conway microdiffusion method, and biogenic amines was done using the High Performance Liquid Chromatography (HPLC). The post-processing treatments on keropok lekor were exposing keropok lekor to UV light for 15 or 30 min, either coated with different concentrations of ascorbic acid (500, 1000 or 1500 ppm) or dipped in hot oil for 3, 6 or 9 s, and stored at the room temperature for 7 d or at chill temperature (4±1°C) for 14 d. When processing keropok lekor, the boiling of keropok lekor at 100°C for 10 min reduced the TPC (4.38±0.47 log10 cfu/g), psychrotrophic counts (2.00 ± 0.00 log10 cfu/g), mesophilic sporeformer counts (1.26 ± 0.34 log10 cfu/g) and total coliform counts (1.71±0.51 log MPN/g) significantly (p>0.05). However, the microbial counts were found to increase significantly (p<0.05) after the cooling process, except for the yeast and mold counts and S. aureus counts. The presumptive predominant microorganisms, isolated before the boiling stage, were members of the Enterobacteriaceae family and those belonging to Pseudomonas, Vibrio, Staphylococcus, Bacillus and Micrococcus genus. After the boiling stage, the presumptive predominant microorganisms were members of Enterobacteriace family and those belonging to Micrococcus, Bacillus, Staphylococcus and Aerococcus genus. As for the chemical quality, TVB and TMA levels were indicated to significantly decrease (p<0/05) after boiling from 7.29 to 4.68 mg/ 100g and 3.38 to 1.81 mg/ 100g, respectively, but not for the putrescine, cadaverine and histamine levels. Before the boiling stage, presumptive microorganisms producing putrescine, cadaverine and histamine were members of the Enterobacteriaceae family, as well as members of Staphylococcus, Pseudomonas and Micrococcus genus. Members of the genus Pseudomonas, which produce biogenic amines, were not isolated from keropok lekor after the boiling stage. The post-processing treatment which was applied on keropok lekor was found to enhance both its quality and shelf life. The results showed that exposing keropok lekor to UV light for 15 min and dipping it in hot oil for 9 s had extended the shelf life of this snack for 5 d when v stored at the room temperature, and for 14 d when stored at 4±1°C. This post processing treatment had also caused a significant reduction in TPC, psychrotrophic count, yeasts and molds count, TVB, as well as TMA and putrescine, cadaverine and histamine level. On the contrary, ascorbic acid was not as effective in increasing the shelf life of keropok lekor or in reducing TVB, TMA and putrescine, cadaverine and histamine level, as compared to dipping it in hot oil

Actor network theory in food safety

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

Stingless bee-collected pollen bee bread: chemical, health benefits and microbiological properties

Stingless bee-collected pollen (bee bread) is a mixture of bee pollen, bee salivary enzymes, and regurgitated honey, fermented by indigenous microbes during storage in the cerumen pot. Current literature data for bee bread is overshadowed by bee pollen, particularly of honeybee Apis. In regions such as South America, Australia, and Southeast Asia, information on stingless bee bee bread is mainly sought to promote the meliponiculture industry for socioeconomic development. This review aims to highlight the physicochemical properties and health benefits of bee bread from the stingless bee. In addition, it describes the current progress on identification of beneficial microbes associated with bee bread and its relation to the bee gut. This review provides the basis for promoting research on stingless bee bee bread, its nutrients, and microbes for application in the food and pharmaceutical industries

Microbiological quality of keropok lekor during processing

Keropok lekor is an important fish product in Malaysia. The customer demands for keropok lekor have been increasing. This study was conducted to analyze the microbiological quality of keropok lekor in every stage of its processing, namely mincing, mixing, kneading, boiling and cooling. When processing keropok lekor, the boiling of keropok lekor at 100°C for 10 min reduced the Total Plate Counts (4.38±0.47 log10 cfu/g), psychrotrophic counts (2.00 ± 0.00 log10 cfu/g), mesophilic sporeformer counts (1.26 ± 0.34 log10 cfu/g) and total coliform counts (1.71±0.51 log Most Probable Number/g) significantly (p>0.05). However, the microbial counts were found to increase significantly (p<0.05) after the cooling process, except for the yeast and mold counts and Staphylococcus aureus counts. The presumptive predominant microorganisms, isolated before the boiling stage, were members of the Enterobacteriaceae family and those belonging to Pseudomonas, Vibrio, Staphylococcus, Bacillus and Micrococcus. After the boiling stage, the presumptive predominant microorganisms were members of Enterobacteriace family and those belonging to Micrococcus, Bacillus, Staphylococcus and Aerococcus

Probiotic properties of bacteria isolated from bee bread of stingless bee Heterotrigona itama

Pollen collected by stingless bee is stored and packed in honey pots following the addition of various enzymes and nectar, or honey which contains microorganisms to undergo lactic acid fermentation to produce bee bread. Naturally fermented foods are known to contain probiotic bacteria. Thus, the aim of this study was to isolate probiotic bacteria from bee bread and characterize the probiotic potential of bacteria with antibacterial activities against foodborne pathogens. Bacteria were identified using 16S rRNA gene sequencing. The probiotic potential such as acid and bile tolerance, digestive enzymes tolerance, cell surface hydrophobicity, cell autoaggregation, antibacterial activity against foodborne pathogens, blood haemolytic activity, and antibiotic susceptibility were determined. A total of 27 bacteria were isolated from bee bread and were identified as Lactobacillus spp., Fructobacillus fructosus, Leuconostoc mesenteroides, Enterococcus faecalis, and Bacillus spp. Most of the Bacillus spp. showed haemolytic abilities. L. musae SGMT17 and L. mindensis SGMT22 had similar antibacterial efficiency against tested pathogens in comparison to L. rhamnosus GG. All of the isolates showed high tolerance to pH 3, 0.3% bile, pepsin, and pancreatin except for F. fructosus strains. Lb. crustorum, Lb. mindensis and Lb. musae showed high hydrophobicity and autoaggregation ranging from 52.09 to 80.52% and 57.47 to 92.77%, respectively, depending on the strain. All strains were susceptible to chloramphenicol, ampicillin and tetracycline, but varied for eight other clinically relevant antibiotics. From the result obtained, Lb. musae SGMT17 and Lb. crustorum SGMT20 showed the highest antibacterial activity and probiotic properties in the human in vitro digestive model. Future studies have to be conducted to assess other therapeutic value and safety of the selected bacteria in vivo

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

The Effect of Mixing Time and Mixing Sequence during Processing on the Physicochemical and Sensory Properties of Keropok Lekor

The common practice of mixing in keropok lekor processing is carried out continuously to produce a homogenize batter with no specific time and sequence established yet. The goal of the work was to study the effect of different mixing time and sequence (intermittent and continuous) against the physicochemical and sensory properties of keropok lekor.  The  keropok lekor batter was mixed for 6, 12 or 18 min non-stop for the continuous mixing, while  the  intermittent mixing was carried out for 6  min  (2  min  mix and 2  min break),  12  min  (4  min  mix and 2  min break),  and  18  min  (6  min  mix and 2  min break).  The  intermittent  mixing  for  6  min  was the best method among all the treatments, where the results  for  the  moisture  content  (56.60±2.20),  protein  content  (10.23±1.21),  water  holding  capacity  (83.33±11.02),  linear  expansion  (5.86±2.32),  cooking  yield  (107.15±0.60),  lightness, redness and yellowness (colour), hardness, cohesiveness, springiness and chewiness (texture profile analysis) and  sensory  evaluation  scores were equivalent (p&gt;0.05) or better (p&lt;0.05) than the  continuous mixing or longer time of treatments.  This indicates that shorter time of mixing (6 min) with intermittent mixing sequence is sufficient to produce a good quality and homogenized dough of keropok lekor

Multiple drug resistance among Staphylococcus aureus strains isolated from cutting boards of commercial food premises: a threat to food and public health safety

Multidrug resistance among bacterial pathogens is an issue of global concern, especially in commercial food premises. This study aimed to isolate and identify the multidrug-resistant S. aureus from cutting boards of 45 restaurants in Sri Serdang, Selangor, Malaysia. Samples were obtained from the surfaces of 55 plastic cutting boards by swabbing and analyzed using 3M™ Petri film™ Staph Express Count Plate and Disk and further identified using Gram staining, coagulase and catalase tests and growth on mannitol salt agar and Baird Parker agar. Agar-disk diffusion technique was employed for antibiotic resistance against 11 antibiotics, and the results were analyzed based on the Clinical and Laboratory Standards Institute criteria. Out of 55 samples , 43.6% (n=24) were found to be positive for S. aureus. Of the 24 S. aureus, 45.8% (n=11) were multidrug-resistant. Resistance to the members of penicillins was 100%, to nalidixic acid (79.2%), to ciprofloxacin (66.7%), to cephalothin (33.3%) and ceftazidime (20.8%). There was no resistance to gentamicin, streptomycin, ceftriaxone, cefotaxime, and sulphafurazole. The emergence of multidrug-resistant S. aureus on cutting boards is an indication of poor personaland sanitary hygiene and could pose a danger of outbreak due to staphylococcal food poisoning among consumers

Polyphasic approach to the identification and characterization of aflatoxigenic strains of Aspergillus section Flavi isolated from peanuts and peanut-based products marketed in Malaysia

Peanuts are widely consumed as the main ingredient in many local dishes in Malaysia. However, the tropical climate in Malaysia (high temperature and humidity) favours the growth of fungi from Aspergillus section Flavi, especially during storage. Most of the species from this section, such as A. flavus, A. parasiticus and A. nomius, are natural producers of aflatoxins. Precise identification of local isolates and information regarding their ability to produce aflatoxins are very important to evaluate the safety of food marketed in Malaysia. Therefore, this study aimed to identify and characterize the aflatoxigenic and non-aflatoxigenic strains of Aspergillus section Flavi in peanuts and peanut-based products. A polyphasic approach, consisting of morphological and chemical characterizations was applied to 128 isolates originating from raw peanuts and peanut-based products. On the basis of morphological characters, 127 positively identified as Aspergillus flavus, and the other as A. nomius. Chemical characterization revealed six chemotype profiles which indicates diversity of toxigenic potential. About 58.6%, 68.5%, and 100% of the isolates are positive for aflatoxins, cyclopiazonic acid and aspergillic acid productions respectively. The majority of the isolates originating from raw peanut samples (64.8%) were aflatoxigenic, while those from peanut-based products were less toxigenic (39.1%). The precise identification of these species may help in developing control strategies for aflatoxigenic fungi and aflatoxin contamination in peanuts, especially during storage. These findings also highlight the possibility of the co-occurrence of other toxins, which could increase the potential toxic effects of peanuts

Effect of pomegranate (Punica granatum L.) peel powder on the antioxidant and antimicrobial properties of fish gelatin films as active packaging

Pomegranate (Punica granatum L.) peel powder was incorporated into fish gelatin film-forming solution (FFS) to develop an active packaging film. The physical, mechanical, antioxidant and antimicrobial properties of the films were investigated. Fish gelatin film without pomegranate peel powder (PPP) was used as the control film. The water vapor permeability (WVP) of the fish gelatin films increased as the content of incorporated PPP increased. However, films with higher PPP contents exhibited higher tensile strengths (TS values), which ranged from 7.48 to 8.02 MPa. PPP significantly (p < 0.05) improved the antioxidant properties of the films in both DPPH and ABTS radical-scavenging activity tests. The film's antimicrobial activities also increased significantly (p < 0.05) after the incorporation of PPP. Staphylococcus aureus (S. aureus) was found to be the most sensitive bacterium to the active film, followed by Listeria monocytogenes (L.monocytogenes) and Escherichia coli (E. coli). The largest inhibition zone (7.00 mm) was observed for S. aureus around the film incorporated with 5% (w/w) PPP. These results revealed that fish gelatin containing PPP has great potential as an active film with antioxidant and antimicrobial properties, and thus it can help maintain the quality and prolong the shelf life of food products