Prevalence of foodborne bacteria isolated from fresh raw ulam

Although vegetables are considered to be an essential part of a healthy diet, studies have shown that they can also represent a hazard for human health as they are usually eaten raw and receive minimal treatment. In recent years, vegetables are among the food groups associated with higher rates of recurrence and are the leading cause of enteric diseases. There is a colossal amount of data available on fresh produce worldwide; however, limited data are available regarding the microbiological quality of ulam in Malaysia. In fact, cross -contamination that occurs during minimal processing of ulam has not yet been studied. Therefore, the aim of this study was to evaluate the microbiological quality and the occurrence of Escherichia coli and Salmonella in ulam. A total of 32 samples of ulam were randomly collected from wet markets and supermarkets in Kuala Terengganu, Malaysia. The samples were analysed for enumeration of aerobic mesophilic bacteria, coliforms, yeast and moulds, Bacillus cereus, Listeria monocytogenes and detection of Escherichia coli and Salmonella. In this study, the microbiological quality of ulam were in the range of 6.36-8.83; 4.14-7.48; 0-8.16; 3.94-6.45 log10 CFU/g for aerobic mesophilic bacteria, coliforms, Salmonella and yeast and moulds, respectively. Escherichia coli and Salmonella were detected in 3.13% and 9.4% of ulam samples, respectively. The findings from the study are intended to provide insight into the potential health risks associated with the consumption of ulam. The strong interdisciplinary approach by various agencies and development of safe agricultural systems will ensure the delivery of safe vegetables to the end-users

Genome Editing and CRISPR/Cas System of Extremophiles and Its Applications

Extremophiles will be the choice of next generation industrial biotechnology (NGIB) as they are known to be contaminant resistant, but engineering their genomes has always been difficult and time consuming task. CRIPR/Cas (clustered regularly interspaced short palindromic repeat and CRISPR associated proteins) system can be employed for this reason. The genome of an industrially important halophile (i.e., Halomonas) was edited to study a combined effect of four different genes on glucose breakdown and production of poly (3-hydroxybutyrate-co-3-hydroxyvalerate). This editing has resulted in 16-fold increase of 3HV, and the mutants generated by CRIPR/Cas system were significantly effective in synthesizing PHBV. Unfortunately, this system does not always work, specifically in extremophilic microorganisms because Cas9 or Cpf1 are from mesophilic bacteria. Therefore, alternatively, the endogenous CRISPR/Cas system is used for editing the genomes of such organisms. This genome editing of extremophiles will open the doors for developing next generation industrial biotechnology (NGIB).

Microbiological Safety and Organoleptic Quality of Homogenized Sausages Manufactured with Commercial Functional Additives

The aim of the study was to compare the microbiological safety and sensory quality of meat products manufactured with commercial functional additives. Four functional additives (AFX, AE100, PANA4, FPRX) were used in industrial conditions in the production of homogenized meat products (thick wiener). In order to determine the microbiological safety of final products, the total number of aerobic mesophilic bacteria and the number of Listeria monocytogenes were measured. Consumer assessment and quantitative flavor profiling (QFP) were used for analysis of organoleptic quality. After 7 days of storage, it was found that the effectiveness of the selected additives against the growth of aerobic mesophilic bacteria was unsatisfactory. Only after application of PANA4 did the product not show undesirable changes that would disqualify it from consumption. Each of the functional additives used had a high level of efficacy in inhibiting the growth of Listeria monocytogenes. Meat products with PANA4 addition had the highest consumer acceptance of the overall appearance. The best intensity of flavor bouquet, meat aroma and color, assessed by QFP method, was characterized by the samples with AFX and PANA4 in their recipe.

The Investigation of Mycotoxins and Enterobacteriaceae of Cereal-Based Baby Foods Marketed in Turkey

In this study, a total of 85 cereal-based baby foods with or without milk (four different brands; A, B, C, and D) collected from Ankara local markets, Turkey were analyzed for mycotoxins, total aerobic mesophilic bacteria (TAMB), and Enterobacteriaceae contamination. Baby foods were analyzed for 12 toxicological important mycotoxins such as aflatoxin B1, B2, G1, and G2; fumonisin B1 and B2; ochratoxin A; sterigmatocystin (STE); deoxynivalenol (DON); zearalenone (ZON); and T-2 toxin and HT-2 toxin by LC-MS/MS multi-mycotoxin method. In addition to these mycotoxins, the presence of aflatoxin M1 (AFM1) was investigated in baby foods containing milk. The classical culture method was used for microbiological analysis. Consequently, at least one mycotoxin was detected in 69.41% of the total samples. The most frequently detected mycotoxins were STE (34.12%) and HT-2 (34.12%). However, AFM1 was not detected in any of the baby foods containing milk. Also, TAMB and Enterobacteriaceae were isolated from 30.59% and 10.59% of samples, respectively. As a result, it was determined that the mycotoxin levels in the analyzed samples were in accordance with the mycotoxin levels specified in the Turkish Food Codex.

Characterization of Argonaute nucleases from mesophilic bacteria Paenibacillus borealis and Brevibacillus laterosporus

Thermophilic Argonaute proteins (Agos) have been shown to utilize small DNA guides for cleaving complementary DNA in vitro, which shows great potential for nucleic acid detection. In this study, we explored mesophilic Agos for the detection of small molecule by cooperating with allosteric transcription factors (aTFs). Two Agos from mesophilic bacteria, Paenibacillus borealis (PbAgo) and Brevibacillus laterosporus (BlAgo), showed nuclease activity for single-stranded DNA at moderate temperatures (37 °C) by using 5′-phosphorylated and 5′-hydroxylated DNA guides. Both Agos perform programmable cleavage of double-stranded DNA, especially in AT-rich regions of plasmid. Furthermore, we developed a simple and low-cost p-hydroxybenzoic acid detection method based on DNA-guided DNA cleavage of Agos and the allosteric effect of HosA, which expands the potential application of small molecule detection by Agos.

Optimization of ozone concentration and storage time in green asparagus (Asparagus officinalis L.) using response surface methodology

Background: Asparagus (Asparagus officinalis L.) green is a vegetable with a great demand worldwide, and likewise, it is highly perishable due to its high respiration rate that accelerates its senescence. Disinfection of vegetables after their harvest is an obligatory practice that can reduce losses by decomposition due to the attack of microorganisms. Therefore, it is vital to preserving its microbiological and sensory characteristics to reach the final consumer. Objective: To evaluate the effect of gaseous ozone (0 to 10 ppm) and storage time (0 to 30 days) on phenol content, overall appearance, count of molds, psychrophilic bacteria, and viable mesophilic aerobes. Methods: the response surface methodology was used, applying a rotatable central composite design. Results: The results indicated that there was a significant influence (p <0.05) of the independent variables on the characteristics studied, as well as an adequate lack of fit of the quadratic regression model (p> 0.05). By means of the contour superposition technique, it was determined that the optimal conditions for the highest retention of phenol content (16.99 mg/g) and overall appearance (7.61 points) and lower counts of viable aerobic mesophilic bacteria (5.3 x 103 CFU/g) they corresponded to 10 ppm of gaseous ozone up to 25.91 days of storage, with adequate quality characteristics in the shoots. Conclusion: the region of interest was determined for optimal retention of phenol content and overall appearance, and a lower count of viable aerobic mesophilic bacteria in green asparagus during postharvest, suggesting to use the initial application of ozone gas at 10 ppm allowing 25.9 days storage at 1 °C. The results indicate that this technology is a good alternative in the conservation of fresh vegetables.

Microbial quality and labeling of minimally processed fruits and vegetables

The consumption of minimally processed, or ready-to-eat (RTE), fruits and vegetables has been growing because people have shorter time to eat and due to the pursuit of convenience and health benefits. Minimal processing includes raw material selection and sorting, pre-washing, debarking, cutting, slicing, sanitizing, rinsing, centrifuging, and packing. Thus, natural protection barriers are affected during cutting methods and they release nutrients that enable microorganism growth. The aim of the current study was to evaluate the levels of aerobic mesophilic bacteria, molds and yeasts, coliforms at 35°C, Escherichia coli and Salmonella sp., as well as the labeling adequacy of minimally processed fruits and vegetables traded in Vitória, Espírito Santo, Brazil. Fruits and vegetables presented aerobic mesophilic bacteria, molds and yeasts, and coliforms at 35°C, above the safe limit for consumption purposes. The count of aerobic mesophilic bacteria in RTE fruits ranged from 4.00 to 6.30 Log CFU/g. The highest count of this microorganism group was recorded for fruit salads. Salmonella sp. was not identified in fruit or vegetable samples, whereas Escherichia coli was detected in four vegetable samples. None of the evaluated labels (n = 40) followed the Brazilian legislation. Minimally processed fruits and vegetables had poor microbiological quality and labeling was also unsatisfactory. The adoption of good manufacturing practices and quality control tools as strategies to produce safe food can help minimizing risks to consumers’ health.