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

Benchmarking software to predict antibiotic resistance phenotypes in shotgun metagenomes using simulated data

The use of shotgun metagenomics for AMR detection is appealing because data can be generated from clinical samples with minimal processing. Detecting antimicrobial resistance (AMR) in clinical genomic data is an important epidemiological task, yet a complex bioinformatic process. Many software tools exist to detect AMR genes, but they have mostly been tested in their detection of genotypic resistance in individual bacterial strains. It is important to understand how well these bioinformatic tools detect AMR genes in shotgun metagenomic data. We developed a software pipeline, hAMRoaster (https://github.com/ewissel/hAMRoaster), for assessing accuracy of prediction of antibiotic resistance phenotypes. For evaluation purposes, we simulated a short read (Illumina) shotgun metagenomics community of eight bacterial pathogens with extensive antibiotic susceptibility testing profiles. We benchmarked nine open source bioinformatics tools for detecting AMR genes that 1) were conda or Docker installable, 2) had been actively maintained, 3) had an open source license, and 4) took FASTA or FASTQ files as input. Several metrics were calculated for each tool including sensitivity, specificity, and F1 at three coverage levels. This study revealed that tools were highly variable in sensitivity (0.25 - 0.99) and specificity (0.2 - 1) in detection of resistance in our synthetic FASTQ files despite similar databases and methods implemented. Tools performed similarly at all coverage levels (5x, 50x, 100x). Cohen’s kappa revealed low agreement across tools.

New emerging techniques in combination with conventional methods in improving the quality, safety, and nutrient values of food products

Quality, safety, and nutrient values of food products can be changed under various conditions along the production chain, even on consumers’ tables. Although based on the scientific reports, many techniques, including conventional and emerging technologies, are approached during harvest, post-harvest, processing, storage, and distribution of food products, the idea of minimal processing of food products still attracted considerable attention.

Purification of Drug Loaded Liposomal Formulations by a Novel Stirred Cell Ultrafiltration Technique

Background: Presently reported methods for purification of liposomal formulations at laboratory scale have drawbacks of adversely affecting critical quality attributes (CQAs) of liposomes such as particle size, PDI, drug entrapment efficiency, etc., and are also not amenable for large scale processing. Objective: The present study was aimed to explore stirred cell ultrafiltration technique as a novel liposome purification method for removal of unentrapped free drug and excess external aqueous fluid, maintaining the physical integrity of liposomes. Method: Purification of brimonidine loaded liposomes (model formulation) was performed by stirred cell ultrafiltration method, and its functional performance and impact on liposomal particle size, PDI, and entrapment efficiency were compared with two widely used laboratory scale methods, i.e., ultracentrifugation and centrifugal ultrafiltration. Results: The novel stirred cell ultrafiltration method demonstrated liposomal purification within ~30 min with complete liposomal recovery showing minimal processing impact, i.e., ˂0.25 fold rise in particle size, ~0.5 fold rise in PDI, and ~4% loss in % entrapment efficiency, respectively. Whereas ultracentrifugation and centrifugal ultrafiltration methods resulted in ~4 fold and ˃2 fold rise in particle size, ˃10 fold and ˃5 fold rise in PDI, and ˃25% and ~6% loss in entrapment efficiency, respectively. Conclusion: The unique and product-friendly operational features of stirred cell ultrafiltration method demonstrated simple, rapid, and efficient liposomal purification without affecting CQAs of liposomal vesicles. This method was also evidently found to be product-friendly, rugged, versatile, and scalable up to large production batch processing, overcoming major drawbacks of presently used methods.

Expert Knowledge Correlated Intrusion Detection System Evaluation Framework for Heterogeneous IoT

The dynamic contexts of heterogeneous Internet of Things (HetIoT) adversely affect the performance of learning-based network intrusion detection systems (NIDS) resulting in increased misclassification rates---necessitating an expert knowledge correlated evaluation framework. The proposed generalizable framework includes intrusion root cause analysis, correlation model, and correlated classification metrics that can be generalized over any NID dataset, corresponding expert knowledge, detection technique, and learning-based algorithm to facilitate context-awareness in reducing false alerts. To achieve this, we perform experimentations on the Bot-IoT dataset---with generalized traffic behaviors from multiple existing NID datasets---employing the Support Vector Machine (SVM) machine learning and Multilayer Perceptron (MLP) shallow neural network classifiers, demonstrating the generalizability, robustness, and improved performance of the propounded framework compared to the existing literature. Furthermore, the proposed framework offers minimal processing overhead on the classifier algorithms.<br>

Inhibitory Activity of Shrimp Waste Extracts on Fungal and Oomycete Plant Pathogens

(1) Background: This study was aimed at determining the in vitro inhibitory effect of new natural substances obtained by minimal processing from shrimp wastes on fungi and oomycetes in the genera Alternaria, Colletotrichum, Fusarium, Penicillium, Plenodomus and Phytophthora; the effectiveness of the substance with the highest in vitro activity in preventing citrus and apple fruit rot incited by P. digitatum and P. expansum, respectively, was also evaluated. (2) Methods: The four tested substances, water-extract, EtOAc-extract, MetOH-extract and nitric-extract, were analyzed by HPLC-ESI-MS-TOF; in vitro preliminary tests were carried out to determine the minimal inhibitory/fungicidal concentrations (MIC and MFC, respectively) of the raw dry powder, EtOAc-extract, MetOH-extract and nitric-extract for each pathogen. (3) Results: in the agar-diffusion-assay, nitric-extract showed an inhibitory effect on all pathogens, at all concentrations tested (100, 75, 50 and 25%); the maximum activity was on Plenodomus tracheiphilus, C. gloeosporioides and Ph. nicotianae; the diameters of inhibition halos were directly proportional to the extract concentration; values of MIC and MFC of this extract for all pathogens ranged from 2 to 3.5%; the highest concentrations (50 to 100%) tested in vivo were effective in preventing citrus and apple fruit molds. (4) Conclusions: This study contributes to the search for natural and ecofriendly substances for the control of pre- and post-harvest plant pathogens.

RESEARCH PROPOSAL: PROBING THE EFFECT OF ACTIVE EDIBLE OIL COATING ON SAFETY, SHELF STABILITY AND QUALITY OF SOFT CHEESE

Consumers' demand, perception, and preference for high quality, safe food, and awareness of health hazards of synthetic and chemical preservatives have attracted the food processors, food technologist's and industries to develop innovative techniques with the incorporation of natural components and minimal processing. Developing and utilizing the active edible coatings for shelf stability of the semi-perishable foods is one of these new innovative techniques. That's why the present study is planned to develop active edible coating using clove and peppermint essential oils as active ingredients and whey powder as the base material. Essential oils of peppermint and clove possess the antioxidant and antimicrobial properties. It is supposed that these properties of essential oils may enhance the safety, quality, and shelf stability of the cheese during storage. Soft cheese will be prepared, and these coatings will be applied to it. Then products will be stored at 4 and 25 ℃ for 15 days and will be analyzed every 3rd day for various safety, quality, and shelf stability attributes. All the obtained data will be statically analyzed to check the level of significance of these coatings.

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.

Impact of Blanching, Freezing, and Fermentation on Physicochemical, Microbial, and Sensory Quality of Sugar Kelp (Saccharina latissima)

Low seaweed consumption in the West is due to lack of availability and consumer familiarity. In this study, the effects of preservation processes on quality aspects of Saccharina latissima products were assessed. First, a blanching (100 °C for 1 or 3 min) treatment was used to produce seaweed salad. In a second study, effects of blanching, freezing, and fermentation on kelp quality were assessed and processed kelp was used to produce sauerkraut. Blanching significantly decreased (p ≤ 0.05) the instrumental kelp a* value and firmness. The a* value negatively correlated with overall liking of salads. To prepare sauerkraut, raw, raw/frozen (−20 °C), blanched (100 °C, 1 min), or blanched/frozen kelp were mixed with cabbage, salted, inoculated with starter cultures and fermented. Inconsistent trends in L* values, firmness, and fungi enumeration were observed after fermentation. Consumers evaluated kelp salad (n = 100) and sauerkraut (n = 80) for acceptability. Blanched kelp salad had higher hedonic scores than raw kelp salad. A 100% cabbage sauerkraut control and blanched kelp/cabbage blends were compared; kelp blends were similar to control for appearance, color, and texture but were lower for overall acceptability. Results suggest improved quality and enhanced consumer acceptability of seaweed products with use of minimal processing.

Comparison of the single-step and double-step sous-vide treatment effect on the quality attributes of chicken breast •

Sous-vide treatment is a modern minimal processing cooking technique that uses a single-step temperature of 55–70 °C and longer time. The quality attributes of meat might be improved by including cooking steps at below 50 °C temperatures in the sous-vide treatment. The aim of this study was to investigate the effects of the double-step sous-vide treatments on the quality attributes of the chicken breast and comparing with the traditional single-step sous-vide treatments. The single-step sous-vide treatments were performed at 60 °C. In the double-step sous-vide treatments the first step temperature was 45 °C and the end temperature was 60 °C. Double-step sous-vide treated chicken breasts obtained higher tenderness, moisture content and lower weight loss compared to the single-step sous-vide treated chicken breasts. Double-step sous-vide treatment provided an attractive cooking method to produce high quality chicken breast, however, challenge tests for specific pathogens would be useful for the assessment of the microbiological quality for different treatment combinations.