Effect of pre-harvest sanitizer treatments on Listeria survival, sensory quality and bacterial community dynamics on leafy green vegetables grown under commercial conditions.

Leafy green vegetables (LGVs) have large surface areas and can be colonized by various microorganisms including pathogens. In this study, we investigated the effect of pre-harvest sanitizer treatments on the survival of inoculated proxy pathogen Listeria innocua ATCC 33090 and the natural microbial community of mizuna, rocket (arugula), red chard and spinach grown under commercial conditions. Electrolyzed water (e-water), peracetic acid (PAA), and 1-bromo-3-chloro-5-dimethylhydantoin (BCDMH) were tested against water controls. We also observed the subsequent sensorial changes of harvested, bagged LGV leaves over a period of 12 days within chill storage alongside the growth, diversity and structure of bacterial populations determined using 16S rRNA gene amplicon sequencing and total viable counts (TVC). Treatment with PAA resulted in the highest reductions of L. innocua (2.4-5.5 log units) compared to the other treatments (0.25-2.5 log units). On day 0 (24 h after sanitizer application), the TVC on sanitizer treated LGVs were significantly reduced compared to water controls, except for rocket. During storage at 4.5 (±0.5)°C sanitisers only hindered microbial growth on LGVs initially and did not influence final bacterial population levels, growth rates or changes in LGV sample colour, decay, odour and texture compared to water controls. Shelf-life was not extended nor was it reduced. The community structure on LGV types differed though a core set of bacterial amplicon sequence variants (ASV) were present across all samples. No significant differences were observed in bacterial diversity between sanitizer treatments, however sanitizer treated LGV samples had initially reduced diversity compared to water treated samples. The bacterial compositions observed at the end point of storage considerably differed from what was observed at initial point owing to the increase in abundance of specific bacterial taxa, mainly Pseudomonas spp., the abundance and growth responses differing between LGV types studied. This study provides a better understanding on the microbiology and sensory impact of pre-harvest applied sanitiser treatments on different LGVs destined for commercial food use.

Microbial communities associated with resin canal discoloration in mango fruit.

Resin canal discoloration (RCD) severely impacts the fruit quality of mango, diminishes consumer confidence, and reduces sales, but the biological cause is still unclear. Using next-generation sequencing, the overall microbial community composition of RCD+ and visually healthy mango fruits was determined for the first time to examine the possible role of bacterial and fungal pathogens in RCD. The diversity profile of bacterial and fungal communities was determined using primers targeting the 16S rRNA gene and Internal Transcribed Spacer (ITS) regions. Results showed that bacterial communities in healthy fruits are clustered together and significantly different from those in RCD+ fruits. Tatumella and Pantoea species were the most abundant bacterial taxa on RCD+ fruit, and both have been linked to disease outbreaks in a variety of fruit crops. Fungal communities were generally similar between RCD+ and normal samples, though non-pathogenic yeasts Meyerozyma and Naganishia tended to dominate the fungal communities on RCD+ fruit. The study indicates that bacteria rather than fungal organisms are more likely to be associated with RCD in mango. This finding will facilitate the isolation and confirmation of RCD-causing organisms and the development of control strategies to manage RCD problem in mango.

Effect of Electric Field Distribution on the Heating Uniformity of a Model Ready-to-Eat Meal in Microwave-Assisted Thermal Sterilization Using the FDTD Method.

Microwave assisted thermal sterilization (MATS) is a novel microwave technology currently used in the commercial production of ready-to-eat meals. It combines surface heating of high-temperature circulation water with internal microwave heating in cavities. The heating pattern inside the food packages in a MATS process depends heavily on the electric field distribution formed by microwaves from the top and bottom windows of the microwave heating cavities. The purpose of this research was to study the effect of the electric field on 922 MHz microwave heating of ready-to-eat meals as they moved through the microwave chamber of a pilot-scale MATS system using the finite-difference time-domain (FDTD) method. A three-dimensional numerical simulation model was developed as a digital twin of the MATS process of food moving through the microwave chamber. The simulation showed that the electric field intensity of the MATS microwave cavity was greatest on the surface and side edge of the cavity and of the food. There was a strong similarity of the experimental heating pattern with that of the electric field distribution simulated by a computer model. The digital twin modeling approach can be used to design options for improving the heating uniformity and throughput of ready-to-eat meals in MATS industrial systems.

Effect of Storage Conditions on Shelf Stability of Undiluted Neutral Electrolyzed Water.

ABSTRACT: Neutral electrolyzed water (NEW) is an oxidizing sanitizer that can be made locally on-site; it is often stored in a ready-to-use format to accumulate the large volumes required for periodic or seasonal use. The shelf stability of NEW sanitizer was, therefore, assessed under various storage conditions to guide the development of protocols for its industrial application. To that end, fresh NEW with an available chlorine concentration (ACC) of 480 mg/L, pH 6.96, and oxidation reduction potential (ORP) of 916 mV was stored under different conditions. These were open or sealed polypropylene bottles, three different surface area-to-volume (SA:V) ratios (0.9, 1.7, and 8.7), and two temperatures (4 and 25°C). NEW stored at 4°C was significantly more stable than NEW stored at 25°C; ACC and pH decreased by 137 mg/L and 0.7, respectively, whereas ORP increased by 23 mV, after 101 days of storage. At 25°C, ACC decreased to <0.01 mg/L after 52 days in bottles with a SA:V ratio of 8.7, with a similar decrease after 101 days in bottles with a SA:V ratio of 1.7. However, pH decreased by up to 3.7 pH units, and ORP increased by up to 208 mV. The antimicrobial efficacy of "aged" electrolyzed oxidizing (EO) water with different ACC and ORP, but the same pH (i.e., 3.4 ± 0.2), was evaluated against Escherichia coli and Listeria innocua to determine any differences in residual antimicrobial activity. EO water with an ACC of ≥7 mg/L and an ORP of 1,094 mV caused a reduction of at least 4.7 log, whereas EO water with nondetectable ACC and considerably high ORP (716 mV) had little antimicrobial effect (<1-log reduction). Results from this study indicate that the efficacy of NEW as a sanitizer for large-scale applications such as horticulture can be maintained for at least 3 months when it is stored in closed containers with low SA:V ratio at low temperatures.

Modulating the Microbiome and Immune Responses Using Whole Plant Fibre in Synbiotic Combination with Fibre-Digesting Probiotic Attenuates Chronic Colonic Inflammation in Spontaneous Colitic Mice Model of IBD.

A probiotic and prebiotic food ingredient combination was tested for synergistic functioning in modulation of the colonic microbiome and remediation of the gastrointestinal immune and inflammatory responses in a spontaneous colitic mouse model. Bacillus coagulans MTCC5856 spores with capability to metabolise complex plant polysaccharides were supplemented with complex whole-plant prebiotic sugarcane fibre (PSCF). The combined and individual efficacies were tested for their influence on the outcomes of chronic inflammation in Muc2 mutant colitic Winnie mice. The mice were fed normal chow diet supplemented with either ingredient or a combination for 21 days. Synbiotic combined supplementation ameliorated clinical symptoms and histological colonic damage scores more effectively than either B. coagulans or PSCF alone. PSCF and B. coagulans alone also induced considerable immunomodulatory effects. Synbiotic supplementation however was the most efficacious in modulating the overall immune profile compared to the unsupplemented Winnie-control. The augmented synbiotic effect could potentially be due to a combination of increased levels of fermentation products, direct immune-modulating abilities of the components, their capability to reduce colonic epithelial damage and/or modulation of the microbiota. The beneficial effects of the supplementation with a complex plant fibre and a fibre-degrading probiotic parallel the effects seen in human microbiota with high plant fibre diets.

Anti-Heartburn Effects of Sugar Cane Flour: A Double-Blind, Randomized, Placebo-Controlled Study.

Gastroesophageal reflux disease (GERD) affects approximately 20% of Australians. Patients suffer a burning sensation known as heartburn due to the movement of acidic stomach content into the esophagus. There is anecdotal evidence of the effectiveness of prebiotic sugarcane flour in controlling symptoms of GERD. This pilot study aimed to investigate the effectiveness of a prebiotic sugarcane flour in alleviating symptoms in medically-diagnosed GERD patients. This pilot study was a single center, double-blinded, placebo-controlled randomized trial conducted on 43 eligible participants. The intervention group (n = 22) were randomized to receive 3 g of sugarcane flour per day, and the control group (n = 21) received 3 g of cellulose placebo per day. Symptoms of gastroesophageal reflux disease were assessed before and after three weeks treatment using the validated Gastroesophageal Reflux Disease-Health Related Quality of Life questionnaire (GERD-HRQL). After three weeks there were significant differences in symptoms for heartburn, regurgitation, and total symptoms scores (p < 0.05) between the sugarcane flour and placebo. Mean GERD-HRQL scores increased in the placebo group for regurgitation (mean increase 1.7; 95% CI 0.23 to 3.2; p = 0.015) and total symptom scores (2.9; 95% CI 0.26 to 5.7; p = 0.033). In contrast, there were significant reductions in heartburn (mean decrease -2.2; 95% CI -4.2 to -0.14; p = 0.037) and total symptom scores (-3.7; 95% CI -7.2 to -0.11; p = 0.044) in the intervention group. This pilot study has shown significant positive effects of sugarcane flour in the reduction of GERD symptoms, and a larger randomized controlled trial is warranted.

Microbiota Modulating Nutritional Approaches to Countering the Effects of Viral Respiratory Infections Including SARS-CoV-2 through Promoting Metabolic and Immune Fitness with Probiotics and Plant Bioactives.

Viral respiratory infections (VRIs) can spread quickly and cause enormous morbidity and mortality worldwide. These events pose serious threats to public health due to time lags in developing vaccines to activate the acquired immune system. The high variability of people's symptomatic responses to viral infections, as illustrated in the current COVID-19 pandemic, indicates the potential to moderate the severity of morbidity from VRIs. Growing evidence supports roles for probiotic bacteria (PB) and prebiotic dietary fiber (DF) and other plant nutritional bioactives in modulating immune functions. While human studies help to understand the epidemiology and immunopathology of VRIs, the chaotic nature of viral transmissions makes it difficult to undertake mechanistic study where the pre-conditioning of the metabolic and immune system could be beneficial. However, recent experimental studies have significantly enhanced our understanding of how PB and DF, along with plant bioactives, can significantly modulate innate and acquired immunity responses to VRIs. Synbiotic combinations of PB and DF potentiate increased benefits primarily through augmenting the production of short-chain fatty acids (SCFAs) such as butyrate. These and specific plant polyphenolics help to regulate immune responses to both restrain VRIs and temper the neutrophil response that can lead to acute respiratory distress syndrome (ARDS). This review highlights the current understanding of the potential impact of targeted nutritional strategies in setting a balanced immune tone for viral clearance and reinforcing homeostasis. This knowledge may guide the development of public health tactics and the application of functional foods with PB and DF components as a nutritional approach to support countering VRI morbidity.

Synbiotic supplementation with prebiotic green banana resistant starch and probiotic Bacillus coagulans spores ameliorates gut inflammation in mouse model of inflammatory bowel diseases.

PURPOSE: The research goal is to develop dietary strategies to help address the growing incidence of inflammatory bowel diseases (IBD). This study has investigated the effectiveness of green banana resistant starch (GBRS) and probiotic Bacillus coagulans MTCC5856 spores for the amelioration of dextran-sulfate sodium (DSS)-induced colitis in mice. METHODS: Eight-week-old C57BL/6 mice were fed standard rodent chow diet supplemented with either B. coagulans, GBRS or its synbiotic combination. After 7 days supplementation, colitis was induced by adding 2% DSS in drinking water for 7 days while continuing the supplemented diets. Animal health was monitored and after 14 days all animals were sacrificed to measure the biochemical and histochemical changes associated with each supplement type. RESULTS: The disease activity index and histological damage score for DSS-control mice (6.1, 17.1, respectively) were significantly higher (p < 0.0001) than the healthy mice. Synbiotic supplementation alleviated these markers (- 67%, - 94% respectively) more adequately than B. coagulans (- 52%, - 58% respectively) or GBRS (- 57%, - 26%, respectively) alone. Compared to DSS-control synbiotic supplementation significantly (p < 0.0001) maintained expressions of tight junction proteins. Moreover, synbiotic effects accounted for ~ 40% suppression of IL-1ß and ~ 29% increase in IL-10 levels in serum while also reducing C-reactive protein (- 37%) compared to that of the DSS-control. While, B. coagulans alone could not induce additional levels of short-chain fatty acid (SCFA) production beyond the caecum, the synbiotic combination with GBRS resulted in substantial increased SCFA levels across the whole length of the colon. CONCLUSION: The synbiotic supplementation with B. coagulans and GBRS ameliorated the overall inflammatory status of the experimental IBD model via synergistic functioning. This supports researching its application in mitigating inflammation in human IBD.

Dataset of volatile compounds in fresh and stored cut watermelon (Citrullus lanatus) under varying processing and packaging conditions.

Headspace volatile data for fresh and stored cut watermelon measured by solid phase microextraction gas chromatography - mass spectrometry (SPME GC-MS) and also proton transfer reaction-mass spectrometry (PTR-MS) are reported [1]. Eight different processing and packaging storage treatments were applied to fresh and stored cut watermelon including varying the processing treatments (with vs. without post-cut sanitation spray), headspace gas composition (ambient vs. modified atmosphere), lidding film permeability (perforated vs. non-perforated), storage temperature (3 and 7 °C) for up to 8 days. A total of 41 volatile compounds were characterized by SPME GC-MS in watermelon headspace on the basis of their electron impact (EI) mass spectra. Reference chemical standards and matching linear retention indices (LRIs) were used to confirm the identity of 32 volatiles (Supplementary Table 1). PTR-MS fragmentation data for 32 key odor-active reference volatiles identified in watermelon are reported (Supplementary Table 2). PTR-MS fragment data for fresh and stored cut watermelon are provided (Supplementary Table 3).

Spoilage microbial community profiling by 16S rRNA amplicon sequencing of modified atmosphere packaged live mussels stored at 4oC.

There is little information on the microbial communities associated with modified atmosphere (MA)-packaged live mussels. There is also a dearth of information on how pre-packaging depuration modifies the microbial communities and spoilage of live mussels. Amplicon sequencing was used to describe spoilage microbial succession in MA-packaged live mussels during storage at 4 °C. Proteobacteria, Cyanobacteria and Firmicutes were the three major phyla observed in the mussel meat and pouch water of undepurated and depurated mussels. Among these phyla, Cyanobacteria was more predominant on day 0 in mussel meat of undepurated and depurated mussels while Proteobacteria was predominant in commercially-depurated mussels. Synechococcus was apparently dominant on days 0-7 in the meat of undepurated mussels and days 0-10 in depurated mussels. Shewanella was dominant on day 0 in commercially-depurated mussels and dominant on day 15 in undepurated while Acidaminococcus was dominant in depurated mussels on day 15. Psychromonas was observed to be dominant in commercially-depurated mussels on day 7 and further shifted to Acinetobacter by day 10 and 15. In the pouch water, Acinetobacter was dominant throughout the storage days in undepurated mussels while Psychrobacter was predominant in both depurated and commercially-depurated mussels. This study demonstrated the impact of depuration on the microbiota and the spoilage mechanism of MA-packaged live mussels. Shewanella was easily removed through depuration. However, spoilage bacteria such as Acidaminococcus could not be easily removed although they are not important at the beginning but grew at the end. Pouch water contributed suitable biological medium for the growth of Acinetobacter and Psychrobacter and both enhanced the growth of spoilage bacteria such as Shewanella and Acidaminococcus.

Synbiotic Supplementation Containing Whole Plant Sugar Cane Fibre and Probiotic Spores Potentiates Protective Synergistic Effects in Mouse Model of IBD.

Inflammatory bowel diseases (IBD) are a chronic inflammatory disorders with increasing global incidence. Synbiotic, which is a two-point approach carrying probiotic and prebiotic components in mitigating inflammation in IBD, is thought to be a pragmatic approach owing to the synergistic outcomes. In this study, the impacts of dietary supplementation with probiotic Bacillus coagulans MTCC5856 spores (B. coagulans) and prebiotic whole plant sugar cane fibre (PSCF) was assessed using a murine model of IBD. Eight-week-old C57BL/6 mice were fed a normal chow diet supplemented with either B. coagulans, PSCF or its synbiotic combination. After seven days of supplementation, colitis was induced with dextran sulfate sodium (DSS) in drinking water for seven days during the continuation of the supplemented diets. Synbiotic supplementation ameliorated disease activity index and histological score (-72%, 7.38, respectively), more effectively than either B. coagulans (-47%, 10.1) and PSCF (-53%, 13.0) alone. Synbiotic supplementation also significantly (p < 0.0001) prevented the expression of tight junction proteins and modulated the altered serum IL-1ß (-40%), IL-10 (+26%), and C-reactive protein (CRP) (-39%) levels. Synbiotic supplementations also raised the short-chain fatty acids (SCFA) profile more extensively compared to the unsupplemented DSS-control. The synbiotic health outcome effect of the probiotic and prebiotic combinations may be associated with a synergistic direct immune-regulating efficacy of the components, their ability to protect epithelial integrity, stimulation of probiotic spores by the prebiotic fibre, and/or with stimulation of greater levels of fermentation of fibres releasing SCFAs that mediate the reduction in colonic inflammation. Our model findings suggest synbiotic supplementation should be tested in clinical trials.

Innovative processes and technologies for modified atmosphere packaging of fresh and fresh-cut fruits and vegetables.

Modified atmosphere packaging (MAP) technology has been commercially viable since the 1970s. Currently, MAP is extensively used worldwide to preserve the quality and extend the shelf-life of whole fresh fruits and vegetables, but is also increasingly used to extend the shelf-life of minimally processed fresh fruit and vegetables. This review discusses new processes and technologies that can be used to improve quality preservation and consumer acceptability of minimally processed produce where high respiration rates and challenging degradation processes operate. New packaging innovations are enabling producers and retailers to further maintain quality for longer. Innovative approaches to extend shelf-life include active MAP with differentially permeable films, films that incorporate antimicrobial properties, edible coatings that confer barriers properties, and the use of non-traditional gases to modify respiration. Intelligent packaging using integrated sensor technologies that can indicate maturity, ripeness, respiration rate and spoilage are also appearing. This review demonstrates that preservation technologies and associated packaging developments that can be combined with modified atmosphere are constantly evolving technology platforms. Adoption of combinations of technology improvements will be critical in responding to commercial trends towards more minimally processed fresh-cut and ready-to-eat fruit and vegetable products, which require specialized packaging solutions.

Control of microbes on barley grains using peroxyacetic acid and electrolysed water as antimicrobial agents.

The extent and type of microbial growth on barley grain is a key determinant of malt quality for beer production, as problematic microbial products can persist into the brewing process and impact beer quality. Microbial composition on malting barley grain are influenced by field growth, storage and malting conditions. The present study investigated the efficacy of electrolysed water (EW) with free chlorine concentrations of 5, 50, 100 and 500 ppm, as well as peroxyacetic acid (PAA) at 100 and 500 ppm, as pre-steep treatments to control microbes on grains during the malting process. The research determined the reduction in the load of Pseudomonas spp., heterotrophic bacteria, yeasts and filamentous fungi on weathered and on non-weathered grains. Pseudomonas spp., heterotrophic bacteria and yeasts were significantly reduced up to 4 logs when treated with 500 ppm PAA. PAA reduced filamentous fungi but 500 ppm free chlorine EW showed greater reductions. None of the treatments had detrimental effect on grain germination. The variation in antimicrobial efficacy among treatments can be attributed to variations in microbial susceptibility as well as differences in anti-microbial mechanisms specific to each antimicrobial agent.

High sensitivity deep-UV LED-based z-cell photometric detector for capillary liquid chromatography.

A new high sensitivity deep-UV LED photometric detector with a z-type flow cell (45 nL or 180 nL) for miniaturised and portable capillary liquid chromatography (LC) was designed and fabricated to overcome sensitivity limitations due to short pathlength in on-capillary detectors. The new detector has a 10 mm geometric pathlength and uses high intensity light-emitting diodes (LED) as light sources in the deep-UV range (254 nm and 280 nm). No optical reference was necessary due to the low drift in the signal. Stray light was minimized by the use of an adjustable slit with a 0.5 mm pinhole. The direct relationship between absorbance and concentration was obtained using dichromate to evaluate the sensitivity and the linearity range of the detector. Performance of the miniaturised version was compared with that obtained from a commercial benchtop detector for capillary LC under the same conditions using the same optical z-cell. The miniaturised version exhibited a superior performance across all parameters, including 3 times higher effective pathlength, 4 times higher upper limit of detector linearity, and 2-5 times lower stray light levels. An application of the new detector was shown with the detection of l-dopa, l-tyrosine, norfenefrine, phenylephrine and tyramine, separated using capillary LC. The baseline noise level recorded was as low as 3.9 µAU. Further, the detector was applied in a miniaturised capillary LC for the indirect detection of common inorganic anions. In comparison to an on-capillary LED detector applied under similar chromatographic conditions, there was a 50 times higher signal to noise (S/N) ratio.

Comparison of cation-exchange capillary columns used for ion chromatographic separation of biogenic amines.

The selectivity for 15 biogenic amines and amino acids shown by three capillary cation-exchange columns, IonPac CS19, CS12A and CS17 (250 × 0.4 mm ID, all from Thermo Fisher Scientific), exhibiting medium, medium low and ultra-low hydrophobicity, and either carboxylic or mixed carboxylic/phosphonic acid functional groups, was investigated. A mixed mode retention mechanism was revealed with ion-exchange, hydrophobic and hydrogen bonding interactions contributing to retention of polar organic molecules on these phases. The relative impact of these interactions was evaluated via the effect of concentration and pH of the eluent (methanesulfonic acid) on the retention of fifteen structurally similar biogenic amines and amino acids. Strong hydrogen bonding interactions were observed between the solute amino acid carboxylic groups and cation-exchange groups from the ion-exchangers. This is the first time retention data correlated with logP data has revealed clustering of the solutes in two groups, according to the presence or absence of a carboxylic acid functional group. In addition, stronger retention behaviour was found for the IonPac CS12A cation-exchanger, containing both carboxylic and phosphonic functional groups. Further assessment of the orthogonality plots of retention factors for the three stationary phases revealed that the columns exhibited different complimentary selectivity that can be utilised to achieve specific separations.

Evaluation of spoilage potential and volatile metabolites production by Shewanella baltica isolated from modified atmosphere packaged live mussels.

Under the current commercial practice, live mussels only have 10days' shelf-life. Observed spoilage indices reduce consumers' acceptance, palatability and shelf-life of modified atmosphere packaged (MAP) live mussels. The aims of this study are to isolate specific spoilage bacteria from modified atmosphere packaged live mussels, evaluate isolates for microbial spoilage indices using qualitative methods and volatile metabolites production. Forty-six hydrogen sulphide producing bacteria were isolated and evaluated for trimethylamine n-oxide (TMAO) reduction, proteolytic and lipolytic activities and hydrogen sulphide production. Twenty-eight isolates were obtained from pouch water and 18 from mussel meat. All the isolates could produce H2S on Iron agar at 25°C while 30/46 produced H2S at 4°C and tolerate 0-6% NaCl. Four (4/46) isolates could not hydrolyse mussel protein. Over 80% isolates reduced TMAO to TMA in 3days with the production of H2S. Results of this study shows hydrogen sulphide producing bacteria isolated from MAP live mussels produce microbial spoilage indices. Isolate with highest enzymatic activities and hydrogen sulphide production was identified as Shewanella baltica using 16S rRNA gene. Axenic culture of the isolate was inoculated into sterile mussel broth. Inoculated sample was further stored at 4°C for 10days for spoilage study. Volatile metabolites produced during storage were evaluated using headspace solid phase micro-extraction gas chromatography mass spectrometry (HS-SPME GC/MS). A total of 44 compounds were identified in the sample after 10days while 27 compounds were identified in inoculated mussel broth. Group of compounds identified are alcohols, aldehydes, phenol, furans, ketone, esters, organic acid, aromatic hydrocarbons, alkanes, nitrogen and sulphur containing compounds. Dimethyl trisulphide, methyl-phenol, 3,5-octadiene and thiohexene were unique to inoculated mussel broth. Understanding spoilage mechanism and attendant spoilage indices will help in designing effective mussel quality protocols and shelf-life extension.

Seafood spoilage microbiota and associated volatile organic compounds at different storage temperatures and packaging conditions.

Seafood comprising of both vertebrate and invertebrate aquatic organisms are nutritious, rich in omega-3 fatty acids, essential vitamins, proteins, minerals and form part of healthy diet. However, despite the health and nutritional benefits, seafood is highly perishable. Spoilage of seafood could be as a result of microbial activity, autolysis or chemical oxidation. Microbial activity constitutes more spoilage than others. Spoilage bacteria are commonly Gram negative and produce off odours and flavours in seafood as a result of their metabolic activities. Storage temperature, handling and packaging conditions affect microbial growth and thus the shelf-life of seafood. Due to the complexity of the microbial communities in seafood, culture dependent methods of detection may not be useful, hence the need for culture independent methods are necessary to understand the diversity of microbiota and spoilage process. Similarly, the volatile organic compounds released by spoilage bacteria are not fully understood in some seafood. This review therefore highlights current knowledge and understanding of seafood spoilage microbiota, volatile organic compounds, effects of storage temperature and packaging conditions on quality of seafood.

Miniaturised electrically actuated high pressure injection valve for portable capillary liquid chromatography.

A miniaturised high pressure 6-port injection valve has been designed and evaluated for its performance in order to facilitate the development of portable capillary high performance liquid chromatography (HPLC). The electrically actuated valve features a very small size (65 × 19 × 19mm) and light weight (33g), and therefore can be easily integrated in a miniaturised modular capillary LC system suited for portable field analysis. The internal volume of the injection valve was determined as 98 nL. The novel conical shape of the stator and rotor and the spring-loaded rotor performed well up to 32MPa (4641psi), the maximum operating pressure investigated. Suitability for application was demonstrated using a miniaturised capillary LC system applied to the chromatographic separation of a mixture of biogenic amines and common cations. The RSD (relative standard deviation) values of retention times and peak areas of 6 successive runs were 0.5-0.7% and 1.8-2.8% for the separation of biogenic amines, respectively, and 0.1-0.2% and 2.1-3.0% for the separation of cations, respectively. This performance was comparable with bench-top HPLC systems thus demonstrating the applicability of the valve for use in portable and miniaturised capillary HPLC systems.

Report: Potential of nano-emulsions as phytochemical delivery system for food preservation.

Nature is a rich source of bioactive phytochemicals. These plant based compounds have rich scope as antioxidants, antimicrobial compounds and food preservatives and so for long time to be used in meat, fruits, vegetables and processed food items, either as added preservative or as coating material in various food applications, but the major limitation is their limited solubility in a food grade medium. Nano-emulsion is a best choice as a medium having vast area of application. The major advantage of nano-emulsion would be the solubility of a vast group of compounds, due to the presence of water and lipid phases. In this way, nano-emulsions can be proved to be the most suitable candidate as phytochemical delivery system for food preservation. In present article, the use of phytochemicals as potent food preservatives has been reviewed, in context of solubility of phytochemicals in nano-emulsion and applications of food grade nano-emulsions to food systems.

Optimizing Prednisolone Loading into Distiller's Dried Grain Kafirin Microparticles, and In vitro Release for Oral Delivery.

Kafirin microparticles have potential as colon-targeted delivery systems because of their ability to protect encapsulated material from digestive processes of the upper gastrointestinal tract (GIT). The aim was to optimize prednisolone loading into kafirin microparticles, and investigate their potential as an oral delivery system. Response surface methodology (RSM) was used to predict the optimal formulation of prednisolone loaded microparticles. Prednisolone release from the microparticles was measured in simulated conditions of the GIT. The RSM models were inadequate for predicting the relationship between starting quantities of kafirin and prednisolone, and prednisolone loading into microparticles. Compared to prednisolone released in the simulated gastric and small intestinal conditions, no additional drug release was observed in simulated colonic conditions. Hence, more insight into factors affecting drug loading into kafirin microparticles is required to improve the robustness of the RSM model. This present method of formulating prednisolone-loaded kafirin microparticles is unlikely to offer clinical benefits over commercially available dosage forms. Nevertheless, the overall amount of prednisolone released from the kafirin microparticles in conditions simulating the human GIT demonstrates their ability to prevent the release of entrapped core material. Further work developing the formulation methods may result in a delivery system that targets the lower GIT.