Quality-Based Thermokinetic Optimization of Ready-to-Eat Whole Edible Crab (Cancer pagurus) Pasteurisation Treatments

Traditional processing practices used in the manufacture of ready-to-eat edible crab products include a double-heat treatment involving an initial cooking step followed by washing and packaging and finally, a second heat pasteurisation. The latter, pasteurisation step, results in the most severe impact on product quality. The main objective of this research was to optimise this pasteurisation step using quality index degradation kinetic approach. Preliminary work involved the characterisation of temperature rise in the crab cold-spot during pasteurisation. Equivalent treatments (F90°C 10°C = 10 min) were defined in order to assess the impact of pasteurisation temperature on different crab quality indexes in both crab meat types, white and brown. Colour degradation of crab white meat was defined as the critical quality parameter to be monitored during thermal pasteurisation. The effect of time and temperature on the kinetics of white meat colour change (¿E*) were characterised and fitted to an exponential equation. Following this, an industry focus group was used to define white meat colour change vs product quality and defined ‘good’ (¿E* = 7), ‘acceptable’ (7 < ¿E* < 9) and ‘unacceptable’ (¿E* = 9) quality. Finally, using the developed equations, optimal pasteurisation conditions were defined and validated. To produce ‘good’ quality crab, optimal temperatures ranged between 96 and 100 °C while temperatures between 104 and 108 °C produced ‘acceptable’ quality in crabs of 400 and 800 g, respectively. Overall, the results show that the equations obtained could be used in a decision support system (DSS) to define heat pasteurisation conditions to optimise the quality of ready-to-eat edible crab

Crab-meat-isolated psychrophilic spore forming bacteria inactivation by electron beam ionizing radiation

The present work was performed to evaluate the potential of electron beam ionizing radiation for the inactivation of three psychrophilic spore forming bacteria (Bacillus mycoides, Bacillus weihenstephanensis and Psychrobacillus psychrodurans) isolated from ready-to-eat brown crab (Cancer pagurus). Inactivation curves for the three spores were performed in both types of crab meat, brown and white. Also the effect of pH and water activity (aw) on the lethal efficacy of ionizing radiation, for the three different psychrophilic spore forming bacteria, was evaluated. The effects of pH, aw and their possible interactions were assessed in citrate-phosphate buffers of different pH, ranging between 7 and 4, and aw, ranging from 0.99 and 0.90, while an aw reduction from 0.90 to 0.80 had a minor impact on their resistance. In contrast to aw, the effect of pH showed a greater variability depending on the spore species. While pH did not affect the resistance of B. weihenstephanensis at any aw, B. mycoides showed slightly higher resistance at pH 5.5¿at aw of 0.90 and 0.80. pH showed a significant effect on the resistance of P. psychrodurans. For the two types of crab meat, slightly differences were observed in 6D values. B. weihenstephanensis was the most resistant, requiring 7.3–7.6¿kGy to inactivate 6 Log10-cycles of this spore forming bacterium, while for B. mycoides and P. psychrodurans 6.1–6.3 and 5.4–5.3¿kGy respectively were necessary to reach the same inactivation level in crab meat. An agreement between spore resistance in crab meats and lab media, with similar characteristics in pH and aw, was also observed. The results obtained in this research demonstrated the potential for ionizing radiation to achieve an appropriate inactivation level of spores naturally present in brown crab with the application of doses lower than 10¿kGy

An assessment of the application of ultrasound in the processing of ready-to-eat whole brown crab (Cancer pagurus)

This study assesses the potential of incorporating ultrasound as a processing aid in the production of whole cooked brown crab (Cancer pagurus). The FDA recommended heat treatment to reduce Listeria monocytogenes by 6 log10 cycles in this product is a F70 7.5 of 2 min. An equivalent F value was applied at 75 °C in presence and absence of ultrasound in water alone or in water with 5% w/v NaCl added. Heat penetration, turbidity and conductivity of the cook water and also salt and moisture content of the crab meat (white and brown) were determined. Ultrasound assisted cooking allowed a reduction of the cooking time by up to 15% while still maintaining an F70 7.5 of 2 min. Ultrasound also enhanced the rate and total amount of compounds released from the crab, which suggests that crabs cooked in the presence of ultrasound would be expected to be cleaner. Ultrasound also proved to be effective in reducing the salt content but hardly affected the final moisture content of the crab meat

Characterisation of invasive group B streptococci based on investigation of surface proteins and genes encoding surface proteins

ABSTRACTThe joint distributions of the six genes bca, bac, ɛ/alp1, alp2, alp3 and rib (encoding α-C-protein, β-C-protein, ɛ/Alp1, Alp2, Alp3, and Rib, respectively) and the proteins α-C-protein, β-C-protein and Rib were investigated in invasive isolates of group B streptococcus (GBS). In total, 297 invasive isolates (123 from neonates, 174 from adults) from south-west Sweden were collected during a 13-year period. Genes were detected using multiplex and specific PCRs, and expression of the surface proteins was demonstrated using monoclonal antibodies. The genes studied were found alone or in combinations in 294 (99%) of the invasive isolates. The most common genes were rib (n = 127 isolates, 43%), alp3 (n = 78, 26%) and ɛ/alp1 (n = 42, 14%). The bac gene was never found alone, but was found in combination with one other gene in 36 isolates. The surface proteins studied were detected alone or in combinations in 152 (51%) isolates, with the most common being Rib (n = 80, 27%), α-C-protein (n = 68, 23%) and β-C-protein (n = 24, 8%). Several genes were associated significantly with particular serotypes (e.g., ɛ/alp1 with serotype Ia; bca and bac with serotypes Ib and II; rib with serotype III; alp3 with serotype V). Overall, it was concluded that demonstration of different genes and surface proteins of GBS strains can be useful in epidemiological studies and in formulation of vaccines, but disappointingly, no single gene or surface protein included in the study was sufficiently common for it to be considered as the basis for a successful GBS vaccine

Efficacy of ultraviolet light (UV-C) and pulsed light (PL) for the microbiological decontamination of raw salmon (Salmo salar) and food contact surface materials

peer-reviewedThe decontamination effect of two light-based technologies on salmon, polyethylene (PE) and stainless steel (SS) was evaluated. Optimization of treatment conditions for ultraviolet light (UV-C) and pulsed light (PL) was carried out on raw salmon, obtaining inactivation levels of 0.9 and 1.3 log CFU/g respectively. The effects of treatments on several microbial groups present in salmon were then evaluated. For both technologies, Pseudomonas spp. were found to be the most resistant group of microorganisms tested. Three different strains from within this group were isolated and speciated, including a P. fluorescens strain which was selected for subsequent studies. PE and SS surfaces were inoculated with a suspension of the P. fluorescens suspended in a ‘salmon juice’ solution, and treated with UV-C and PL at different doses (mJ/cm2). PE surfaces were effectively decontaminated a low doses for both technologies, with a reduction of >4 log cycles observed. Decontamination of SS was also effective when treated with PL, although at higher doses than for PE. When SS was treated with UV-C, the maximum reduction of P. fluorescens achieved was 2 log cycles, even at the highest dose

Metabolic mapping by use of high-resolution magic angle spinning1H MR spectroscopy for assessment of apoptosis in cervical carcinomas

Background High-resolution magic angle proton magnetic resonance spectroscopy (HR1H MAS MRS) provides a broad metabolic mapping of intact tumor samples and allows for microscopy investigations of the samples after spectra acquisition. Experimental studies have suggested that the method can be used for detection of apoptosis, but this has not been investigated in a clinical setting so far. We have explored this hypothesis in cervical cancers by searching for metabolites associated with apoptosis that were not influenced by other histopathological parameters like tumor load and tumor cell density. Methods Biopsies (n = 44) taken before and during radiotherapy in 23 patients were subjected to HR MAS MRS. A standard pulse-acquire spectrum provided information about lipids, and a spin-echo spectrum enabled detection of non-lipid metabolites in the lipid region of the spectra. Apoptotic cell density, tumor cell fraction, and tumor cell density were determined by histopathological analysis after spectra acquisition. Results The apoptotic cell density correlated with the standard pulse-acquire spectra (p < 0.001), but not with the spin-echo spectra, showing that the lipid metabolites were most important. The combined information of all lipids contributed to the correlation, with a major contribution from the ratio of fatty acid -CH2 to CH3 (p = 0.02). In contrast, the spin-echo spectra contained the main information on tumor cell fraction and tumor cell density (p < 0.001), for which cholines, creatine, taurine, glucose, and lactate were most important. Significant correlations were found between tumor cell fraction and glucose concentration (p = 0.001) and between tumor cell density and glycerophosphocholine (GPC) concentration (p = 0.024) and ratio of GPC to choline (p < 0.001). Conclusion Our findings indicate that the apoptotic activity of cervical cancers can be assessed from the lipid metabolites in HR MAS MR spectra and that the HR MAS data may reveal novel information on the metabolic changes characteristic of apoptosis. These changes differed from those associated with tumor load and tumor cell density, suggesting an application of the method to explore the role of apoptosis in the course of the disease

Silicon microcantilever sensors to detect the reversible conformational change of a molecular switch, Spiropyan

The high sensitivity of silicon microcantilever sensors has expanded their use in areas ranging from gas sensing to bio-medical applications. Photochromic molecules also represent promising candidates for a large variety of sensing applications. In this work, the operating principles of these two sensing methods are combined in order to detect the reversible conformational change of a molecular switch, spiropyran. Thus, arrays of silicon microcantilever sensors were functionalized with spiropyran on the gold covered side and used as test microcantilevers. The microcantilever deflection response was observed, in five sequential cycles, as the transition from the spiropyran (SP) (CLOSED) to the merocyanine (MC) (OPEN) state and vice-versa when induced by UV and white light LED sources, respectively, proving the reversibility capabilities of this type of sensor. The microcantilever deflection direction was observed to be in one direction when changing to the MC state and in the opposite direction when changing back to the SP state. A tensile stress was induced in the microcantilever when the SP to MC transition took place, while a compressive stress was observed for the reverse transition. These different type of stresses are believed to be related to the spatial conformational changes induced in the photochromic molecule upon photo-isomerisation

The Potential of Biobanked Liquid Based Cytology Samples for Cervical Cancer Screening Using Raman Spectroscopy.

Patient samples are unique and often irreplaceable. This allows biobanks to be a valuable source of material. The aim of this study was to assess the ability of Raman spectroscopy to screen for histologically confirmed cases of Cervical Intraepithelial neoplasia (CIN) using biobanked liquid based cytology (LBC) samples. Two temperatures for long term storage were assessed; 80°C and -25°C. The utility of Raman spectroscopy for the detection of CIN was compared for fresh LBC samples and biobanked LBC samples. Two groups of samples were used for the study with one group associated with disease (CIN 3) and the other associated with no disease (cytology negative). The data indicates that samples stored at -80°C are not suitable for assessment by Raman spectroscopy due to a lack of cellular material and the presence of cellular debris. However, the technology can be applied to fresh LBC samples and those stored at -25°C and is, moreover, effective in the discrimination of negative samples from those where CIN 3 has been confirmed. Pooled fresh and biobanked samples are also amenable to the technology and achieve a similar sensitivity and specificity for CIN 3. This study demonstrates that cervical cytology samples stored within biobanks at temperatures that preclude cell lysis can act as a useful resource for Raman spectroscopy and will facilitate research and translational studies in this area

Current Management Strategies in Osgood Schlatter: A cross‐sectional mixed method study

AbstractBackground: Osgood Schlatter (OS) is the most common knee condition in adolescent athletes aged 9-16. Without evidence to guide clinical practice it is unclear how OS is managed. The aim of this study is to investigate how international healthcare professionals (General Practitioners, Physiotherapists, Rheumatologists, Sports and Exercise Medicine Doctors and Orthopaedic Surgeons) diagnose and manage OS.Methods: This mixed-method study used a convergent parallel design. A quantitative questionnaire and semi-structured interview covered prognosis, diagnosis, treatment, and return to play of adolescents with OS. For quantitative data those who reported likely/very likely considered 'for' and unlikely/very unlikely 'against' (for specific diagnostic/management strategy). Qualitative data analysis used a phenomenological approach.Results: Two hundred and fifty-one healthcare professionals completed the questionnaire. The most common diagnostic criterion was pain at the tibial tuberosity (97% for). The most common treatments were patient education (99%) and exercise therapy (92%). Other treatments options were more heterogeneous, e.g. pain medication (31% for, and 34% against). Managing training load (97%), pain intensity (87%) and psychological factors (86%) were considered the most important factors influencing the return to activities. Several themes emerged from the interviews (on N=20) including imaging, pain management, family, psychosocial factors influencing prognosis.Conclusion: Diagnosis criteria of OS was relatively well agreed upon, whereas triangulation of qualitative and quantitative data showed heterogeneity of treatments. Psychosocial factors including family were highlighted as critical in the management of OS.Keywords: Adolescents; Apophysitis; Musculoskeletal Pain; Osgood Schlatter; Osteochondrosis

A comprehensive MRI investigation to identify potential biomarkers of Osgood Schlatter disease in adolescents: A cross sectional study comparing Osgood Schlatter disease with controls

BackgroundOsgood–Schlatter disease (OSD) is the most common knee pain complaint among adolescents playing sports. Despite this, there remains controversy over the pathophysiology and whether specific anatomical characteristics are associated with OSD.PurposeThis study aimed to systematically and comprehensively characterize adolescents with OSD using magnetic resonance imaging (MRI) compared to pain-free controls, including both tissue abnormalities that may be associated with OSD, as well as anatomical characteristics. A secondary objective was to identify potential imaging biomarkers associated with pain.Study DesignCross-sectional study.MethodsAdolescents with OSD and controls were recruited from 2020 to 2022. Following a clinical exam, demographics, pain, sports participation, and Tanner stage were collected. Knee MRI was conducted on the participants' most symptomatic knee (OSD) or the dominant leg (controls).ResultsSixty-seven adolescents (46 with OSD and 30 controls) were included. 80% of participants with OSD had at least one tissue alteration compared to 54% of controls. Compared to controls, OSD had 36.3 (95%CI 4.5 to 289.7) higher odds of bony oedema at the tibial tuberosity, and 32.7 (95%CI 4.1 to 260.6) and 5.3 (95%CI 0.6 to 46.2) higher odds of bony oedema at the tibial epiphysis and metaphysis respectively. Participants with OSD also had higher odds of fluid/oedema at the patellar tendon (12.3 95%CI 3.3 to 46.6), and superficial infrapatellar bursitis (7.2). Participants with OSD had a more proximal tendon attachment (mean tibial attachment portion difference, −0.05, 95% CI: −0.1 to 0.0, p = 0.02), tendon thickness (proximal mean difference, −0.09, 95% CI: −0.4 to 0.2, p = 0.04; distal mean difference, −0.6, 95% CI: −0.9 to −0.2, p = 0.01). Those with bony/tendon oedema had 1.8 points (95% CI: 0.3 to 3.2) higher pain on palpation than those without (t = −2.5, df = 26.6, p = 0.019), but there was no difference between these groups in a functional single leg pain provocation.ConclusionAdolescents with OSD present with tissue and structural abnormalities on MRI that differed from age-matched controls. The majority had findings in the patellar tendon and bone, which often co-occurred. However, a small proportion of OSD also presents without alterations. It appears these findings may be associated with clinical OSD-related pain on palpation of the tibial tuberosity.Clinical RelevanceOur highlight the pathophysiology on imaging, which has implications for understanding the mechanism and treatment of OSD