Assessment of microbiological safety and physicochemical changes of grey oyster mushroom (Pleurotus sajor-caju) during storage at 4 °C and 25 °C

This study aimed to evaluate the microbiological and physicochemical properties of grey oyster mushroom during storage (day 0, 3, 6, 9, 12) at 4 °C and 25 °C. The microbial quality and safety analyses were aerobic plate count (APC), yeast and mould count, Escherichia coli count, Bacillus cereus count, and Listeria monocytogenes count, while the physicochemical analyses were pH, water activity, colour, and firmness. Grey oyster mushroom stored at 4 °C showed increasing trend in all microbial counts. A similar trend was observed at 25 °C, but with higher microbial counts except for L. monocytogenes which had a slight reduction from 1.82 ± 1.16 at day 0 to 0.24 ± 0.34 log CFU/g at day 6. The pH of grey oyster mushroom was quite stable when stored at 4 °C (6.42 ± 0.03 at day 0 to 6.46 ± 0.21 at day 12). A decrease in pH was observed when the mushroom was stored at 25 °C (6.42 ± 0.03 at day 0 to 5.38 ± 0.93 at day 6). The Browning Index (BI) increased which indicated by the colour changes on the mushroom cap (front and back) especially at 25 °C. Firmness analysis carried out on mushroom cap and stalk showed a decreasing trend during storage, at which 25 °C displayed prominent loss of firmness in cap and stalk as compared to 4 °C. In conclusion, slower deterioration was observed in grey oyster mushroom stored at 4 °C as compared to 25 °C. This is based on lower microbial counts, and minimal changes in pH, BI, and firmness of grey oyster mushroom

Novel in vitro diagnosis of equine allergies using a protein array and mathematical modelling approach: a proof of concept using insect bite hypersensitivity

Insect bite hypersensitivity (IBH) is a seasonal recurrent skin allergy of horses caused by IgE-mediated reactions to allergens present in the saliva of biting insects of the genus Culicoides, and possibly also Simulium and Stomoxys species. In this work we show that protein microarrays containing complex extracts and pure proteins, including recombinant Culicoides allergens, can be used as a powerful technique for the diagnosis of IBH. Besides the obvious advantages such as general profiling and use of few microliters of samples, this microarray technique permits automation and allows the generation of mathematical models with the calculation of individual risk profiles that can support the clinical diagnosis of allergic diseases. After selection of variables on influence on the projection (VIP), the observed values of sensitivity and specificity were 1.0 and 0.967, respectively. This confirms the highly discriminatory power of this approach for IBH and made it possible to attain a robust predictive mathematical model for this disease. It also further demonstrates the specificity of the protein array method on identifying a particular IgE-mediated disease when the sensitising allergen group is known

Allergenicity of pasteurised whole raw egg powder compared with fresh whole raw egg

Netting, MJ; Makrides, M; Gold, M; Quinn, P; Penttila,