Effect of high-oxygen atmosphere packaging on mechanical properties of single muscle fibres from bovine and porcine <Emphasis Type="Italic">longissimus dorsi</Emphasis>

The effect of storage in high-oxygen atmosphere packaging for 48 h at 4 °C on the myofibrillar component of meat toughness was studied performing tensile tests on single muscle fibres, isolated from beef and pork longissimus dorsi (LD). Storage of bovine LD for 48 h in the presence of oxygen significantly increased the breaking strength of single muscle fibres when compared with storage in a 100% nitrogen atmosphere. In contrast, the breaking strength of porcine LD stored for 2 days post-mortem in the presence of oxygen in the packages was not influenced.     

Aptamers for safety and quality assurance in the food industry: detection of pathogens

Aptamers are biomolecular ligands composed of nucleic acids. They can be developed to bind specifically to a range of target molecules and subsequently exploited in a fashion analogous to more traditional biomolecules such as antibodies. Methods for the production of aptamers and their potential applications to the food industry in the form of rapid assays and biosensors are discussed. In contrast to antibody‐based diagnostics, aptamers can be produced in animal‐free systems which have clear ethical and financial benefits. This review identifies a need for the development of new aptamers with specificity against micro‐organisms and highlights their potential use for the detection of food‐borne pathogens.     

Co-precipitation of whey and pea protein – indication of interactions

The aim was to optimise the yield of co-precipitation of whey protein isolate (WPI) and pea protein isolate (PPI) and compare co-precipitates and protein blends with respect to solubility. The yield of co-precipitates was tested with different protein ratios of WPI and PPI in combination with different temperatures and acid precipitation (pH 4.6). The highest precipitation yield was obtained at protein ratios WPI < PPI, high temperature and alkaline protein solvation. The solubility was measured by an instability index and absorption spectroscopy of re-suspended precipitated proteins at pH 3, 7 and 11.5. Co-precipitates had significantly lower solubility than protein blends. Protein ratios WPI > PPI, low precipitation temperature and high pH showed the highest solubility. Differences in protein composition between co-precipitates and protein blends were observed with SDS-PAGE and matrix-assisted laser desorption ionisation time-of-flight, and indicated different protein–protein interaction in samples, which needs further investigations.     

Personal exposure to PM2.5 in Chinese rural households in the Yangtze River Delta

High levels of PM_2.5 exposure and associated health risks are of great concern in rural China. For this study, we used portable PM_2.5 monitors for monitoring concentrations online, recorded personal time‐activity patterns, and analyzed the contribution from different microenvironments in rural areas of the Yangtze River Delta, China. The daily exposure levels of rural participants were 66 μg/m³ (SD 40) in winter and 65 μg/m³ (SD 16) in summer. Indoor exposure levels were usually higher than outdoor levels. The exposure levels during cooking in rural kitchens were 140 μg/m³ (SD 116) in winter and 121 μg/m³ (SD 70) in summer, the highest in all microenvironments. Winter and summer values were 252 μg/m³ (SD 103) and 204 μg/m³ (SD 105), respectively, for rural people using biomass for fuel, much higher than those for rural people using LPG and electricity. By combining PM_2.5concentrations and time spent in different microenvironments, we found that 92% (winter) and 85% (summer) of personal exposure to PM_2.5in rural areas was attributable to indoor microenvironments, of which kitchens accounted for 24% and 27%, respectively. Consequently, more effective policies and measures are needed to replace biomass fuel with LPG or electricity, which would benefit the health of the rural population in China.     

Orlistat after initial dietary/behavioural treatment: changes in body weight and dietary maintenance in subjects with sleep related breathing disorders

Background  

Sleep related breathing disorders (SRBD) are associated with increased morbidity and mortality and weight loss is recommended to overweight or obese patients with SRBD. However, maintenance of weight loss is difficult to achieve and strategies for weight loss maintenance is needed. Orlistat is a pharmacological agent that reduces the intestinal absorption of fat and may favour long-term weight maintenance.     

Viability of Listeria monocytogenes in an experimental model of nigiri sushi of halibut (Hippoglossus hippoglossus) and salmon (Salmo salar)

Sushi is a traditional Japanese food, mostly consisting of raw seafood in combination with rice. However, eating sushi has become popular among consumers in many countries outside Japan. Sushi is not free from health risks and foodborne illness linked to this product has been caused by Listeria monocytogenes. The aim of our work was to study viability of L. monocytogenes in emulated nigiri sushi comprised of halibut and salmon. Raw samples of halibut and salmon were inoculated with the pathogen and subsequently put on top of vinegar marinated sushi rice followed by storage for 7 days at 4 and 8 °C. As controls, inoculated seafood without rice was used. The experiments demonstrated that the level of L. monocytogenes in nigiri sushi was significant lower during storage over 7 days at 4 and 8 °C compared to controls, in case of inoculated seafood only. The pH drop in the fish muscle, caused by the sushi rice, is believed to be the reason for the decrease in viability of L. monocytogenes in nigiri sushi.     

Sensory characteristics of meat cooked for prolonged times at low temperature

The present study evaluated the sensory characteristics of low temperature long time (LTLT) treated Semitendinosus from pork and beef and Pectoralis profundus from chicken. Semitendinosus and Pectoralis profundus muscles were heat treated at 53°C and 58°C for T_c + 6 h, T_c + 17 h, and T_c + 30 h (only Semitendinosus from pork and beef). T_c was the time for the samples to equalize with the temperature in the water bath. Tenderness increased with increasing heating temperature and time in pork and beef, but not in chicken. Juiciness decreased with increasing heating temperature and time in all species, and cooking loss increased with increasing temperature. A done appearance was developed with increasing heating time at 58 °C in pork and beef, while in chicken the done appearance was only affected by temperature. Flavor attributes were less affected by the LTLT treatment for all species.     

Acrylamide–asparagine relationship in baked/toasted wheat and rye breads

Acrylamide in baked and toasted wheat and rye bread was studied in relation to levels of asparagine in flour, dough, bread and toasts. Asparagine was consumed during bread preparation resulting in reduced acrylamide content in the products. In wheat bread, 12% of the asparagine initially present in the flour (0.14 g kg^?1) remained after yeast fermentation and baking; for rye bread, 82% of asparagine remained after sourdough fermentation and baking. Asparagine present in untoasted wheat bread had totally reacted after hard toasting. Toasted wheat and rye bread slices contained 11–161 and 27–205 µg kg^?1 acrylamide, respectively, compared to untoasted wheat and rye bread with <5 and 7–23 µg kg^?1 acrylamide, respectively. The dietary intake of acrylamide from bread (untoasted) of 2 µg day^?1 is relatively low; however, acrylamide exposure from bread increases several fold for people eating toasted bread.