Skimmed milk structural dynamics during high hydrostatic pressure processing from in situ SAXS

Understanding the changes in milk at a nanostructural level during high-pressure (HP) treatment can provide new insights to improve the safety and functionality of dairy products. In this study, modifications of milk nanostructure during HP were studied in situ by small-angle X-ray scattering (SAXS). Skimmed milk was pressurized to 200 or 400 MPa at 25, 40 or 60 °C and held for 5 or 10 min, and the effect of single- and double-HP treatment was also investigated. In most cases, the SAXS patterns of skimmed milk are well fitted with a three-population model: a low-q micellar feature reflecting the overall micelle size (~0.002 Å−1), a small casein cluster contribution at intermediate-q (around 0.01 Å−1) and a high-q (0.08–0.1 Å−1) population of milk protein inhomogeneities. However, at 60 °C a scattering feature of colloidal calcium phosphate (CCP) which is normally only seen with neutron scattering, was observed at 0.035 Å−1. By varying the pressure, temperature, holding and depressurization times, as well as performing cycled pressure treatment, we followed the dynamic structural changes in the skimmed milk protein structure at different length scales, which depending on the processing conditions, were irreversible or reversible within the timescales investigated. Pressure and temperature of the HP process have major effects, not only on size of casein micelles, but also on “protein inhomogeneities” within their internal structure. Under HP, increasing processing time at 200 MPa induced re-association of the micelles, however, the changes in the internal structure were more pressure-dependent than time dependent

The Lactobacillus flora in vagina and rectum of fertile and postmenopausal healthy Swedish women

<p>Abstract</p> <p>Background</p> <p><it>Lactobacillus </it>species are the most often found inhabitants of vaginal ecosystem of fertile women. In postmenopausal women with low oestrogen levels, <it>Lactobacillus </it>flora is diminishing or absent. However, no studies have been performed to investigate the correlation between oestrogen levels and the lactobacilli in the gut. The aim of the present study was to investigate the relation in healthy women between vaginal and rectal microbial flora as well as possible variations with hormone levels.</p> <p>Methods</p> <p>Vaginal and rectal smears were taken from 20 healthy fertile women, average 40 years (range 28-49 years), in two different phases of the menstrual cycle, and from 20 postmenopausal women, average 60 years (range 52-85 years). Serum sex hormone levels were analyzed. Bacteria from the smears isolated on Rogosa Agar were grouped by Randomly Amplified Polymorphic DNA and identified by multiplex PCR and partial 16S rRNA gene sequencing.</p> <p>Results</p> <p><it>Lactobacillus crispatus </it>was more often found in the vaginal flora of fertile women than in that of postmenopausal (p = 0.036). Fifteen of 20 fertile women had lactobacilli in their rectal smears compared to 10 postmenopausal women (p = 0.071). There was no correlation between the number of bacteria in vagina and rectum, or between the number of bacteria and hormonal levels. Neither could any association between the presence of rectal lactobacilli and hormonal levels be found.</p> <p>Conclusion</p> <p><it>Lactobacillus crispatus </it>was more prevalent in the vaginal flora of fertile women, whereas the <it>Lactobacillus </it>flora of rectum did not correlate to the vaginal flora nor to hormonal levels.</p

Garden and landscape-scale correlates of moths of differing conservation status: significant effects of urbanization and habitat diversity

Moths are abundant and ubiquitous in vegetated terrestrial environments and are pollinators, important herbivores of wild plants, and food for birds, bats and rodents. In recent years, many once abundant and widespread species have shown sharp declines that have been cited by some as indicative of a widespread insect biodiversity crisis. Likely causes of these declines include agricultural intensification, light pollution, climate change, and urbanization; however, the real underlying cause(s) is still open to conjecture. We used data collected from the citizen science Garden Moth Scheme (GMS) to explore the spatial association between the abundance of 195 widespread British species of moth, and garden habitat and landscape features, to see if spatial habitat and landscape associations varied for species of differing conservation status. We found that associations with habitat and landscape composition were species-specific, but that there were consistent trends in species richness and total moth abundance. Gardens with more diverse and extensive microhabitats were associated with higher species richness and moth abundance; gardens near to the coast were associated with higher richness and moth abundance; and gardens in more urbanized locations were associated with lower species richness and moth abundance. The same trends were also found for species classified as increasing, declining and vulnerable under IUCN (World Conservation Union) criteria

Effect of Microwave Frying on Acrylamide Generation, Mass Transfer, Color, and Texture in French Fries

[EN] The objective of this work was to evaluate the effect of microwave power on acrylamide generation, as well as moisture and oil fluxes and quality attributes of microwave-fried potatoes. Concretely, 25 g of potato strips, in 250 mL of fresh oil (at room temperature), were subjected to three different microwave powers (315, 430, and 600 W) in a conventional microwave oven. Microwave frying resulted in an acrylamide reduction ranged from 37 to 83% compared to deep-oil frying. Microwave-fried French fries presented lower moisture and higher fat content than deep-oil fried potatoes. Concretely, microwave-fried potatoes presented values of moisture and texture more similar to potato chips than French fries, nonetheless with lower fat levels (less than 20 g/100 g wb) and acrylamide content (lower than 100 ¿g/kg wb) at the reference time. This study presents an alternative way of frying to address the production of healthier potato chips.The authors would like to thank the Universitat Politecnica de Valencia for the PhD scholarship given to Mariola Sansano Tomas.Sansano, M.; De Los Reyes Cánovas, R.; Andrés Grau, AM.; Heredia Gutiérrez, AB. (2018). Effect of Microwave Frying on Acrylamide Generation, Mass Transfer, Color, and Texture in French Fries. Food and Bioprocess Technology. 11(10):1934-1939. doi:10.1007/s11947-018-2144-zS193419391110AACC. (1995). Approved methods of the American association of cereal chemists (9th ed.). St. Paul: The Association.Adedeji, A. A., Ngadi, M. O., & Raghavan, G. S. V. (2009). Kinetics of mass transfer in microwave precooked and deep-fat fried chicken nuggets. Journal of Food Engineering, 91(1), 146–153.Ahrné, L., Andersson, C.-G., Floberg, P., Rosén, J., & Lingnert, H. (2007). Effect of crust temperature and water content on acrylamide formation during baking of white bread: steam and falling temperature baking. LWT-Food Science and Technology, 40(10), 1708–1715.Amrein, T. M., Limacher, A., Conde-Petit, B., Amadò, R., & Escher, F. (2006). Influence of thermal processing conditions on acrylamide generation and Browning in a potato model system. Journal of Agricultural and Food Chemistry, 54(16), 5910–5916.Andrés, A., Arguelles, Á., Castelló, M. L., & Heredia, A. (2013). Mass transfer and volume changes in French fries during air frying. Food and Bioprocess Technology, 6(8), 1917–1924.Barutcu, I., Sahin, S., & Sumnu, G. (2009). Acrylamide formation in different batter formulations during microwave frying. LWT - Food Science and Technology, 42(1), 17–22.Belgin Erdoǧdu, S., Palazoǧlu, T. K., Gökmen, V., Şenyuva, H. Z., & Ekiz, H. İ. (2007). Reduction of acrylamide formation in French fries by microwave pre-cooking of potato strips. Journal of the Science of Food and Agriculture, 87(1), 133–137.Biedermann, M., Noti, A., Biedermann-Brem, S., Mozzetti, V., & GROB, K. (2002). Experiments on acrylamide formation and possibilities to decrease the potential of acrylamide formation in potatoes. Mitteilungen aus Lebensmitteluntersuchung und Hygiene, 93(6), 668–687.Bråthen, E., & Knutsen, S. H. (2005). Effect of temperature and time on the formation of acrylamide in starch-based and cereal model systems, flat breads and bread. Food Chemistry, 92(4), 693–700.Buffler, C. R. (1993). Microwave cooking and processing: Engineering fundamentals for the food scientist. (A. Books, Ed.). New York: Van Nostrand Reinhold.Datta, A. K. (1990). Heat and mass transfer in the microwave processing of food. Chemical Engineering Progress, 86(6), 47–53.Datta, A. K. (2001). Handbook of microwave technology for food application. CRC Press.De los Reyes, R., Heredia, A., Fito, P., De los Reyes, E., & Andrés, A. (2007). Dielectric spectroscopy of osmotic solutions and osmotically dehydrated tomato products. Journal of Food Engineering, 80(4), 1218–1225. 2.Granda, C., & Moreira, R. G. (2005). Kinetics of acrylamide formation during traditional and vacuum frying of potato chips. Journal of Food Process Engineering, 28(5), 478–493.Lizhi, H., Toyoda, K., & Ihara, I. (2008). Dielectric properties of edible oils and fatty acids as a function of frequency, temperature, moisture and composition. Journal of Food Engineering, 88(2), 151–158.Oztop, M. H., Sahin, S., & Sumnu, G. (2007). Optimization of microwave frying of potato slices by using Taguchi technique. Journal of Food Engineering, 79(1), 83–91.Parikh, A., & Takhar, P. S. (2016). Comparison of microwave and conventional frying on quality attributes and fat content of potatoes. Journal of Food Science, 81(11), E2743–E2755.Pedreschi, F., & Moyano, P. (2005). Oil uptake and texture development in fried potato slices. Journal of Food Engineering, 70(4), 557–563.Sahin, S., Sumnu, G., & Oztop, M. H. (2007). Effect of osmotic pretreatment and microwave frying on acrylamide formation in potato strips. Journal of the Science of Food and Agriculture, 87(15), 2830–2836. https://doi.org/10.1002/jsfa.3034 .Sansano, M., Juan-Borrás, M., Escriche, I., Andrés, A., & Heredia, A. (2015). Effect of pretreatments and air-frying, a novel technology, on acrylamide generation in fried potatoes. Journal of Food Science, 80(5), 1120–1128.Sansano, M., Heredia, A., Peinado, I., & Andrés, A. (2017). Dietary acrylamide: What happens during digestion. Food Chemistry, 237, 58–64.Schiffmann, R. (2017). 7 - Microwave-assisted frying. In The microwave processing of foods (2nd edn, pp. 142–151). Sawston: Woodhead Publishing.Tang, J., Feng, H., & Lau, M. (2002). Microwave heating in food processing. In X.Young, J. Tang, C. Zhang, & W. Xin (Eds.), Advances in Agricultural Engineering (pp. 1–44). New York: Scientific Press.Tareke, E., Rydberg, P., Karlsson, P., Eriksson, S., & Törnqvist, M. (2002). Analysis of acrylamide, a carcinogen formed in heated foodstuffs. Journal of Agricultural and Food Chemistry, 50(17), 4998–5006.Taubert, D., Harlfinger, S., Henkes, L., Berkels, R., & Schömig, E. (2004). Influence of processing parameters on acrylamide formation during frying of potatoes. Journal of Agricultural and Food Chemistry, 52(9), 2735–2739.Venkatesh, M. S., & Raghavan, G. S. V. (2004). An overview of microwave processing and dielectric properties of agri-food materials. Biosystems Engineering, 88(1), 1–18

Bumble Bees (Bombus spp) along a Gradient of Increasing Urbanization

BACKGROUND: Bumble bees and other wild bees are important pollinators of wild flowers and several cultivated crop plants, and have declined in diversity and abundance during the last decades. The main cause of the decline is believed to be habitat destruction and fragmentation associated with urbanization and agricultural intensification. Urbanization is a process that involves dramatic and persistent changes of the landscape, increasing the amount of built-up areas while decreasing the amount of green areas. However, urban green areas can also provide suitable alternative habitats for wild bees. METHODOLOGY/PRINCIPAL FINDINGS: We studied bumble bees in allotment gardens, i.e. intensively managed flower rich green areas, along a gradient of urbanization from the inner city of Stockholm towards more rural (periurban) areas. Keeping habitat quality similar along the urbanization gradient allowed us to separate the effect of landscape change (e.g. proportion impervious surface) from variation in habitat quality. Bumble bee diversity (after rarefaction to 25 individuals) decreased with increasing urbanization, from around eight species on sites in more rural areas to between five and six species in urban allotment gardens. Bumble bee abundance and species composition were most affected by qualities related to the management of the allotment areas, such as local flower abundance. The variability in bumble bee visits between allotment gardens was higher in an urban than in a periurban context, particularly among small and long-tongued bumble bee species. CONCLUSIONS/SIGNIFICANCE: Our results suggest that allotment gardens and other urban green areas can serve as important alternatives to natural habitats for many bumble bee species, but that the surrounding urban landscape influences how many species that will be present. The higher variability in abundance of certain species in the most urban areas may indicate a weaker reliability of the ecosystem service pollination in areas strongly influenced by human activity

Democratic directionality for transformative food systems research

Effective interfaces of knowledge and policy are critical for food system transformation. Here, an expert group assembled to explore research needs towards a safe and just food system put forward principles to guide relations between society, science, knowledge, policy and politics

Antioxidative protection of dietary bilberry, chokeberry and Lactobacillus plantarum HEAL19 in mice subjected to intestinal oxidative stress by ischemia-reperfusion

<p>Abstract</p> <p>Background</p> <p>Ischemia-reperfusion (I/R) in the intestines is an inflammatory condition which activates leukocytes and reactive oxygen species (ROS) and leads to lipid peroxidation and DNA damage. Bilberry and chokeberry fruits are rich sources of polyphenols which may act as antioxidants and prevent lipid peroxidation. Lactic acid bacteria (LAB) may improve microbial status in the intestines and increase the metabolic activity towards polyphenolic degradation. The aim of the study was to clarify antioxidative effects of bilberry and chokeberry fruits alone and with addition of a LAB-strain, <it>Lactobacillus plantarum </it>HEAL19, in an I/R-model in mice.</p> <p>Methods</p> <p>Male BALB/cJ mice were fed the experimental diets for 10 days. Diets consisted of standard chow supplemented with either bilberry (<it>Vaccinium myrtillus</it>) or chokeberry (<it>Aronia × prunifolia</it>) powder alone or in combination with the LAB-strain <it>Lactobacillus plantarum </it>HEAL19. I/R-injury was induced by holding superior mesenteric artery clamped for 30 minutes followed by reperfusion for 240 minutes. Thereafter, colonic and caecal tissues and contents were collected. Malondialdehyde (MDA) was used as indicator of lipid peroxidation and was measured by a calorimetric assay, lactobacilli were cultured on Rogosa agar plates and <it>Enterobacteriaceae </it>on VRBG agar plates, anthocyanins and phenolic acids were analysed by HPLC-DAD-ESI-MSn.</p> <p>Results</p> <p>MDA was significantly decreased in the colon of groups fed bilberry alone (p = 0.030) and in combination with <it>L. plantarum </it>HEAL19 (p = 0.021) compared to the IR-control but not in chokeberry-fed groups. Supplementation with bilberry or chokeberry alone reduced the total number of lactobacilli on the mucosa. Higher concentrations of anthocyanins were found in the colon than in the caecum content of mice. A more varied composition of different anthocyanins was also observed in the colon content compared to the caecum of bilberry-fed mice. Phenolic acids formed by microbial degradation of the dietary polyphenols in the gut could be detected. More phenolic metabolites were found in the intestines of bilberry-fed mice than in the chokeberry-fed ones.</p> <p>Conclusions</p> <p>Bilberry alone and in combination with <it>L. plantarum </it>HEAL19 exerts a better protection against lipid peroxidation than chokeberry. These dietary supplements may be used to prevent or suppress oxidative stress.</p

Changing Bee and Hoverfly Pollinator Assemblages along an Urban-Rural Gradient

The potential for reduced pollination ecosystem service due to global declines of bees and other pollinators is cause for considerable concern. Habitat degradation, destruction and fragmentation due to agricultural intensification have historically been the main causes of this pollinator decline. However, despite increasing and accelerating levels of global urbanization, very little research has investigated the effects of urbanization on pollinator assemblages. We assessed changes in the diversity, abundance and species composition of bee and hoverfly pollinator assemblages in urban, suburban, and rural sites across a UK city.Bees and hoverflies were trapped and netted at 24 sites of similar habitat character (churchyards and cemeteries) that varied in position along a gradient of urbanization. Local habitat quality (altitude, shelter from wind, diversity and abundance of flowers), and the broader-scale degree of urbanization (e.g. percentage of built landscape and gardens within 100 m, 250 m, 500 m, 1 km, and 2.5 km of the site) were assessed for each study site. The diversity and abundance of pollinators were both significantly negatively associated with higher levels of urbanization. Assemblage composition changed along the urbanization gradient with some species positively associated with urban and suburban land-use, but more species negatively so. Pollinator assemblages were positively affected by good site habitat quality, in particular the availability of flowering plants.Our results show that urban areas can support diverse pollinator assemblages, but that this capacity is strongly affected by local habitat quality. Nonetheless, in both urban and suburban areas of the city the assemblages had fewer individuals and lower diversity than similar rural habitats. The unique development histories of different urban areas, and the difficulty of assessing mobile pollinator assemblages in just part of their range, mean that complementary studies in different cities and urban habitats are required to discover if these findings are more widely applicable