Antioxidant capacity and phenolic compounds in commercially grown native Australian herbs and spices

The antioxidant capacities and phenolic composition in six native, commercially grown, Australian herbs and spices were investigated. Tasmannia pepper leaf, followed by anise myrtle and lemon myrtle contained the highest levels of total phenolics (TP; 102.1; 55.9 and 31.4 mg gallic acid equivalents (GAE)/g dry weight (DW), respectively). Tasmannia pepper leaf exhibited the highest oxygen radical absorbance capacity (ORAC assay) followed by lemon myrtle and anise myrtle. Anise myrtle exhibited the highest total reducing capacity [TRC; Ferric Reducing Antioxidant Power (FRAP) assay], followed by Tasmannia pepper leaf and lemon myrtle. Australian bush tomato, with TP content of 12.4 ± 0.9 mg GAE/gDW and TRC of 206.2 μMol Fe⁺²/gDW, resembled the Chinese Barbary Wolfberry fruit. The TP content of Tasmannia pepper berry (16.86 mg GAE/gDW) was similar to that of black pepper, but it’s TRC was 25% lower. Cinnamic acids and flavonoids, tentatively identified by mass spectrometry, were identified as the main sources of antioxidant activities.     

Salmonella and Campylobacter biofilm formation: a comparative assessment from farm to fork

It takes several steps to bring food from the farm to the fork (dining table), and contamination with food‐borne pathogens can occur at any point in the process. Campylobacter spp. and Salmonella spp. are the main microorganisms responsible for foodborne disease in the EU. These two pathogens are able to persist throughout the food supply chain thanks to their ability to form biofilms. Owing to the high prevalence of Salmonella and especially of Campylobacter in the food supply chain and the huge efforts of food authorities to reduce these levels, it is of great importance to fully understand their mechanisms of persistence. Diverse studies have evaluated the biofilm‐forming capacity of foodborne pathogens isolated at different steps of food production. Nonetheless, the principal obstacle of these studies is to reproduce the real conditions that microorganisms encounter in the food supply chain. While there are a wide number of Salmonella biofilm studies, information on Campylobacter biofilms is still limited. A comparison between the two microorganisms could help to develop new research in the field of Campylobacter biofilms. Therefore, this review evaluates relevant work in the field of Salmonella and Campylobacter biofilms and the applicability of the data obtained from these studies to real working conditions. © 2018 Society of Chemical Industry     

Biomagnification of perfluoroalkyl compounds in the bottlenose dolphin (Tursiops truncatus) food web

The environmental distribution and the biomagnification of a suite of perfluoroalkyl compounds (PFCs), including perfluorooctane sulfonate (PFOS) and C8 to C14 perfluorinated carboxylates (PFCAs), was investigated in the food web of the bottlenose dolphin (Tursiops truncatus). Surficial seawater and sediment samples, as well as zooplankton, fish, and bottlenose dolphin tissue samples, were collected at two U.S. locations: Sarasota Bay, FL and Charleston Harbor, SC. Wastewater treatment plant (WWTP) effluents were also collected from the Charleston area (n = 4). A solid-phase extraction was used for seawater and effluent samples and an ion-pairing method was used for sediment and biotic samples. PFCs were detected in seawater (range <1-12 ng/L), sediment (range <0.01-0.4 ng/g wet weight (ww)), and zooplankton (range 0.06-0.3 ng/g ww). The highest PFC concentrations were detected in WWTP effluents, whole fish, and dolphin plasma and tissue samples in which PFOS, C8 and C10-PFCAs predominated in most matrices. Contamination profiles varied with location suggesting different sources of PFC emissions. Biomagnification factors (BMFs) ranged from <1 to 156 at Sarasota Bay and <1 to 30 at Charleston. Trophic magnification factors (TMFs) for PFOS and C8-C11 PFCAs indicated biomagnification in this marine food web. The results indicate that using plasma and liver PFC concentrations as surrogate to whole body burden in a top marine predator overestimates the BMFs and TMFs.     

Physico-chemical characterization of protein fraction from stabilized wheat germ

Food Science and Biotechnology - Wheat germ shows the highest nutritional value of the kernel. It is highly susceptible to rancidity due to high content of unsaturated fat and presence of oxidative...     

Probabilistic models for the prediction of target growth interfaces of Listeria monocytogenes on ham and turkey breast products

Abstract: This study developed growth/no growth models for predicting growth boundaries of Listeria monocytogenes on ready‐to‐eat cured ham and uncured turkey breast slices as a function of lactic acid concentration (0% to 4%), dipping time (0 to 4 min), and storage temperature (4 to 10 °C). A 10‐strain composite of L. monocytogenes was inoculated (2 to 3 log CFU/cm²) on slices, followed by dipping into lactic acid and storage in vacuum packages for up to 30 d. Total bacterial (tryptic soy agar plus 0.6% yeast extract) and L. monocytogenes (PALCAM agar) populations were determined on day 0 and at the endpoint of storage. The combinations of parameters that allowed increases in cell counts of L. monocytogenes of at least l log CFU/cm² were assigned the value of 1, while those limiting growth to <1 log CFU/cm² were given the value of 0. The binary data were used in logistic regression analysis for development of models to predict boundaries between growth and no growth of the pathogen at desired probabilities. Indices of model performance and validation with limited available data indicated that the models developed had acceptable goodness of fit. Thus, the described procedures using bacterial growth data from studies with food products may be appropriate in developing growth/no growth models to predict growth and to select lactic acid concentrations and dipping times for control of L. monocytogenes. Practical Application: The models developed in this study may be useful in selecting lactic acid concentrations and dipping times to control growth of Listeria monocytogenes on cured ham and uncured turkey breast during product storage, and in determining probabilities of growth under selected conditions. The modeling procedures followed may also be used for application in model development for other products, conditions, or pathogens.     

Technological characterization and survival of the exopolysaccharide-producing strain Lactobacillus delbrueckii subsp. lactis 193 and its bile-resistant derivative 193+ in simulated gastric and intestinal juices

The capacity of lactic acid bacteria to produce exopolysaccharides (EPS) conferring microorganisms a ropy phenotype could be an interesting feature from a technological point of view. Progressive adaptation to bile salts might render some lactobacilli able to overcome physiological gut barriers but could also modify functional properties of the strain, including the production of EPS. In this work some technological properties and the survival ability in simulated gastrointestinal conditions of Lactobacillus delbrueckii subsp. lactis 193, and Lb. delbrueckii subsp. lactis 193+, a strain with stable bile-resistant phenotype derived thereof, were characterized in milk in order to know whether the acquisition of resistance to bile could modify some characteristics of the microorganism. Both strains were able to grow and acidify milk similarly; however the production of ethanol increased at the expense of the aroma compound acetaldehyde in milk fermented by the strain 193+, with respect to milk fermented by the strain 193. Both microorganisms produced a heteropolysaccharide composed of glucose and galactose, and were able to increase the viscosity of fermented milks. In spite of the higher production yield of EPS by the bile-resistant strain 193+, it displayed a lower ability to increase viscosity than Lb. delbrueckii subsp. lactis 193. Milk increased survival in simulated gastric juice; the presence of bile improved adhesion to the intestinal cell line HT29-MTX in both strains. However, the acquisition of a stable resistance phenotype did not improve survival in simulated gastric and intestinal conditions or the adhesion to the intestinal cell line HT29-MTX. Thus, Lb. delbrueckii subsp. lactis 193 presents suitable technological properties for the manufacture of fermented dairy products; the acquisition of a stable bile-resistant phenotype modified some properties of the microorganism. This suggests that the possible use of bile-resistant derivative strains should be carefully evaluated in each specific application considering the influence that the acquisition of a stable bile-resistant phenotype could have in survival ability in gastric and intestinal conditions and in technological properties.     

Boys don't write romance: the construcion of knowledge and social gender identities in english classrooms

Teachers have been under pressure in the United Kingdom to devise pedagogic strategies to raise boys' achievement. This article reviews the emergence of the concept of a 'setting' from within the sociocultural literature as the basis for considering the interaction between gender and learning. The second section reports findings from an empirical study of two teachers in one school who taught the same creative writing activity to their classes. The strategies in each classroom to improve boys' achievement in English varied, and involved mixed, gendered seating and single sex grouping. The strategies had unintended effects in terms of how subject knowledge was realised, and therefore what was available to learn and by whom. To demonstrate and explain these effects we illustrate how hegemonic representations of gender were reconstructed in each setting and present individual cases to illustrate students' experience of the settings. How settings mediate the interrelation between gender and learning at the interpersonal plane of analysis are discussed, and the reconstruction of knowledge and social gender identities at the personal plane.     

Characterization of environmental estrogens in river water using a three pronged approach: active and passive water sampling and the analysis of accumulated estrogens in the bile of caged fish

Estrogenicity of river water is highly variable and it is difficult to obtain an average measure of the estrogenicity. Consequently it is difficult to tie the estrogenic effects observed in fish to their level of exposure to estrogens. To get a better handle on average estrogenic exposure we tested a recently developed passive sampling system (polar organic chemical integrative sampler, POCIS). In addition, we investigated the bioaccumulation of estrogens in caged brown trout and measured plasma vitellogenin in males as a bioindicator of estrogenic effects. We developed a mini-caging method to suit the hydrological conditions in small rivers and to improve upon the often poor survival of salmonids in caging trials. POCISs were positioned upstream and downstream of 5 sewage treatment works' discharges and left on site for 3 weeks (as were the caged fish), during which period 3 water grab samples were taken at each site. Concentrations of estrogens were determined using a yeast-based reporter gene assay and chemical analysis. Results from grab sampling, passive sampling, and bioaccumulation were correlated; however, plasma vitellogenin concentrations were elevated at only 1 of 5 sites. POCISs provide an integrated and biologically meaningful measure of estrogenicity in thatthey accumulate estrogens in a pattern similar to that of brown trout. Mini-caging appears a significant methodological advance; no fish were lost, moreover, all fish survived in excellent health.     

The bone‐protective effect of a Taiwanese yam (Dioscorea alata L. cv. Tainung No. 2) in ovariectomised female BALB/C mice

BACKGROUND: Yam products have been marketed for treating postmenopausal syndromes. This study investigated the effects of Dioscorea alata L. cv. Tainung No. 2 (TNG yam) on the bone density of ovariectomised (OVX) female BALB/c mice and the mechanism whereby TNG yam exerted this effect. Sham and OVX control groups were fed a control diet while remaining OVX mice were randomly allocated into experimental diets, i.e. yam (630 g TNG powder kg^?1), E2 (20 mg 17β‐oestradiol kg^?1), or genistein (2 g genistein kg^?1) diet. After 12 weeks of feeding, the uterine weight, indices of bone mass and caecal short chain fatty acids were determined. RESULTS: Neither a yam nor genistein diet restored the OVX‐induced uterine atrophy as did the E2 diet. The femoral and lumbar bone mineral density (BMD) of mice fed the yam diet was greater than those of the sham group, respectively (P < 0.05 vs OVX control), while the lumbar BMD of yam and sham groups were similar (P > 0.05 vs sham). The femoral ash and calcium content in the yam group was significantly greater than that in the OVX control group, respectively (P < 0.05 vs OVX control). The total short chain fatty acid content in the caecum, only enhanced in the yam group, was not correlated with the calcium content of either bone or the plasma calcium level. CONCLUSION: TNG yam prevented loss of BMD and improved bone calcium status without stimulating uterine hypertrophy in OVX BALB/c mice. TNG yam may be beneficial for postmenopausal women for preventing bone loss. Copyright © 2008 Society of Chemical Industry