Effect of vacuum ageing on quality changes of lamb steaks from early fattening lambs during aerobic display

The effects of vacuum ageing on the quality changes of lamb steaks during retail display were assessed. Biceps femoris and Quadriceps femoris muscles from thirty early fattening lambs fed barley straw and concentrate or alfalfa and concentrate were used. Half of the muscles were vacuum aged for three weeks (VA), and the other half were not aged (control). Control and VA muscles were sliced and aerobically displayed. Weight loss, pH, aldehyde contents, instrumental color characteristics and color acceptance were measured at display days 1, 3, 7 and 14. At day 1 redness was higher in VA lamb. However, redness of VA lamb decreases more rapidly during further storage. Redness and color acceptance decreased in VA lamb from day 3, whereas in not-aged lamb the decrease was observed from day 7 onwards. From days 7 to 14 a drop of color acceptance accompanied by an increase in pH and a decrease in lightness was observed in control and VA lamb.     

Identification of material parameters for modelling delamination in the presence of fibre bridging

Delamination processes often exhibit an increase in delamination resistance, or R-curve, with crack extension. It is shown that cohesive laws can represent the R-curves due to large-scale fibre bridging and that the shape of the cohesive laws can be derived from conventional experimental results. Two approaches are investigated for determining the shape parameters of cohesive laws. The first approach consists of extracting the cohesive parameters from experimental R-curves through the use of a new semi-analytical equation. The second approach consists of a numerical optimization procedure that identifies material parameters by reducing the error between a finite element model and the experimental load–deflection results. The second approach is advantageous when fibre bridging introduces inaccuracies in the experimental energy release rate measurements. In addition, the second approach can be extended to allow more complex approximations of cohesive laws.     

Occurrence of Escherichia coli O157, O111 and O26 in raw ewe's milk and performance of two enrichment broths and two plating media used for its assessment

The occurrence of Escherichia coli O157, O111 and O26 in 159 raw ewe's milk samples was examined. Sample-aliquots were incubated simultaneously in TSB added with yeast extract (YETSB) and mTSB with novobiocin (N-mTSB). Serogroup-specific immunomagnetic separation (IMS) was then used and IMS beads were plated in a cefixime tellurite (CT)-containing media (CT-SMAC, CT-SBMAC and CT-RMAC for E. coli O157, O111 and O26, respectively) and E. coli O157:H7 chromogenic ID agar. A sweep of confluent growth from each medium was examined for the presence of E. coli O157 and O111 using PCR, and for E. coli O26 using a latex agglutination test. Enumeration of E. coli O157 and O111 was performed in the samples tested positive for the correspondent serogroup using the most probable number (MPN) method combined with PCR. Percentage occurrences of E. coli O157, O111 and O26 were 18.2, 8.2 and 5.7, respectively. Mean E. coli O157 and O111 levels were 0.22 and < 0.04 MPN/mL, respectively. Enrichment in YETSB resulted in higher detection rates of E. coli O157 and O26 than in N-mTSB. When YETSB was used as enrichment broth and for these last two serogroups, the analysis of the confluent growth from the CT-media gave more positive results than that from E. coli O157:H7-ID medium.     

Nutrient limitation leads to penetrative growth into agar and affects aroma formation in Pichia fabianii,P. kudriavzevii and Saccharomyces cerevisiae

Among fermentative yeast species, Saccharomyces cerevisiae is most frequently used as a model organism, although other yeast species may have special features that make them interesting candidates to apply in food‐fermentation processes. In this study, we used three yeast species isolated from fermented masau (Ziziphus mauritiana) fruit, S. cerevisiae 131, Pichia fabianii 65 and Pichia kudriavzevii 129, and determined the impact of nitrogen and/or glucose limitation on surface growth mode and the production of volatile organic compounds (VOCs). All three species displayed significant changes in growth mode in all nutrient‐limited conditions, signified by the formation of metafilaments or pseudohyphae. The timing of the transition was found to be species‐specific. Transition in growth mode is suggested to be linked to the production of certain fusel alcohols, such as phenylethyl alcohol, which serve as quorum‐sensing molecules. Interestingly, we did not observe concomitant increased production of phenylethyl alcohol and filamentous growth. Notably, a broader range of esters was found only for the Pichia spp. grown on nitrogen‐limited agar for 21 days compared to nutrient‐rich agar, and when grown on glucose‐ and glucose‐ plus nitrogen‐limited agar. Our data suggest that for the Pichia spp., the formation of esters may play an important role in the switch in growth mode upon nitrogen limitation. Further biological or ecological implications of ester formation are discussed. Copyright © 2014 John Wiley & Sons, Ltd.     

Interactive movie elements in a pervasive game

This paper presents our research initiatives around new user experiences in the area of pervasive mixed reality crossmedia gaming. In a prototypical game, The Epidemic Menace, we combined static and interactive story telling elements to create a mixed reality experience. As part of this research initiative we also investigated how elements of the real world and virtual worlds could produce a new environment where physical and digital objects can co-exist and interact with each other, we wanted to evaluate how linear stories could be integrated into a game flow and how they could be used to extend game experiences. A new form of interactive entertainment that is not limited to hardware based games or linear storylines but includes a truly interactive TV experience was one of our goals.     

Tourism SMME Development on the Urban Fringe: The Case of Parys,South Africa

Tourism is increasingly regarded as a viable avenue for local economic development. Small towns on the urban fringe have benefitted from tourism development in South Africa, the town of Parys being one of them. Parys has experienced tourism development over the past few years which has resulted in local economic growth, as especially reflected in the trade industry, amidst the decline of sectors such as manufacturing and mining. The study focusses on the factors that gave rise to the development of tourism in this town, as well as on opportunities and barriers to further development. A profile of tourism, small, medium and micro enterprises, is provided along with other main findings regarding the nature of the tourism industry in the area which includes the unique selling points of the area, visitor characteristics, demand and target market segments. Strategic development initiatives, in the light of the findings, recommend for the future development of the tourism industry in the area to include tourism product development focussed on attractions; the identification of key market segments such as budget tourists and the family market; destination and product marketing; investment in tourism infrastructure and ensuring the responsible management of tourism development in the area.     

Carbon Fiber-Reinforced Smart Laminates with Embedded SMA Actuators—Part II: Numerical Models and Empirical Correlations

Up to now one of the main limitations for a large use of shape memory alloys (SMA)-based smart composite structures in the aerospace industry is the lack of useful numerical tools for design; in addition, some technological aspects still need a more detailed investigation. This article shows numerical modeling approaches adopted for the implementation of SMA constitutive laws in commercial codes such as ABAQUS. Two different approaches were selected. The first one is based on the thermomechanical model proposed by Turner and the other one follows the thermodynamic macromechanical constitutive law developed by Lagoudas. The implementation in ABAQUS code was followed by a procedure to evaluate model parameters and to experimentally validate the reliability of code predictions for specifically designed test situations. This article presents the test campaign carried out for the definition of these parameters and the numerical-experimental correlation for both the models.     

Energetic and economic evaluation of a poplar cultivation for the biomass production in Italy

The cultivation of crops for biomass production on good soils allows to reduce surplus production of food crops and increase the sustainability of energy production from the environmental point of view. The short rotation forestry (SRF), is only at a preliminary study level in Italy but, is already a reality in North Europe where was already developed an high planting density (6000–8000 cuttings ha^-1) technique and a whole mechanization of plantation and biomass harvest.On the basis of this cultivation technique, it was realized as an energetic and economic evaluation of a poplar SRF in Northern Italy. In detail, they were considered data of poplar growth in a plantation for the production of two-year whips in Western Po Valley considering SRF duration of 8 years and a biomass (20 t ha⁻¹ D.M.) harvest every 2 years. Indeed it was assumed to operate on a plantation in production (12.5% of the surface replanted every year) with a spacing 3.00 × 0.4 m (6700 cutting per hectare) that allows the use of conventional tractors.In this computing system it was pointed out a ratio between output and input energy of 13 and a cost of 80 € t⁻¹ of D.M. Nevertheless a positive energetic balance, the economic sustainability of poplar SRF depends, due to the present monopolistic energy management in the same countries, on political choices of chip price or public subventions to the producers.