This study examined the effects of wet aging on water-soluble flavor compounds, descriptive flavor, consumer acceptability, and willingness-to-pay of beef strip steaks. Twenty USDA Select boneless beef loins (NAMP #180) were dorsally divided into four equal portions, which were randomized to receive either 0, 7, 14, or 21 d of wet aging. Short-chained peptide concentration increased from 4.11 mg/g on d 0 to 5.12 mg/g on d 7 (P = 0.011) and subsequently increased to 7.14 mg/g on d 21 (P < 0.001). Cooked beef contained 1.85 mg/g less short-chained peptides than raw beef (P < 0.001). Wet aging for 21 d increased the concentrations of amino acids, which are precursors for the Maillard reaction, including methionine, threonine, cystine, serine, tryptophan, and phenylalanine (P < 0.001). Wet aging decreased the nucleotide concentrations (P ≤ 0.003) and increased hypoxanthine concentration, a compound that imparts bitter flavor (P < 0.001). Flavor intensity of steaks was greater on d 14 than on d 21 (P = 0.009). Steaks that were not aged (d 0) had a more intense umami taste than those aged for 7 and 21 d (P ≤ 0.042); whereas d 7 steaks had less off-flavor, described as metallic, oxidized, and cardboard, than steaks from other aging treatments (P ≤ 0.038). Demand analysis indicated that 14-d steaks would be sold at 5.2, 5.2, and 6.7 units (0.454kg/unit) less (P < 0.001) than steaks aged for 0, 7, and 21 d if holding price constant at $14/0.454kg. Wet aging alters the content of water-soluble flavor compounds in beef, which contributes to flavor development during cooking. Wet aging for 21 d decreased umami taste and flavor intensity. However, amino acid concentrations increased during aging, which contributes to meaty and browning flavors that may be more prevalent in other direct heating methods such as grilling. In addition, results indicated that wet aging for 14 d was not sufficient to provide the flavor and tenderness improvements that were apparent after 21 d of aging since aging beef for 14 d decreased consumer acceptance and demand.

No description available.

No description available.

No description available.

Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Standards define target reliability levels that govern the safety of designed structures. These target levels should be around an economic optimum for the class of structure under consideration. However, society may have safety requirements in excess of that required to achieve an economic optimum. The LQI criterion can be used to determine society’s willingness to invest in safety, thereby defining a minimum acceptable safety- or reliability level. This thesis determines economically optimised reliability levels for reliability class two concrete structures in South Africa, over a range of typical input parameters. Rackwitz’s (2000) approach is used here, adjusted for the South African context. The structure is described using a simple limit state function, defined as the difference between load and resistance, with resistance a function of a global safety parameter. South African construction costs, costs of increasing safety, failure costs and discount rates are used in the objective function for economic optimisation. Life Quality Index (LQI) theory is used as a basis to derive society’s willingness to pay (SWTP) for safety and the corresponding reliability level is found by applying the LQI criterion. In the South African context the derivation of SWTP presents some challenges, which is discussed. Situations where the minimum required reliability would exceed the economically optimum reliability level are discussed. Various reliability based cost optimization case studies are conducted covering a broad range of typical concrete design situations. From these case studies a range of target reliability indices are derived for typical concrete structural components and failure modes. Obtained values are compared to current South African target levels of reliability provided by the South African loading code and recommendations are made. The approach used by Rackwitz (2000) is compared with results obtained from case studies and used as basis to estimate optimum reliability levels for other types of buildings. Functions are written in MATLAB to allow replication of the study for others seeking to derive optimum reliability indices. / AFRIKAANSE OPSOMMING: Standaarde spesifiseer teiken betroubaarheidsvlakke wat die veiligheidsvlak van ontwerpte strukture bepaal. Hierdie teikenvlak moet rondom die ekonomiese optimum wees vir die klas van struktuur onder oorweging. Die samelewing verkies moontlik ‘n hoër veiligheidsvlak as wat deur die ekonomiese optimum dikteer word. Die LKI (Lewens Kwaliteit Indeks) maatstaf kan gebuik word om die samelewing se bereidwilligheid om in veiligheid te belê te bepaal en sodoende ‘n minimum veiligheidsvlak bepaal. Hierdie tesis bepaal die ekonomiese optimum betroubaarheidsvlak vir klas twee beton strukture in Suid-Afrika vir wisselende parameters. Rackwitz (2000) se benadering word in hierdie studie gebruik en is aangepas vir Suid-Afrikaanse omstandighede. Die struktuur word beskryf deur ‘n eenvoudige limiet staat funksie, gedefinieer as die verskil tussen die las en weerstand, met die weerstand as die funksie van ‘n globale veiligheidsparameter. Suid-Afrikaanse konstruksie koste, veiligheidsvermedering koste, falingskoste en diskonteer koerse word gebruik vir optimering. Die LKI teorie word gebruik om SBB (Samelewing Bereidheid om te Belê) vir veiligheid af te lei en die ooreenkomstige betroubaarheidsvlak word bepaal deur die LKI maatstaf toe te pas. In die afleiding hiervan vir Suid-Afrikaanse omstandighede is sekere uitdagings teegekom wat bespreek word. Situasies waar die minimum betroubaarheidsvlak hoer is as die ekonomiese optimum word bespreek. Verskillende betroubaarheids gebaseerde optimering gevalstudies word gedoen op tipiese beton struktuur elemente. Van hierdie gevalstudies is optimum betroubaarheidsindekse vir die tipiese beton elemente en galingsmodusie afgelei. Die betroubaarheidsindekse word vergelyk met huidige betroubaarheidsindekse soos wat voorgeskryf is in die Suid-Afrikaanse laskode (SANS10160-1(2011)). Rackwitz (2000) se benadering word vergelyk met die resultate van die gevallestudies en word gebruik as basis om optimum betroubaarheidsvlakke vir ander tipes geboue te voorspel. MATLAB funksies is geprogrameer om minimum en optimum betroubaarheidsindekse af te lei.

Die Zeiten der Plattensammlung sind vorbei, Kassetten und CDs sind der MP3-Datei gewichen und nun wird Musik ausschließlich gestreamt. Dieses Zukunftsszenario ist bis dato noch nicht eingetreten, aber wird dies überhaupt passieren? Wird der Kauf von physischen Musikdatenträgern und digitalen Musikdateien dank der immer stärker ansteigenden Streaming Aktivitäten komplett eingestellt? Oder können beide Formen nebeneinander existieren? Um diesen Fragen auf den Grund zu gehen, wurde im Rahmen dieser Arbeit eine Umfrage mit 1.661 Studenten der Technischen Universität Dresden durchgeführt. Die Ergebnisse geben Aufschluss über die Nutzungshäufigkeiten von kostenfreien und kostenpflichtigen Streaming Anbietern sowie von CDs / Schallplatten und MP3 Musikdateien. Zudem wird aufgezeigt, dass eine geringe Zahlungsbereitschaft bei den Studenten besteht. Es werden bereits selten mehr als 5 € in Musik investiert, doch seitdem die Studenten Streaming Dienste nutzen, geben sie nach eigenen Angaben noch weniger Geld für Musik aus als zuvor. Diesem Negativtrend steht die Erkenntnis gegenüber, dass die Probanden seit der Nutzung von Streaming Angeboten weniger Musik illegal herunterladen. Auch wenn der Großteil weniger Musik kauft, so ist es etwa der Hälfte aller Befragten sehr wichtig, Musik zu besitzen, vor allem in physischer Form. Zudem wurden Nutzungsmotive der Möglichkeiten des Musikhörens erfasst, um deren Stärken und Schwächen aufzuzeigen. Die Ergebnisse verdeutlichen, dass die kostenfreie Variante des Streamens zwar häufig genutzt wird, sich die traditionellen Musikdatenträger und Musikdateien jedoch immer noch großer Beliebtheit erfreuen. Von einer kompletten Verdrängung des Kaufens von Musik kann demnach nicht ausgegangen werden.

We estimate the willingness to pay for electricity generated from renewable energy in the Czech Republic. Discrete choice experiment is used to elicit preferences for various attributes of renewable electricity support scheme (PM emission, GHG emission, size of RE power plant, revenue distribution, and costs). Original survey is carried with 404 respondents living in two regions - Ustecky (polluted area) and Southern Bohemia (cleaner area). We find that respondents prefer decentralized renewable electricity sources over centralized, local air quality improvements over reduction in greenhouse gas emissions. Estimated marginal willingness to pay for 1% reduction in emission of particulate matter equals to 49 CZK, respectively 3.7 % of average monthly electricity bill. In total, WTP for green electricity is larger than current compulsory contributions to renewable energy support scheme. Powered by TCPDF (www.tcpdf.org)

Cette thèse a pour but d'étudier les méthodes d'évaluation des ressources environnementales : la méthode des Coûts de Transport (CT) à préférences révélées et la méthode d'évaluation contingente (EC) à préférences déclarées afin de proposer les contributions suivantes. Dans le chapitre 1, nous montrons qu'il est possible si les données sur les deux méthodes sont disponibles pour les mêmes observations, d'obtenir une meilleure mesure de la disposition à payer (DAP) par la combinaison des deux méthodes en utilisant la technique du maximum de vraisemblance simulé. Dans le chapitre 2, nous montrons qu'une nouvelle approche: le "special regressor" pourrait être une solution pour traiter les problèmes d'endogénéité en EC. En utilisant des données sur la DAP pour réduire les risques subjectifs de mortalité due à la présence d' Arsenic dans l'eau potable , nous montrons que le problème d'endogénéité du niveau subjectif de risque de mortalité peut être réglé efficacement. Enfin dans le chapitre 3, en utilisant une nouvelle enquête sur l'électrification rurale au Rwanda, nous proposons un nouveau design de la méthode d'EC en permettant aux personnes interrogées de choisir entre une contribution en temps ou en argent. Ainsi, en plus de mesurer une DAP classique, nous obtenons aussi une disposition à contribuer du temps mesurée en jours, qui est une mesure aussi voire même plus pertinente que la DAP dans le contexte d'un pays en développement. / This dissertation aims at investigating the methods of the environmental resources valuation: revealed preferences Travel Cost (TC) method and stated preferences Contingent Valuation (CV) method in order to propose the following contributions. In chapter 1, we show that it is possible if both CV and TC data are available for the same observations, to obtain a better measure of willingness to pay (WTP) by combining the two methods using Simulated maximum Likelihood technique. In chapter 2, we show that the new special regressor approach could be a solution to treat endogeneity issues in CV. Using data on WTP for reducing subjective mortality risks due to arsenic in drinking water, we show that the endogeneity of the subjective mortality risk level can be treated effectively. Finally in chapter 3, using a new survey about rural electrification in Rwanda, we propose a new design for the CV method by allowing people to choose between a contribution in time or in money. Thus, in addition to measure a conventional WTP, we also obtain a willingness to contribute time measure which is as or even more relevant than WTP in the context of a developing country.

<p>Commercial and regional brewers are increasingly investing in sustainability equipment that reduces input use, operating costs, and environmental impact. These technologies often require significant upfront costs that can limit market access to microbreweries. One potential solution for these brewers is to market their product as sustainable and charge a premium for their product to offset some of the costs. A stated preference choice experiment of a nationally-representative sample is undertaken to elicit consumer willingness-to-pay (WTP) for sustainability attributes in beer, thus determining whether a market for sustainably-made beer exists. The facets of sustainability, including water reduction, energy reduction, and landfill diversion, are portrayed through eco-labels affixed the front of the primary packaging (aluminum can or glass bottle). Multiple specifications are employed to handle model shortcomings and incorporate discrete heterogeneity. Across all model specifications, <a>consumers show a positive and statistically significant marginal WTP for landfill diversion practices and carbon reduction practices, ranging from $0.40 to $1.37 per six-pack and $0.67 to $1.21 per six-pack, respectively. </a>These results indicate consumers do in fact place value on beer produced using sustainable practices, and the demographics of consumers with the greatest WTP are similar to that of craft beer consumer.</p>

La Valeur statistique de la vie humaine (VSVH) est un outil d’analyse économique, qui est définie comme la valeur qu’une personne est prête à payer (CAP) pour réduire le risque de mortalité ou de morbidité. L’intérêt d’un tel outil est d’estimer monétairement le bénéfice social d’un projet d’investissement destiné à réduire le risque, mais aussi d’établir un arbitrage entre plusieurs alternatives. Répondre à l’aléa moral dans un contexte de rareté des ressources est parfaitement adéquat avec la VSVH. Avec l’estimation des personnes de leurs capacités de paiement en fonction de leurs perceptions du risque et de leur niveau de revenu, les personnes sont positionnées comme les seules juges de la valeur de leurs vies. Parce que, les personnes déterminent librement les CAPs en fonction de leurs préférences personnelles et que ces préférences sont intégrées dans la détermination d’un choix social, la VSVH ne contredit pas le cadre normatif d’établissement d’une décision. Néanmoins, le welfarisme comme une source des méthodes d’estimation de la VSVH est en relation directe avec l’utilitarisme. Au final, la valeur estimée par la VSVH est de nature subjective. Dans le domaine de la santé, la VSVH doit dépasser le cadre subjectif d’une estimation pour répondre à l’éthique normative qui décrit la pratique médicale, notamment la prise en considération de l’autonomie personnelle, la notion personnelle de la bonne vie et la notion universelle de la personne. L’objectif de notre travail est de rechercher les arguments d’établissement d’une valeur de référence de la VSVH qui endosse un cadre normatif. Cela nécessite une analyse approfondie au sein de la théorie économique du bien-être. / The value of statistical life (VSL) is an economic analytical tool, which is defined as the value that a person is ready to pay (WTP) in order to reduce the risk mortality or morbidity. The advantage of such a tool is to monetarily estimate the social benefit of an investment project which is made to reduce the risk, but also to establish an arbitrage between several alternatives. Respond to the moral hazard in a context pertaining to the scarcity of resources, which is perfectly in keeping with VSL. With people’s estimation on their willingness to pay, depending on how they perceive risks and their income level, people are positioned as the sole judges as for the value of their lives. Because people freely determine the WTP depending on their personal preferences and these preferences are included in order to determine a social choice. The value of statistical life doesn’t contradict the normative framework of establishing a decision. Nonetheless, welfarism which is a source of estimating methods of VSL is directly related to utilitarianism. Eventually, the estimated value by VSL is subjective nature. In the health sector, the VSL needs to surpass the subjective framework of an estimation in order to answer the normative ethic which describes the medical practice, especially by taking personal self-sufficiency into account but also the personal notion of a good life and the universal notion of the person. Researching establishing arguments of reference value pertaining to VSL which takes on a normative framework and this is objective when it comes to our work. This theoretically requires an in-depth analysis within the economic theory of well-being.