Modelling consumer behavioural intentions towards food with implications for marketing quality low-input and organic food

The paper is based upon a study of European consumers’ behavioural intentions towards food purchase for four food products in six countries. The analytical method employs a structural equation model within the marketing framework of the quality-value-satisfaction-loyalty (QVSL) paradigm. The paper focuses on country-based versions of the model. The sample consists of 5072 regular consumers of the four products and includes consumers of conventional foods, quality low-input foods and organic foods. The model establishes the determinants of behavioural intentions towards foods that consumers purchase regularly. In addition, it provides the facility to examine the potential of quality low-input foods and organic foods. The results reveal the contribution of satisfaction, perceived value and perceived quality to improving behavioural intentions and how these constructs could contribute to the improved effectiveness of marketing conventional, quality low-input and organic foods to existing and potential consumers.     

Species,roasting degree and decaffeination influence the antibacterial activity of coffee against Streptococcus mutans

Coffee beverage has been associated with antibacterial activity against Streptococcus mutans, a cariogenic bacterium. This study aimed at identifying natural compounds in coffee that contribute to such activity and investigate the influence of species, roasting and decaffeination on it. Coffee chemical compounds and aqueous extracts of green and roasted regular and decaffeinated Coffea arabica and Coffea canephora beans were tested. MIC, biofilm inhibition and biofilm reduction results were correlated with the concentration of coffee compounds in the extracts. 5-Caffeoylquinic acid, trigonelline and caffeic acid solutions showed bacteriostatic activity (MIC = 0.8 mg/mL). Lighter and regular extracts showed higher inhibitory activity than darker and decaffeinated extracts, with an inverse correlation between bacterial colony-forming units and roasting degree. Only regular C. canephora extracts showed biofilm formation inhibition. The joint effect of chlorogenic acids, trigonelline and caffeine or other compounds removed by decaffeination seems to be one of the causes for coffee antibacterial activity against S. mutans.     

Dimensions of depressive symptoms and smoking cessation.

Because different psychopathologic components of depressive symptoms may have distinct etiologies, examining their differential effects on smoking cessation may elucidate mechanisms underlying the smoking-depression relationship. Negative affect (NA), somatic features (SF), low positive affect/anhedonia (PA), and interpersonal disturbance (IP) have been identified as unique dimensions of depression that can be measured using the Center for Epidemiologic Studies Depression Scale (CESD). This study examined common and unique associations between CESD subscales and baseline smoking characteristics, nicotine withdrawal, and relapse in 157 participants enrolled in a smoking cessation trial for heavy social drinkers. Each dimension was univariately associated with negative and positive reinforcement smoking motives. Only SF had unique relations with tolerance smoking motives and univariate associations with nicotine dependence severity. Only PA predicted cessation-related changes in withdrawal symptoms on quit day. Analyses predicting abstinence at 8, 16, and 26 weeks post quit date showed that NA, SF, and PA each univariately predicted relapse, ps< or =.0083. Only low PA predicted poorer outcomes incrementally to the other dimensions, even when controlling for level of nicotine dependence, smoking frequency, and history of major depression, p = .0018. Interventions targeting anhedonia and low positive affect may be useful for smokers trying to quit.     

Reactivity characteristics of nanoscale zerovalent iron--silica composites for trichloroethylene remediation

Spherical silica particles containing nanoscale zerovalent iron were synthesized through an aerosol-assisted process. These particles are effective for groundwater remediation, with the environmentally benign silica particles serving as effective carriers for nanoiron transport. Incorporation of iron into porous sub-micrometer silica particles protects ferromagnetic iron nanoparticles from aggregation and may increase their subsurface mobility. Additionally, the presence of surface silanol groups on silica particles allows control of surface properties via silanol modification using organic functional groups. Aerosolized silica particles with functional alkyl moieties, such as ethyl groups on the surface, clearly adsorb solubilized trichloroethylene (TCE) in water. These materials may therefore act as adsorbents which have coupled reactivity characteristics. The nanoscale iron/silica composite particles with controlled surface properties have the potential to be efficiently applied for in situ source depletion and in the design of permeable reactive barriers.     

Disentangling oil weathering at a marine seep using GC x GC: broad metabolic specificity accompanies subsurface petroleum biodegradation

Natural seeps contribute nearly half of the oil entering the coastal ocean. However, environmental fate studies generally monitor fewer than 5% of these petroleum compounds. Hence, the rates and relevance of physical, chemical, and biological weathering processes are unknown for the large majority of hydrocarbons, both released from natural seeps and also from human activities. To investigate the specific compositional changes occurring in petroleum during subsurface degradation and submarine seepage, we studied the natural oil seeps offshore Santa Barbara, California with comprehensive, two-dimensional gas chromatography (GC x GC). With this technique, we quantified changes in the molecular diversity and abundance of hydrocarbons between subsurface reservoirs, a proximal sea floor seep, and the sea surface overlying the seep. We also developed methods to apportion hydrocarbon mass losses due to biodegradation, dissolution, and evaporation, for hundreds of tracked compounds that ascended from the subsurface to the sea floor to the sea surface. The results provide the first quantitative evidence of broad metabolic specificity for anaerobic hydrocarbon degradation in the subsurface and reveal new trends of rapid hydrocarbon evaporation at the sea surface. This study establishes GC x GC as a powerful technique for differentiating biological and physical weathering processes of complex mixtures at a molecular level.     

Application of classification and regression trees for sensitivity analysis of the Escherichia coli O157:H7 food safety process risk model

Microbial food safety process risk models are simplifications of the real world that help risk managers in their efforts to mitigate food safety risks. An important tool in these risk assessment endeavors is sensitivity analysis, a systematic method used to quantify the effect of changes in input variables on model outputs. In this study, a novel sensitivity analysis method called classification and regression trees was applied to safety risk assessment with the use of portions of the Slaughter Module and Preparation Module of the E. coli O157:H7 microbial food safety process risk as an example. Specifically, the classification and regression trees sensitivity analysis method was evaluated on the basis of its ability to address typical characteristics of microbial food safety process risk models such as nonlinearities, interaction, thresholds, and categorical inputs. Moreover, this method was evaluated with respect to identification of high exposure scenarios and corresponding key inputs and critical limits. The results from the classification and regression trees analysis applied to the Slaughter Module confirmed that the process of chilling carcasses is a critical control point. The method identified a cutoff value of a 2.2-log increase in the number of organisms during chilling as a critical value above which high levels of contamination would be expected. When classification and regression trees analysis was applied to the cooking effects part of the Preparation Module, cooking temperature was found to be the most sensitive input, with precooking treatment (i.e., raw product storage conditions) ranked second in importance. This case study demonstrates the capabilities of classification and regression trees analysis as an alternative to other statistically based sensitivity analysis methods, and one that can readily address specific characteristics that are common in microbial food safety process risk models.     

Calculation and uses of mean sediment quality guideline quotients: a critical review

Fine-grained sediments contaminated with complex mixtures of organic and inorganic chemical contaminants can be toxic in laboratory tests and/or cause adverse impacts to resident benthic communities. Effects-based, sediment quality guidelines (SQGs) have been developed over the past 20 years to aid in the interpretation of the relationships between chemical contamination and measures of adverse biological effects. Mean sediment quality guideline quotients (mSQGQ) can be calculated by dividing the concentrations of chemicals in sediments by their respective SQGs and calculating the mean of the quotients for the individual chemicals. The resulting index provides a method of accounting for both the presence and the concentrations of multiple chemicals in sediments relative to their effects-based guidelines. Analyses of considerable amounts of data demonstrated that both the incidence and magnitude of toxicity in laboratory tests and the incidence of impairment to benthic communities increases incrementally with increasing mSQGQs. Such concentration/response relationships provide a basis for estimating toxicological risks to sediment-dwelling organisms associated with exposure to contaminated sediments with a known degree of accuracy. This sediment quality assessment tool has been used in numerous surveys and studies since 1994. Nevertheless, mean SQGQs have some important limitations and underlying assumptions that should be understood by sediment quality assessors. This paper provides an overview of the derivation methods and some of the principal advantages, assumptions, and limitations in the use of this sediment assessmenttool. Ideally, mean SQGQs should be included with other measures including results of toxicity tests and benthic community surveys to provide a weight of evidence when assessing the relative quality of contaminated sediments.     

Hurricane Katrina's impact on New Orleans soils treated with low Lead Mississippi River alluvium

Before Hurricane Katrina flooded 80% of New Orleans, 25 heavily Pb contaminated properties were treated with 15 cm of low Pb Mississippi River alluvium from the Bonnet Carré Spillway (BCS). Four phases of soil collection on the properties included pretreatment (phase 1) median surface soil Pb was 1051 mg/kg (range 5-19 627); after BCS cover (phase 2) the median soil Pb decreased to 6.3 mg/ kg (range 3-18); just before Katrina, a soil collection was partially completed (phase 3); and finally, a post-Katrina collection (phase 4) on all 25 properties. Twenty-three properties were flooded. The objective was to compare Pb changes of phases 2 and 3 pre-Katrina with the post-Katrina (phase 4) soil collection. The post-Katrina soil Pb (phase 4) (median of 16.3, range 5.5-1,155) increased significantly (P-value = 3.7 x 10(-10)) from the clean soil, phase 2 results. Matched soil samples collected in phase 3 before flooding and phase 4 after flooding showed that on initially vacant lots the amounts of Pb were not significantly different (P-value = 0.97); but, on properties with homes, the changes were significant (P-value = 0.03). After catastrophic flooding, the clean soil remained relatively undisturbed; the soil Pb changes were small with increases of median Pb of 12 and 6 mg/kg for vacant lots and properties with homes, respectively. Processes accounting for Pb increases include Pb-based paint abatement on one property, home construction on the vacant lots, and resuspension and deposition of Pb dust. As part of the post-Katrina recovery, the combined benefits of Pb-safe paint abatement or renovation and clean soil cover should outweigh the estimated annual cost of Pb poisoning of children returning to New Orleans.     

Rheological characterization and electrokinetic phenomena of charged whey protein dispersions of defined sizes

A multi-step processing technique produced large colloidal particles from whey proteins, prompting instantaneous thickening upon hydration. Analysis of the rheological characteristics and zeta potential of the modified whey suspensions of defined particle sizes allowed investigation into the role of size on ingredient functionality. Preliminarily, the modified protein powders were sieved to achieve three size ranges, and analyzes were conducted on each of the three distributions and the non-sieved fractions. Following hydration, steady and oscillatory shear analyzes were performed using a controlled stress rheometer to determine rheological characteristics. Intrinsic viscosity was determined with a capillary viscometer and application of the Huggins equation. Zeta potential was calculated from colloidal electrophoretic mobility, measured with a ZetaPALS analyser. After thorough hydration, particle-size analysis revealed a size increase of >1.3 times for each fraction. When analysed on a protein basis, increasing particle size yielded an increase to intrinsic viscosity, flow behavior index, zero shear viscosity, and a decreased zeta potential and consistency coefficient. Knowledge of the interrelationship between zeta potential, rheological properties, and particle size of the modified whey ingredient will further advance an understanding of the functionality of this protein ingredient.