Food technology neophobia and consumer attitudes toward foods produced by new and conventional technologies: A case study in Brazil

AbstractNew food technologies are promoting innovations in the food sector. However, not all technologies are accepted and understood by consumers; some cause resistance. The present work sought to study the behavior of Brazilian consumers in relation to different food technologies. A questionnaire was administered to a representative sample of 389 respondents in Belo Horizonte-MG, Brazil. Questionnaire collected information on consumer perceptions regarding new technologies by means of the Food Technology Neophobia Scale (FTNS), translated and validated into Portuguese, in addition to familiarity and willingness to try yogurts labeled such as traditional, pasteurized, organic, genetically modified, enriched with bioactive proteins and nanotechnology. Results suggested that neophobia regarding food technology is important to explain consumer behavior in relation to new technologies, especially for nanotechnology. Participants were less familiar with foods labeled as GM and nanotechnology, and willingness to try these products was lower. Consumers are still wary of GM and nanotechnology, possibly due to lack of assurance that these foods are safe for human health and the environment. For new food technologies (such as nanotechnology) that are still recent, communication is very important, being decisive for the consolidation of consumer perceptions, and consequently for the acceptance of these innovations on the market

Statistical investigation of Kluyveromyces lactis cells permeabilization with ethanol by response surface methodology

The aim of our study was to select the optimal operating conditions to permeabilize Kluyveromyces lactis cells using ethanol as a solvent as an alternative to cell disruption and extraction. Cell permeabilization was carried out by a non-mechanical method consisting of chemical treatment with ethanol, and the results were expressed as β-galactosidase activity. Experiments were conducted under different conditions of ethanol concentration, treatment time and temperature according to a central composite rotatable design (CCRD), and the collected results were then worked out by response surface methodology (RSM). Cell permeabilization was improved by an increase in ethanol concentration and simultaneous decreases in the incubation temperature and treatment time. Such an approach allowed us to identify an optimal range of the independent variables within which the β-galactosidase activity was optimized. A maximum permeabilization of 2,816 mmol L−1 oNP min−1 g−1 was obtained by treating cells with 75.0% v/v of ethanol at 20.0 °C for 15.0 min. The proposed methodology resulted to be effective and suited for K. lactis cells permeabilization at a lab-scale and promises to be of possible interest for future applications mainly in the food industr

Thermophysical Properties of Lemon Juice as Affected by Temperature and Water Content

To design equipment for food processing and estimate process times for refrigerating, freezing, heating, or drying of foods, the thermophysical properties must be known, Since the thermophysical properties of foods are strongly dependent upon chemical composition and temperature, composition and temperature based models provide a means of estimating these properties. In this work, the thermophysical properties of lemon juice were determined at a water mass fraction of (0.381 to 0.900) and a temperature of (273.45 to 353.75) K. Density and thermal conductivity varied from (962.3 to 1282.8) kg.m(-3) and (0.344 to 0.624) W.m(-2).K(-1), respectively. Heat capacity and thermal diffusivity varied from (2446.5 to 4060.1) J.kg(-1).K(-1) and (0.1160.10(-6) to 0.1785.10(-6)) m(2).s(-1), respectively. Simple polynomial functions were fitted to the experimental data, and good agreements were obtained. In the tested range, water content showed greater influence oil the thermophysical properties.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Hydrophobic interaction adsorption of whey proteins: effect of temperature and salt concentration and thermodynamic analysis

The adsorptive behavior of bovine serum albumin (BSA) and β-lactoglobulin (β-lg) on hydrophobic adsorbent was studied at four temperatures and different salt concentrations. The Langmuir model was fitted by experimental equilibrium data showing that an increase in temperature and salt concentration results in an increase on the capacity factor of both proteins. A thermodynamic analysis coupled with isotherm measurements showed that salt concentration and temperature affected the enthalpic and entropic behavior of the adsorption process of both proteins, mainly to the β-lg. The fast variation in the Z value for temperature over than 303.1 K suggest a great conformational change occurring in the β-lg structure, which almost duplicated the maximum adsorption capacity of this protein

Thermophysical Properties of Industrial Sugar Cane Juices for the Production of Bioethanol

To design equipment for biofuel production and all optimizing process for heating, settling, and filtration of industrial sugar cane juices, the thermophysical properties Must be known. Since the thermophysical properties of biological materials are strongly dependent upon chemical composition and temperature, composition- and temperature-based models provide a means of estimating these properties. In this work, the thermophysical properties of untreated sugar cane juice (USCJ), mixed Sugar cane juice (MSCJ), and clarified sugar cane juice (CSCJ) were determined at a temperature range of (277.4 to 373.4) K. Simple polynomial models as a function of temperature were fitted to the experimental data, showing good agreement. Thermal conductivity and heat capacity varied front (0.475 to 0.493) W.m(-1).K(-1) and (3601.8 to 3802.9) J.kg(-1).K(-1), respectively. Density varied from (1044.5 to 1189.5) kg.m(-3).Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Effect of pH and salt concentration on the solubility and density of egg yolk and plasma egg yolk

This work aimed to evaluate the solubility and density of egg yolk and plasma egg yolk in three types of salts (NaCl, Na2SO4 and (NH4)2SO4) at different pH values (3.0, 4.03, 6.5, 8.7 and 10.0) and salt concentrations (0.05, 0.1, 0.2, 0.3 and 0.5 mol/l). Solubility data of both egg products showed a distinct behaviour for each type of salt. A 4th-order polynomial model fitted the solubility data with R^2 values higher than 0.83. It was observed the increase of the density as the salt concentration increase. The model used for density data correlation shown R^2 values higher than 0.94

Dispersed phase hold-up in a Graesser raining bucket contactor using aqueous two-phase systems

This study presents dispersed hold-up data for an aqueous two-phase system containing polyethylene glycol (PEG) 1500 Da and potassium phosphate (PPP) at pH 7 and 25 °C in a Graesser raining bucket contactor. The influences of the operational variables rotor speed and phase flow ratio on the hold-up were analyzed. Densities, viscosities and interfacial tension were measured. The results obtained were correlated by the equation proposed by Richardson and Zaki, for the description of the slip velocities