FUNCTIONALITY COMPARISON BETWEEN DERIVATIZED WHEY PROTEINS AND A PREGELATINIZED STARCH

A process has been patented to produce stabilizing ingredients from whey proteins which are applicable over a wide range of typical food conditions and do not require heat or the addition of salts to induce thickening functionality. Once reconstituted in deionized water, solutions were evaluated and compared with water holding performance and rheological attributes of a pregelatinized cornstarch. Rotational viscometry was performed at pH values between 3 and 8, temperatures between 5 and 90C, and shear rates between 1 and 100 s⁻¹. Derivatized whey protein powders and pregelatinized starch displayed pseudo-plastic behavior under shear at all temperatures tested. During temperature ramps from 5 to 90C, derivatized whey protein flow properties were essentially unchanged by varying pH. However, viscosity after the temperature increase was higher than initial values, possibly due to additional protein denaturation and hydrophobic interactions. Derivatized powders were stable and retained desired functionality over a wide range of food processing and preparation conditions and may therefore possess applicability to many products currently utilizing modified starches or hydrocolloids to texturize.     

Investigation of the Heat Transfer Characteristics

In the present study a numerical investigation of the heat transfer in an annular combustion chamber of a typical industrial gas turbine was done using a Galerkin-based finite-element solution of the problem. Results were obtained for three basic cases: constant flux incident on the entire combustion segment, constant flux in three quadrants of the chamber and a different magnitude constant flux in the other quadrant, and different magnitude fluxes on the upstream and downstream portions of the chamber. The chamber Biot numbers, dimensionless heat flux, and dimensionless structural wall and thermal barrier coating thicknesses were found to have a crucial effect on the chamber temperature distribution. It was shown that changing the magnitude of the heat flux in a single quadrant prominently alters the temperatures throughout the wall in this area, leading to exceedingly steep temperature gradients. It was also found that any step decrease in downstream incident flux leads to a sharp drop in temperatures at the interface of the thermal barrier coating and the combustion gases.     

OPTIMISATION OF THE PREPARATION OF RANEY COPPER-ZINC CATALYSTS FOR METHANOL SYNTHESIS

The large number of variables involved in the preparation of Raney copper-zinc catalysts for methanol synthesis were screened by statistical methods using a Plackett-Burman screening design. Three important variables, leach reaction temperature, leach digestion temperature and leach digestion time were further investigated using a central composite design. It was found that active Raney copper-zinc catalysts were produced using high (348-358?K) extraction temperature, low (298-318?K.) digestion temperature and long (70-80 min) digestion time     

Obesity. The food research agenda

It is estimated that almost 287 million children will be obese by 2010, and the overall obese population could rise to 700 million by 2015. The metabolic syndrome is a condition characterized by central obesity, hypertension, and disturbed glucose and insulin metabolism, and has been linked to increased risk of both type 2 diabetes and cardiovascular diseases. Diet, socioeconomic, and lifestyle factors have a central role to play in the obesity epidemic. In this respect, the role of particular dietary components on satiety and regulation of food and energy intake, are discussed as are technological approaches to manufacture of foods with low obesigenicity.     

Calcium Alginate Films: Thermal Properties and Permeability to Sorbate and Ascorbate

Calcium alginate films were prepared by the pH-controlled release of calcium ions into alginate solution or by the cooling of hot calcium alginate gels. Thermogravimetry and calorimetry showed that the controlled Ca release films contained a greater amount of high-temperature component, and required extra energy to dissociate the tightly crosslinked calcium alginate. Structural differences were reflected by the permeability of the two films to potassium sorbate: 1.06 × 10^–7 (controlled Ca release) and 1.58 × 10^–7 cm²sec^–1 (cooled). Apparent activation energy was estimated to be for the diffusion of potassium sorbate 24.1 KJ·mol^–1, sodium ascorbate 23.7, and ascorbic acid 36.2. Results suggested that the pH of the diffusant solution had an interactive effect on the alginate film.     

Coase Revisited: Business Groups in the Modern Economy

Ronald Coase's celebrated query as to why economic actors typicallyaggregate into entities called ‘firms’ rather thantransacting as individuals in a market has engendered a vigorousstream of research. This paper asks a parallel question: whyis it that in all modern economies, firms themselves aggregateinto larger entities, often more stable than any literaturepredicts, which are here referred to as ‘business groups’?After establishing some working definitions, and discussingthe curious conjunction of empirical importance and analyticalinvisibility of business groups, an attempt is made to establishthe most significant dimensions along which such groups vary.We end with some speculations on the role of these groups ineconomic development.     

Inflorescence and bunch architecture development in Vitis vinifera L.

Inflorescence development from budburst to harvest was analysed in four cultivars of grapevine. Two cultivars with tight or compact bunches (Riesling, Chardonnay) and two with loose or open bunches (Exotic and Sultana) were selected to define differences in bunch development for future genetic analysis. A range of phenotypic characters for both inflorescence and shoot architecture were measured. Differences in the rate of rachis elongation rates were observed between tight and loose bunch cultivars commencing at the earliest stages of inflorescence development after budburst. At anthesis, five phenotypic characters showed significant differences between tight and loose cultivars: (1) total inflorescence length, (2) node number per inflorescence rachis, (3) combined length of two consecutive internodes of the rachis and (4) shoot node position at which the inflorescence was present and (5) mature tendril length. A quantitative estimate of bunch compactness was calculated at bunch maturity. Exotic and Sultana had significantly more open space than did compact bunch cultivars Riesling and Chardonnay. Comparison of flower number at anthesis and berry number at maturity indicated that the proportion of berries set was similar in all cultivars studied and, therefore, did not contribute to variability in bunch openness between cultivars. Internode length of the inflorescence rachis was the major trait responsible for inflorescence openness. Cellular studies using SEM, fluorescence microscopy and DNA content demonstrated that differences in rachis internode lengths were mostly associated with cell expansion.