Accumulation of Chlorogenic Acid in Shredded Carrots During Storage in an Oriented Polypropylene Film

Chlorogenic acid content of four samples of shredded carrots was measured and related to their flavor stability during storage wrapped in oriented polypropylene film (OPP). Chlorogenic acid was quantified by HPLC/UV: Shredded carrots accumulated chlorogenic acid faster in OPP film. This appeared related to higher sensory quality retention during storage.     

Edible composite films of wheat gluten and lipids: water vapour permeability and other physical properties

Edible composite films comprised of wheat gluten as the structural matrix and various concentrations of different lipids as the moisture barrier component were tested for water vapour permeability, dispersion in water, opacity and mechanical properties. the effects of lipids on the functional properties of gluten-based composite films depended on the lipid characteristics and on the interactions between the lipid and the protein structural matrix. Beeswax, a solid and highly hydrophobic lipid, was the most effective lipid for improving moisture barrier properties of films; but these films were opaque, weak and disintegrated easily in water. Combining wheat gluten proteins with a diacetyl tartaric ester of monoglycerides reduced water vapour permeability, increased strength and maintained transparency.     

Inspection and maintenance planning: an application of semi-Markov decision processes

In this paper, we consider a system which deteriorates stochastically from one time unit to another. The state of the system, which is a continuous random variable, can be observed only by inspection. The goal of this paper is to derive a predictive maintenance policy which indicates, at each inspection and according to the observed value, whether a preventive maintenance is necessary and when the next inspection should be done. The objective is to minimize the long-run average cost incurred by inspections, preventive maintenance and unexpected breakdowns. The problem is modelled by a semi-Markov decision process. Analytical properties are derived, and based on these properties, numerical methods are constructed to compute an optimal policy.     

PREDICTION OF SOLIDS CIRCULATION RATE IN THE RISER OF AN INTERNALLY CIRCULATING FLUIDIZED BED (ICFB)

A predictive mathematical model based on pressure drop in the riser of an Internally Circulating Fluidized Bed (ICFB) is developed to predict solids circulation rate (Gs). The values of G_s predicted using the model agree well with the experimental data. The model also predicts well G_s at higher operating temperatures in the riser of an ICFB.     

Effects of controlled atmospheres on microbial spoilage, electrolyte leakage and sugar content of fresh 'ready-to-use' grated carrots

The effects of controlled atmospheres (CO2 concentrations ranging from 0.03 to 40% and O2 concentrations ranging from 21 to 1%, measured in pack) were studied on fresh 'ready-to-use' grated carrots, stored at 10°C. High CO2 or low O2 conditions favour the growth of lactic acid bacteria (LAB) on grated carrots, but not in a sterile carrot medium, and induce an increased potassium ion leakage. A 25% CO2 and 2% O2 atmosphere improves retention of sugars.
Grated carrots were inoculated by a strain of Leuconostoc mesenteroides , which caused increased potassium ion leakage and exudation only under an atmosphere containing 40% CO2 and 10% O2.
The origin of the spoilage of 'ready-to-use' grated carrots is discussed.     

Extruded Microchannel-Structured Heat Exchangers

Abstract

In the search for more compact air/liquid heat exchangers, one possibility is to increase the heat transfer coefficient and surface area by a decrease of the size of the fluid channels. A practical example could be seen in the air/water cross-flow heat exchangers used in cars. For such exchangers, minimization of the total volume leads to a very thin structure, with a lot of small and short air channels. We have designed and patented a cross-flow heat transfer surface with microchannels that has such a structure and can be manufactured industrially at a reasonable cost by extrusion either in aluminum or in polymers. The thermo-hydraulic performance of the structure has been simulated using standard correlations and CFD codes, and prototypic structures are under investigation to validate simulations. Compared to classical heat exchangers, our design is superior in flexibility and compactness for air/liquid applications.