Impact of maltodextrins and antistaling enzymes on the differential scanning calorimetry staling endotherm of baked bread doughs

Differ ent concentrations (1.2-3.6%) of maltodextrin preparations with average degrees of polymerization (DP) varying between 4 and 66 reduced the differential scanning calorimetry (DSC) staling endotherm in baked and stored (7 days, 23 degrees C) bread doughs from 3.4 mJ/mg to values within a 3.0-1.9 mJ/mg range. Commercial enzymes used in industrial practice as antistaling agents for bread also reduced amylopectin retrogradation. This suggested that the maltodextrins used are promising antistaling components and that the staling of bread and amylopectin retrogradation are related phenomena. In addition, the results obtained suggest that starch hydrolysis products resulting from enzymic attack may well be responsible for the antistaling effect induced by antistaling enzymes.status: publishe

Physico-chemical properties of cassava starch

Cassava starch was isolated from flour of four IITA (International Institute of Tropical Agriculture, Ibadan, Nigeria) cassava genotypes planted in the dry and in the rainy season and harvested at 6, 9, 12,15 and 18 months after planting. The amylose contents of the starch samples varied between 17.9 and 23.6%. Within a single genotype and planting season, no systematic changes in particle size distribution as a function of crop age at harvest were found; particle sizes varied between 9.5 and 12.7 mu m and between 11.8 and 13.6 mu m for samples of the dry season and the rainy season, respectively. The starch samples varied in differential scanning calorimetry (DSC) gelatinisation temperature and exhibited peak multiplicity depending or planting season and harvest Lime. Even at a moisture dry matter ratio of 6.0 (w/w) peak multiplicity was still observed, suggesting that the phenomenon is a property of the starch itself rather than resulting from low moisture gelatinisation.status: publishe

Transforming a competency model to parameterised questions in assessment

The problem of comparing and matching different learners’ knowledge arises when assessment systems use a one-dimensional numerical value to represent “knowledge level”. Such assessment systems may measure inconsistently because they estimate this level differently and inadequately. The multidimensional competency model called COMpetence-Based learner knowledge for personalized Assessment (COMBA) is being developed to represent a learner’s knowledge in a multi-dimensional vector space. The heart of this model is to treat knowledge, not as possession, but as a contextualized space of capability either actual or potential. The paper discusses a system for automatically generating questions from the COMBA competency model as a “guide-on-the-side”. The system’s novel design and implementation involves an ontological database that represents the intended learning outcome to be assessed across a number of dimensions, including level of cognitive ability and subject matter. The system generates all the questions that are possible from a given learning outcome, which may then be used to test for understanding, and so could determine the degree to which learners actually acquire the desired knowledge

Impact of genotype and crop age on the breadmaking and physicochemical properties of flour produced from cassava (Manihot esculenta Crantz) planted in the dry season

The bread making potential of cassava flour (in cassava flour/defatted soya flour/glyceryl monostearate recipes (80:20:3, w/w)) prepared from 10 IITA cassava genotypes harvested at the International Institute of Tropical Agriculture (IITA) at 6, 9, 12, 15 and 18 months after planting, was investigated. Bread quality in general was much more dependent on the age of the cassava at harvest time than on the effects of genotype. Thus, the quality of the bread (judged by the regularity of the crumb) produced from flour from crops harvested 12 months after planting was the best in general, with that from flour resulting from 9-month plants superior to that resulting from 6-month plants. Harvesting at 15 or 18 months led to a reduction in bread quality although the effects varied for different genotypes. Brabender peak viscosity varied widely within each set of flour samples harvested at any particular harvest time, but also with the harvest time itself. By differential scanning calorimetry (DSC) (moisture: dry matter ratio 2.1 w/w), the 6-month samples were characterised by two endothermic transition peaks, one at ca 72°C and one at ca 78°C. With increasing age at harvest time (up to 15 months), the 72°C peak became relatively more important, resulting in a 'disappearance' of the 78°C peak in the thermogram. The 18-month samples again showed a 78°C gelatinisation peak or at least a shoulder thereof. The peak multiplicity of the 6-month samples also occurred in DSC experiments with moisture: dry matter ratio of 6.0 (w/w), showing that such samples have a unique gelatinisation pattern. Differences in the analytical values (a-amylase activity, and starch, fibre and protein content) could not explain the differences in bread making potential

Economic evaluation of pressure ulcer care: a cost minimization analysis of preventive strategies.

Contains fulltext : 80890.pdf (publisher's version ) (Closed access)The purpose of this study was to determine the cost for prevention and treatment of pressure ulcers from a hospital perspective and to identify the least resource-intensive pressure ulcer prevention strategy. Cost analyses were examined from a hospital perspective using direct costs. The study was carried out alongside a prospective cohort study on the incidence and risk factors for pressure ulcers. Two large teaching hospitals in the Netherlands with (partly) opposing approaches in prevention, a technological versus a human approach, were analyzed. The main outcome measures were resource use, costs of preventive measures and treatment, and pressure ulcer incidence in both hospitals. Pressure ulcer prevention through a predominantly technical approach resulted in a similar incidence rate as prevention through a predominantly human approach. However, the technical approach was considerably less expensive

Simple ion chromatographic method for the determination of chlormequat residues in pears

Current methods for quantitative determination of chlormequat residues in food crops are characterized by rather low recoveries and the need for derivatization tin case of gas chromatography, GC), or by high capital investment tin case of Liquid chromatography-mass spectrometry, LC-MS). We propose a cation-exchange chromatography method for the analysis of chlormequat in pears. The method is based on extraction of the target compound with 40 mM HCl, followed by centrifugation and filtration, The filtrate is directly injected into an ion chromatograph equipped with a commercially available cation-exchange column and a suppressed conductivity detection system. While the limit of detection (LOD) (0.5 mg/kg) may not be small enough to allow dietary analysis, the method meets all validation requirements and is an alternative for the existing GC and LC-MS methods in quality control. (C) 2001 Elsevier Science BN. All rights reserved.status: publishe