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Different 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.

The breadmaking potential of cassava flour (in cassava flour/defatted soya flour/glyceryl monostearate recipes (80/20/3, w/w/w)) is not merely dependent on the age of the crop at harvest, but also on the season of planting and time of harvesting. Effects of cassava genotype are less important for determining bread quality. In flours obtained from crops harvested at different times after planting, differences in gelatinisation onset temperatures measured by Brabender visco-amylography and by differential scanning calorimetry accounted for the observed differences in breadmaking potential of cassava flour of single genotypes and planting seasons to some extent. Cassava starch produced breads with a drier crumb, with a finer structure and with a more bulged crust than cassava flour. Differentiations in baking performance between starch samples, although smaller, still existed. This showed that the breadmaking potential of cassava flour samples is determined both by the starch and by the non-starch fractions. Differentiation of cassava samples in the breadmaking process did not occur at the mixing or fermentation stage of the batter but during baking.Key words: cassava flour, cassava starch, breadmaking potential, gelatinisation, differential scanning calorimetry. J Sci Food Agric 0022-5142/95/%09.00 0 1995 SCI. Printed imGreat Britain A 1991 Emulsifiers and/or extruded starch in the production of breads from cassava. Cereal Chem 68 323-327. Defloor I, Leijskens R, Bokanga M, Delcour J A 1994 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. J Sci Food Agric 66 193-202. Delcour J A, Defloor I 1993 Fortschritte bei der Herstellung von Brot aus einheimischen Rohstoffen. Getreide, Mehl und Brot 47 34-39. Dubois D K 1959 Wheat starch: a key to better cakes. Bakers Dig 33 38-42. Eliasson A C 1986 On the effects of surface active agents on the gelatinisation of starch-a calorimetric investigation. Carbohydr Polym 6 463-476. Kim J C, De Ruiter D 1968 Bread from non-wheat flours. Food Techno1 22 867-878. Kim J C, De Ruiter D 1969 Bakery products with non-wheat flours. Bakers Dig 43 58-63. Kugimiya M, Donovan J W, Wong R Y 1980 Phase transition of amylose-lipid complexes in starches: a calorimetric SAS 1987 SASISTAT Guide for Personal Computers. (Version study. Starch 32 265-270. 6). SAS Institute, Cary, NC, USA.

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The breadmaking 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 breadmaking potential.