Breads assessing

Fig. 38.6. Three-dimensional configuration according to a non-metric multidimensional scaling applied to 24 types of bread differing in appearance as assessed by 12 panellists.

Having made the loaves they have to be tested. When the loaves have cooled they can be measured and assessed. As bread is a perishable product it is convenient to photograph or otherwise make a record of the loaves produced to allow comparisons with samples made on a previous occasion. Digital photography is particularly convenient for this application. An alternative way of recording the amount that a loaf has risen is to photocopy a slice of bread with a ruler to allow the dimensions to be compared with future slices. 

The composition of the volatile fraction of bread depends on the bread ingredients, the conditions of dough fermentation and the baking process. This fraction contributes significantly to the desirable flavors of the crust and the crumb. For this reason, the volatile fraction of different bread types has been studied by several authors. Within the more than 280 compounds that have been identified in the volatile fraction of wheat bread, only a relative small number are responsible for the different notes in the aroma profiles of the crust and the crumb. These compounds can be considered as character impact compounds. Approaches to find out the relevant aroma compounds in bread flavors using model systems and the odor unit concept are emphasized in this review. A new technique denominated "aroma extract dilution analysis" was developed based on the odor unit concept and GC-effluent sniffing. It allows the assessment of the relative importance of the aroma compounds of an extract. The application of this technique to extracts of the crust of both wheat and rye breads and to the crumb of wheat bread is discussed. 

Crust volatiles were isolated immediately after baking by extraction with dichloromethane and sublimation in vacuo ( ). Application of aroma extract dilution analysis 6) to the acid-free crust extract led to the detection of 31 odorants. After separation and enrichment, these compounds were identified by comparison of the MS/EI, MS/Cl and retention data on two columns of different polarity to reference compounds. Aroma quality was also assessed. The results of the identification experiments (Table I) revealed that 2(E)-none-nal (No. 1), followed by 2(E),4(E)-decadienal (No. 2) and 3-methyl-butanal (No. 3) showed the highest FD-factors in the crust of the chemically leavened bread. Additionally l-octen-3-one, 2(Z)-nonenal, 2(E),4(E)-nonadienal and an unknown compound with a metallic odor contributed high FD-factors to the overall flavor (For a discussion of FD-factors, see Chapter by Schieberle and Grosch, this book). 

Crispness is a desirable sensory property in many cereal foods such as toast, the crust of bread, crispbreads, crisps, biscuits, extruded snacks and breakfast cereals. Since it is a subjective sensory assessment crispness is difficult to define unambiguously and its perception varies greatly between individuals and also between countries (Bourne 2002). In general it is known that crisp foods are at low moisture, in the brittle or glassy state well above Tg and fracture rapidly (see also Chapters 5 and 7). We can... 

A two-component PARAFAC model is fitted to a sensory data set of different breads. Ten breads are assessed by eight assessors on eleven different attributes. The left plot of Figure 7.14 shows a scatter plot of the attribute loadings (B) of the PARAFAC model. It is seen that two attributes have low loadings in both components. The right plot shows that this is also reflected by the small Mahalanobis distances, indicating that these attributes are not relevant for the problem or at least not consistent with the main variation in the data. 

In the data set BREAD, five breads made and were assessed by a sensory panel of eight people using a fixed vocabulary of 11 different attributes. The data are arranged in a 10 x 11x8 array and a model is sought of these data in order to be able to predict the composition (salt in this case) in unknown samples. 

The two pre-intervention surveys were conducted to determine the status of urinary iodine levels in a representative sample of Tasmanian primary schoolchildren following more than a decade without regular monitoring. The four post-intervention surveys were conducted to examine the effects on urinary iodine levels following the voluntary fortification of bread with iodine. In addition to the assessment of urinary iodine levels, information on SES and geographical location was collected both pre- and post-intervention. Pre-intervention data on dietary sources of iodine were also collected. 

In texture analysis, softness and firmness express fhe same concept inversely, although they are not simple reciprocals. Softness is defined as the deformation occurring at constant load and is normally what is measured qualitatively by a consumer to gauge freshness of bread. Firmness is the force required to provide a constant deformation it is the measurement usually made to assess the progress of crumb firming of bread using an insfrument such as the Baker compressimeter or the... 

Excise, a tax on manufactured goods before they went to sale, had first been imposed in 1643. It covered an expanding range of essential goods, like beer and meat (though not bread). It spawned a horde of excise officers, the hope being it would finance the war. But by 1645 assessments, fines on delinquents estates and sale of crown-fee farm rents overtook it. 

B. G. Osborne. Investigations into the use of near infrared reflectance spectroscopy for the quality assessment of wheat with respect to its potential for bread-baking. J Sci Food Agric 35 106-110, 1984. 

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