Search

Background and objectives: Only a limited number of methods are available for the assessment of dough properties for doughs containing all the ingredients of a bakery product. The aim of this work was to analyze industrial samples of Danish pastry doughs with alveograph analysis. An adjusted protocol was developed, in which analysis conditions and data analysis were modified compared to the standard alveograph method for assessment of flour quality. A sampling and handling protocol for dough from the industrial production was also developed. Findings: The Danish pastry doughs analyzed with the adjusted protocol were more dependent on mixing time and extrusion order than the flour-water dough analyzed with the standard protocol. Two different types of industrial Danish pastry dough with similar recipes could be differentiated with the adjusted protocol. Conclusions: Industrial samples of Danish pastry dough and possibly also other full formula doughs can be analyzed with alveography using the adjusted protocol, if adjustments with respect to the mixing time are made. Significance and novelty: The findings in this work enables alveograph analysis of full formula dough, which might be used to evaluate the effects of different variables in an industrial setting.

Multi-tissue partial volume estimation in MRI images is investigated with a viewpoint related to spectral unmixing as used in hyperspectral imaging. The main contribution of this paper is twofold. It firstly proposes a theoretical analysis of the statistical optimality conditions of the proportion estimation problem, which in the context of multi-contrast MRI data acquisition allows to appropriately set the imaging sequence parameters. Secondly, an efficient proportion quantification algorithm based on the minimisation of a penalised least-square criterion incorporating a regularity constraint on the spatial distribution of the proportions is proposed. Furthermore, the resulting developments are discussed using empirical simulations. The practical usefulness of the spectral unmixing approach for partial volume quantification in MRI is illustrated through an application to food analysis on the proving of a Danish pastry.

International audience; This chapter starts with the interest of imaging the heterogeneous structure of bakery products at multi-scales as well as the way some drawbacks of MRI applied to these particular products (especially low signal-to-noise ratio) have been circumvented with success in earlier MRI studies. Lying on numerous examples from the literature, the chapter then presents different types of original information which can be extracted from MRI images of bakery products: (i) the mapping of proportions (gas, ice, liquid water, or liquid fat) or of temperature, (ii) extraction from images of probability distribution function in size of gas cells, and (iii) displacement of matter. Since these changes are often combined, the analysis highlights the ways or the configurations favorable for unravelling the different contributions to the variation in the MRI signal and more generally the precautions to be taken for adequate interpretation of the MRI signal in the different configurations.

International audience; This study characterized the size distributions of eye-shaped bubbles as a function of different number of fat layers (NFL) (4-128) in Danish pastry. This allowed for the first time, without which it is difficult to objectively define a coarse crumb texture typical of craft products, a too fine crumb texture typical of over-lamination, or and the sizes of the bubbles typical of maximum lift. Ten to 20 mm wide bubbles did not differ in number with the NFL, except in over-laminated pastry in which their number decreased. Five-10 mm wide bubbles increased in number between 16 and 48 fat layers and explained the difference in crumb texture (more regular) and lift (+16%). One to 5 mm wide bubbles, rather round in shape, increased with the NFL, contributing to more regular crumb texture and predominated in over-laminated pastry. The number of eye-shaped bubbles was then correlated with the number of fat fragments, giving a ratio of 5 of the widths of bubbles to fat fragments. This result was logical knowing that bubbles also increase in size in the fat layers, as demonstrated earlier by MRI monitoring of Danish pastry during proving. This result also offered the opportunity of optimizing the alveolar structure of finish Danish pastry from the lamination step, using the degree of fat fragmentation at this step. The impact of these results on the usual view of bubble growth in Danish pastry is last discussed.

The effects of the number of fat layers (4-162 layers) on expansion and loss of CO2 and water in Danish pastries (yeasted puff pastry) were studied at each processing step. Proving contributed to most of the expansion (200-300%) and no specific role of fat layers was evidenced at this stage; this was confirmed by measurements of CO2 released. Relative expansion during baking ranged from 20% to 65% for 4 to 32 fat layers and remained unchanged above 48 layers. Images cross sections of Danish pastry showed that bubbles were few for 4 fat layers, but very large (3-4 cm) and elongated in the direction of layering. For high numbers of fat layers, bubbles were numerous, smaller and round (2-7 mm). The loss of water vapor retention during baking in relation to fragmentation of fat layers during sheeting explained the leveling-off of expansion and the decreasing size of bubbles. © 2015 Published by Elsevier Ltd.

International audience; Proving of a real sized Danish pastry (10cm×5cm) was studied by MRI to visualize dough and fat layers and their evolution. The number of fat layers was varied from 4 to 12, the latter being relevant to the lower range used on an industrial scale. A new method of quantification of the three components, gas, gas-free dough and fat, in partial volume was applied to MRI images of Danish pastry during proving. The method estimated accurately the proportion of gas with a maximal bias of 5%. Sheeting steps up to 3 did not modify the inflation process of pastry and hence did not alter the gluten network and its capacity to retain gases at the global scale. A degassing effect of lamination was observed from the third sheeting step (dough layers with median thickness of about 750?m). Thickness between dough layers was not the same from the bottom to the top of the laminated dough and this was amplified during proving. However, the gas proportion in these layers was homogenous and there was no effect of the position of the layer on its expansion. Large bubbles (> 0.5mm) were visualized in dough layers but they were not elongated at this step of processing, as are bubbles typical of Danish pastry once baked. Eye-shaped bubbles were instead visualized in fat layers; their number increased more rapidly than that of fat layers. They contributed to less than 10% of overall inflation. Finally, large, undetectable portions of fat (40±13mm equivalent to about 80 pixels) were assigned to missing fat material and breaks in the layering, considered as undesirable by the bakers. These void spaces represented 7.7% of the expected total length of fat layers in the MRI images, a proportion also reported from CLSM images of the same pastries. © 2017 Elsevier Ltd

Examples of problems and causes of quality defects in the manufacture of laminated and shortcrust pastries are described and potential solutions are discussed.

This study shows the effects of fat types on the quality properties Danish pastry prepared with butter, margarine, and shortening as a roll-in fat. The viscoelastic properties of dough for Danish pastry and its volume, surface color, and texture after baking were investigated. The Danish pastry prepared with butter as a roll-in fat showed the biggest volume and relatively small and uniform cell structure in the crumb compared to those prepared with margarine and shortening. Danish pastry dough prepared with shortening was the most elastic during a frequency sweep test using 0.1 to 0.8 Hz while the dough of Danish pastry prepared with shortening and margarine had similar rheological properties at a frequency sweep from 1.0 to 10 Hz. The hardness values of Danish pastry prepared with margarine and shortening were found to be 1.51±0.04 and 2.99±0.19 N, respectively, which are significantly different from the texture of the Danish pastry prepared with butter (p < 0.05).

Tiny article about a specially kind of cake that was, and is, popular i the South of Denmark and is formed on special steel forms that is put into the fire, goderåd

Significant physicochemical properties of Danish pastry samples have been identified to establish a methodology for optimally designing product with maximized palatability, using the food kansei model (Ikeda et al., 2004). A series of procedures for textural measurements and analyses has been proposed for the samples, as follows: 1) fixing linear ranges in which force is proportional to strain, and 2) identifying the intrinsic textural attributes from viscoelastic moduli obtained by creep tests. Analysis of variance was used to select food kansei variables at the level of 5% among the instrumental and sensory data. Multiple regression analysis was employed to correlate palatability with the rotated principal component scores of perception. The optimal values of ingredients and physicochemical properties were consequently determined by multivariate-spline and regret function. The results of validation by cluster analysis indicated that the maximum height, density, water and oil contents, instant elasticity E0 , and permanent viscosity ηN were the optimal combination for describing physicochemical properties of Danish pastry samples.

The principles and key ingredients, recipe and process parameters for the manufacture of hamburger buns are described. Particular attention is focussed on the role of brews and ferments and their process control requirements. The technology involved in the manufacture of part-baked bread products is discussed and the needs for product storage and bake-off identified. The manufacture of yeasted laminated products such as Danish pastry and croissant are reviewed. The importance of optimising the formation of the base dough and the subsequent introduction of the laminating fat are considered. Control of the laminating process is particularly important for the delivery of their relevant final product qualities.

International audience; It has been thought that all fat and dough layers in laminated dough had the same thickness at the end of lamination. Moreover dough rheology (taking into account elastic recoil) is too complex to generalize calculation of the final thickness of the dough after lamination. Confocal laser scanning microscopy can differentiate the fat from the dough when combined with fluorophore staining (Nile Red and Alexa), and an algorithm was applied to quantify their respective thicknesses. When fat consistency was close to that of dough, the median thickness of fat was fairly close to theoretical values. Successive sheeting steps resulted in homogenization of layer thicknesses. The surface area of fat in relation to paste was greater than expected, especially follow numbers of sheeting steps, and also for samples with higher numbers of sheeting steps, presenting an exceptionally thick layer of fat (including that produced by back flow). Elastic recoil was between 20 and 90% higher than the targeted roll out; no significant effect of a harder fat consistency was found. Elastic recoil was less when the amount of fat in the sample was greater.

The mechanism commonly assumed to explain the exceptional lift of laminated doughs is that fat layers act as a barrier to steam produced during baking. Successive folding and sheeting steps increase the number of fat layers and the lift, up to a point (48 fat layers in our study) where fat layers would suddenly rupture. Void spaces in the fat layers were characterized on confocal laser scanning microscopy images of Danish pastry from 8 to 64 fat layers: the greater the number of fat layers, the greater the average number of void spaces, following a power law from 16 layers. At 64 fat layers, Danish pastry appeared to be over-laminated. The size of small void spaces (2–50 μm) was shown to be independent of the number of fat layers. The number of large void spaces was linearly dependent on the number of fat layers. These results failed to show any transition at 48 fat layers.

35歳，男性。初診半年前から特定の菓子パン摂食後の仕事中に蕁麻疹が生じるようになった。約1ヵ月前には，血圧低下，呼吸困難などのアナフィラキシー症状を呈した。小麦とグルテンのプリックテストは共に陽性であったが，IgE-RASTは陰性を示した。患者血清を用いたIgE免疫ブロットでω-5グリアジン特異IgEが陽性であり，小麦依存性運動誘発アナフィラキシーと診断した。症状の誘発には，グルテン摂取に加えてアスピリン内服と運動の同時負荷が必要であり，かつ菓子パン以外の小麦食品では蕁麻疹をみないため，菓子パン内に含まれる少量のサリチル酸誘導体などの添加物が発症に関与している可能性が考えられた。

Microbial transglutaminase forms nondisulfide covalent crosslinks in proteins and is increasinglybeing used in foods. We have previously demonstrated beneficial effects of microbial transglutaminase duringbreadmaking, which are comparable to traditional oxidizing improvers, hypothesized to act via formation of disul-fide crosslinks. Transglutaminase substantially improved the lift of puff pastry. It also had a dramatic effect on thevolume of yeasted croissants made with both white flour and a blend of wholemeal and white flour. Furthermore,these effects were preserved after the pastry and croissant doughs had undergone frozen storage for periods of up to90 d. Transglutaminase, therefore, offers a potential solution to the problem of pastry and croissant dough deterio-ration on frozen storage.Key Words: transglutaminase, pastry, croissant, flour improver Introduction O XIDIZING FLOUR IMPROVERS ARE BELIEVED TO HAVE BENE -ficial effects due to the oxidation of cysteine residues in glu-ten proteins to form disulfide bridges, which crosslink andstrengthen the protein (Lillard and others 1982). The resultingchange in protein structure is hypothesized to account for thechanges in dough properties (for example, improved gas reten-tion) and the improvement in the quality of the baked loaf(Kauffman 1986). Whether oxidation is exclusively necessary forflour improvement, or whether such benefits are directly due toprotein crosslinking, is still uncertain. We are, therefore, explor-ing methods of introducing crosslinks into gluten proteins with-out using oxidative methods and evaluating their effects.Transglutaminase (protein-glutamine dough, we undertook a trial in which control pastry rings were com--glutamyltransferase,E.C. 2.3.2.13) catalyzes acyl-transfer reactions, introducing cova-lent crosslinks in proteins (Nonaka and others 1989). Crosslinksform between lysine residues and glutamine residues to form an -( -Glu)-Lys bond without decomposing the nutritional quality ofthe lysine residue (Seguro and others 1996). The enzyme has noobvious food safety implications and has been approved for fooduse in Japan (Anonymous 1996). We have previously reported thebeneficial effects of transglutaminase in the breadmaking process(Gerrard and others 1998). We report herein the beneficial effectsof microbial transglutaminase in pastry and croissant production.Pastries and croissants are high-value baked goods that are in-creasingly popular when sold as frozen doughs, to be baked by theconsumer or a retail outlet. Unfortunately, freezing of pastry doughand croissant dough leads to deterioration in product quality (Brachand Hanneforth 1995; Inoue and others 1994). We, therefore, decid-ed to explore the possibility of using transglutaminase to alleviatesome of the detrimental effects of this frozen storage.