Continuous monitoring of dough fermentation and bread baking by magnetic resonance microscopy

Prediction method of CO2 production from electrical resistance of bread dough measured with a simple electrical multimeter in fermentation

Novel devices were created to monitor CO₂ production in dough fermentation. Three devices were made with probes of 15 mm, 40 mm square, and needle types, connected to a multimeter. Dough samples (0.5%, 1.0%, and 1.5% yeast) were filled in tailor-made container for fermentation and evaluated. Ratios of CO₂ were predicted from the electrical resistance of the dough, because of dielectric characteristics of CO₂ and dielectric theory. As fermentation progressed, the dough was expanded by holding of CO₂, the resistance rapidly increased in the early stage and gradually increased in the late stage, in all cases. The production of CO₂ was well estimated with respect to the yeast content. The comparisons of the predicted and experimental volume ratios showed similar patterns except for only one type (the 15 mm square). It was concluded that the electrical method could be an efficient alternative to the volumetric method to measure CO₂ production.

Porous Crumb Structure of Leavened Baked Products

Quality evaluation of the porous crumb structure of leavened baked goods, especially bread, has become a vast study area of which various research studies have been carried out up to date. Here is a brief review focusing on those studies with six main parts including porous crumb structure development, crumb cellular structure analysis, application of fractal dimension for evaluating crumb cellular structure, mechanical and sensorial properties of crumb structure, changes of porous crumb structure with staling, and modifications to obtain a well-developed porous crumb structure and retard staling. Development of the porous crumb structure mainly depends on dough ingredients and processing conditions. Hence, certain modifications for those factors (incorporating food hydrocolloids, emulsifiers, improvers, etc.) have been conducted by cereal sciences for obtaining well-developed porous crumb structure and retard staling. Several image analysis methods are available for analyzing microstructural features of porous crumb structure, which can directly affect the mechanical and sensorial properties of the final product. A product with a well-developed porous crumb structure may contain the property of higher gas retention capacity which results in a product with increased volume and reduced crumb hardness with appealing sensorial properties.

Use of multiparametric magnetic resonance microscopy for discrimination among different processing protocols and anatomical positions of Slovenian dry-cured hams

A novel multiparametric magnetic resonance microscopy (MRM) approach was applied to the Slovenian Kraški pršut dry-cured ham samples in order to evaluate its potential for discrimination among biceps femoris and semimembranosus muscle from two hams, differing in processing (salting duration) and thus in water and salt content. The approach is based on apparent diffusion coefficient (ADC) mapping as well as on longitudinal (T1) and transversal (T2) nuclear magnetic resonance relaxation time mapping. Three-dimensional maps were acquired and analyzed by one dimensional (1D) ADC, T1, and T2 distributions as well as by paired two-dimensional ADC-T1, ADC-T2 and T1-T2 distributions. The discriminating potential of the applied MRM approach was confirmed by differences among both 1D and 2D distributions of different ham samples. In addition, distribution peak positions highly correlated with the conventionally determined moisture content.

MR microscopy for noninvasive detection of water distribution during soaking and cooking in the common bean

Magnetic resonance microscopy (MRM) was used to study water distribution and mobility in common bean (Phaseolus vulgaris) seed during soaking at room temperature (20°C) and during the cooking of presoaked and dry bean seed in near-boiling water (98°C). Two complementary MRI methods were used to determine the total water uptake into the seed: the T2-weighted 3D RARE method, which yielded an increased signal from regions of highly mobile (bulk) water and a suppressed signal from regions of poorly mobile (bound) water; and the 3D SPI method, which yielded an increased signal from regions of water restricted in motion and a suppressed signal from the bulk water regions owing to the short repetition time of the method. Based on these results, it can be concluded that during soaking water enters the bean through the micropyle, migrating below the seed coat. The raphe and hypocotyl are hydrated first, while the cotyledon tissue is hydrated next. It was also observed that the imbibition rate increases with an increasing soaking temperature.