Rapid Visco Analyser (RVA) profiles were recorded for raw maize grits and two extruded nonexpanded pellets based on wheat and maize. Large differences were found between the profiles obtained when an impeller mill was used to prepare the samples compared with a disk mill. The differences were related to differences in particle properties of the ground products (particle‐size distribution, particle shape, and protein content). Generally, milling the samples with the impeller mill resulted in greater starch conversion than with a disk mill. For raw maize grits, this was shown by X‐ray diffraction, differential scanning calorimetry (DSC), and alkaline viscosity measurements. Several other laboratory mills were tested and all produced particulates with a sieve range of 125–212 μm that had substantially differing RVA profiles. Cooling the sample during milling did not nullify the milling effects. All the laboratory mills produced <20% of the particulates of the size range required for the RVA analysis. The mill used for sample preparation can exert a significant effect on the RVA for both raw and processed cereal samples, even if measurements are made on a defined sieve fraction.

The embryonic genome is formed by fusion of a maternal and a paternal genome. To accommodate the resulting diploid genome in the fertilized oocyte dramatic global genome reorganizations must occur. The higher order structure of chromatin in vivo is critically dependent on architectural chromatin proteins, with the family of linker histone proteins among the most critical structural determinants. Although somatic cells contain numerous linker histone variants, only one, H1FOO, is present in mouse oocytes. Upon fertilization H1FOO rapidly populates the introduced paternal genome and replaces sperm-specific histone-like proteins. The same dynamic replacement occurs upon introduction of a nucleus during somatic cell nuclear transfer. To understand the molecular basis of this dynamic histone replacement process, we compared the localization and binding dynamics of somatic H1 and oocyte-specific H1FOO and identified the molecular determinants of binding to either oocyte or somatic chromatin in living cells. We find that although both histones associate readily with chromatin in nuclei of somatic cells, only H1FOO is capable of correct chromatin association in the germinal vesicle stage oocyte nuclei. This specificity is generated by the N-terminal and globular domains of H1FOO. Measurement of in vivo binding properties of the H1 variants suggest that H1FOO binds chromatin more tightly than somatic linker histones. We provide evidence that both the binding properties of linker histones as well as additional, active processes contribute to the replacement of somatic histones with H1FOO during nuclear transfer. These results provide the first mechanistic insights into the crucial step of linker histone replacement as it occurs during fertilization and somatic cell nuclear transfer.

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Finally, the effect of the retrogradation of the amylopectin fraction on its digestibility was assessed in extruded potato starch ribbons containing 35% (w/w) water and stored at different temperatures. After 14 days of storage, the digestibility decreased from 77.0 ± 0.9% in the freshly extruded samples to between 28.0 ± 1.7% and 42.1 ± 0.3%, depending on the storage temperature. This suggested a measurable difference in the α-amylase susceptibility between the A and B polymorphs of retrograded amylopectin.