Increased textural complexity in food enhances satiation.

For the first time this study has shown a direct effect of food textural complexity on satiation. Independent of oral processing time, increasing the textural complexity of a food significantly decreased food intake. Foods with complex textures stimulate many sensory perceptions during oral processing, with a succession of textures perceived between first bite and swallow. Previously the impact of texture on satiation (commonly tested by increasing viscosities of semi-solids) has been explained by texture's influence on oral processing time; a long oral processing time enhances satiation. The results of the current study show that subjects in a randomised cross-over trial who consumed a "starter" (preload) model food with high textural complexity went on to eat significantly less of a two course ad libitum meal. Subjects who consumed a "starter" model food with low textural complexity, but with the same flavour, energy density and oral processing time, ate significantly more of the same ad libitum meal. The results show that increasing the number of textures perceived during chewing of a solid food triggers the satiation response earlier than when chewing a less texturally complex food. Increasing textural complexity of manufactured foods, to allow for greater sensory stimulation per bite, could potentially be used as a tool to enhance the satiation response and decrease food intake.

Simulating Polyproline II-Helix-Rich Peptides with the Latest Kirkwood-Buff Force Field: A Direct Comparison with AMBER and CHARMM.

We simulated the dynamics of a set of peptides characterized by ensembles rich in PPII-helical content, to assess the ability of the most recent Kirkwood-Buff force field (KBFF20) to sample this conformational peculiarity. KBFF has been previously shown to capably reproduce experimental dimensions of disordered proteins, while being limited in confidently sampling structured proteins. Further development of the force field bridged this gap. It is however still unknown what are the main differences between KBFF and AMBER/CHARMM force fields. A direct comparison is now possible as both AMBER/CHARMM force fields have been used to sample peptides rich in PPII-helical content. We found that KBFF20 samples' PPII-helical content qualitatively matches both AMBER and CHARMM force fields, with the main difference being the KBFF ability to populate the αR region of the Ramachandran plot in the set of simulated peptides. Overall, KBFF20 is a well-balanced force field, able to sample the dynamics of both structured and unstructured proteins.

Aberrant imprinting may underlie evolution of parthenogenesis.

Genomic imprinting confers parent-of-origin-specific gene expression, thus non-equivalent and complementary function of parental genomes. As a consequence, genomic imprinting poses an epigenetic barrier to parthenogenesis in sexual organisms. We report aberrant imprinting in Boechera, a genus in which apomicts evolved from sexuals multiple times. Maternal activation of a MADS-box gene, a homolog of which is imprinted and paternally expressed in the sexual relative Arabidopsis, is accompanied by locus-specific DNA methylation changes in apomicts where parental imprinting seems to be relaxed.

The effect of textural complexity of solid foods on satiation.

Previous studies have shown that food texture affects satiation by influencing the eating rate, bite size and oral transit time. However, investigations into the direct effect of texture on satiation are limited. The objective of the current study was to investigate the effect of textural complexity on satiation, independent of oral processing time and energy density. A preload-test meal design was used in this study; model foods with three levels of textural complexity (low, medium and high) were consumed as preload foods followed by a two-course ad libitum meal. This study was a randomized cross-over trial with 38 subjects. The results clearly showed that food with greater textural complexity led to significantly lower food intake overall. The first course of the meal and total food intake was significantly reduced (p<0.05) although food intake at the second course did not differ between groups. Despite the differing total intake, all subjects rated to have the same sense of satiety after three hours post-trial and the time taken to the next eating occasion did not differ between different preload conditions. Increased textural complexity in food enhances satiation and may potentially impact on satiety however this needs to be further confirmed in future studies. The findings suggest that foods with more complex textures can be a helpful tool in reducing the short-term food intake and enhancing the satiation response.