Insight into the mechanism of myofibrillar protein gel improved by insoluble dietary fiber

Dietary fiber intake provides many health benefits. However, average fiber intakes for US children and adults are less than half of the recommended levels. Individuals with high intakes of dietary fiber appear to be at significantly lower risk for developing coronary heart disease, stroke, hypertension, diabetes, obesity, and certain gastrointestinal diseases. Increasing fiber intake lowers blood pressure and serum cholesterol levels. Increased intake of soluble fiber improves glycemia and insulin sensitivity in non-diabetic and diabetic individuals. Fiber supplementation in obese individuals significantly enhances weight loss. Increased fiber intake benefits a number of gastrointestinal disorders including the following: gastroesophageal reflux disease, duodenal ulcer, diverticulitis, constipation, and hemorrhoids. Prebiotic fibers appear to enhance immune function. Dietary fiber intake provides similar benefits for children as for adults. The recommended dietary fiber intakes for children and adults are 14 g/1000 kcal. More effective communication and consumer education is required to enhance fiber consumption from foods or supplements.

Several methods for determination of the secondary structure of proteins by spectroscopic measurements are reviewed. Circular dichroism (CD) spectroscopy provides rapid determinations of protein secondary structure with dilute solutions and a way to rapidly assess conformational changes resulting from addition of ligands. Both CD and Raman spectroscopies are particularly useful for measurements over a range of temperatures. Infrared (IR) and Raman spectroscopy require only small volumes of protein solution. The frequencies of amide bands are analyzed to determine the distribution of secondary structures in proteins. NMR chemical shifts may also be used to determine the positions of secondary structure within the primary sequence of a protein. However, the chemical shifts must first be assigned to particular residues, making the technique considerably slower than the optical methods. These data, together with sophisticated molecular modeling techniques, allow for refinement of protein structural models as well as rapid assessment of conformational changes resulting from ligand binding or macromolecular interactions. A selected number of examples are given to illustrate the power of the techniques in applications of biological interest. Copyright 2000 Academic Press.

This paper reviews current knowledge about factors of importance for pork quality with special emphasis on technological quality attributes. It is evident that production and slaughter factors can be used to control technological quality traits. However, most of the present knowledge is based on studies investigating the influence of a single or at the most two factors. This survey reveals that: -Most important, an understanding of how production and slaughter factors interact in relation to pork quality is a must to give the maximum number of tools to control pork quality and hereby meat quality demands of tomorrow. -The existence of a new genetic pool (elimination of the halothane and RN(-) genes in the commercial pig populations of tomorrow) force the meat science into a renaissance, as the influence of production and slaughter factors on pork quality may be fundamentally different in this new genetic pool. -A basic understanding on how muscle glycogen stores are influenced by genotype and feeding regime and the interaction with pre-slaughter handling might be the next major breakthrough in controlling technological pork quality. -Introduction of new production systems claim parallel studies to prevent unforseen negative effect on quality. -A holistic approach is needed to give an overall understanding of the influence of production, peri and post mortem factors on pork quality.