Intracellular sources of sugars

Polyhydroxyalkanoates are polyesters accumulated as energy storage materials by various bacteria in the form of intracellular granules, reaching up to 80% of bacterial biomass weight. They can be synthesized by different sources of renewable and non-renewable carbon, such as molasses (from sugar cane) and even some effluents from the food industry. Nowadays, PHAs have been obtained from bacteria and some genetically modified plants. 

Plants are very attractive and potential sources of cellulose primarily because they are abundant and relatively cheap to harvest. Cellulose can be extracted from lignocellulosic fibers, which are available aU over the world. A wide variety of plant materials like cotton, ramie, sisal, flax, wheat straw, tubers, sugar beet, soya bean, etc., are known for cellulose microfibril production. Wood is another main important source of extracting cellulose fibrils, where cellulose microfibrils were reinforced by intracellular amorphous materials made of hemicelluloses, lignin, resin, etc. Extraction of pure cellulose microfibrils from these lignocelluloseic materials involves chemical treatments such as alkali extraction and bleaching. 

The sequential addition of sugars as molecules destined for secretion move through the membrane system of the cell suggests that glycosylation may be involved in controlling this movement. The nucleotide sugars may, for example, be a source of energy for this intracellular movement. 

The origin of meat flavor has been shown to arise from the combination of two primary sources. The first is the tissue fat, both extracellular and intracellular, which produces carbonyl and other lipid and lipid-oxidation products. The fat component of meat flavor is viewed as being responsible for the species specific flavor in meat (9). The second major component of meat flavor is the lean portion. The proteins, peptides, and amino acids of the lean, add not only to the muscle food s general meaty flavor, but also undergo Maillard reactions with sugars to produce Amadori and Heyns compounds having meat flavor characteristics. 

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