The nutritional enhancement of plant foods 199 H2 sitosteryl oleate 5-0-palmityil-B-D-glucoside sitosteryl B-D-gluccside Fig 8.1 Structure of plant sterol and stanol esters 8.1)These products do not require the development of specifically bred plants since it is possible to extract stanols and sterols from existing plants(albeit in the case of the stanols from the bark of a tree) for use in their manufacture. Experiments with plant stanol esters were shown to lower serum cholesterol consistently by about 10-15% and LDL-cholesterol by about 20%o in patients with high serum cholesterol levels as well as in normal individuals 16, 17 Similar effects have been seen with plant sterol esters but at least I g/day of plant sterols need to be consumed. Consequently, they require extraction and addition to foods Plant sterols can be in the free form or predominantly esterified with long chai fatty acids or with phenolic acids as in rice-bran oil(ferulate) and shea butter (cinnamates). Sterol esters are better absorbed than the free sterols and most sterol esters are hydrolysed to the free sterols in the intestine As campesterol esters are better absorbed than sitosterol esters, serum level of campesterol could rise to those levels that are found in the very few people who suffer toxic symptoms from phytosterolemia. Thus there may be a benefit in increasing the sitosterol to campesterol ratio in plants8.1) These products do not require the development of specifically bred plants since it is possible to extract stanols and sterols from existing plants (albeit in the case of the stanols from the bark of a tree) for use in their manufacture. Experiments with plant stanol esters were shown to lower serum cholesterol consistently by about 10–15% and LDL-cholesterol by about 20% in patients with high serum cholesterol levels as well as in normal individuals.16, 17 Similar effects have been seen with plant sterol esters but at least 1 g/day of plant sterols need to be consumed.18 Consequently, they require extraction and addition to foods. Plant sterols can be in the free form or predominantly esterified with long chain fatty acids or with phenolic acids as in rice-bran oil (ferulate) and shea butter (cinnamates). Sterol esters are better absorbed than the free sterols and most sterol esters are hydrolysed to the free sterols in the intestine. As campesterol esters are better absorbed than sitosterol esters, serum levels of campesterol could rise to those levels that are found in the very few people who suffer toxic symptoms from phytosterolemia. Thus there may be a benefit in increasing the sitosterol to campesterol ratio in plants. The nutritional enhancement of plant foods 199 Fig. 8.1 Structure of plant sterol and stanol esters