DEVELOPMENTAL CHANGES IN PHYTOSTEROL AND PHYTOSTANOL COMPOSITION OF DENT CORN (ZEA MAYS L.) KERNEL FRACTIONS

This study was conducted to monitor phytosterol and phytostanol accumulation in the pericarp, endosperm and germ fractions of the dent corn kernel during maturation. The accumulation pattern of total phytosterol content was different in the three corn kernels parts. The highest level of total phytosterols (4,670.8 mg/100 g of oil) was detected in the pericarp fraction at 30 days after pollination (DAP). In the different corn oil samples, three forms of phytosterol were detected: 4-desmethylsterols, 4-monomethylsterols and 4,4-dimethylsterols. The level of total 4-desmethylsterols was higher than those of 4-monomethylsterols and 4,4-dimethylsterols in the different parts of the developing corn kernel. At 30 DAP, the pericarp fraction was distinguished by the highest level of total 4-desmethylsterols (4,393.3 mg/100 g of oil); however, the endosperm part was distinguished by the highest levels of total 4,4-dimethylsterols (340.6 mg/100 g of oil) and 4-monomethylsterols (18.2 mg/100 g of oil). beta-sitosterol was the most abundant sterol in the three corn kernel parts during maturation. At 30 DAP, the pericarp and endosperm parts showed the highest (3,245.8 mg/100 g of oil) and the lowest (384.2 mg/100 g of oil) levels of beta-sitosterol, respectively. The most active phase of phytostanol accumulation was observed in the endosperm part between 20 and 40 DAP. PRACTICAL APPLICATIONS Recently, there is a considerable interest in phytosterol and phytostanol compounds because of their cholesterol-lowering properties. In addition, those compounds may possess anticancer, anti-inflammatory, anti-atherogenicity and antioxidation activities. Thus, one of the main objectives of the industry is to identify plant matrices rich in those high value-added phytocompounds. At present, several functional food products enriched with phytosterols and phytostanols are available on the market. This study suggested that the pericarp fraction of the immature corn kernel (30 days after pollination) could potentially be used as a good source of phytosterols. However, the endosperm part of the immature corn kernel may be a good source of phytostanols.