Analysis of pecan nut (Carya illinoinensis) unsaponifiable fraction. Effect of ripening stage on phytosterols and phytostanols composition

• Published in: Food chemistry 2014-12, Vol.164, p.309-316
• Main Authors: Bouali, Intidhar, Trabelsi, Hajer, Herchi, Wahid, Martine, Lucy, Albouchi, Ali, Bouzaien, Ghaith, Sifi, Samira, Boukhchina, Sadok, Berdeaux, Olivier
• Format: Article
• Language: English
• Subjects: 4,4-Dimethylsterols; 4-Desmethylsterols; 4-Monomethylsterols; Biological and medical sciences; Carya - chemistry; Carya - growth & development; Chemical Sciences; Flame Ionization; Food engineering; Food toxicology; Gas Chromatography-Mass Spectrometry; Life Sciences; Medical sciences; Nuts - chemistry; Nuts - growth & development; Other; Pecan nuts; Phytosterols - analysis; Phytosterols - chemistry; Plant Oils - analysis; Plant Oils - chemistry; Ripening stage; Stanols; Toxicology
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2014.05.029

•Phytosterols were analysed by GC–FID and GC–MS.•Ripening of pecan nut fruits was concomitant to a decrease of total phytosterols content.•The maturation process was associated with a significant decrease in total phytostanols content.•Maturity influenced both quality and quantity of Carya illinoinensis sterolic compounds. Changes in 4-desmethylsterol, 4-monomethylsterol, 4,4-dimethylsterol and phytostanol composition were quantitatively and qualitatively investigated during the ripening of three varieties of Tunisian-grown pecan nuts (Mahan, Moore and Burkett). These components have many health benefits, especially in lowering LDL-cholesterol and preventing heart disease. The phytosterol composition of whole pecan kernel was quantified by Gas Chromatography–Flame Ionisation Detection (GC–FID) and identified by Gas Chromatography–Mass Spectrometry (GC–MS). Fifteen phytosterols and one phytostanol were quantified. The greatest amount of phytosterols (2852.5mg/100g of oil) was detected in Mahan variety at 20weeks after the flowering date (WAFD). Moore had the highest level of phytostanols (7.3mg/100g of oil) at 20 WAFD. Phytosterol and phytostanol contents showed a steep decrease during pecan nut development. Results from the quantitative characterisation of pecan nut oils revealed that β-sitosterol, Δ5-avenasterol, and campesterol were the most abundant phytosterol compounds at all ripening stages.