Influence of rootstock, harvest time, and storage conditions on triterpene content of apple peel

Triterpenoids are a large group belonging to the isoprenoid group of compounds. The oleanolic acid (OA) and ursolic acid (UA) are two major triterpenic compounds in apple. Many studies have identified the pharmacological effects of triterpenoids and their derivatives in preventing different cancers and immune disease. However, the pre-harvest and postharvest factors associated with the content of triterpenes remain unclear. In the present study, the triterpene contents (OA and UA) were determined in order to identify the effect of different factors at harvest time and after cold and ultra lower oxygen (ULO) storages. The analyses were performed using high performance liquid chromatography (HPLC). The largest differences in triterpene content were found between rootstocks. The results showed that both at harvest time, and after cold storage except the first harvest time samples, the apples from rootstock MM106 had significantly higher triterpene content compared with those from M9; after ULO storage, the differences were found on first and third harvest time samples. The harvest time and storage had limited impact on triterpene content. Selecting suitable rootstock might increase the triterpene content in apple peel in practice production.