No abstract

In previous studies we reported the presence of compounds with spectral characteristics similar to pheophytin α (Pheo α), which often accompany the Pheo α peak in the chromatographic profile of virgin olive oils (VOO) at 410 nm under normal-phase HPLC conditions. The occurrence and levels of these compounds were found to be affected by storage conditions of the oil samples. In the present study we investigated whether the major Pheo a degradation products, identified as pyropheophytin α (coeluting with the respective epimer) and 13 2 -OHpheophytin α, could be used as estimates of VOO history. The content of Pheo α and its degradation products was determined for a great number of authentic olive oil samples of unknown history. Results are discussed in comparison with other quality indices (e.g., antioxidant content) when necessary. High amounts of the pyro form (20-30% of total pheophytins) were related to thermal abuse or lengthy storage. The presence of allomers indicated oxygen availability. The levels of these products, 0-20% of the total pheophytin content for 62% of the samples, seemed to be influenced by the presence of pro-and antioxidants. When low levels of Pheo α are not accompanied by other degradation products, light exposure for a certain period of storage can be assumed.

The present work was undertaken in order to examine whether K 232 values and other UV absorbance characteristics could replace the determination of peroxide value (PV) in routine quality control and also in storage studies of virgin olive oil (VOO). For this reason, PV and extinction coefficients were determined for a large number of VOO samples (n = 40). The samples were then stored at 45 7C for several weeks. Changes in the lipid matrices were monitored by periodic measurements of the same quality indices. UV absorption spectra and the respective derivative ones were obtained before and during storage. Regression data showed that the PV is correlated with the K 232 value not only at time zero but also during storage. Evidence derived from the first derivative spectrum is strongly related to the oxidative status of the oil. The findings may be used (a) to simplify the decision tree suggested for "the verification of consistency of a VOO sample with commercial category declared" in the EEC Regulation N o 1989Regulation N o (2003, which takes into account acidity measurement, PV and absorbance values (K 270 , DK, K 232 ), and (b) to collect qualitative and quantitative information about the oxidation process during storage.

An 8.7 year-old boy with cryptorchidism and growth hormone (GH) deficiency due to septooptic dysplasia presented testicular descent related to the commencement of hGH treatment. This case suggests a role for GH in testicular descent.