Francisca Gutiérrez

Quality of oils from olives stored under controlled atmosphere

Olive (Olea europaea cv. “Picual”) fruits were stored under five different storage conditions (°C/%CO2/%O2; ambient; 5:0:21; 5:3:20; 5:3:5; and 5:<1:5) to determine their influence on the chemical and sensorial quality of oil extracted from the olives at the end of the storage period. Results showed that storage of fruits at 5°C prevented the fast alteration that is produced in oils extracted from fruits stored at ambient temperatures. The use of controlled atmosphere at 5°C with 3% CO2 and/or 5% O2 did not present clear advantages on acidity, peroxide value, K270 and K232 coefficients, stability and sensorial quality. Cooling of fruit keeps physical, chemical and sensorial characteristics of oil below maximum established values for the period of time assayed (60 d).

Contribution of olive seed to the phenolic profile and related quality parameters of virgin olive oil

BACKGROUND Conflicting results have been reported about the effect of fruit de-stoning on the virgin olive oil (VOO) phenolic profile. The aim of the present study was to determine whether olive seed plays any role in the synthesis of this oil phenolic fraction. RESULTS Increases of around 25% of total phenolic compounds were observed in oils obtained from de-stoned olive fruits in three main Spanish cultivars. To investigate the involvement of olive seed in determining the phenolic profile of VOO, whole intact olive fruits were added with up to 400% olive stones. Excellent regression coefficients were found in general for the decrease of total phenolic compounds and, particularly, of o-diphenolics in the resulting oils. On the other hand, it was found that olive seed contains a high level of peroxidase (POX) activity (72.4 U g(-1) FW), accounting for more than 98% of total POX activity in the whole fruit. This activity is able to modify VOO phenolics in vitro, similar to the effect of adding stones during VOO extraction. CONCLUSION Olive seed plays an important role in determining VOO phenolic profile during the process to obtain an oil that seems to be associated with a high level of POX activity. Copyright