Pyropheophytin a in Soft Deodorized Olive Oils.

Raquel B Gómez-Coca,María Del Carmen Pérez-Camino,Mahmoud Alassi,Wenceslao Moreda

doi:10.3390/foods9080978

Raquel B Gómez-Coca, María Del Carmen Pérez-Camino + Show 2 more

Open Access

https://doi.org/10.3390/foods9080978

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Abstract

Mild refined olive oil obtained by neutralization and/or by soft deodorization at a low temperature and its blending with extra virgin olive oil (EVOO) is not allowed and is difficult to detect. Chlorophyll derivatives, pheophytins and pyropheophytin, and their relative proportions were proposed as parameters to detect such processes. The objective of this study is to determine changes in EVOO, in terms of pheophytins and pyropheophytin, occurring after several well-controlled mild refining processes. The changes on those chlorophyll pigments due to the processes depend on the temperature, stripping gas, acidity and oil nature. The data obtained show that, at temperatures below 100 °C, the rate at which pyropheophytin a is formed (Ra) is lower than the rate at which pheophytins a+a’ disappear (Ra+a’). As a consequence, the Ra+a’ and Ra ratios are considered to be directly linked to pheophytins a+a’ decrease instead of to pyropheophytin a formation. Stripping gas very slightly affects the transformation of the chlorophyll pigments; actually both acidity and N2 enhance the increment in the Ra+a’ and Ra ratios. In relation to the oil nature, the higher the initial pheophytin a+a’ content, the higher the increase in the Ra+a’ and Ra relations.

Highlights

Olive tree (Olea europaea) is one of the most expanded crops in the world. This has repercussions regarding the nutritional point of view and with respect to the economy of, mainly, Mediterranean countries. Both the International Olive Council (IOC) and the European Union consider virgin olive oil (VOO) as just the oil obtained from the fruit of the olive tree solely by mechanical or other physical processes under conditions, thermal conditions, that do not lead to alterations in the oil, and which has not undergone any treatment other than washing, decantation, centrifugation, and filtration [1,2]
Refined olive oil (ROO) is a flavorless, colorless product that cannot be sold by retail and that has to be mixed with genuine VOO
We observed that changes in chlorophyll pigments, due to soft the deodorization process, depend on the temperature, the limit of which was 100 ◦ C

Summary

Introduction

Olive tree (Olea europaea) is one of the most expanded crops in the world This has repercussions regarding the nutritional point of view and with respect to the economy of, mainly, Mediterranean countries. Both the International Olive Council (IOC) and the European Union consider virgin olive oil (VOO) as just the oil obtained from the fruit of the olive tree solely by mechanical or other physical processes under conditions, thermal conditions, that do not lead to alterations in the oil, and which has not undergone any treatment other than washing, decantation, centrifugation, and filtration [1,2]. The high market price that VOO can reach has made it target of both mislabeling and illegal blending, and much work has been done to uncover such practices, including that on the detection of the correct proportion of olive oil in legal blends with seed oils [5,6]

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