Virgin Olive Oil Processing Technology - Influence

Virgin Olive Oil Processing Technology - Influence of Malaxation
Temperature and Time on Yield and Overall Oil Quality.
Inarejos-García A.M., Gómez-Rico A., Salvador M.D.
and Fregapane G.
Departamento de Química Analítica y Tecnología de los Alimentos,
Universidad de Castilla - La Mancha, Ciudad Real, España.
The production of a high quality product requires good manufacture practices
throughout the process. The aim of this study was therefore to improve the knowledge
on the technological variables involved in the kneading operation that affect the overall
quality of the Cornicabra virgin olive oil, a product that possesses great economic
importance in our region. In fact, malaxation is much more than a simple physical
separation, since a complex bioprocess take place, which is relevant to the final product
quality.
A continuous experimental virgin olive oil mill plant (Pieralisi, Fattoria), working at 200
kg/h olive paste, and equipped with an olive washing machine, a hammer crusher, a
single-stage kneader, a two-phase horizontal decanter and a vertical centrifuge was
employed. The olive paste was kneaded at different temperatures (20-40ºC) and times
(30-90 min) both in the described pilot plant and in a laboratory scale equipment
(Abencor).
In order to study the influence of malaxation, oil yield mass balance data, quality
indexes (e.g. free acid content, peroxide index, K232, K270, bitter index), antioxidants
and nutritional relevant minor compounds (e.g. individual phenolic compounds, αtocopherol, β-carotene), oxidative stability and antiradical capacity (Rancimat, DPPH)
were analysed and the experimental data discussed.