The effect of malaxation temperature on the virgin olive oil phenolic profile under laboratory‐scale conditions

Abstract

The relationship between olive paste malaxation temperature and the concentration of olive oil hydrophilic phenols (HP), i.e. simple phenols, secoiridoids and lignans, was investigated. Malaxation experiments were performed at laboratory scale for 45 min at 21, 24, 27, 30, 33 and 36 7C. A significant (p ,0.05) increment of total phenols concentration was found with a maximum at 27 7C, whereas for higher temperatures (30-36 7C) a progressive decrement was observed. A similar pattern was recorded approximately for all the secoiridoid compounds, i.e. a quasi-linear increment of concentrations with increasing temperature until 30 7C, followed by a marked decrease in correspondence with the higher malaxation temperature (33 and 36 7C). The amount of simple phenols increased linearly with increasing temperature and no decrements were observed up to the maximal temperature investigated (36 7C), while no significant differences were found for lignans. A small increment of peroxide values and total chlorophyll was recorded as a function of the increasing malaxation temperature, whereas no differences were observed in the free acidity. The results highlight that there is not a univocal relationship between HP concentration and malaxation temperature. An equilibrium between degradation (chemical and biochemical oxidation and hydrolysis) and transfer (partitioning) phenomena was hypothesized.

Rosemary Aromatization of Extra Virgin Olive Oil and Process Optimization Including Antioxidant Potential and Yield

“…Kalua et al (2006) and Kalua et al (2007) reported compatible results in their two different studies where no significant change in phenolic content of olive oil sample was observed with changing temperature and time of malaxation step. Moreover adverse effect of temperature on total phenolic content was also reported by Parenti et al (2008) in which temperature higher than 27°C adversely affected the transition of phenolics to olive oil.…”

Antimicrobial activity of amurca (olive oil lees) extract against selected foodborne pathogens

“…It is likely that the lower temperature delayed the hydrolytic and oxidative degradation of phenolic compounds in the amurca extract. It has been reported that the total phenolic content of olive oil was increased in cold pressed olives (Parenti et al, 2008). Also, oil that was obtained from olives stored at 5 to 10 °C experienced lower hydrolytic, oxidative degradation and off-odour development (Clodoveo et al, 2007;Inarejos-García et al, 2010).…”

Influence of olive paste preparation conditions on virgin olive oil triterpenic compounds at laboratory-scale

“…All of these operations can affect the quality, chemical composition and sensory characteristics of the final product, and therefore optimisation of these extraction steps is necessary (Kiritsakis, 1998). The malaxing process has been widely investigated and several works have reported the effect of the malaxation variables: temperature (Parenti, Spugnoli, Masella, & Calamai, 2008;Ranalli, Contento, Schiavone, & Simone, 2001), time (Di Giovacchino, Costantini, Ferrante, & Serraiocco, 2002;Ranalli, Pollastri, Contento, Iannucci, & Lucera, 2003) and even both (Gó mez-Rico, Inarejos-Garci´a, Salvador, & Fregapane, 2009;Jimé-nez, Hermoso, & Uceda, 1995;Kalua, Bedgoog, Bishop, & Prenzler, 2006) on the composition and quality of virgin olive oil. The influence of the separation process has also been largely described (Salvador, Aranda, Gómez-Alonso, & Fregapane, 2003;Torres & Maestri, 2006).…”

“…Moreover, to our knowledge, there is little data on the effect of the crushing level although its regulation is essential for obtaining good process yields (Uceda, Jiménez, & Beltrán, 2006) and may have significant influence on the transfer of components to the oil . On the other hand, most of the olive oil processing studies are mainly focussing on volatile and phenolic compounds (Gó mez-Rico et al, 2009;Kalua et al, 2006;Parenti et al, 2008), hence neglecting other minor compounds like pigments, sterols, squalene, and triterpenes amongst others.…”