Effect of crushing temperature on virgin olive oil quality and composition

Abstract

The objective of the current study was to assess the influence of a modified crushing process and kneading operation on the quality parameters, volatile compounds, and the fatty acid and sterol profiles of virgin olive oil from the Edremit yaglik variety. In the study, olive oil samples were produced in two different processes. The first one was produced without malaxation and the second one was produced with the malaxing process. During crushing, the effect of different temperatures was tested. The results demonstrate that different crushing temperatures generally did not affect the amount of free fatty acids, or peroxide value. Total phenol contents were positively affected by the additional malaxation process. Fatty acids and sterol composition were not significantly altered at different crushing temperatures or during the subsequent malaxation application. PCA enabled a clear classification of the oils obtained from different processing techniques.

Effect of olive oil production steps on the physicochemical properties and phenolic compounds of olive oil

“…This reduction originated from the activation of polyphenoloxidase and peroxidase enzymes which oxidised phenolic components (Yorulmaz et al, 2012). Contrary to present study, Kula et al (2018) reported that total phenolic contents of olive oils increased from 150.70 mg kg -1 to 250.60 mg kg -1 with malaxation process at 30°C. Total phenolic content of olive oil belonged to Ayvalık variety was 191.23 mg kg -1 when olive paste was malaxation for 20 min (Yorulmaz et al, 2017).…”

“…In another study, crushing methods such as metallic crusher+stones, metallic crusher and stone mill did not significantly affect the free fatty acid (0.14-0.17% for Ogliarola di Bitonto+Leccino varieties; 0.16-0.17% for Peranzana+Leccino varieties), and peroxide (5.9-6.2 meq O2 kg -1 for Ogliarola di Bitonto+Leccino varieties; 4.9-5.7 meq O2 kg -1 for Peranzana+Leccino varieties) values of olive oils (Preziuso et al, 2010). Kula et al (2018) observed that free fatty acid and peroxide values of olive oil extracted from crushed paste were established as 0.71% and 5.30 meq O2 kg -1 oil while these values were determined as 0.70% and 6.42 meq O2 kg -1 oil for olive oil obtained from crushed+malaxed paste, respectively. As indicated by Caponio et al (2014), free fatty acid and peroxide values of olive oils were determined as 0.28% and 2.65 meq O2 kg -1 , respectively.…”

“…informed that the oleic acid content (75.85%) of Gemlik olive oil was higher than the oil of Ayvalık variety (68.95%), while the highest and lowest palmitic acid contents were found as 14.51% in Ayvalık olive oil and 11.42% in Gemlik olive oil, respectively. Kula et al (2018) observed an increase in the linoleic acid content (from 9.9% to 16.4%) and a decrease in the palmitic and oleic acid amounts (from 12.6% to 11.2% and from 72.7% to 67.9%, respectively) of olive oil when the malaxation process applied at 30°C. After malaxation process for 20 min, the oleic, linoleic and palmitic acid contents of olive oil were determined as 70.35%, 11.98% and 13.64%, respectively (Yorulmaz et al, 2017).…”

Hammer Mill Sieve Design Impacts Olive Oil Minor Component Composition

“…Given the relevance of phenolic and volatile compounds for both sensory and nutritional value of olive oil, the impact of processing parameters on their profile and concentration is of upmost interest to control product composition. Literature is rich in studies about crushing, [5][6][7][8] malaxation, [9][10][11][12] and centrifugation, [13][14][15] the three main unit operations in olive oil processing. Nevertheless, the impact of crushing parameters on the extraction efficiency and minor compounds is still not well understood.…”

Geographical Characterization of Olive Oils from the North Aegean Region Based on the Analysis of Biophenols with UHPLC-QTOF-MS

“…Biophenols can be influenced by many parameters, for instance, olive variety [ 16 , 17 , 18 ], agronomic factors [ 19 , 20 ], cultivation practices [ 21 ], as well as olive oil processing such as malaxation conditions and type of extraction system [ 5 , 22 , 23 ]. The phenolic profile and concentration levels of individual biophenols are strongly related to the geographical location where the Olea europaea trees are cultivated [ 7 , 24 , 25 , 26 , 27 ].…”