Hammer Mill Sieve Design Impacts Olive Oil Minor Component Composition

Abstract

Crushing of the olive fruit is the first operation for olive oil extraction. The hammer mill is one of the most popular devices used in modern facilities due to its easy maintenance and high product output. The effect of hammer mill rotor speed and sieve design, including screen size and screen open area on extraction yield, overall quality and minor component composition, is evaluated at the laboratory scale. Quality parameters such as free fatty acids (FFA), peroxide value (PV), and UV absorbances (K232, K270, and ΔK) are unaltered by crushing parameters. Extraction efficiency, chlorophylls content, total phenol content, 3,4‐DHPEA‐EDA, and p‐HPEA‐EDA increase with faster hammer mill rotor speed and smaller screen size. Volatiles (E)‐2‐hexenal, hexanal, 1,5‐hexadiene‐(3,4)‐diethyl, 3‐ethyl‐1,5‐octadiene, and (E)‐2‐hexenol are only affected by screen size. Screen open area is found to be a relevant factor regarding extraction efficiency, chlorophylls, total, and individual phenols as well as the volatile compounds 1,5‐hexadiene (3,4)‐diethyl, 3‐ethyl‐1,5‐octadiene, hexanal, and (E)‐2‐hexenal. Practical Application: It is found that screen open area is a relevant factor regarding extraction efficiency, chlorophylls, total and individual phenols and volatile compounds, in addition to the screen size and rotor speed. This is useful information for millers who are interested in optimizing extraction efficiency as well as the minor compounds of extra virgin olive oil. Hammer mill sieve design impacts extraction efficiency, chlorophylls, total and individual phenols, and the volatile compounds during laboratory‐scale extraction of olive oil.

Demonstration of the Effectiveness of a Pilot, Variable Speed Crusher Featuring an In‐Line Oxygen Dosing System

“…Consequently, their abundance depends on the concentration and activity of the enzymes involved in the LOX pathway. [ 36 , 4 ]…”

Olive Oil from “Sikitita” under Super‐High‐Density Planting System in California: Impact of Harvest Time and Crop Season

“…Total phenols were determined by the Folin–Ciocalteu method according to a previously described protocol (Polari et al, 2018a). Individual phenols were extracted by SPE‐diol phase cartridges and quantified by HPLC as in a previous publication by our group (Polari and Wang, 2019).…”

“…Volatile compounds were extracted using solid‐phase microextraction and identified and quantified by gas chromatography‐mass spectrophotometry (GC–MS) analysis according to a previously published methodology (Polari and Wang, 2019).…”

Total Analysis of the Major Secoiridoids in Extra Virgin Olive Oil: Validation of an UHPLC-ESI-MS/MS Method

“…In addition, an increase in malaxation time will increase the time those enzymes are working, having more reaction from LIG and OLA to OLC and OLE, respectively, then increasing OLC and OLE concentration and decreasing LIG and OLA [ 30 ]. Finally, the type and diameter of sieve also affect the oil composition [ 31 ]. Thus, an accurate analysis of those compounds could shed light on how agronomical and technical factors affect the bioactive components of EVOO.…”