Virgin olive oil yield as affected by physicochemical talc properties and dosage

Abstract

The aim of this work was to assess the effect of physicochemical characteristics of micronized natural talc (MNT) and its dosage on the industrial oil yield (IY) during virgin olive oil (VOO) extraction of Hojiblanca fruits. For this purpose, laboratory scale experiments were performed testing four commercial MNTs differing in their particle size (D50) and carbonate rate at doses ranging from 0 to 3%. The most efficient MNT was characterized by the highest carbonate rate and the lowest particle size achieving the highest improvement of the IY for a dose of 2%. It was also found that the effect of particles size and carbonate rate depends on the MNT dose, being much more pronounced at lower doses and that the use of MNTs with low carbonate levels or high particle size could be compensated using higher doses of talc. Practical applications: This study provides deeper insights into the clarification of the effect of the addition of different doses of MNT, with different physicochemical characteristics on oil yield of Hojiblanca olive fruits. The information contained in this study should be taken into account to choose the suitable MNT dose considering its physicochemical characteristics in order to improve the oil yield for the so‐called difficult pastes. Physical and chemical characteristics of talc affect VOO yield.

Olive Oil Processing: Current Knowledge, Literature Gaps, and Future Perspectives

“…This adsorption was also shown for pectins in a model system (Aguilera et al, ; Sadkaoui et al, , ). Crucial variables affecting oil extraction yield except talc dosage are particle size and calcium carbonate rate, as suggested in laboratory experiments (Moya et al, ; Sadkaoui et al, ). Therefore, for the optimization of oil extraction yield, the talc dosage has to be adapted to its physicochemical properties (Sadkaoui et al, ).…”

“…According to the literature, the malaxation variables that have a major impact on the extraction yield and the quality of the final oil are the duration (time) and temperature of the process, the composition of the atmosphere in the malaxer (Abenoza et al, ; Aguilera et al, , ; Aiello et al, ; Amirante et al, ; Angerosa et al, ; Carrapiso et al, ; Catania et al, ; Di Giovacchino et al, ; Gomez‐Rico et al, ; Jolayemi et al, ; Kalua et al, ; Leone et al, , ; Lercker et al, ; Lukić et al, ; Malheiro et al, ; Masella et al, ; Migliorini et al, ; Parenti et al, ; Raffo et al, ; Sánchez‐Ortiz et al, ; Servili et al, , ; Stefanoudaki et al, ; Taticchi et al, ; Vezzaro et al, ), the extent of cell damage and the degree of emulsification produced in the crushing stage (Preziuso et al, ), and the properties of the paste (e.g. rheological properties), as well as the addition of lukewarm water (Carrapiso et al, ) and coadjuvants (Aguilera et al, ; Caponio et al, ; Carrapiso et al, ; Clodoveo, ; Cruz et al, ; Espinola et al, ; Moya et al, ; Sadkaoui et al, , b; Squeo et al, ; Tamborrino et al, ). Furthermore, modifications of the classical malaxers and pretreatment processes showed an effect on the olive oil properties and extraction yield (Abenoza et al, ; Almeida et al, ; Bejaoui et al, , b, ; Clodoveo, ; Clodoveo et al, , ; Clodoveo and Hachicha Hbaieb, ; Juliano et al, ; Leone et al, , ; Puértolas and Martínez De Marañón, ).…”

“…The addition of coadjuvants during malaxation is recommended to help break down oil/water emulsions and consequently make oil extraction easier and more efficient (Aguilera et al, ; Ben Brahim et al, ; Ben‐David et al, ; Canamasas and Ravetti, ; Caponio et al, , ; Carrapiso et al, ; Cruz et al, ; De Faveri et al, ; Espinola et al, , ; Majetić Germek et al, ; Moya et al, ; Pérez et al, ; Sadkaoui et al, , , b; Squeo et al, ; Tamborrino et al, ). The most common coadjuvants examined in the literature are talc, calcium carbonate, salt, and enzymes.…”

“…Talc is also an authorized food additive (E553b in Europe and GRAS‐182.2437 in US). Researchers reported that the use of talc in certain concentrations (0.3–1%) as a coadjuvant during malaxation increases the oil extraction yield (Ben‐David et al, ; Canamasas and Ravetti, ; Caponio et al, ; Carrapiso et al, ; Cruz et al, ; Espinola et al, , ; Majetić Germek et al, ; Moya et al, ; Sadkaoui et al, , ), whereas it can allow for a reduction of malaxation time (Espinola et al, ). It was proposed that the action of talc is based on the adsorption of pectins and of pectic‐protein electrostatic complexes on its surface, which act as emulsifiers in the olive paste.…”

“… Studies in small scale : Aliakbarian et al (); Ben Brahim et al (); Ben‐David et al (); Canamasas and Ravetti, ; Carrapiso et al (); Cruz et al (); De Faveri et al (); Espinola et al (, ); Majetić Germek et al (); Najafian et al (); Pérez et al (); Sadkaoui et al (); Vierhuis et al ().…”