Micronized natural talc with a low particle size and a high carbonate rate is more effective at breaking down oil‐in‐water emulsion

Abstract

Micronized natural talc (MNT) has demonstrated to be very useful to break down emulsions formed during the virgin olive oil extraction process, improving the oil yield. This study was aimed to obtain more insights into the mechanisms of MNT to break down oil‐in‐water emulsions. For this purpose, laboratory scale experiments were performed in order to evaluate the effect of different pectin concentrations (0.5, 1, 1.5, and 2%), used as an emulsifier agent, on the behavior of an oil‐in‐water interface. Afterward, to evaluate the effect of MNT dosage as well as its physicochemical characteristics on breaking o‐reducing emulsions, four MNTs differing in their particle size (D50) and carbonate rate were assayed at doses ranging from 0 to 1%. Increasing pectin concentration gave a rise in the emulsifying activity (EA). The emulsifier effect of pectins was weakened by the addition of increasing MNT dose. MNT physicochemical characteristics markedly affected the breaking of oil‐in‐water emulsions. Nonetheless, its effect depends on the dose of MNT applied to the emulsion. The highest decrease in EA was observed for MNT with the lowest D50 (2.4 μm) and the highest carbonate rate (4%) at 0.5%. In general, MNT containing lower D50 and high rate of carbonate showed better capacity for breaking oil‐in‐water emulsion. Practical applications: So far as can be ascertained, no quantitative study has been made, in vitro, on the relative merits of MNT addition as a technological aid in breaking down oil‐in‐water emulsions. This study provides deeper insights into the clarification of the effect of pectins as emulsifier agents, on aqueous emulsions of Hojiblanca virgin olive oil and how the addition of different doses of MNT, with different physicochemical characteristics, carried out the breaking of the oil‐in‐water emulsions. Effect of micronized natural talc physicochemical characteristics and dosage on the break‐down of oil‐in‐water emulsion.

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

“…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. 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, ).…”

“…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 pilot/industrial scale : Aguilera et al (, ); Caponio et al (); Caponio et al (); García et al (); Moya et al (); Ranalli and De Mattia (); Ranalli et al (, , b, , b, c, ); Sadkaoui et al (, ); Sharma et al (); Squeo et al (); Tamborrino et al ().…”

Has the use of talc an effect on yield and extra virgin olive oil quality?

“…Sadkaoui et al studied the effect of the physicochemical properties of MNT on the emulsifying activity of pectins in an oil‐in‐water system (pectins may be considered mainly responsible for oil emulsification during the processing of difficult olive pastes) and showed that both the dosage and type of MNT significantly affected the breakdown of oil‐in‐water emulsions. The authors highlighted that the MNT dose was the main factor explaining the variability of the emulsifying activity values.…”