Adding talc particles improves physical properties of palm oil‐based shortening

Abstract

This paper reports the effects of adding talc particles on the physical properties of palm oil (PO)‐based shortening formed by working refined PO (RPO) after rapid cooling. We examined the thermal and viscoelastic behavior of RPO in bulk fat systems, and the polymorphism and hardness of the shortening in the presence and absence of talc particles. In addition, the microstructure of fat crystals formed was observed. The effects of talc addition are summarized as follows: (i) When RPO was cooled at a rate of 5°C/min, crystallization of the high‐melting fraction, including tripalmitoylglycerol (PPP) and 1,3‐dipalmitoyl‐2‐oleoyl glycerol (POP), was preferentially promoted to form small‐sized microcrystals. During cooling, the increase in the viscoelasticity of RPO was suppressed at low temperatures. (ii) When the shortening was stored at 5°C, β′‐crystallization of 1‐palmitoyl‐2,3‐dioleoyl glycerol (POO) and β‐crystallization, probably of a molecular compound (MC) of POP and 1,2‐dipalmitoyl‐3‐oleoyl glycerol (PPO), were delayed compared to β′‐crystallization of PPP and POP. During storage, the homogeneity of the fat crystal dispersion improved and the hardness of the shortening decreased. These results indicate that talc improved the physical properties of the PO‐based shortening by changing the crystallization kinetics and the networking processes of the fat crystals. Practical applications: The present study showed that adding talc particles effectively improved the physical properties of palm oil (PO)‐based shortening during storage. This is considered beneficial for resolving problems in the quality control of PO‐based products, such as post‐hardening and the formation of granular crystals due to low rates of crystallization. Storage modulus (G′) of refined palm oil (RPO) with and without talc particles in bulk fat systems, obtained from dynamic viscoelasticity measurements during cooling at a rate of 5°C/min. Adding talc particles drastically changed the three‐stage increases in G′ of pure RPO, promoting the first‐stage increase but suppressing subsequent increases at low temperatures.

Tripalmitin‐Driven Crystallization of Palm Oil: The Role of Shear and Dispersed Particles

“…The second (i.e., T m = 32.0 AE 1.7 C) and third (i.e., T m = 36.9 AE 1.5 C) endotherms remained convoluted, regardless of dispersion or shear speed. The literature has suggested that β' crystals of POP, PPO, and PPP appear within this range, however, it should be noted that these studies cooled their systems to temperatures far below 20 C (Bayés-García et al, 2015;Minato et al, 1997;Yoshikawa et al, 2016). Finally, the fourth endotherm (i.e., T m = 43.2 AE 0.7 C) appeared to be most separated from the other endotherms and was completely removed from the thermal profile as both dispersion concentration and shear speed increased.…”

“…Finally, the fourth endotherm (i.e., T m = 43.2 AE 0.7 C) appeared to be most separated from the other endotherms and was completely removed from the thermal profile as both dispersion concentration and shear speed increased. This peak has been most commonly associated with β crystals (Braipson-Danthine and Gibon, 2007;Che Man et al, 1999) and, more specifically, PPP β crystals (Yoshikawa et al, 2016).…”

“…Since pure POO, POP, and PPO remained liquid at 20 C, it was presumed that a binary mixture resulting from any of these TAG would remain liquid as well when cooled to 20 C, despite their tendency to form either eutectic mixtures or MC at lower temperatures (Bayés-García et al, 2015;Yoshikawa et al, 2016). Because of this, our attention first shifted toward creating binary mixtures between each of these TAG with PPP explicitly.…”

“…From an industrial perspective, formulations that include dispersed particles such as sugar crystals or milk powder may also significantly affect PO crystallization and polymorphic behavior. For example, Yoshikawa et al (2016) reported in detail the impact of talc particles on the thermal and rheological properties of PO bulk fat and shortening. Specifically, they observed that addition of talc enhanced lower-melting crystals while reducing the amount of higher-melting crystals present.…”

Crystallization kinetics of safflower and olive oils during low-temperature storage

“…The crystallization behavior of oils with high melting points, such as palm oil and cacao butter, has been investigated as well as the effect of adding other oils and fats or talc (de Oliveira et al, 2015;Quast et al, 2013;Yoshikawa et al, 2016). The crystallization behavior of vegetable oils with low melting points, sunflower (Calligaris et al, 2008) and olive oils (Barba et al, 2013;Bayés-García et al, 2017), has also been investigated.…”