Characterization of shortening
Shortening A (product name: golden shortening) was purchased from Samyang (Republic of Korea), and shortening B (product name: Combi shooting) was purchased from Ottogi (Republic of Korea). Shortening A was composed of palm oil and beef tallow. Shortening B was composed of palm olein oil, palm stearin oil, palm hydrogenated oil, tallow, and d-Tocopherol. The melting temperatures of shortenings A and B were measured on a water bath and judged visually. The solid phase shortening at room temperature was initially transferred to a glass vial using a spatula. During the transfer of the shortening to the syringe, the shortening in the glass vial was immersed in hot water (~100 °C) in a beaker for 10–20 s. Liquid shortening was transferred into a 100 μl syringe (Hamilton, 81065-1710RNR) using a pipette, and was then left to stand until solid. A syringe needle of 168 ID was connected to the syringe containing the shortening, and the syringe was vertically installed in a Fusion Touch 100 syringe pump (CHEMYX). The syringe plunger was pushed by a mechanical force from the syringe pump25 and extruded the sample at a flow rate of < 200 nl/min.
Crystal embedding in shortening
Solid shortening in glass vials was dissolved by soaking in hot water (>100 °C) for 20 seconds. The shortening solution (50 μl) was transferred to a 100 μl syringe and stored at room temperature until it reached a solid state. The crystal suspension (20 μl) was transferred to a 100 μl syringe. This syringe was vertically orientated for 10 min. When crystals settled on the bottom, the supernatant was removed using a pipette. The syringes containing the shortening and crystals were connected using a syringe coupler and mixed with the plunger gently moving back and forth more than 30 times. The mixture sample was transferred to a syringe and the emptied partner syringe with the coupler was removed. The syringe containing the crystals embedded shortening was connected with a syringe needle of 168 μm ID for SMX experiments.