Fig 1.
A Schematic illustration of the components in hagfish slime. Hagfish exudate is expelled from ventro-lateral pores. Upon contact with water, the thread skeins unravel to long fibers and the vesicles swell, rupture, and mucin strands are formed. The fibers and the mucin together form the slime. B Soy protein isolate suspension. C Soy milk.
Fig 2.
Frequency sweeps (left) and amplitude sweeps (right) of hagfish slime in milliQ, in a 4% w/v soy protein isolate (SPI) suspension (SPI slime), and in commercial soy milk (soy slime).
Fig 3.
A CC27 couette geometry with hagfish slime that was mixed into a 4% w/v soy protein isolate (SPI) suspension. B Light microscopy images of soy milk, soy milk with 10 mg/ml porcine gastric mucin (PGM), and soy milk with hagfish mucin (≈ 0.026 mg/ml), showing distinct flocculation.
Fig 4.
A Amplitude sweep and B flow curve of hagfish mucin (≈ 0.026 mg/ml) in soy milk and in milliQ. Soy milk + 1% v/v buffer solution and mucin in milliQ are given as a reference. The arrows in B indicate the direction of the shear ramp, i.e. from low to high shear rates and vice versa.
Fig 5.
A Liquid retention measurements of hagfish slime formed with water and with soy milk. Pictures of the corresponding liquid retention measurements of B hagfish slime in milliQ and C hagfish slime in soy milk over time (concentration of exudate in milliQ = 4.25 mg/ml, concentration of exudate in soy milk = 1.88 mg/ml).
Fig 6.
A Frequency sweeps and B amplitude sweeps depicting G’ of hagfish exudate mixed into a dilution series of soy milk, showing the effect of a decreasing soy concentration on the rheological properties of soy slime.
Fig 7.
Schematic comparison of a salt induced flocculation of soy milk used in traditional tofu manufacture to the hagfish mucin induced flocculation.
Fig 8.
A Time temperature sweep as a tofu cooking simulation of soy milk, slime in soy milk and slime in soy milk + 10 mM CaCl2. B Amplitude sweeps of soy slime + 10 mM CaCl2 after the time temperature measurement (blue), uncooked soy slime (black) and hagfish slime in milliQ (grey). The overlaid dotted lines denote G’ of the corresponding measurements for soy protein isolate (SPI) suspensions. C Light microscopy image of a cooked 4% w/v soy protein isolate (SPI) suspension + 10 mM CaCl2 gelled with hagfish exudate (after the time-temperature sweep). The arrowhead depicts a structuring hagfish slime fiber embedded in the gelled soy matrix.