Heat stability mechanism: Low-acyl gellan gum, once firmly crosslinked with divalent cations (Ca²⁺/Mg²⁺ from fruit), forms a thermally stable gel with a melting point of 120–150°C — far above standard baking temperatures. Modified waxy corn starch gelatinizes at 65–75°C, providing viscosity that prevents early boil-out during oven ramp-up before gellan's network is thermally challenged.
Synergistic network: Above gelatinization, swollen starch granules act as active fillers within the gellan gel matrix, increasing G' (elastic modulus) by 3–5× compared to gellan alone. This dual-network prevents both runny texture (hot) and syneresis (cooled post-bake).
✦ Bake-stable fruit filling: Low-acyl gellan 0.30–0.40% + Modified waxy starch (cross-linked) 6–8% + Calcium lactate 0.3% + Sucrose 35% + Fruit puree/concentrate 40–50%, pH 3.2–3.8, cook to 95°C before filling
Gloss control: Gellan's clear gel network (transmittance >90% in water) gives high surface gloss that starch alone cannot achieve. Surface stickiness is eliminated because the rigid gellan network prevents surface reflow of hot sugar melt. Test boil-out by baking pastry shells with 30g filling at 220°C/18 min: target spread <2 mm beyond original footprint.
