Glazing gels are being used in bakeries to give shine and protection (from drying and discolouring) to fruit on open fruit pies, to cakes with a 'bavarois' top layer, and to baked goods like croissants. In most cases, they are applied by spraying (typically at 85°C) with a spray gun (e.g. Bakon Food Equipment) from a bag-in-box packaging or containers (up to 1000kg), but it is possible to apply them simply by brushing. The gel should than set immediately after depositing. However, over-heating by keeping the gel at high temperatures for too long times, or under-heating, can result in under-performing. But also for convenience reasons, as well as to protect the fruit from heat damage, bakers would appreciate a cold-prepared glazing gel. This can be achieved by mixing two phases (e.g. a Ca-source and an alginate or pectin), but that usually results in too fast gel formation leaving no time to apply it on the cake. Other options: a viscous liquid, or a liquid with a yield stress, but liquids do not have a 'dry touch', and stick to the plastic foil used to separate different cakes in a box. Applying a liquid that forms a gel with calcium from the fruit1 is yet another option, but the diffusion of Ca usually is too slow to prevent run-off before gel setting. The best option so far is to use a gel with thixotropic, pseudoplastic or shear-thinning properties. This paper compares weak gels with two gelling agents: low-methoxyl amidated pectin Genupectin LM104AS from CPKelco (Degree of Esterification=26, Degree of Amidation=22, no Ca added to the gel) and Na-alginate (high M type, Grindsted FD155 from DuPont Danisco). Screening of weak gels of a wide variety of gelling agents learned that these two gelling agents performed best (easy to 'liquefy' without leaving gel lumps by stirring with a wire whisk or spoon, and formation of a 'dry-touch' gel within an hour).
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