Gelatin dessert
Jelly ( borrowed from the French gelée and going back to the Latin gelare for " freeze " or " bring to solidify ," even jelly ) called or Sulz, is a gelatinous solidified meat or fruit juice.
Meat jelly ( aspic ), for example for aspic used to outshine and binding sauce, fruit jelly for jams and desserts. Chemically, it is gels.
Production
For jellies for savory dishes of meat broth are traditionally added and boiled calf's feet, with fish bones meet in the fish stock the same purpose. A slow- cooked and sufficiently concentrated chicken broth gelled without any additional aids. In order to obtain a clear jelly, the broth must be degreased.
In these processes, the gelatin contained in the bone is responsible for the gelling.
Sweet jelly like jam are formed by the pectin contained in fruits. These are the fruits with sugar and, if they are not acidic enough, cooked gently with acid ( lemon). Pektinarme fruits (for example, blackberries) must be mixed with pectin (e.g. apples ).
Gellant
Industrial gelatin is made from offal and available in pure form as a leaf or powdered gelatin. It is tasteless and can therefore both sweet and savory dishes can be added. Often you still be added to starch and food dyes, and other inert components, such as for glaze. Is well known that even sugar and starch (potato starch, wheat starch, corn starch, etc.) a stiffening glue effect. Commercial jellies contain further often, besides sugar and glucose and fructose syrup, citric acid, as well as a gelling aid.
Gelling is enriched with pectin and makes it possible to process pektinarme fruits without further additions to jams and jellies. In addition, there is also a pure pectin, e.g. in liquid form, one can add to the food.
For several years, the original Japanese, derived from seaweed agar is used as a strong, tasteless gelling agent in Europe in the food industry and as a vegan (and vegetarian ) alternative to gelatin. This also applies to carrageenan.
Surcharge aids
Basically, all dishes can be so similar to whipped cream whipped with sufficient gelling. This is due to the contained proteins that make this possible. Of course, this is in the solidified state, in which the chemical process is completed, no longer possible. This fact, and many of the resulting possibilities were known to molecular gastronomy almost only food chemists.
Food Chemistry
The special thing about jellies is the extremely high ability of gel-forming substances to capture water in macromolecules and thus to " solidify " when the mixture of water and gelling cools. With a sheet of gelatin ( approximately two grams ) can bind multiple deciliter water. This process is reversible if the jelly is heated. The gelling agents used in the kitchen, this temperature is about 30 ° C, so the jelly melts in your mouth, giving the flavoring substances contained free.
Gelatin, the primary gelling agent in cooking, is obtained from the collagen of the muscle and bones of animals. Here, the collagen molecules, fibrils forming the tough (connective tissue ), cleaved and dissolved by cooking, acid or bases. Slow cooling of the solution, the collagen molecules combine to long, tangled chains that bind large amounts of water molecules per se - the jelly solidifies. Due to rapid cooling or movement of the process can be disrupted and the jelly remains more or less liquid.
Pectin is the basis of fruit jellies. It is found in many fruits, especially apples, included. In order to solve it from the cell walls, pectin-rich fruits are cooked with sugar. The sugar removes water from the cells, their walls destroyed and the pectin can be released more easily. Is there enough sugar in the solution, binds the released water to the sugar - the pectin molecules can only react with each other and not with the water. That, they combine on cooling to form a framework in which the water is " locked up " is, however, they must be present in sufficiently high concentration, and the solution must be acidic, since the pectin molecules otherwise repel each other ( by ionization ). The ideal pH is 3.3.
Food legislation jellies are from aqueous extracts of fruit or fruit juice thickened jelly as simple (fruit juice content of at least 35 %) or jelly called extra ( fruit juice content of at least 45 %).
Beyond the culinary arts gelling agent such as gelatine and others are versatile and are increasingly used because of their ability to store large amounts of water or aqueous solutions, and because of their adherence - bone glue on photo emulsion to diapers. In this technical contexts is called gel instead of jelly.
Other occurrences
The eggs of a frog made of jelly. Within this jelly -like layer is the resulting tadpole.