Lab, (also Laab, calf lab, cheese stomach), is a mixture from enzymes (Chymosin and Pepsin) and for the thick putting of the milk with the production of cheese is used. To become sour lab will won from the lab stomach of young at the milk-drinking age and has the characteristic to split the milk protein Kasein in such a way that the milk thickens, without, therefore with lab produced cheese is marked also as sweet milk cheese. The lab was already in the antiquity well-known, and Aristoteles praises the lab of young deer or deer as particularly effective.

Characteristics

The enzyme contained in the lab brings already in small dose very large quantities (1: 6000-600.000 parts) of milk for coagulating. It expresses the strongest effect with 41-42 "°C, loses its Kraft at higher temperature against it very fast. Weakly sour reaction favours the lab effect, alkaline against it and certain salts waives it. The effect of the lab leading to coagulating is to be due to the splitting off of a part (Glycomakropeptid) the Kaseinmizelle (more exact the by Chymosin. Thus the Mizellen loses its "sleeve" and it takes place an aggregation of the Mizellen, which finally leads to the Gelbildung. The gel essentially consists after its training of a firm phase, the protein network, as well as the sweet whey included in it. The lab enzyme works thereby only as catalyst, with the gap reaction is thus not used. Therefore already very small quantities are sufficient for the thick putting of the milk. A larger quantity of lab and increased temperatures increase the reaction rate and change so the structure of the forming gel. The reaction comes to some time to succumbing, since the substrate is used (enzyme reaction). To be broken off the reaction can do only by inactivating the enzyme, e.g. by heat, acid, caustic solution etc. this is however with cheese production not necessary and besides to considerable changes of the cheese developing from it would lead. After cutting the gel in cubes a part of the sweet whey withdraws from the gel network during the Over the temperature, size of the break cube/break grains as well as the duration of the the dry weight of the developing cheese can be steered. With low temperature and large break grains one obtains soft cheese, with high temperature and small break grains hard cheese.

In practice the lab is usually used during the cheese preparing in temperatures between 25 and 40 "°C.

Production of animal lab

Animal lab is won from the internal skin of the fourth stomach (lab stomach) younger, still milk of sucking In addition, usually lab of calves use finds, it can from sheep, goats and other animals come.

For preparing a lab liquid of large strength and durability one cuts dried, at least three months old stomachs of suction calves, from which one separated the foldless part, into small pieces and leaves 100 parts untouched of the same with 1 litre water, 50 g common salt and 40 g boric acid at usual temperature under frequent five days, adds then further 50 g common salt and filters. From good lab liquid 1 part must bring at least 6000 parts to fresh whole milk with 35 "°C in 40 minutes to coagulating.

Also lab powder, which 3000-300,000 parts milk is to coagulate, comes into the trade.

A Labessenz suitable for the whey preparing (Liquor seriparus) one receives by three-day-long Mazerieren from 3 parts to freshly scraped off mucous membrane of the lab stomach with 26 parts far (very weakly sour, 8-9 per cent alcohol containing) wine and 1 part common salt. A fully the filtrate, warmed up to 35-40 "°C, brings 0.5 litres to milk to coagulating.

Substitutes

Since the calf lab can be won only by slaughtered young animals, in such a way manufactured cheese is not vegetarian. The Jewish food laws do not regard cheese with animal lab were manufactured as more koscher, since it comes to a mixture of milk and meat.

Therefore there are the following substitutes:

• vegetable: Seem to the lab enzyme very similarly working enzymes particularly in the lab herbs, which gave also the name to this kind. Further occurrences in the Pflanzenreich are: Juice of the fruits of the melon tree, milk of the fig tree, seed of Punceria (Withania coagulans), blooms of the artichoke and the Eberwurz (Carlina corymbosa). As Gerinnungsmittel with the production of Panir lemon juice can be used.

• mikrobiell: Today Chymosin can be produced also on mikrobiellem way in fermenters, become as lab substitutes among other things mold fungi (lat. Mucor) used (Mucor mihei, Mucor pusillus Lindt or Endothia parasitica). Due to the different amino acids the production process for the cheese must be adapted. As Gerinnungsmittel with the production of Panir yogurt can be used.

• genetically: An alternative is rekombinante Chymosin in such a way specified, which is formed by genetically changed micro organisms and whose amino acid sequences are to a large extent to those from calf lab identical.

Related links

• Chemistry of the Kaseinspaltung
• History of the lab
• Milk production and

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