DE285211C - - Google Patents

Description

IMPERIAL

PATENT OFFICE

Many attempts have already been made to convert milk acidified with yoghurt bacteria into a Transferring canned goods, d. H. in hermetically sealed tin cans or similar vessels to produce in a durable form. The attempts made so far in this direction have mostly failed because the yogurt milk, if it contains the nutritionally important Bact. bulgaricum in really viable Form and sufficient quantity contains, already at room temperature in a short time, considerably acidified and therefore soon inedible will. On the other hand, it happens when you z. B. the milder 'and only a little Post-acidifying Diplostreptococcus bulgaricus through appropriate measures during vaccination the excess weight over the strongly acidic Bact. bulgaricum seeks to bestow, easily before that in the heated or sterilized milk any surviving spores of hay, Potato, butyric acid and similar putrefactive bacilli germinate and the lactic acid bacteria overgrowth: whereby a strong putrefaction with gas formation is brought about, so that the cans cambered or the bottles be blown up, in which case, of course, the contents are spoiled.

It has already been proposed that the rapid onset of strong acidification of the milk inoculated with yoghurt bacteria, in which Bact. bulgaricum at the same time or in was added in quick succession together with the other yoghurt bacteria, by avoiding the need to produce yogurt or similar products certain milk either in different parts with the separated pure cultures of the individual types of bacteria are treated and the various parts are then united, or that one the separated pure cultures in longer intermediate pauses one after the other on the allows milk to be fermented to act.

However, the processes just mentioned are not suitable for producing more correct ones Canned sour milk, which can be kept for months. In these procedures, if the milk to be used has not been sterilized at very high heat, the subsequent, The occurrence of butyric acid fermentation cannot be safely avoided. So z. B. in the patent 269598 in the penultimate paragraph of the description also only has a shelf life of "several days" spoken.

The very fact that it is extremely difficult to use harmless means d. H. by things that are not too extensive and that do not change the milk in a disadvantageous way In this regard, heating to get the milk free of germs is very important in producing a long-life canned yoghurt difficult. Even though smaller attempts are often successful in obtaining germ-free milk by heating, it is as soon as it is larger quantities of milk, no matter how clean, are involved, as a result of surviving Spores on operational reliability in the production of canned yoghurt are not to be expected.

It has now been shown that the development of yoghurt bacteria, especially the mildly souring Diplostreptococcus bulgaricus, can be accelerated considerably if the

boiled milk before inoculation with low ι gene, not to coagulate the proteins sufficient amounts of a chemically pure organic or inorganic acid, in particular Lactic acid, or citric acid, is acidified. It is true that one has similar with others Procedure already proposed, the milk before the action of certain pure cultures To add sugar and the like

ίο are intended to increase the effectiveness of the bacteria. However, it should be noted that until the sugar and the like are converted into lactic acid A few hours always pass within which the harmful butyric acid bacilli spores and similar species can germinate, especially since sugar and related substances are excellent Provide breeding ground for them. On the other hand, undesirable, too strong, i.e. H. over 100 Thörner degrees essential Further acidification is avoided if the freshly bred Bact. bulg. before after inoculation in liquid cultures briefly heated to a temperature of 60 to 70 ° C but only so long that it remains viable, i.e. still capable after heating is to coagulate milk.

In this way, the abuses described at the beginning of the manufacturing process are eliminated completely avoided from permanent yoghurt; it becomes a flawless, mildly acidic, durable product in which the spores of any surviving putrefactive germs do not develop. The procedure just indicated with acidification of the milk before inoculation with certain Pure yogurt bacteria cultures to avoid undesirable (butyric acid etc.) Fermentation also enables the production of a long-life sour milk preserve that only is prepared with Diplostreptococcus bulgaricus, as it is for some purposes z. B. off Dietary reasons may be desirable, according to the old methods without acidification was not possible with certainty.

Described in an exemplary embodiment, the method proceeds in the following manner themselves:

Heated milk that has been made aseptic as possible, thickened or not, is mixed, after cooling to about 45 to 55 ° C with stirring, with appropriately previously dissolved pure citric acid ( ¹ Z ₂ to 1 g per liter or equivalent amounts of lactic acid), then mixed with it in the known manner Pure cultures of Diplostreptococcus bulgaricus in solid or liquid form inoculated in appropriate proportions. About 1 to 2 percent of the pure liquid culture is taken. After the first inoculum has spread sufficiently, 1 percent of a liquid pure culture of the Bact. bulgaricum added, which can be increased by heating for half an hour to about 60 ° C or by heating to higher temperatures for a shorter period of time, e.g. B. 15 minutes at 65 ⁰ C, was temporarily weakened in their acidifying capacity. The pretreated and inoculated milk is then enclosed airtight in cans or other suitable vessels and ^{incubated in a known manner at 40 to 50 °} C. until it coagulates.

Although the addition of acid would be expected to increase the acidity of the finished yoghurt is reached, this is not the case, the acidity of the curdled milk is hardly or only imperceptibly increased compared to milk that has not been pre-acidified. on the other hand also shows Bact. bulgaricum due to the heating in its growth and milk coagulation capacity not in that To a certain extent weakened, as one can see from its milder acidity in the case of the one described Procedure should expect. If you vaccinate namely by the above procedure produced yoghurt milk in the usual way on sterilized or pasteurized, Unleavened milk anew, then it becomes more acidic than the former and becomes acidic much more when stored, even at room temperature. However, it is not For example, it is the case that the heated, inoculated Bulgaricus culture is not at all in the acidified Milk comes to develop, because even microscopically it can be clearly demonstrated that after the incubation there are more Bulgarian germs than immediately after the vaccination.

Claims (1)

Patent claim: Process for the production of a sour milk preserve prepared by means of yoghurt bacteria, characterized in that heated and appropriately cooled milk is mixed with such quantities of a suitable organic or inorganic acid in order to accelerate the action of the yoghurt bacteria that the milk does not completely coagulate, whereupon the milk pretreated in this way initially with a pure culture of Diplostreptococcus bulgaricus and then with a no attenuated prior to inoculation by temporarily heating at temperatures of about 60 to 70 ⁰ C in its souring 'pure culture of Bact. bulgaricum (Bact. Massol) is inoculated.