Food or edible material: processes – compositions – and products – Direct application of electrical or wave energy to food... – Heating by electromagnetic wave
Patent
1988-07-28
1989-11-14
Yeung, George
Food or edible material: processes, compositions, and products
Direct application of electrical or wave energy to food...
Heating by electromagnetic wave
426521, 426639, A23L 316
Patent
active
048806480
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a process for manufacturing fruit preparations containing whole fruits and storable without preservatives, in which freely rolling fruits are mixed with crystalline sugar or highly concentrated sugar solution and the mixture of fruits and juice is thereafter heat sterilised.
Storable fruit preparations are required by the foods industry for different purposes. They can be offered to the consumer as pure fruit products, for example, as compote, or as additives to, for example, sweet foods, acidified milk products and more especially yoghourt.
One of the most attractive offers is yoghourt which is mixed with largely intact, lumpy fruits.
Since fruits form an ideal substrate for more especially yeasts and fungi of various types and promote the formation of resistant spores, such fruit preparations have to be sufficiently sterilised. The sterilisation was formerly effected either by the addition of preservatives and/or by heat treatment.
It is true that the preservatives, such as ascorbic acid or sorbic acid, which are used for preserving fruits or fruit mixtures are per se nutritionally and physiologically unobjectionable, but they do, however, act as antioxidants and thus destroy important substances, for example, vitamins, which are contained in the fruits. On mixing with yoghourt, the preservatives contained in the fruit preparations in part also suppress the products of metabolism of the microorganisms which are desired in the yoghourt and block their enzyme systems. The result is accordingly that they do have a preserving effect on the fruit preparation, but after mixing into the yoghourt mass, lower the physiological value thereof.
In general, therefore, fruit preparations which are provided for the preparation of fruit yoghourt have added thereto as little as possible of preservatives or made heat-stable without preservatives. In this connection, the heat preservation is effected by transfer of heat from an energy carrier with high energy content to the fruit preparation to be preserved with correspondingly lower energy level. In this connection, the preparation is heated to at least 85.degree. to 125.degree. C.; this temperature has to be reached by each particle which is contained in the preparation. If there are lumpy fruits in the preparation, then the duration of the temperature treatment necessary for preserving purposes is overproportionally increased and what happens is not only a destruction of the macrostructures and microstructures of the fruits, but also aroma losses, colour changes and transpositioning of acid and sugar, which leads to the destruction of important substances contained therein. More especially fruits with relatively soft fruit flesh, hereafter designated as "soft fruits", are almost completely destroyed under such circumstances and are transformed into a fruit pulp.
If the mechanical loading and also the height and time of effect of the temperature are lowered, it is true that the fruits can be largely kept intact, but this produces a high bacteriological risk, since more especially spores cannot be thoroughly killed off.
In order to counteract this risk, the yoghourt mass, after being mixed with the fruit preparation, is frequently once again subjected to a heat treatment. With this, however, not only the undesired microorganisms, but also the valuable yoghourt bacteria are killed off; furthermore, enzymes and vitamins are inactivated and proteins are destroyed.
It has been proposed to avoid these disadvantages by treating the prepared and packed yoghourt in a multi-frequency process (cf. separate leaflet from "Die Molkereizeitung, Welt der Milch", No. 39 (1977)). With this process, the carton trays are placed in a rotating water bath, which reaches to just below the filling height of the cartons. They are treated horizontally with radiation in the high-frequency range and vertically with radiations in the ultra-high frequency range. The necessary temperature level and treatment period is lowered considerably as compared with the conventional tempe
REFERENCES:
patent: 3658554 (1972-04-01), Hirota
patent: 4298623 (1981-11-01), Anderson et al.
patent: 4542033 (1985-09-01), Agarwala
patent: 4562085 (1985-12-01), Ruggiero
Heaton, "Effect of Pretreatment on Quality of Sweet Peach Pickles", Journal of Food Science, vol. 46 (1981), pp. 906-911.
LandOfFree
Process for manufacturing storable fruit preparations containing does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for manufacturing storable fruit preparations containing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for manufacturing storable fruit preparations containing will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1852124