Packed food product concentrate and method for preparing thereof Field of the invention

The present invention relates to a method for preparing a packed food product concentrate from vegetable or vegetable and animal based material, which food product has been prepared by cooking in a package in counterpressure, and a food product concentrate produced by the method.

Prior art

Nowadays people are eating more frequently outside their home. The main meal of the day is generally consumed at school, institution, working place or a lunch restaurant nearby. The significance of lunch meals has created a new field of business, the nationwide food service chains. By efficiency, versatility, nutritional and good food they aspire to take care of the nourishment of their clients at a reasonable price.

Things affecting the budget of the meal are, in addition to the work of preparing thereof, also the price of the raw materials used and the waste of raw materials and ready food. In most cases the food is prepared from fresh and/or raw material by cooking all by themselves, or at the most by boiling down from prefabricated components.

When using non-prefabricated raw materials, for example vegetable material, the availability causes great uncertainty about the sufficiency of the raw materials, especially during spring time. As it is not possible to estimate accurately the preparation waste and the amount of the eaters beforehand, the amount of raw materials provided should be adequate, generally excessive. To make sure that there is enough food, it is often prepared in excessive amounts just in case and the aver- age costs of the waste are added in advance to the price of the meals.

Generally the amount of summer events is constantly increasing: almost every village or municipality have their own events. Behind the meetings are generally things which are considered common, such as traditions, music, spirituality etc. In the events there can be thousands or even tens of thousands of people gathered together. The food service of the events is often carried out as voluntary work in ad hoc kitchens outdoors. To prepare and serve thousands of servings during a short period of time (for example lunch time) by non-professionals requires speed, easiness and safety from the preparability of the food. This can be seen in the

menu: there are mainly soups and porridges available because large amounts of them can be quickly prepared in big pots.

In the mass events the soups are generally prepared from separate fresh, prepared and frozen food components and beforehand weighed out spices. The com- ponents are portioned out to cauldrons and pots into water/liquid, the ingredients are added in the order defined by the cooking time and cooked. The preparation of food consisting of several components requires accuracy when measuring and portioning out the ingredients. In mass eating events care and accuracy are required repeatedly because the food must be quickly prepared, served and the pot put for new use.

To carry out the food service in exceptional circumstances great care is required also in the handling of the food products. The hygiene risks must be minimized as far as possible. When using many components of different type in the preparation of food the possibility of a mistake increases. Different types of food products re- quire proper storage for all food product groups. There must be cold, cool and frozen storages available.

When preparing large amounts of food in large pots the cooking time must be chosen by the ingredient requiring the longest time. Then parts of the compounds are overcooked and will be disintegrated by a small mechanical stress. The composi- tion of soups will become unpleasant. Especially susceptible to disintegration are for example potatoes, vegetables and fish.

Porridges are prepared either by cooking from scratch or by heating precooked and packed fully ready porridge.

As an alternative to self made soups and porridges ready soups and porridges are nowadays available. They will either be emptied to the cooking pot and heated, or the packages are dunked in hot water bath and emptied after the heating into serving utensil. The ready soups and porridges are prepared as ready meals surviving for few days or as pasteurized 4-5 week products. The food contains also all the liquid, they are fully cooked to ready products and cooled after that. In the soups the amount of added water is approximately 40% of the amount of the ready soup. In porridges the amount of liquid is up to 85%, for example in rice pudding. Because of the energy required to heat and cool the liquid contained in said foods the ready soups and porridges are not able to compete in price with foods prepared on the spot as the energy costs for the liquids will be doubled.

One example of prior art methods is disclosed in US 3 607 312 which describes a method of preparing and preserving ready-to-eat food comprising vacuum packaging the food in a gas tight pouch, cooking the food in the pouch by immersing in hot water, rapidly chilling the food to about 30 ⁰ F but not freezing, storing at 3O ⁰ F until needed for consumption, and heating in hot water to serving temperature. When serving temperature is reached, the packages are opened, and the food placed on plates and served.

Brief description of the invention

The present invention provides a method for preparing a packed food product from vegetable or vegetable and animal based material cooked in the package, wherein to obtain a food product concentrate the material is cooked in a package under pressure and no liquid is added to it before or during the cooking.

The present invention also relates to a packed food product concentrate containing vegetable or vegetable and animal based material cooked in the package, which is obtained by cooking the material in a package under pressure and no liquid has been added to it before or during the cooking.

The advantage of the invention is that the preparation of food products, such as for example soups and porridges, is faster. The concentrates according to the invention are cooked and it is enough that liquid is added and they will be heated to suit- able temperature, such as >80°C, before serving. The preparation may be quickened by using preheated liquid.

Further another advantage of the invention is that the composition and taste of for example soups is better. By using the method of the invention several components, such as potatoes, meat and fish will become well cohesive in their structure and they tolerate long cooking, keeping hot and mixing.

Further another advantage of the invention is that hygienic safety will be increased. In exceptional circumstances, for example outdoors, only one package needs to be handled containing all the other components except the liquid. Because of long shelf-life (generally 4-12 months) the products can be proved to be microbiologically clean in advance. Possibilities of errors in wrong storage temperature decreases and cold storages are needed for only one type of food matter.

Further another advantage of the invention is that the waste decreases as everything in the package can be exploited. Because of the quickness the food can be

prepared with a small delay according to the real consumption without having food in large amounts in reserve.

Detailed description of the invention

In the method of the present invention all or almost all the raw material, such as dry and solid matter of the ready food, such as soup or casserole, porridge, gruel or gratin, are mixed evenly together, weighed or otherwise portioned out into portions, packed, for example in vacuum or airlessly, and cooked after that in their package to obtain the food product concentrate of the invention. In one embodiment of the invention the raw materials are cooked in counterpressure in a pres- sure vessel, such as in counterpressure autoclave. The mixture may contain all or at least the basic raw materials except the liquid to prepare said food. Methods for preserving only one type of raw material, for example only potatoes or the like, are excluded from the present invention because the aim of the invention is to provide a ready meal which is easily preparable into edible form and contains most of the ingredients of the meal except the added liquid.

A counterpressure autoclave is generally used for preparing food products, inter alia for cooking or sterilizing a separate vegetable material or ready foods for sale on the consumer market. With the counterpressure the temperature of the product may be raised high enough to achieve adequate degree of sterilization. On the other hand, on the catering market ready foods prepared by said method are available only by special order. To heat and cool large amounts of liquid increases the price of soups and because of inadequate price competition they have not become common on the market.

For autoclave cooking the food products are generally packed into tin cans or glass jars or vacumized deep-drawn film package. With the chosen package size and form the adequate amount of heat to sterilize the packed food product is ensured everywhere inside the package. Generally large packages are flat because the thickness defined by the heat conducting properties of the product can not be exceeded. Also in the present invention the counterpressure technique may be exploited to raise the temperature. Generally at least 9O ⁰ C temperatures may be used, but for the good shelf-life of the food product it is preferred that the temperature is over 100 ⁰ C. The counterpressure may be in the range of 100-400 kPa and the temperature in the range of 100-125 ⁰ C, preferably the counterpressure in the range of

150-250 kPa and the temperature in the range of 105-120 ⁰ C. With the counter- pressure the effects of the steam pressure forming inside the packages of liquids-containing raw materials can be reversed and the packages will e.g. maintain the form they have at the time of packing. The "package" as used herein refers to any suitable package or packing, especially to any air-tight package or packing which can maintain vacuum or airless conditions. Examples of the packages include tin cans or glass jars, deep-drawn vacumized film packages made of plastic or the like or any other suitable packages known by a person skilled in the art. In one embodiment the food product of the invention has been packed into flat packages having thickness of for example 15-50 mm, preferably 20-40 mm, which enables fast heat transfer to the products.

The food product according to the invention may contain in addition to the vegetable material, such as tubers of tuberous root plants such as potato or potato-like plants, for example sweet potato, yam, taro, or grains such as rice, barley, wheat, rye, oat, maize, millet and buckwheat, processed grain products, root crops, vegetables or fruits, also one or more of the following: spices, flavoring agents, structure modifying agents, preservatives, nutritional and health promoting components.

The food product according to the invention may be preparable to the final edible form for serving for example either by adding the product into cold or preheated liquid or by adding liquid into the product and further heating the mixture in a vessel, such as a plate, a bowl, a kettle or a pot to boil it, or by heating in a casserole in any suitable heating device. The liquid to be added before eating may be water, milk product or any other fluid agent to produce porridge, gruel, soup, casserole, gratin or the like. Generally the amount of liquid to be added at the final stage is in the range of 25-50 weight-% for grain products, whereupon the solid food product gets its final form, such as porridge or the like.

In one embodiment, when reheating the food product, also spices are added before eating. The invention is now described by some non-limiting examples.

Examples

Example 1 : Meat soup, thickness of the package max 40 mm

The meat may be cut, raw or precooked. The potatoes are cut and all components are added, they are dosed into a package and vacumized, after which the product is cooked and cooled in the package in an autoclave. The autoclave may be for example Stock Automat 1100 BV.

Heating temperature 110 ⁰ C, counterpressure 220 kPa, cooking time 25 minutes. Example 2: Fish soup, thickness of the package max 40 mm

The fish may be fresh or raw frozen and precut. The potatoes are cut and all components are added, they are portioned out into a package and vacumized, after which the product is cooked and cooled in the package in an autoclave.

Heating temperature 110 ⁰ C, counterpressure 200 kPa, cooking time 25 minutes. Example 3: Vegetable soup, thickness of the package max 45 mm

The vegetables may be for example carrot, Swedish turnip, leek, cauliflower, bean, tomato, zucchini, pea, maize, sweet pepper etc. The spices may be herbs such as tarragon, thyme etc. The potatoes are cut and all components as fresh or as pre- cut frozen are added, they are portioned out into a package and vacumized, after which the product is cooked and cooled in the package in an autoclave.

Heating temperature 110 ⁰ C, counterpressure 200 kPa, cooking time 20 minutes. Example 4: Beef Bourguignon, thickness of the package max 35 mm

The ingredients are cut, all the components are mixed together, portioned out into a package and vacumized, after which the product is cooked and cooled in the package in an autoclave.

Heating temperature 112°C, counterpressure 200 kPa, cooking time 20 minutes.