A shelf-stable food composition and a process for the preparation thereof

Field of invention

The present invention relates to a shelf-stable food composition with a low acidic content, and a process for the preparation thereof.

Background of the invention

A cooking base is commonly used in the preparation of soup, sauce and gravy for various culinary products. It is convenient to use and may even enhance the taste of culinary products in which they are used. Cooking bases have become an important element or ingredient in food preparation, whether in Asian or Western countries. The usefulness and practical advantages of cooking bases are clearly shown if one were to contemplate the amount of time and effort that one will have to expend in order to prepare a fresh homemade cooking base.

A cooking base normally requires multiple ingredients to prepare whereby the difficulties will start at the procurement stage in which various ingredients have to be purchased. Thereafter, one will have to go through the laborious process of cleaning, cutting, milling, frying and other necessary steps. All these have to be carried out and completed before one can actually use the prepared cooking base for a desired dish.

Furthermore, despite the large amount of time and effort spent on preparing a high quality cooking base, it is usually

suitable only for one specific dish or type of dish. Therefore, it is possible that different cooking bases have to be prepared (by using different ingredients and going though the same laborious process) for different dishes. In addition, the home-prepared cooking base is not shelf stable i.e. it will turn bad if it is not used within a short time. Therefore, it is a rather cumbersome process that yields limited practical benefit. This is particularly obvious in today' s society whereby people have less time to spend in the kitchen due to other commitments.

It is under such a background that there are many cooking bases, stocks, seasonings or sauces being developed and introduced into the market. A wide variety of ready-to-use products are available in the market for various culinary applications .

However, the cooking base available in the market is normally suitable for use in the preparation of one specific type of culinary product only and consumers may have to purchase different types of cooking bases for used in preparing different types of dishes. For example, some cooking bases are specially designed for use in chicken dishes and are not recommended for use with other dishes such as fish or vegetables.

In addition, most of these products have high acidic contents. Apart from the fact that these ready-to-use cooking bases available in the market are not as fresh as homemade cooking bases, these products are commonly made with such chemical mixes such as monosodium glutamate (MSG) or other flavouring compounds as main ingredients. In order to achieve a longer

shelf life, these products are generally added with other additives or chemicals for preservation purposes. One of the commonly adopted methods for preserving such products is to add a high amount of salt to the products. Salt produces a bacteriostatic effect by creating an environment not conducive to bacteria growth. However, a high level of salt will impart a harsh and salty taste to the product that is not very palatable. It is also a well known fact that excessive salt intake is bad for health, especially as it will increase the risk of cardiovascular diseases such as heart disease and hypertension .

Microorganisms are also sensitive to acids in various degrees. Therefore, preservation can also be achieved by using the addition of food acids. The preserving effect of acid is due to the hydrogen ion concentration and its destabilisation effect on bacterial cells. However, the addition of food acids results in a higher acidic content to the food products and the food products will therefore possess a sourish taste that is unpleasant to the consumers.

Apart from preserving food products by adding additives and chemicals, the other common way of food preservation is by sterilisation. Sterilisation is a process that effectively kills or eliminates microbiological organisms which might be present in the products. There are a few methods to achieve the sterilisation including thermal processing and irradiation. The most common way of sterilisation is by thermal processing which exposes the product to a relatively high temperature for a long period of time. While the food products may now be free of microorganisms and therefore have a longer shelf life, the thermal processing can literally ruin

the texture and colour of the products. Such high temperature and prolonged processing will inevitably overcook or overheat the products and as a result thereof, impair the taste of the product, as the product is made of food material which is heat-sensitive. Besides, radiation such as X-rays, gamma rays, or ultraviolet light may also be applied to the food products for sterilisation purposes. However, sterilisation via the application of radiation is expensive and may therefore increase the costs for production and the selling price of the product.

Hence, most consumers still prefer a homemade cooking base, as conventional products available in the market are normally are high in chemical additives as well as the fact that they are unable to produce a taste that closely resembles that of the homemade cooking base. As such, a food composition that has a taste that closely mimics the taste of homemade cooking bases will be a welcome addition to the kitchen.

Summary of the invention

In view of the above, it is therefore an object of the present invention to provide a ready-to-use food composition that has a taste which closely resembles the taste of a homemade product whereby it can be used as a direct replacement of homemade cooking product.

The term "homemade" as used herein refers to a version of food composition which is just cooked whereby the flavour, texture and colour of the food composition are closer to the natural or fresh product, and the nutrient content of the materials

used is maintained at levels similar to that found in home cooked food.

Another object of the present invention is to provide a food composition which is shelf-stable under normal storage conditions and once opened, it can be kept for at least two weeks .

The term "shelf-stable" as used herein refers to a version of food composition which is able to be stored at room temperature for a prolonged period of time while the texture and taste of the composition are substantially retained.

A further object of the present invention is to provide a food composition which does not contain preservatives and can be used as a cooking base across a variety of dishes for both vegetarians and non-vegetarians.

Still, another objective of the present invention is to provide a food composition that can be used as a basis for various dishes, or be added into such dishes to enhance the taste and deliciousness .

It is also an object of the present invention to provide a food composition which has a low acidic content in the range of pH3.7 to pH3.9.

The food composition of the present invention is in the form of a cooking base, paste, dip, cube, powder or granule for use in the preparation of various culinary products.

The shelf stability of the present food composition is achieved through a few means. One of them is the application of heat. However, the parameter used in the present invention is at a lower value i.e. at a lower temperature for the same time or the same temperature for less time, or both lower temperature and less time. Preferably, the application of heat is carried out at a temperature between 85 ^° C and 95 ^° C for between 10 and 20 minutes during the preparation of the food composition to eliminate undesirable microorganisms, and effecting in the resulting food composition a pre-determined water activity value (A _w value) and an optimum salt content to prevent the growth of undesirable microorganisms.

According to a preferred embodiment of the present invention, the water activity value is in the range of 0.6 to 0.9 and more preferably at 0.8. The salt content is preferably in the range of 13% to 22% by weight based on the total weight of liquid content, more preferably at 13% by weight based on the total weight of liquid content.

The application of heat, the water activity value and the salt content as described above are essential for impeding microbial growth, resulting in a longer shelf life.

The present invention further relates to a process of making the above described food composition which comprises the steps of: a) milling an ingestible raw material; b) frying the milled ingestible raw material in an edible oil; c) adding tomato paste to the fried material of step (b) and mixed well to form a mixture; d) adding salt to the mixture;

e) treating the salt added mixture with heat at a predetermined temperature for a certain amount of time to form the food composition

In the preferred embodiment, the process of preparing a food composition of the present invention further comprises a step of frying a spice, preferably onion which has been milled into a smaller form, in an edible oil prior to the step of frying the milled ingestible raw material in an edible oil.

According to the present invention, the ingestible raw material comprises any one or a combination of vegetables, legumes, leaves, flowers, stems, seeds, fruits or any other edible materials obtainable from a plant, preferably the ingestible raw material is any one or a combination of ginger and garlic.

The salt added mixture as mentioned in the above list of steps is treated with heat through the pasteurisation process which is carried out at a temperature between 85° C and 95° C for between 10 and 20 minutes.

After pasteurisation, dehydrated leafy vegetables, vegetable bits or vegetable particulates such as dehydrated coriander leaves or onion bits can be added to the mixture to enhance the flavour of the composition.

The food composition of the present invention may be further processed into any physical form comprising cooking base, paste, liquid sauce, cubes, powder or granules. Also, the food composition of the present invention may be used to produce any other food products.

Detailed description of the preferred embodiments

The present invention concerns a food composition that is flavorful and is useful as an ingredient or base for various culinary applications. Alternatively, the food composition of the present invention can be added into various culinary products as a taste enhancer for imparting the deliciousness .

The food composition of the present invention is prepared through a process which will be described in detail below and the food composition is suitable to be used in the preparation of soups, sauces, gravies, dishes, or it can be used as garnish, seasoning or dip for dishes.

The process of preparing a food composition according to the present invention is designed to produce a food composition which possesses a unique taste that is closer to the natural and fresh product. It also closely resembles the taste of a homemade product .

The process according to the present invention comprises the steps of: a) milling an ingestible raw material; b) frying the milled ingestible raw material in an edible oil; c) adding tomato paste to the fried material of step (b) and mixed well to form a mixture; d) adding salt to the mixture; e) treating the salt added mixture with heat at a predetermined temperature for a certain amount of time to form the food composition .

In the preferred embodiment of the present invention, the ingestible raw material is an edible plant comprising any one or a combination of leaves, flowers, stems, seeds, legumes, fruits or any other edible materials obtainable from a plant. Preferably the ingestible raw material is any one of ginger or garlic or a combination thereof.

The ingestible raw materials used can be fresh, frozen or aseptically packed garlic or ginger or a combination thereof.

As the first step of the production, the ingestible raw materials are subjected to the preparation process of peeling off the skin, cleaning, draining and milling into smaller particulates or pieces or be reduced into paste form.

The milled ingestible raw material can be used directly to prepare the food composition or alternatively, it can be mixed with an edible oil preferably a vegetable oil comprising any one or a combination of corn oil, sunflower oil, safflower oil, olive oil, maize oil, canola oil, grape seed oil, sesame oil or palm olein to form a pre-mixed material. The pre-mixed material will be subjected to a heat treatment, preferably a pasteurisation process that is carried out at a temperature between 85 °C and 95 °C for between 10 and 20 minutes. The pasteurised pre-mixed material will then be left to cool until at least 60 °C after which they will be stored for future use.

Apart from the earlier mentioned list of steps involved in the process of preparing the food composition, the process of the present invention further comprises a step of frying a spice in an edible oil prior to the step of frying the milled ingestible raw material in an edible oil. The spice according

to the present invention is preferably onion which has been subjected to a preparation process that is similar to the preparation process for the ingestible raw materials.

The milled ingestible raw material or the pre-mixed material is then fried together with the fried onion in the edible oil until a stage where the pre-mixed material and the onion emanate an acceptable level of fragrance. Tomato paste and salt at an amount that is sufficient to improve the taste appealing properties of the food composition are added to the fried composition and all materials are mixed well and evenly.

Thereafter, the final composition will go through a heat treatment which is a pasteurisation process at a temperature between 85 °C and 95 °C for a period between 10 and 20 minutes.

If it is so desired, dehydrated leafy vegetables, vegetable bits or vegetable particulates such as coriander leaves or onion bits can be added to the composition after the heat treatment to enhance and boost the taste of the composition.

The pasteurised composition will be left to cool before it is sent for packaging.

The food composition of the present invention may be further processed into any physical form comprising cooking base, paste, liquid sauce, cubes, powder or granules.

The steps involved in the process of preparing the food composition according to the present invention are not consequent and can be performed in a modular fashion. It can be performed either in a batch process, semi-continuous

process, or continuous process, depending on the availability of equipment and the desirable manufacturing parameters.

One of the important features of the food composition of the present invention is that the food composition does not contain any preservatives or chemical additives for preservation purpose. The food composition of the present invention is not added with any additional food acid during processing. Therefore, the food composition of the present invention has a more natural taste as compared to those products that are added with food acids for preservation purposes. The products with high acidic content normally possess a sourly taste that is unpleasant to the palate. The food composition of the present invention has a substantially low acidic content in the range of pH3.7 to pH3.9.

Although no preservatives or chemicals additives are added, the food composition produced in accordance with the afore- described process is a shelf-stable food composition which can be kept in refrigerator for about two weeks after opening, without any alteration or impairment to its taste or texture. This feature is achieved by managing and controlling the factors that can affect or inhibit the growth of microorganisms such as temperature, water activity, acidity, redox potential and others. The factors that are managed and controlled in the present invention to minimise or inhibit the growth and activeness of microorganisms are basically temperature, water activity and salt related factors. The temperature is applied to the food composition during processing whereas water activity and salt related factors are controlled in the finished product itself.

During the process of making the food composition, the undesirable microorganisms are killed or eliminated via heat application. Contrary to the conventional methods, the heat application of the present invention is performed at a lower value i.e. at a lower temperature for the same time, the same temperature for less time, or both lower temperature and less time. The value used is well controlled so that the heat applied to the food composition is sufficient to kill or eliminate undesirable microorganisms without adversely affecting the texture and natural taste of the food composition .

Preferably, the application of heat is carried out during the pasteurisation process. Under the pasteurisation process, a number of harmless or beneficial microorganisms will remain in the food composition. This is different from a sterilisation process normally applied in the production of food products. Sterilisation is performed at a higher temperature and may destroy all lifeforms in the product. The high temperature may also overcook or overheat the food product that is sensitive to heat and as a result thereof, impairing the organoleptic properties of the food product. Whereas, the heat applied to the food composition of the present invention is sufficient to kill or eliminate undesirable microorganisms while the organoleptic properties of the food composition are retained.

In the preferred embodiment of the present invention, the pasteurisation is carried out at a temperature between 85 °C and 95 °C for a period between 10 and 20 minutes which can result in the food composition having a pre-determined water activity value (A _w value) and an optimum salt content to

prevent the growth of undesirable or pathogenic microorganisms .

The finished product obtained from the process as described above has a water activity value between 0.6 and 0.9, preferably at 0.8 and a substantially low salt content between 13% and 22% by weight based on the total weight of liquid content, with a preferred content of 13% by weight based on the total weight of liquid content. These parameters are in existence in the finished products whereby the stability of the product can be maintained and thus achieving a longer shelf life for the product.

The term water activity (A _w ) as used herein is a measurement of water content. It refers to the ratio of the vapour pressure of water in the product to the vapour pressure of pure water at the same temperature. Pure distilled water has a water activity of exactly one. As the temperature increases, A _w will typically increase. Products that have higher A _w value are usually more supportive of the microorganisms' growth as most microorganisms require A _w value of at least 0.91 and above to grow. Therefore, if water activity of a product is kept below a certain value, the growth of microorganisms is restricted.

This results in a longer shelf life for that particular product .

The three factors as described above, i.e. the application of heat, control of water activity and control of salt content act synergistically in inhibiting microbial growth. With the combination of these three factors, the stability of the food composition can be increased effectively which results in a

shelf-stable food composition that retains the natural taste and nutritional contents.

The present invention also relates to food products prepared using the above-described food composition and food products prepared through the process of the present invention.

The present invention will now be further illustrated by the following Examples. The examples are intended for illustration only and the present invention is not in any way limited by the examples.

Example 1

250 kg of fresh onion of which the skin had been peeled off, washed and drained was milled into particulates of about 3 to 5 mm. The onion obtained from the milling process was about 180 kg. The other ingredients, i.e. ginger and garlic were prepared through a similar procedure. The amounts of ginger and garlic obtained from the milling process were about 150 kg and 200 kg respectively.

14 kg of corn oil was heated to a temperature of about 100 °C in a wok or tank. 23.5 kg of milled onion was then added into the heated oil and fried until fragrant. 6 kg of milled garlic and 5 kg of milled ginger were then added to the fried onion and all ingredients were fried together until fragrant. 6.6 kg of salt and 27 kg of tomato paste were added to the fried ingredients and mixed well with other ingredients. After that, a pasteurisation step was carried out to the resulting mixture at 90 °C for 15 minutes to eliminate contaminants. To further enhance the flavour, 7 kg of dehydrated green coriander leaves

and 23 kg of water were added to the pasteurised mixture and mixed well to form a cooking base. The cooking base was afterwards packed and left to cool.

The cooking base was found to be shelf stable at room temperature for more than 12 months in moisture tight packaging and has excellent colour stability. The cooking base can be kept in refrigerator for about two weeks after opening, without any alteration or impairment to its taste or texture. The cooking base has a water activity of 0.8 and a salt content of 13% by weight based on the total weight of liquid content .

Example 2

In this example, the ingredients of onion, garlic and ginger were first prepared into a pre-mix. To prepare the pre-mix, the fresh milled onion which was prepared through a procedure similar to that as described in Example 1 was further mixed with corn oil and salt to form an onion pre-mix. The resulting mixture was then treated at 90 °C for 15 minutes after which it was left to cool before being packed and stored for future use. Garlic pre-mix and ginger pre-mix were prepared through a similar procedure as that for preparing onion pre-mix.

The pre-mixes of onion, garlic and ginger were prepared in a formulation as follows:

To prepare a cooking base by using the pre-mixes, 70.50 kg of onion pre-mix was first heated in wok to a temperature of 100 °C and fried until fragrant. 15 kg of ginger pre-mix and 14.50 kg of garlic pre-mix were then added to the fried onion and all ingredients were fried together until fragrant. The mixture of ingredients was at about 29 kg after the frying process. 9 kg of corn oil, 5 kg of salt, 27 kg of tomato paste and 23 kg of water were added one after another into the mixture to form the cooking base. 7 kg of dried onion bits that were 1 to 2 mm in size was further added to the mixture to enhance the flavour. A pasteurisation step was then carried out at 90 °C for 15 minutes to eliminate contaminants. The cooking base was afterwards packed and left to cool.

The cooking base has a water activity of 0.8 and a salt content of 13% by weight based on the total weight of liquid content .

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modification and variations are possible. The embodiments were chosen and described in order

to best explain the principles of the invention and its practical application, to hereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular are contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents .