A PROCESS FOR PREPARING A HEAT-TREATED INTERMEDIATE ONION PREPARATION, A HEAT-TREATED INTERMEDIATE ONION PREPARATION BY SAID PROCESS, A FOOD COMPOSITION COMPRISING IT, AND A PROCESS FOR PREPARING IT

Abstract

This document provides a procedure for preparing a heat-treated intermediate onion preparation.

Description

DESCRIPTIVE MEMORANDUM Field of invention The invention relates to a process for making a heat-treated intermediate onion preparation for use in industrial food production. Background of the invention Ready-to-eat products, such as meals, soups, and sauces, are products that only require heating before consumption. These products include stews, fried rice, curries, soups, and sauces (pasta) such as Bolognese sauce, etc. They can be packaged in cans, jars, or other containers. Many products like soups and sauces contain onions. The industrial process for preparing soups and sauces is relatively simple. It typically involves mixing the onions with other food ingredients such as spices, salt, flavorings, thickeners, and water to form the final product, like a sauce or soup. The mixture is then heated to approximately 70°C, followed by preservation and packaging in suitable containers. In a home kitchen, raw onions are usually used to prepare soup or sauce. However, to produce such ready-to-eat products in an industrial setting, onions are typically pre-processed in what can be called an intermediate onion preparation before being mixed with the other ingredients of the final food product, such as soup. Intermediate ingredients in an industrial food setting refer to ingredients that have been processed but are generally not intended to be sold and consumed as such. Instead, intermediate ingredients are designed MOELLER Y CO SA MESSERER - 30529767664 Digitally signed by PORTALTRAM ITES - INPI. Date: 2019.06.28 08:55:28 -03:001 Reason: Digitally Signed by the INPI Location: Buenos Aires, Argentina to be used to formulate what is called the final application, a soup, a sauce or a dish such as a stew that will be consumed as such. However, the flavor falls far short of what one would expect from a homemade version. To improve the taste of industrially prepared soups, a heat-treated intermediate onion preparation can be made in a separate pre-processing step. This involves heating the onions separately in a tank called a soffritto, typically with a volume of 2500-3000 liters, where 200 kg of onions are heated to 95°C for 15-30 minutes. The result is slightly better than onions prepared at 70°C, but there is often so little onion flavor that onion aroma is frequently added separately to such industrially prepared soups. Patent JP63-16775 discloses a process for preparing roasted onions by first drying fresh onions, which typically have over 90% moisture by weight, to 30-80% moisture by weight. This is followed by sealing the onions in a can and heating the can in a retort. In the food industry, retorts are large pressure cookers used for the sterilization stage in the canning process. Retorts can be tunnels several meters long with a diameter of approximately 1.5 meters into which racks of cans are inserted. Patent JP63-16775 discloses how to heat the onions for 35 minutes at 116°C in a retort and instructs that the temperature should be kept below 130°C to avoid a burnt taste. Document JP 2001 / 190 240 discloses that the process described in document JP6316775 results in an off-flavor: an unpleasant odor typical of high-temperature cooking, such as in a retort. Document JP 2001 / 190 240 aims to overcome this off-flavor induced by high temperatures. It discloses a separate two-stage heating procedure. In the first heating stage, the temperature is reduced compared to JP63-16775: 900 parts of onion and 100 parts of water are heated for 15 minutes at 109°C and 0.04 MPa (gauge pressure) in a pressure cooker or retort. This is followed by a second heating stage in an open pan at moderate heat to reduce the onion preparation to approximately 60% of its weight (600 parts) of the heat-treated onion preparation.Document JP 2001 / 190 240 teaches how to apply the second heating stage in the "open system" for the time necessary to evaporate the unpleasant odor developed during high-temperature cooking. The resulting onion product is said to be sweet and free of that unpleasant smell. In their search for a good-tasting intermediate onion preparation, the present applicants reproduced the process described in document JP 2001 / 190 240, and indeed, the onion preparation thus made was sweet with little off-flavor. However, surprisingly, it also had very little onion flavor. Therefore, the food industry still needs an improved process for pre-processing onions into a heat-treated intermediate onion preparation that has a delicious onion flavor (sautéed / fried) without the unpleasant aftertaste, for example, that occurs when onions are heated at high temperatures in a retort. Furthermore, it would be desirable to provide a heat-treated intermediate onion preparation with such an intense onion flavor profile that it allows for a reduction in the amount of onion used and even the need to add onion flavoring. Summary of the invention According to the invention, a process is provided for preparing a heat-treated intermediate onion preparation comprising the steps of: a) Providing chopped onion, b) Optionally, mix 0 to 100 parts by weight of a liquid phase with 100 parts by weight of chopped onion, c) Heat the chopped onion in a heating phase from 25°C to 95% of the holding temperature in a heating time of less than 20 minutes, preferably less than 5 minutes; therefore, the holding temperature is preferably from 135°C to 180°C, more preferably from 140°C to 170°C, and even more preferably from 145°C to 160°C, d) Maintain the chopped onion during the holding phase for a holding time at the holding temperature, whereby the holding phase corresponds to the holding time and begins at 95% of the holding temperature and continues when the temperature increases to the holding temperature and then decreases to 95% of the holding temperature, and the holding time is from 10 seconds to 7 minutes, preferably from 30 seconds to 6 minutes, more preferably from 1 to 5 minutes, whereby the pressure during the holding phase is at least the saturated vapor pressure of water and preferably the oxygen level is at atmospheric oxygen levels, preferably the heat treatment is such that the chopped onion is completely sterilized, e) Cool the chopped onion after the holding phase to a filling temperature, preferably below 90°C, preferably below 80°C, preferably below 30°C, preferably within a cooling time of less than 20 minutes, preferably less than 15 minutes, more preferably less than 10 minutes, preferably between 5 seconds and 15 minutes, more preferably between 30 seconds and 10 minutes to form the heat-treated intermediate onion preparation, f) Optionally, add the heat-treated intermediate onion preparation at the filling temperature, preferably at atmospheric pressure, to process and prepare a food product; g) Optionally, fill the heat-treated intermediate onion preparation into a container at the filling temperature, preferably at atmospheric pressure. The invention also provides a heat-treated intermediate onion preparation as described below, a process for preparing a food composition comprising the step of adding a heat-treated intermediate onion preparation made according to the invention in a process for preparing a food composition, and a food composition comprising said heat-treated intermediate onion preparation. Surprisingly, the present invention provides a process suitable for industrial-scale use at very high temperatures, resulting in a heat-treated intermediate onion preparation with a more intense flavor profile without the undesirable off-flavors of high-temperature heated onions. The flavor of this heat-treated intermediate onion preparation is so intense that it allows for a reduction in the amount of chopped onion, the addition of onion flavoring, salt, and consequently, environmental resources. While JP63-16775 also discloses a single heating stage for producing a heat-treated onion preparation, it differs from the present invention because JP63-16775 does not directly and unambiguously disclose a specific heating time for the retort process. Using an industrial retort, the heating time from ambient temperature to a holding temperature of 120°C will generally be at least 35 minutes. JP63-16775 also advises against using temperatures above 130°C. Document JP 2001 / 190 240 advises against using a single heating stage as in the present invention, as it discloses the need for a second heating stage in an open pan to evaporate the off-flavor developed during the first heating stage. Surprisingly, although the present invention employs a higher holding temperature than that of document JP63-16775, namely above 130°C, the intermediate onion preparation according to the present invention does not exhibit an undesirable off-flavor requiring elimination by a second heating stage. While document JP 2001 / 190 240 discloses a maximum holding temperature of 140°C, we note that the corresponding heating time is not disclosed directly and unambiguously. Detailed description of the invention The process according to the invention comprises a single heating stage carried out under the conditions described herein. The single heating stage has three consecutive phases: a heating phase, a holding phase at a holding temperature, and a cooling phase. As is known in the food processing art, heating a product is a dynamic process, and the temperature of the heating medium may not correspond to the temperature of the food being heated. For example, milk can be sterilized by steam injection. The steam temperature can be up to 160°C. However, to sterilize the milk, the steam injection only needs to be heated to 135°C for 1-2 seconds. Therefore, the food product is only heated to 135°C while the steam is much hotter.In the present invention, the temperature such as the holding temperature refers to the temperature of the onion measured with temperature probes inside the heating device. In a first stage of the invention, chopped onion is provided. It may be fresh or frozen onion. The onion may be used as is or optionally mixed with a liquid phase in a w / w ratio of 0 to 100 parts by weight of liquid phase to 100 parts by weight of chopped onion. The liquid phase may be water, oil, or a mixture thereof. Any food-grade oil, such as sunflower oil, olive oil, canola oil, etc., may be used. Preferably, the ratio of 0 to 100 parts of liquid phase to 100 parts of chopped onion is 5 to 100, and more preferably 10 to 100 parts of liquid phase to 100 parts of chopped onion. Whether or not the chopped onion is mixed with the liquid phase, it may also be referred to as the onion preparation for the present purpose.Depending on the desired flavor in the soup, sauce, or dish where the intermediate onion preparation will be used, an expert may find it helpful to add, for example, a little ginger or spices such as curry. The chopped onion is then heated during the heating phase from room temperature (25°C) to 95°C. The corresponding heating time is the time required to heat the chopped onion from 25°C to 95% of the holding temperature. The heating time is preferably less than 20 minutes, more preferably less than 8 minutes, and even more preferably less than 5 minutes. The holding temperature is preferably greater than 135°C to 180°C, more preferably greater than 140°C to 170°C, and even more preferably greater than 145°C to 160°C. After the heating phase, the chopped onion is held at the holding temperature for a specified time. The holding phase begins at 95% of the holding temperature and continues as the temperature rises to the holding temperature and then falls back to 95% of the holding temperature. The holding time is preferably 10 seconds to 7 minutes, preferably 30 seconds to 6 minutes, and more preferably 1 to 5 minutes, ensuring that the chopped onion is sterilized. Therefore, the pressure during the holding phase is at least the saturated vapor pressure of water (corresponding to 0.36 to 1.0 MPa) and the oxygen level is at atmospheric levels. The holding phase ends when the next cooling phase begins.Ideally, the heat treatment is such that the chopped onion is completely sterilized. The cooling phase corresponds to the cooling time that begins when the temperature has returned to 95% of the holding temperature and stops at the filling temperature. The filling temperature is preferably below the atmospheric boiling point of onions, preferably below 90°C, preferably below 80°C, preferably below 30°C, preferably between 10°C and 90°C, more preferably between 10°C and 80°C, preferably between 10°C and 30°C. The cooling time is preferably less than 20 minutes, preferably less than 15 minutes, more preferably less than 10 minutes, preferably between 5 seconds and 15 minutes, more preferably between 30 seconds and 10 minutes. The filling temperature depends on how the heat-treated intermediate onion preparation is used. Advantageously, the heat-treated intermediate onion preparation can be added at the filling temperature to a process for preparing a food product such as soup or sauce. For example, the chilled heat-treated intermediate onion preparation can be conveyed through a tube and added directly to a container with the remaining ingredients of a soup or sauce, where the soup or sauce is prepared in the normal manner. In that case, the filling temperature can be approximately 72°C or higher if it is desired that the heat-treated intermediate onion preparation remain aseptic. Preferably, the addition of the heat-treated intermediate onion preparation is carried out at atmospheric pressure. It may also be desirable to prepare the heat-treated intermediate onion preparation at a different time or place than the production of the food product, such as a soup or sauce. The heat-treated intermediate onion preparation can then be filled into a container at the filling temperature and stored before use, for example, in an aseptic bag inside a box for storage at room temperature. Preferably, filling is done at atmospheric pressure. Therefore, after the holding phase, the chopped onion is cooled to the filling temperature for a cooling time as described above to form the heat-treated intermediate onion preparation. Preferably, the onion is heated using ohmic heating, steam injection heating, or thermal conduction heating. Preferably, the process of the invention does not comprise a step in which the onion is heated in an open system to reduce the amount of intermediate onion preparation to less than 65% of its weight compared to the weight of the intermediate onion preparation before heating in the open system. Heating in an open system is a heating step in an open container that allows water to evaporate, thus reducing the weight of the intermediate onion preparation, such as heating in an open pan over moderate heat. Preferably, the process of the invention does not comprise a step in which the onion is heated in an open system at a temperature of 80°C to 100°C for 330 minutes.Preferably, the process of the invention does not comprise a step in which the onion is heated in an open system at a temperature of 80°C to 100°C for 3-30 minutes, thereby reducing the amount of intermediate onion preparation to less than 65% of its weight compared to the weight of the intermediate onion preparation before heating in the open system. Instead, the process according to the invention is normally carried out when substantial amounts of water do not evaporate. Preparation of heat-treated intermediate onion The heat-treated intermediate onion preparation according to the invention, as prepared in the examples, had a smooth, almost pasty appearance, although individual pieces of onion were still visible. The heat-treated intermediate onion preparation according to the invention preferably comprises at least 0.01 µg / g of methylpropyl disulfide by dry weight of the intermediate onion preparation, preferably from 0.01 to 6 µg / g of methylpropyl disulfide by dry weight of the intermediate onion preparation. Preferably, the heat-treated intermediate onion preparation is prepared according to the procedure described herein. Methylpropyl disulfide (MSD) measurement The DSMP was measured using static headspace gas chromatography-mass spectrometry (sHS-GC-MS). Approximately 10 grams of frozen sample were placed in a 20 mL headspace vial and homogenized using an Ultra-Turrax. Headspace equilibration was performed at 60 °C for 30 minutes with gentle stirring. 500 μL of the headspace was injected in split mode (25:1 split ratio) at 250 μL / s with an injector temperature of 200 °C. The syringe temperature was 80 °C. The GC column was a 30 m x 250 μm x 1.4 μm Restek RTX624 column programmed from 35 °C (1 min) to 205 °C (2 min) at 10 °C / min. The carrier gas was helium at 1 ml / min. The mass spectrometer operated in full scan mode at 70 eV ionization energy, scanning the mass range from m / z 29 to 300.The temperatures of the transfer line, ionization source, and quadrupole were 240 °C, 230 °C, and 150 °C, respectively. Quantification was performed using the internal standard method (internal standard dibutoxymethane). Calibration lines were prepared in either 1:1 (v / v) water / sunflower oil or 19:1 (v / v) water / sunflower oil, depending on the matrix of the sample being analyzed. Process equipment Although the applicants did not use a standard retort to carry out the invention using the specific parameter combination, other standard equipment may be used. The present invention has the advantage that a person skilled in the art, with knowledge of the required process parameters of the invention, can select the appropriate equipment from standard food industry apparatus to carry out the invention. The invention can be used in conjunction with standard processing lines without the need for personnel to work at supra-atmospheric pressures. The process according to the invention can be applied in batch or continuous mode. An example of batch mode was used for Examples 3 and 4 below, where the applicants used a steel tube with an inner diameter of 10 mm and an outer diameter of 12 mm, approximately 15–20 cm long, which was immersed in oil at the holding temperature. Cooling was carried out by removing the tube from the hot oil and cooling it in water to the filling temperature. This relatively small configuration can be used when only small volumes are required. In continuous mode, the process according to the invention can be carried out in suitable heat exchangers capable of achieving the combination of short heating time and high holding temperature. These include scraped surface heat exchangers, tube-in-tube heat exchangers, annular tube heat exchangers, shell-and-tube heat exchangers, and spiral heat exchangers.Preferably, the onion is heated in a tube within a heat exchanger tube, a tubular heat exchanger, a helical coil heat exchanger, or a scraped surface heat exchanger. Such heat exchangers are available, for example, from Alva Laval. Preferably, in the process according to the invention, the onion is heated in a tube having a hydraulic diameter of 0.1 to 10 cm, preferably less than 0.4 to 5 cm, and more preferably 0.6 to 3 cm. The hydraulic diameter, DH, is a term commonly used when dealing with flow in non-circular pipes and channels. It is defined as: Where • A is the cross-sectional area, • P is the wetted perimeter of the cross-section For example, for a circular tube: DH=D (where D is the diameter of the tube). For an annular space: DH=Dout-Din (where Din represents the diameter of the inner tube; Dout represents the diameter of the outer tube) Without wishing to be limited by any particular theory, it is thought that the combination of short heating times and short holding times at the relatively high holding temperature translates into unexpected advantages. The combination of these advantages is not known when using standard industrial retorts. While heating to temperatures of 140–180°C can be achieved, for example, in a pressure retort, the heating time for a retort to reach 120°C is at least 50 minutes. A domestic pressure cooker is not designed to reach temperatures above 115 or 117°C. The invention also provides a food composition comprising a heat-treated intermediate onion preparation prepared according to the invention, preferably in an amount of 0.1 to 50% by weight of the total food composition, preferably the food composition being a soup, a sauce or a dish. The invention also provides a process for preparing a food composition comprising the step of adding a heat-treated intermediate onion preparation prepared according to the invention in a process for preparing a food composition, preferably in an amount of 0.1 to 50% by weight of the total food composition, preferably the food composition being a soup, a sauce or a dish. The invention is further illustrated by the following non-restrictive examples. It will be clear to a person skilled in the art how to carry out the invention using equivalent means without departing from the invention. Examples Example 1 JP 2001 190240 (comparative) An intermediate onion preparation was prepared according to the two-stage heating process of JP 2001 190240. In the first stage, 900 parts of diced fresh onion and 100 parts of water were heated in a standard 6 L kitchen pressure cooker at 109°C for 15 minutes. 0.14 MPa. (Domestic cooking pressure cookers are generally designed to reach a maximum temperature of just under 120°C.) The heating time was 16.6 minutes from 25°C to 109°C. After that, the onion was heated in an open pan over moderate heat until the onion reduced to 60% of its weight. The resulting intermediate onion preparation had a sweet taste, but showed little onion flavor. Example 2 Reference pan (comparative) A chef prepared a medium-temperature onion dish in a pan (for example, sautéed) using 50 parts diced fresh onion and 50 parts oil. This homemade version is often considered the benchmark for industrially prepared food products. The result was described as having a multidimensional flavor: caramelized, sweet, with hints of cooked onion and roasted notes. Examples 3, 4 and 5 (according to the invention) Diced fresh onions and oil were processed with water as shown in the table below. Examples 3 and 4 were produced in a batch process as described above. Example 5 was produced in a continuous helical coil heat exchanger process, filled into a bag, and sealed. 3 (invention) HTC oil+oil tube 4 (invention) HTC oil+water tube 5 (invention) HTC oil+oil+water pilot Heating phase from 25°C to holding temperature (min) 3.5 min (6:20 all together) 3.5 min (6:20 all together) Check with HH (3.5 min) Holding temperature 150°C 150°C 165°C Holding time 3 min 3 min Check HH (1.5 min) Holding pressure 0.5 MPa 0.5 MPa 0.7 MPa Cooling to less than 50°C (min) 3.5 min 3.5 min 4 min Filling temperature 20°C 20°C 20°C Composition Onion + oil Onion + water Onion + water + oil Vegetable ingredient: onion (% by weight) 50 50 74 Oil 50 0 4 Water (% by weight) 0 50 22 Total 100 100 100 Taste +++++ +++ ++++ Methylpropyl disulfide (MSD) measurement The DSMP was measured as described above. Example DSMP (microg / g dry weight of heat-treated intermediate onion preparation) 1 (comparative) <0.02 2 (comparative) ND 3 >=0.02 4 >=0.02 5 >=0.02 Example 6 (comparative) An onion preparation was prepared according to the process of JP 2005 061425. Two kilograms of onions were peeled, chopped, placed in a pan, and heated to 95°C for 180 minutes, either uncovered (6-A) or covered (6-B). The flavor of the resulting onion preparations is summarized below: 6-A 6-B Flavor profile Bitter and burnt Sweet but almost no onion flavor;

Claims

1. A process for preparing a heat-treated intermediate onion preparation, characterized in that it comprises the steps of: a) Providing chopped onion, b) Optionally, mixing from 0 to 100 parts by weight of a liquid phase comprising water, oil, or a mixture thereof with 100 parts by weight of chopped onion, c) Heating the chopped onion in a heating phase from 25°C to 95% of the holding temperature in a heating time of less than 20 minutes, preferably less than 5 minutes; the holding temperature being 135°C to 180°C, preferably above 140°C to 170°C, more preferably 145°C to 160°C, d) Holding the chopped onion during the holding phase for a holding time at the holding temperature,Therefore, the holding phase corresponds to the holding time and begins at 95% of the holding temperature and continues when the temperature increases to the holding temperature and then decreases to 95% of the holding temperature, and the holding time is from 10 seconds to 7 minutes, preferably from 30 seconds to 6 minutes, more preferably from 1 to 5 minutes, whereby the pressure during the holding phase is at least the saturated vapor pressure of water and preferably the oxygen level is at atmospheric oxygen levels, preferably the heat treatment is such that the chopped onion is completely sterilized, e) Cool the chopped onion after the holding phase to a filling temperature, preferably to less than 90ºC, preferably to less than 80ºC, preferably to less than 30ºC, preferably in a cooling time of less than 20 minutes,preferably less than 15 minutes, more preferably less than 10 minutes, preferably between 5 seconds and 15 minutes, more preferably between 30 seconds and 10 minutes to form the heat-treated intermediate onion preparation; f) Optionally, adding the heat-treated intermediate onion preparation at the filling temperature, preferably at atmospheric pressure, to process and prepare a food product; g) Optionally, filling the heat-treated intermediate onion preparation into a container at the filling temperature, preferably at atmospheric pressure. Nine claims follow.