CN102919806A - Lipid aroma condensate prepared through fat thermal oxidation and preparation method thereof - Google Patents

Abstract

The invention discloses a method and a product thereof for preparing a fat aroma concentrate by using fat as a raw material and adopting a two-step process of heating, oxidation and degradation. The specific method is as follows: the first step, in the presence of antioxidants and water, put the fat into the air to heat and stir to oxidize, the air flow rate is 0.1-2m ³ /kg.h, the temperature is 100-180°C, the time is 0.5-5h, and the stirring speed is 200-1000rpm/min; the second step, the product obtained in the first step is passed through nitrogen to heat and degrade, the nitrogen flow rate is 0.1-0.5m ³ /kg.h, the heating temperature is 100-180°C, and the time is 0.5-6h. The resulting product has a rich, harmonious and mellow fat aroma, and can be used as a raw material for heat-reactive flavors, or as a natural food additive in various seasonings or foods such as chicken essence, instant noodle seasoning, soup, sausage, canned food, and quick-frozen dumplings.

Description

Fat aroma concentrate prepared by thermal oxidation of fat and preparation method thereof

technical field

The invention relates to a method for preparing a fat aroma concentrate by using fat as a raw material through a two-step process of heating, oxidation and degradation and the product thereof. The obtained fat aroma concentrate has a rich, harmonious and mellow fat aroma, which can be used as a raw material for heat-reactive essence, and also It can be directly used in food as a natural food additive.

Background technique

The invention relates to a method for preparing a fat aroma concentrate by thermally oxidizing fat and the product thereof. The obtained fat aroma concentrate has a strong, harmonious and mellow fat aroma.

Auto-oxidation of fat produces an unpleasant rancid smell, but thermal oxidation of fat under certain conditions can produce oxidation products with rich oily aroma and frying aroma. The olfactory substances produced by fat oxidation mainly include hydrocarbons, aldehydes, ketones, furans, etc., among which aliphatic aldehydes and ketones are the main components of fat fragrance, and they are combined with hydrocarbons and furans in an appropriate ratio , can form a pleasing aroma of fat and frying. In the preparation of heat-reactive meat flavors, aliphatic aldehydes can also be used as precursors to participate in the Maillard reaction to generate heterocyclic meat flavor components with a lower threshold. Existing patents (Sun Baoguo, Xie Jianchun, Liang Menglan, Peng Qiuju, Wen Zhiyong. A method for preparing meat flavor flavor precursors through controlled oxidation of fat ZL200410030864.4) adopt an oxidation process under anhydrous conditions, air ventilation, and heating to prepare Fat oxidation products rich in small molecular aldehydes and ketones. The oxidation products have higher peroxide value, higher carbonyl content value, lower acid value, and rich fat aroma. They are used in thermal reactions (providing meat aroma before) body), the advantage of the meat flavor obtained is that the characteristic aroma of meat is obvious and the flavor is full, but this oxidation product with a higher peroxide value will cause the added food product to have a higher peroxide value and not meet the relevant product standards (national standard There are control requirements for the peroxide value of various food products), and it may also cause bad flavor due to automatic oxidation and degradation in food, so it is not suitable for direct addition and use in food.

In order to solve the problem in the prior art that the obtained fat oxidation product is not suitable for direct addition and use in food due to its high peroxide value, this application provides a The invention discloses a method for preparing a fat aroma concentrate with low peroxide value, low acid value and high carbonyl content value which is safe and easy for industrial production, and obtains a new type of fat aroma concentrate with low peroxide value. This low peroxide value fat aroma concentrate and its preparation method have not been reported in the prior art.

Contents of the invention

The object of the present invention is to provide a method for obtaining a fat aroma concentrate by adopting a two-step process of heating, oxidation and degradation. This method overcomes the shortcomings and deficiencies of the existing methods. The fat aroma concentrate prepared by this process has a lower peroxide value, a higher carbonyl content value, and a lower acid value. It not only has a rich fat aroma, but also has a harmonious and round aroma. It is used directly in food as a natural food additive.

The technical scheme adopted in the present invention is as follows:

A method for preparing fat aroma concentrate by thermal oxidation of fat, which uses fat as raw material and consists of a two-step process of heating oxidation and degradation. The first step is to heat in the presence of 0.01-0.8 wt% antioxidant to reach a reaction temperature of 100-100 At 180°C, add 0.5-6wt% fat liquid, maintain the reaction temperature of 100-180°C, start stirring, feed air and time, and carry out oxidation reaction for 0.5-5 hours; the second step is to prepare the product obtained in the first step Introduce nitrogen to heat and degrade, the reaction temperature is 100-180°C, and the time is 0.5-6h.

The fat described in the present invention is one of animal fat, vegetable oil, fatty acid triglyceride, natural unsaturated fatty acid, or a combination of the above-mentioned various oils and fats. The antioxidant is vitamin C or vitamin E or a combination of the two, and the added amount of the antioxidant is 0.01-0.8% by weight of the fat.

The liquid in the present invention is tap water, mineral water, distilled water, deionized water, or sodium chloride solution with a mass concentration of 0.5-10%. The added amount of the liquid is 0.5-6 wt% of the fat content. Especially when sodium chloride solution is used, the evaporation loss of water is small and the reaction temperature is relatively stable.

The air described in the present invention is provided by an air compressor, should not contain any poisonous or harmful components, and is filtered through molecular sieves or activated carbon. The air flow rate is controlled at 0.1~2m ³ /kg.h.

The nitrogen described in the present invention can be provided by steel cylinders or nitrogen generators, should not contain any poisonous and harmful components, and can be ordinary nitrogen or high-purity nitrogen. The nitrogen flow rate is controlled at 0.1-0.5m ³ /kg.h.

The reaction temperature of the present invention is lower than the oil temperature under kitchen frying and frying conditions, and is 100-180°C, preferably 120-160°C. The reaction temperatures of the first step and the second step may be the same or different.

The oxidation time of the present invention varies according to other conditions such as the amount of water added, heating temperature, and air flow, and the oxidation time is generally 0.5 to 5 hours.

The degradation time of the present invention changes according to other conditions such as the index (peroxide value, acid value, carbonyl content value) of the product obtained in the first step, the heating temperature of the second step, the nitrogen flow rate, etc., when the peroxidation of the first step product When the value is higher or the second heating degradation temperature is lower, the required degradation time will be longer. The heating degradation time is generally 0.5-6 hours, preferably 1-2 hours.

The stirring of the present invention adopts electromechanical stirring, and the stirring rate is 200-1000r.min ^-1 , preferably 400-700r.min ^-1 .

The peroxide value of the product obtained in the first step of the present invention is 15-170meq oxygen/kg, preferably 60-100meq oxygen/kg, and the acid value is 0.5-2g KOH/kg or less, preferably <1g KOH/kg, carbonyl The content is 0.1-2%, preferably 0.1-1.2%. The peroxide value of the fat incense concentrate obtained in the present invention is 0～2meq oxygen/kg, preferably 0meq oxygen/kg, and the acid value is 0.5～2g.KOH/kg or less, preferably <1.0g KOH/kg, carbonyl The content is 0.1-2%, preferably 0.6-1%. (For the analysis method of peroxide value, please refer to: IOPAC, standard methods for the analysis of oils, fats and derivatives, the 6th, P199-200 and P210-211 pages. For the analysis method of acid value, please refer to: Food Analysis Method, Qian Yi Zhao Guojun Translated, Shanghai Science Popularization Press. For the analysis method of total carbonyl content, see: Organic semi-trace qualitative analysis, Science Press, P305-309 pages).

The method for preparing fat aroma concentrate by thermal oxidation of fat in the present invention can effectively reduce the peroxide value of fat oxidation products, and maintain a higher carbonyl content value and lower acid value. The requirement is low, the safety performance is good, and it can prevent the re-oxidation of carbonyl compounds such as aldehydes and ketones obtained by degradation, and improve the yield of products.

The fat aroma concentrate product obtained in the present invention is an oxidation product with a lower peroxide value, a higher carbonyl content value, and a lower acid value. It can also be used as a natural food additive in various seasonings or foods such as chicken essence, instant noodle seasoning, soup, sausage, canned food, and quick-frozen dumplings.

Detailed ways:

Example 1

In a 500ml four-neck flask equipped with an electric stirrer, a thermometer, and a reflux condenser, add 100g of lard and 0.05gVE, and when the temperature reaches 130°C, add 5mL of sodium chloride solution (concentration: 10%), maintain 130°C, and start Stir, feed air (filtered by activated carbon) and time, the air flow rate is 0.24m ³ /kg.h, the stirring speed is 500r.min ^-1 , oxidize for 1.5h, stop the reaction, the measured peroxide value is 70meq oxygen/kg fat, The acid value is 0.69g.KOH/kg fat, and the carbonyl content is 1.17%.

Change to nitrogen, heat to continue the experiment, the nitrogen flow rate is 0.1m ³ /kg.h, start timing when the temperature reaches 160°C, heat and degrade for 2 hours, the product is milky white, the peroxide value is 0.5meq oxygen/kg fat, and the acid value is 1.56g .KOH/kg fat, the carbonyl content is 0.66%.

Example 2

In a 500ml four-necked flask equipped with an electric stirrer, a thermometer, and a reflux condenser, add 100g of tallow and _0.04gVE , when the temperature reaches 125°C, add 3mL of water, keep it at 125°C, start stirring, and introduce air (through molecular sieves) Filtration) and timing, the air flow rate is 0.12m ³ /kg.h, the stirring speed is 700r.min ^-1 , oxidized for 2h, stop the reaction, the measured peroxide value is 100meq oxygen/kg fat, acid value is 0.8gKOH/kg fat, carbonyl Content 1.3%.

Change to nitrogen, heat to continue the experiment, the nitrogen flow rate is 0.2m ³ /kg.h, start timing when the temperature reaches 156°C, heat and degrade for 3 hours, the product is milky white, the peroxide value is 2.0meq oxygen/kg fat, and the acid value is 1.63g .KOH/kg fat, the carbonyl content is 0.75%.

Example 3

In a 500ml four-neck flask equipped with an electric stirrer, a thermometer, and a reflux condenser, add 100g of chicken fat and 0.08g of V _E , and when the temperature reaches 120°C, add 2mL of sodium chloride solution (5%) to maintain the temperature at 120°C , start stirring, feed air (activated carbon filter) and time, the air flow rate is 0.24m ³ /kg.h, the stirring speed is 700r.min ^-1 , oxidize for 0.5h, and the measured peroxide value is 76meq oxygen/kg fat, acid The value is 0.47g.KOH/kg fat, and the carbonyl content is 1.08%;

Change to nitrogen and continue the experiment with heating. The nitrogen flow rate is 0.4m ³ /kg.h. When the temperature reaches 160°C, start timing. Heat and degrade for 2 hours. The product is light yellow, the peroxide value is 0meq oxygen/kg fat, and the acid value is 0.95 g. KOH/kg fat, the carbonyl content is 1.2%.

Claims (9)

1. a fatty thermal oxide prepares the method for the fragrant concentrate of fat, it is characterized in that: take fat as raw material, formed by heated oxide, degraded two step process, the first step, heating in the presence of the antioxidant of 0.01～0.8wt% when arriving 100～180 ℃ reaction temperature, add the liquid of 0.5～6wt% of fat mass, keep 100～180 ℃ reaction temperature, begin to stir, pass into air and timing, carry out oxidation reaction, the time is 0.5～5h; Second step, first step products therefrom is passed into nitrogen add thermal degradation, 100～180 ℃ of reaction temperatures, time 0.5～6h.

2. described fatty thermal oxide prepares the method for the fragrant concentrate of fat according to claim 1, and it is characterized in that: fat is a kind of for animal tallow or vegetable oil or aliphatic acid triglyceride or natural unrighted acid, or the combination of above-mentioned various greases.

3. described fatty thermal oxide prepares the method for the fragrant concentrate of fat according to claim 1, and it is characterized in that: described liquid is running water or mineral water or distilled water or deionized water, or mass concentration is 0.5～10% sodium chloride solution.

4. described fatty thermal oxide prepares the method for the fragrant concentrate of fat according to claim 1, and it is characterized in that: the flow that passes into air during first step oxidation reaction is 0.1～2m ³/ kg.h, mixing speed is 200～1000r.min ^-1, the flow when second step passes into nitrogen is 0.1～0.5m ³/ kg.h, the reaction temperature of the first step and second step is identical or different, and reaction temperature is 120～160 ℃.

5. described fatty thermal oxide prepares the method for the fragrant concentrate of fat according to claim 1, and it is characterized in that: described antioxidant is vitamin C or vitamin E or both combinations.

6. described fatty thermal oxide prepares the method for the fragrant concentrate of fat according to claim 1, and it is characterized in that: the peroxide value of the fragrant concentrate of gained fat is 0～2meq oxygen/kg, and acid number is 0.5～2g.KOH/kg, and carbonyl content is 0.1～2%.

7. the fragrant concentrate of the fat that obtains of one of described method according to claim 1-6, it is characterized in that: the peroxide value of the fragrant concentrate of gained fat is 0～2meq oxygen/kg, and acid number is 0.5～2g.KOH/kg, and carbonyl content is 0.1～2%.

8. the fragrant concentrate of described fat according to claim 7 is characterized in that peroxide value is 0meq oxygen/kg, and acid number＜1.0gKOH/kg, carbonyl content are 0.6～1%.

9. the purposes of the fragrant concentrate of described fat according to claim 7 is characterized in that preparing meat flavor or directly using in flavoring or food as natural additive for foodstuff as the thermal response raw material.