Vegetable shortening with high oxidation resistance and preparation method thereof

Abstract

The invention discloses shortening with high oxidation resistance and a preparation method thereof, and belongs to the technical field of shortening preservation, and the shortening is prepared from the following components in parts by weight: 75-82 parts of beta'crystal form grease, 0.1-0.5 part of zein nanoparticles coated with a composite antioxidant, 0.5-0.8 part of polyglycerol fatty acid ester polyethylene glycol solid dispersion and 15-17 parts of water. The shortening with high oxidation resistance has good freezing resistance under the preservation condition of 4 DEG C, has high oxidation resistance at normal temperature, can effectively improve the problem of low solubility of polyglycerol fatty acid ester in a low-temperature environment, and improves the performance and effect of the shortening in the aspect of preventing grease crystallization.

Description

Technical Field

[0001] The invention relates to the technical field of shortening preparation, and in particular to shortening with high oxidation resistance and a preparation method thereof. Background Art

[0002] Shortening, also known as white oil, looks white and resembles lard. It is one of the special fats used in the baking industry. It has a certain plasticity or consistency and can be used as an ingredient for pastries, surface spraying or demoulding, etc. It can also be used to crisp or soften baked foods so that proteins and carbohydrates will not become hard blocks during processing, thereby achieving the purpose of improving the taste.

[0003] In the early days, shortening referred to good lard. Later, as the demand for shortening in the baking industry increased significantly, the consumption of shortening made from hydrogenated vegetable oil or a few other animal and plant fats greatly exceeded that of lard. Shortening now refers to refined animal and plant fats, hydrogenated oils or mixtures of the above fats, solid fats formed by rapid cooling and kneading, or solid or fluid fat products formed without rapid cooling and kneading. Shortening is an emulsion, usually composed of fats, water, emulsifiers and other ingredients. Emulsifiers can reduce the surface tension of the oil-water interface, so that the originally immiscible oil and water can be evenly mixed together to form a stable emulsion, reducing the resistance during application, making the texture of the shortening more delicate and uniform, and smoother to apply, improving the application performance of the shortening. It is not recommended to freeze shortening, because during the freezing process, the oil and water molecules inside the shortening may have a tendency to separate due to changes in the intermolecular forces, and the water in the shortening will freeze into ice, affecting the texture of the shortening.

[0004] Fats and oils are prone to crystallization during freezing or storage, causing the texture of shortening to become hard and rough. The influencing factors are as follows: Temperature factor: When shortening is in a low temperature environment, such as frozen storage, the temperature of the fat drops and the molecular movement slows down. At this time, the interaction between the fatty acid molecules in the fat gradually increases, making it easier for them to arrange according to a certain rule to form crystals. For example, common palm oil will crystallize when the temperature is lower than its solidification point. Fats and oils composition: Different types of fats and oils have different fatty acid compositions, and the difficulty and characteristics of crystallization are also different. Generally speaking, fats and oils with a high content of saturated fatty acids, such as animal fats and some hydrogenated vegetable oils, are more likely to crystallize, because the molecular structure of saturated fatty acids is more regular, the interaction between molecules is stronger, and it is easier to form a stable crystal structure when the temperature drops. Storage time: As time goes by, the fat molecules in shortening will continue to undergo small movements and changes. During storage, even if the temperature is relatively stable, the fat molecules may gradually change to a more stable crystalline state, especially when there are small temperature fluctuations in the storage environment, this crystallization trend will be more obvious.

[0005] The effects of crystallization on the texture of shortening are as follows: The texture becomes hard: When the fat crystallizes, its internal structure changes from the original liquid or semi-solid soft texture to a solid hard crystal structure, which makes the overall texture of the shortening hard and loses its original softness and plasticity. For example, shortening that was originally easy to spread at room temperature may require greater force to spread after crystallization. The taste becomes rough: When the crystallized fat is chewed in the mouth, the crystal structure will give people a rough taste. Compared with the uncrystallized shortening, the crystallized shortening will not melt in the mouth as smoothly as before, but will have some graininess or roughness, affecting the overall taste quality of the food. For example, when making baked goods such as biscuits, if the shortening used has crystallized, the taste of the biscuits may become less delicate.

[0006] When making shortening, polyglycerol fatty acid ester (PGE) has high emulsifying properties, which can prevent oil-water separation, improve spreadability, and can also be used as an anti-crystallization agent for fats. Summary of the invention

[0007] In order to overcome the shortcomings of the prior art, one of the objects of the present invention is to provide a shortening with high antioxidant properties, which has good antifreeze properties under storage conditions of -20°C and high antioxidant properties at room temperature, can effectively improve the low solubility problem of polyglycerol fatty acid esters in low temperature environments, and improve its performance and effect in preventing oil crystallization.

[0008] The second object of the present invention is to provide a method for preparing shortening with high antioxidant properties, wherein the shortening prepared by the method has small crystal particles and is evenly distributed.

[0009] One of the purposes of the present invention is achieved by the following technical solution:

[0010] A shortening with high antioxidant property comprises, by weight, 75-82 parts of β' crystal oil, 0.1-0.5 parts of zein nanoparticles coated with a composite antioxidant, 0.5-0.8 parts of polyglycerol fatty acid ester polyethylene glycol solid dispersion, and 15-17 parts of water.

[0011] Furthermore, based on weight parts, the composition includes 80 parts of β' crystal oil, 0.5 parts of zein nanoparticles coated with a composite antioxidant, 0.8 parts of a polyglycerol fatty acid ester polyethylene glycol solid dispersion, and 15 parts of water.

[0012] Furthermore, the polyglycerol fatty acid ester polyethylene glycol solid dispersion is prepared by hot melt extrusion, spray drying, and coprecipitation.

[0013] Furthermore, the composite oxidant is a natural antioxidant, which is composed of vitamin E (VE), butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and clove essential oil. These antioxidants can remove free radicals and prevent oil oxidation.

[0014] Furthermore, the β' crystal oil is a mixture of one or more of palm oil, cottonseed oil, soybean oil and rapeseed oil.

[0015] Furthermore, the specific preparation steps of the zein nanoparticles coated with the composite antioxidant are as follows:

[0016] S1, dissolving components: dissolving the composite antioxidant and zein particles in ethanol with a mass percentage of 80% to 92%;

[0017] S2, injecting anti-solvent: injecting the ethanol solution containing the composite antioxidant and the zein particles into water or carbon dioxide supercritical fluid to form nanoparticles, and spray drying to form the zein nanoparticles coated with the composite antioxidant.

[0018] Furthermore, in step S2, the anti-solvent is one of water and supercritical carbon dioxide.

[0019] The second object of the present invention is achieved by adopting the following technical solution:

[0020] A production process of shortening with high antioxidant properties comprises the following steps:

[0021] S1, mixing oils and fats capable of forming β' crystal forms to obtain an oil and fat mixture, adding immobilized Lipozyme 435 lipase to the oil and fat mixture, and performing an ester exchange reaction at a temperature range of 60-90° C. After the reaction, centrifugally separating the immobilized Lipozyme 435 lipase to obtain an ester exchange oil and fat;

[0022] S2, adding the zein nanoparticles coated with the composite antioxidant, the polyglycerol fatty acid ester polyethylene glycol solid dispersion, and the water to the transesterified oil according to the formula amount, and stirring evenly;

[0023] S3, through a scraper heat exchanger, through a rapid cooling process, a kneading process, and then through aging, the shortening with high oxidation resistance is produced.

[0024] Furthermore, in step S3, the temperature of the rapid cooling process is 16.5°C; the stirring rate of the kneading process is 560r / min, and the stirring time is 6min.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The invention provides a shortening with high antioxidant properties. Polyglycerol fatty acid ester is used as an emulsifier to build a bridge between oil and water. Even during the freezing process, it can firmly connect them together, thereby effectively preventing the occurrence of oil-water separation. Polyglycerol fatty acid ester can also be used as an oil crystallization inhibitor. It can interfere with the crystallization process of oil molecules and prevent the formation of fatty acid crystals in the oil, thereby preventing the oil from crystallizing at low temperatures, so that the shortening can remain in a more stable liquid or semi-solid state at low temperatures, so that the shortening can still maintain good texture and taste after freezing. By highly dispersing polyglycerol fatty acid esters in the solid carrier polyethylene glycol, the solubility and dissolution rate of polyglycerol fatty acid esters in water can be significantly improved, and the low solubility of polyglycerol fatty acid esters in low temperature environments can be effectively improved, and its performance and effect in preventing oil crystallization can be improved. It has good antifreeze properties under storage conditions of -20°C, and indirectly improves the antioxidant properties of shortening with high antioxidant properties; in the zein nanoparticles coated with composite antioxidants, the composite antioxidants are embedded inside the zein nanoparticles, thereby improving the distribution of the composite antioxidants at the emulsion interface and enhancing the antioxidant activity of the composite antioxidants. The combined use of multiple antioxidants such as vitamin E (VE), butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and clove essential oil often has an antioxidant effect greater than the sum of the single use, playing a synergistic role.

[0027] (2) The present invention provides a method for preparing shortening with high antioxidant properties, which includes a scraper heat exchanger, a quenching process, and a kneading process, wherein the temperature of the quenching process is 16.5°C; the stirring rate of the kneading process is 560r / min, and the stirring time is 6min. The shortening produced is snow-white and delicate, with uniform crystal arrangement and delicate organizational structure. It has good storage stability and antioxidant properties. During storage, the oil is not easily oxidized, rancid or deteriorated, thereby extending the shelf life of the shortening with high antioxidant properties. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with specific embodiments. It should be noted that, under the premise of no conflict, the embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0029] Zein is a food protein widely found in plants. It is easily soluble in 80% to 92% ethanol or 70% to 80% acetone, but insoluble in water or anhydrous ethanol. Zein has a unique solubility. It is insoluble in water or anhydrous alcohol, but can be dissolved in an alcohol aqueous solution with a volume fraction of 60% to 95%. CAS No.: 9010-66-6, purchased from Hubei Weideli Chemical Reagent Co., Ltd.

[0030] Polyglycerol fatty acid esters, CAS number: 67784-82-1, were purchased from Shandong Pingju Biotechnology Co., Ltd.

[0031] The food quality physical property tester JC510-XL500 was purchased from Beijing Jiasheng Xingye Technology Co., Ltd.

[0032] Polyglycerol fatty acid ester (PGE) is a nonionic emulsifier with one end being lipophilic and the other end being hydrophilic, which can "pull" oil and water together and prevent them from separating. The solubility of polyglycerol fatty acid ester in water is limited and usually dispersed. Especially in low temperature environment, the solubility of polyglycerol fatty acid ester is further reduced, which may cause the emulsion to be unstable and easy to stratify, which not only affects the appearance of the product, but also may make the problem of oil crystallization more prominent. If polyglycerol fatty acid ester cannot be fully dispersed in water, it will not be evenly distributed on the interface of oil and water, thus affecting its emulsification and the effect of regulating oil crystallization, which may cause some oil molecules to still aggregate and crystallize, affecting the texture and taste of shortening. Therefore, polyglycerol fatty acid ester can prevent oil-water separation, improve spreadability, enhance stability and whipping properties, and extend shelf life. Polyglycerol fatty acid ester (PGFE) also has good thermal stability and chemical stability, and is not easy to decompose under high temperature and light conditions.

[0033] High cost: The production process of polyglycerol fatty acid esters is relatively complicated. It first needs to be condensed with glycerol, and then the final product is obtained through direct esterification or transesterification of polyglycerol and fatty acids. Although polyglycerol fatty acid esters have good emulsifying properties, their solubility in water is limited and usually requires specific temperature and stirring conditions to be fully dispersed.

[0034] Example 1

[0035] The shortening provided in this embodiment has high antioxidant properties, including 80 parts of β'-crystal palm oil, 0.5 parts of zein nanoparticles coated with a composite antioxidant, 0.8 parts of polyglycerol fatty acid ester polyethylene glycol solid dispersion, and 15 parts of water.

[0036] In this embodiment, the composite oxidant is a natural antioxidant, which is composed of vitamin E (VE), butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and clove essential oil.

[0037] In this embodiment, the polyglycerol fatty acid ester polyethylene glycol solid dispersion can significantly improve the solubility and dissolution rate of polyglycerol fatty acid ester in water by highly dispersing polyglycerol fatty acid ester in the solid carrier polyethylene glycol. The polyglycerol fatty acid ester polyethylene glycol solid dispersion is prepared by adopting one of the hot melt extrusion method, spray drying method and coprecipitation method. The specific preparation method is as follows.

[0038] Preparation of polyglycerol fatty acid ester polyethylene glycol solid dispersion by hot melt extrusion: polyglycerol fatty acid ester and polyethylene glycol are mixed evenly, the mixture is added into a hot melt extruder, and heated to an appropriate temperature (usually 100-200°C) to melt the mixture. Under the action of mechanical shear force, the melt is extruded through the extruder screw, and the extrudate is cooled and shaped by air cooling, water cooling or cooling rollers. The cooled solid dispersion is crushed, pelletized or rolled to obtain a polyglycerol fatty acid ester polyethylene glycol solid dispersion.

[0039] Preparation of polyglycerol fatty acid ester polyethylene glycol solid dispersion by spray drying: polyglycerol fatty acid ester and polyethylene glycol are dissolved in an organic solvent ethanol, the solution is atomized into fine droplets through a spray drying device, the droplets come into contact with heated gas and are rapidly evaporated to form fine solid dispersed particles, and the dried solid dispersion is collected for subsequent treatment.

[0040] In this embodiment, in the zein nanoparticles coated with the composite antioxidant, the composite antioxidant is embedded inside the zein nanoparticles, thereby improving the distribution of the composite antioxidant at the emulsion interface and enhancing the antioxidant activity of the composite antioxidant. The specific preparation steps of the zein nanoparticles coated with the composite antioxidant are as follows:

[0041] S1. Dissolving components: dissolving the composite antioxidant and zein particles in 80% to 92% ethanol by mass;

[0042] S2. Injecting anti-solvent: Injecting the ethanol solution containing the composite antioxidant and zein particles into water or carbon dioxide supercritical fluid, so that the multi-component components spontaneously form nanoparticles at the same time, and spray drying to form zein nanoparticles coated with the composite antioxidant. Zein particles are a hydrophobic protein with good embedding properties.

[0043] In this embodiment, an ethanol solution containing a composite antioxidant and zein particles is injected into water or a carbon dioxide supercritical fluid.

[0044] Water: Water is one of the commonly used anti-solvents because it is incompatible with many organic solvents (such as ethanol, acetone, etc.). For zein, water can effectively promote the precipitation of protein particles.

[0045] Supercritical fluid: such as supercritical carbon dioxide (CO2). In the supercritical anti-solvent process, supercritical fluid acts as an anti-solvent and can effectively cause the solute to form ultrafine powder.

[0046] Unsaturated fatty acids in shortening easily react with oxygen, resulting in oxidation of the oil, producing unpleasant odors and flavor deterioration. Oxidation not only affects the quality of the oil, but may also generate harmful substances. The addition of natural antioxidants in this embodiment can effectively delay the oxidation of the oil, and the use of compound antioxidants can improve the durability of the antioxidants, ensuring that they can effectively prevent the oxidation of the oil throughout the shelf life.

[0047] Use oxygen scavengers, which can remove oxygen from food and delay the occurrence of oxidation reactions. Common oxygen scavengers Ascorbic acid (vitamin C): It can remove oxygen from food and is oxidized to dehydroascorbic acid.

[0048] Changes in physical state: Low temperatures may cause changes in the physical state of antioxidants, such as from liquid to solid, which may affect their distribution and diffusion in oils and fats.

[0049] Use metal ion chelators Metal ion chelators can chelate with trace metal ions in oils and fats to prevent metal ions from catalyzing oil oxidation.

[0050] In this embodiment, oil with excellent antioxidant properties is used, such as palm oil. Palm oil has β' crystals, natural semi-solid components and excellent antioxidant properties, and is an ideal raw material for making shortening.

[0051] The shortening with high oxidation resistance prepared in this embodiment is placed in a well-sealed container, which can prevent it from absorbing too much water or odor during the freezing process, thereby reducing the risk of oil-water separation and avoiding direct contact with oxygen.

[0052] This embodiment also provides a production process of shortening with high antioxidant properties, comprising the following steps:

[0053] S1, mixing palm oil capable of forming β' crystal form to obtain a fat mixture, adding immobilized Lipozyme 435 lipase to the fat mixture, performing an ester exchange reaction at a temperature range of 60-90° C., and after the reaction, separating the immobilized Lipozyme 435 lipase by centrifugation to obtain an ester exchanged fat;

[0054] S2. Add the zein nanoparticles coated with the composite antioxidant, the polyglycerol fatty acid ester polyethylene glycol solid dispersion, and water to the transesterified oil according to the formula amount, and stir evenly;

[0055] S3. Through a scraped surface heat exchanger, the shortening is subjected to a rapid cooling process and a kneading process. The temperature of the rapid cooling process is 16.5° C., the stirring rate of the kneading process is 560 r / min, and the stirring time is 6 min. After aging, shortening with high antioxidant properties is produced.

[0056] The effect of the transesterification reaction in this embodiment:

[0057] Changes in fatty acid composition and distribution: The transesterification reaction can rearrange fatty acid chains to generate new triglyceride molecules. This change can lead to a narrower melting point distribution of the oil, thereby promoting the formation of more uniform and fine crystals.

[0058] Regulation of crystal growth rate: Due to the change in fatty acid composition, the crystal growth rate of oils and fats after interesterification may slow down, which helps to form smaller crystals and improve the crystallization characteristics of oils and fats.

[0059] Improvement of crystal morphology: Transesterification can change the crystal morphology of oils and fats, thus affecting their taste, spreadability and other application properties. For example, the β' crystals formed by transesterification usually have a better taste and a higher melting point.

[0060] Increase the content of saturated triglycerides: Ester exchange can increase the content of saturated triglycerides, which tend to form β' crystal form with higher melting point and slower crystal growth rate.

[0061] Improve the compatibility of oils and fats: Ester exchange can make the distribution of triglyceride types in oils and fats more uniform, thereby improving the compatibility of the system and avoiding the migration, aggregation and fractional crystallization of triglycerides with large differences in melting points.

[0062] In this embodiment, the temperature of the quenching process is 16.5°C, the stirring rate of the kneading process is 560r / min, and the stirring time is 6min. The shortening produced is snow-white and fine, with uniform crystal arrangement and fine organizational structure, and has good storage stability and antioxidant properties.

[0063] Role in Antioxidation:

[0064] Microstructure: Uniform crystal arrangement in oils and fats means that the fatty acid triglycerides (TAGs) in the oils and fats form a uniform crystal network. This uniform crystal network can reduce defects and uneven areas in the oils and fats, thereby improving the overall stability of the oils and fats. Uniform crystal arrangement can reduce the exposed area of ​​the oil surface and reduce the sites of contact with oxygen. Oxidation reactions are usually more likely to occur in uneven areas on the surface of oils and fats because these areas have more active sites, thereby reducing the probability of oxidation reactions. Uniform crystal arrangement can prevent the migration of oils and fats during storage and use. Oil migration will cause uneven distribution of oils and fats in the product, affecting the texture and taste of the product.

[0065] The role of delicate organizational structure:

[0066] Micro-uniformity: A fine structure means that the crystals in the oil are smaller and more evenly distributed. Small crystals have a higher surface area to volume ratio and can be more evenly dispersed in the oil, forming a more stable emulsion or suspension.

[0067] Improve emulsion stability: Fine tissue structure can improve the emulsion stability of oil. Emulsion stability refers to the ability of oil to maintain uniform dispersion when mixed with other ingredients (such as water, protein, etc.). Fine tissue structure can prevent oil from separating from other ingredients and improve the overall stability of the product.

[0068] Reduce oxidation reaction: The fine structure can reduce the large crystals in the oil, which are easy to become the starting point of oxidation reaction. The fine structure can evenly distribute the antioxidants and improve the efficiency of the antioxidants, thus effectively preventing the oxidation of oil.

[0069] Example 2

[0070] The shortening provided in this embodiment has high antioxidant properties, which comprises, by weight, 75 parts of β'-crystalline cottonseed oil, 0.3 parts of zein nanoparticles coated with a composite antioxidant, 0.5 parts of a polyglycerol fatty acid ester polyethylene glycol solid dispersion, and 17 parts of water.

[0071] In this embodiment, the composite oxidant is a natural antioxidant, which is composed of vitamin E (VE), butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and clove essential oil.

[0072] This embodiment also provides a production process of shortening with high antioxidant properties, comprising the following steps:

[0073] S1, mixing cottonseed oil that can form β' crystal form to obtain a fat mixture, adding immobilized Lipozyme 435 lipase to the fat mixture, performing an ester exchange reaction at a temperature range of 60-90° C., and after the reaction, separating the immobilized Lipozyme 435 lipase by centrifugation to obtain an ester exchanged fat;

[0074] S2. Add the zein nanoparticles coated with the composite antioxidant, the polyglycerol fatty acid ester polyethylene glycol solid dispersion, and water to the transesterified oil according to the formula amount, and stir evenly;

[0075] S3. Through a scraped surface heat exchanger, the shortening is subjected to a rapid cooling process and a kneading process. The temperature of the rapid cooling process is 16.5° C., the stirring rate of the kneading process is 560 r / min, and the stirring time is 6 min. After aging, shortening with high antioxidant properties is produced.

[0076] Example 3

[0077] The present embodiment provides a shortening with high antioxidant properties. The present embodiment provides a shortening with high antioxidant properties, which comprises, by weight, 80 parts of β' crystalline soybean oil, 0.1 parts of zein nanoparticles coated with a composite antioxidant, 0.6 parts of a polyglycerol fatty acid ester polyethylene glycol solid dispersion, and 16 parts of water.

[0078] In this embodiment, the composite oxidant is a natural antioxidant, which is composed of vitamin E (VE), butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and clove essential oil.

[0079] This embodiment also provides a production process of shortening with high antioxidant properties, comprising the following steps:

[0080] S1, mixing soybean oil capable of forming β' crystal form to obtain a fat mixture, adding immobilized Lipozyme 435 lipase to the fat mixture, performing an ester exchange reaction at a temperature range of 60-90° C., and after the reaction, separating the immobilized Lipozyme 435 lipase by centrifugation to obtain an ester exchanged fat;

[0081] S2. Add the zein nanoparticles coated with the composite antioxidant, the polyglycerol fatty acid ester polyethylene glycol solid dispersion, and water to the transesterified oil according to the formula amount, and stir evenly;

[0082] S3. Through a scraped surface heat exchanger, the shortening is subjected to a rapid cooling process and a kneading process. The temperature of the rapid cooling process is 16.5° C., the stirring rate of the kneading process is 560 r / min, and the stirring time is 6 min. After aging, shortening with high antioxidant properties is produced.

[0083] Example 4

[0084] The shortening provided in this embodiment has high antioxidant properties, which comprises, by weight, 81 parts of β'-crystal rapeseed oil, 0.3 parts of zein nanoparticles coated with a composite antioxidant, 0.5 parts of a polyglycerol fatty acid ester polyethylene glycol solid dispersion, and 15 parts of water.

[0085] In this embodiment, the composite oxidant is a natural antioxidant, which is composed of vitamin E (VE), butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and clove essential oil.

[0086] This embodiment also provides a production process of shortening with high antioxidant properties, comprising the following steps:

[0087] S1, mixing rapeseed oil capable of forming β' crystal form to obtain a fat mixture, adding immobilized Lipozyme 435 lipase to the fat mixture, performing an ester exchange reaction at a temperature range of 60-90° C., and after the reaction, separating the immobilized Lipozyme 435 lipase by centrifugation to obtain an ester exchanged fat;

[0088] S2. Add the zein nanoparticles coated with the composite antioxidant, the polyglycerol fatty acid ester polyethylene glycol solid dispersion, and water to the transesterified oil according to the formula amount, and stir evenly;

[0089] S3. Through a scraped surface heat exchanger, the shortening is subjected to a rapid cooling process and a kneading process. The temperature of the rapid cooling process is 16.5° C., the stirring rate of the kneading process is 560 r / min, and the stirring time is 6 min. After aging, shortening with high antioxidant properties is produced.

[0090] Comparative Example 1

[0091] Different from Example 1, this comparative example provides a shortening with high antioxidant properties, comprising 80 parts of β'-crystal palm oil, 0.5 parts of zein nanoparticles coated with a composite antioxidant, 0.8 parts of polyglycerol fatty acid ester, and 15 parts of water.

[0092] In this comparative example, the composite oxidant is a natural antioxidant, which is composed of vitamin E (VE), butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and clove essential oil.

[0093] Comparative Example 2

[0094] Different from Example 1, the shortening with high antioxidant property provided in this comparative example comprises 80 parts of β'-crystal palm oil, 0.5 parts of composite antioxidant, 0.8 parts of polyglycerol fatty acid ester polyethylene glycol solid dispersion and 15 parts of water.

[0095] In this comparative example, the composite oxidant is a natural antioxidant, which is composed of vitamin E (VE), butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and clove essential oil.

[0096] Comparative Example 3

[0097] Different from Example 1, the shortening with high antioxidant property provided in this comparative example comprises 80 parts of β'-crystal palm oil, 0.5 parts of composite antioxidant, 0.8 parts of polyglycerol fatty acid ester and 15 parts of water.

[0098] In this comparative example, the composite oxidant is a natural antioxidant, which is composed of vitamin E (VE), butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and clove essential oil.

[0099] Experimental example

[0100] Antioxidant performance test

[0101] Principle: The prepared oil sample is dissolved in chloroform and glacial acetic acid, and a saturated potassium iodide solution is added. The peroxide in it reacts with potassium iodide to generate iodine. The precipitated iodine is titrated with a standard sodium thiosulfate titration solution. The peroxide value is expressed as the mass fraction of peroxide equivalent to iodine. The peroxide value is an important indicator for measuring the degree of oxidation of oils and fats, reflecting the content of peroxides in the oils and fats. The higher the peroxide value, the higher the peroxide content in the oils and fats, and the more serious the oxidation of the oils and fats.

[0102] According to the determination method provided in the "National Food Safety Standard Determination of Peroxide Value in Food" (GB 5009.227), the peroxide value (PV) of the shortening with high antioxidant properties prepared in Examples 1-4 was determined. The peroxide value is an important indicator for measuring the degree of oil oxidation. The higher the peroxide value, the more serious the oil oxidation.

[0103] Testing process:

[0104] 1. Sample Preparation

[0105] Edible hydrogenated oil, shortening, cocoa butter substitute

[0106] For solid samples, select representative samples and place them in a sealed container for mixing before sampling. If necessary, place the sealed container containing the solid sample in a constant temperature water bath, slowly heat it until it is just melted, melt it completely at this temperature, shake it to mix it, and take a sample for measurement immediately while the sample is in liquid state.

[0107] Determination of samples

[0108] Avoid testing samples under direct sunlight. Avoid strong light during sample preparation, and weigh shortening as soon as possible after preparation.

[0109] The shortenings with high antioxidant properties prepared in Examples 1-4 and Comparative Examples 1-3 were stored at -20°C, taken out for experiment, slowly rewarmed, stirred for a period of time after rewarming, and averaged. 2 g to 3 g (accurate to 0.001 g) of shortening samples with high antioxidant properties prepared in Examples 1-4 and Comparative Examples 1-3 were weighed respectively, placed in a 250 mL iodine volumetric flask, 30 mL of chloroform-glacial acetic acid mixture was added, and the sample was gently shaken until it was completely dissolved; 1.00 mL of potassium iodide saturated solution was accurately added. , plug the bottle cap tightly, shake gently for 0.5min, and place in a dark place for 3min; take out and add 100mL water, shake well and immediately titrate the precipitated iodine with sodium thiosulfate standard titration solution (when the peroxide value is estimated to be 0.15g / 100g or less, use 0.002mol / L standard titration solution: when the peroxide value is estimated to be greater than 0.15g / 100g, use 0.01mol / L standard titration solution) and titrate to light yellow, add 1mL starch indicator, continue titration and shake vigorously until the blue color of the solution disappears as the end point. At the same time, a blank test is performed, and the volume V0 of the sodium thiosulfate standard titration solution consumed in the blank test shall not exceed 0.1mL. The calculation results are expressed as the arithmetic mean of the two independent determination results obtained under repeatability conditions, and the results retain two significant figures. The peroxide value determination results of the shortening samples with high antioxidant properties prepared in Examples 1-4 and Comparative Examples 1-3 are shown in Table 1.

[0110] When the peroxide value is expressed as the mass fraction of peroxide equivalent to iodine, it is calculated according to the following formula:

[0111]

[0112] Where:

[0113] X1-peroxide value, the unit is the mass fraction of peroxide equivalent to iodine per 100 grams of sample (g / 100g);

[0114] V-volume of sodium thiosulfate standard titration solution consumed by the sample / oil extract, in milliliters (mL);

[0115] V0-the volume of sodium thiosulfate standard titration solution consumed in the blank test, in milliliters (mL);

[0116] C-concentration of sodium thiosulfate standard titration solution, in moles per liter (mol / L);

[0117] 0.1269 - the mass of iodine equivalent to 1.00 mL of sodium thiosulfate standard titration solution [c(Na2S2O3) = 1.000 mol / L], in grams per millimole (g / mmol);

[0118] 100-conversion factor converted to 100g of sample / oil extract;

[0119] m-sample mass, in grams (g); 0.02538

[0120] Table 1

[0121]

[0122]

[0123] It can be seen from the measurement results in Table 1 that, compared with the shortening samples with high antioxidant properties provided by Comparative Examples 1-3, the peroxide values ​​of the shortening samples with high antioxidant properties provided by Examples 1-4 are significantly lower than the peroxide values ​​of the shortening samples with high antioxidant properties provided by Comparative Examples 1-3; when Example 1 is compared with Comparative Example 1, and Comparative Example 2 is compared with Comparative Example 3, the peroxide value of the shortening sample with high antioxidant properties provided by Example 1 is significantly lower than that of Comparative Example 1, and the peroxide value of the shortening sample with high antioxidant properties provided by Comparative Example 2 is significantly lower than that of Comparative Example 3, indicating that the polyglycerol fatty acid ester polyols have good The ethylene glycol solid dispersion can significantly improve the solubility and dissolution rate of polyglycerol fatty acid esters in water by highly dispersing polyglycerol fatty acid esters in the solid carrier polyethylene glycol, can effectively improve the problem of low solubility of polyglycerol fatty acid esters in low temperature environment, improve its performance and effect in preventing oil crystallization, and indirectly improve the antioxidant performance of shortening samples with high antioxidant properties; the peroxide value of the shortening sample with high antioxidant properties provided by comparative example 1 is significantly higher than that of comparative example 2, indicating that the low solubility of polyglycerol fatty acid esters in low temperature environment has a great influence on the shortening sample with high antioxidant properties. Compared with comparative example 2, the peroxide value of the shortening sample with high antioxidant properties provided by Example 1 is significantly lower than that of comparative example 2, indicating that the composite antioxidant of the present invention is embedded in the zein nanoparticles, thereby improving the distribution of the composite antioxidant at the emulsion interface and enhancing the antioxidant activity of the composite antioxidant. The peroxide value of the shortening sample with high antioxidant properties provided in Comparative Example 2 is significantly higher than that of Comparative Example 3, indicating that the low solubility of polyglycerol fatty acid esters in low temperature environments has a great influence on the shortening sample with high antioxidant properties.

[0124] Texture Instrument Hardness Test Results

[0125] The shortenings with high antioxidant properties prepared in Examples 1-4 and Comparative Examples 1-3 were stored at -20°C, taken out during the experiment, slowly rewarmed, and the hardness of the shortening samples with high antioxidant properties prepared in Examples 1-4 and Comparative Examples 1-3 was directly measured using a texture analyzer, which can quantify the degree of hardening of the texture. The higher the hardness value, the harder the shortening. The surface of the sample was touched by hand to evaluate the roughness of the sample, and the results are shown in Table 2.

[0126] Texture curve analysis (TPA) The movement trajectory of the probe during TPA testing is: the probe starts from the starting position, first presses against the test sample at a certain rate, and then compresses the sample at a certain distance at the test rate after contacting the surface of the sample, and then returns to the compression trigger point, stays for a period of time and continues to compress the same distance downward, and then returns to the position before the probe is tested at the post-test rate. The hardness value is the maximum peak value during the first compression.

[0127] Table 2

[0128] Example Hardness(g) Roughness sensory test Example 1 126.523 Delicate and silky Example 2 163.854 Delicate and silky Example 3 152.451 Delicate and silky Example 4 139.843 Delicate and silky Comparative Example 1 523.623 Strong sense of roughness Comparative Example 2 182.653 Delicate and silky Comparative Example 3 546.325 Strong sense of roughness

[0129] It can be seen from the measurement results in Table 1 that, compared with the shortening samples with high antioxidant properties provided by Comparative Examples 1-3, the hardness values ​​of the shortening samples with high antioxidant properties provided by Examples 1-4 are significantly lower than the hardness values ​​of the shortening samples with high antioxidant properties provided by Comparative Examples 1-3; the shortenings with high antioxidant properties provided by Comparative Examples 1 and 3 do not have polyglycerol fatty acid ester polyethylene glycol solid dispersions prepared, and their hardness values ​​are significantly high, indicating that the polyglycerol fatty acid ester polyethylene glycol solid dispersion can significantly improve the solubility and dissolution rate of polyglycerol fatty acid ester in water by highly dispersing polyglycerol fatty acid ester in the solid carrier polyethylene glycol, can effectively improve the problem of low solubility of polyglycerol fatty acid ester in low temperature environment, improve its performance and effect in preventing oil crystallization, directly reduce the hardness of the shortening samples with high antioxidant properties, and the roughness sensory evaluation is delicate and silky; while the sensory evaluation of the shortenings with high antioxidant properties provided by Comparative Examples 1 and 3 is strong in roughness.

[0130] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A shortening with high antioxidant properties, characterized in that: According to weight parts, it comprises 75-82 parts of β' crystal oil, 0.1-0.5 parts of zein nanoparticles coated with composite antioxidant, 0.5-0.8 parts of polyglycerol fatty acid ester polyethylene glycol solid dispersion, and 15-17 parts of water.

2. A shortening with high antioxidant properties as claimed in claim 1, characterized in that: In parts by weight, the composition comprises 80 parts of β'-crystal oil, 0.5 parts of zein nanoparticles coated with a composite antioxidant, 0.8 parts of a polyglycerol fatty acid ester polyethylene glycol solid dispersion, and 15 parts of water.

3. The shortening with high oxidation resistance as claimed in claim 1, characterized in that: The polyglycerol fatty acid ester polyethylene glycol solid dispersion is prepared by hot melt extrusion, spray drying and coprecipitation.

4. The shortening with high oxidation resistance as claimed in claim 1, characterized in that: The composite oxidant is a natural antioxidant, which consists of vitamin E, butylated hydroxytoluene, butylated hydroxyanisole and clove essential oil.

5. The shortening with high antioxidant properties as claimed in claim 1, characterized in that: The β' crystal oil is a mixture of one or more of palm oil, cottonseed oil, soybean oil and rapeseed oil.

6. The shortening with high antioxidant properties as claimed in claim 1, characterized in that: The specific preparation steps of the zein nanoparticles coated with the composite antioxidant are as follows: S1, dissolving components: dissolving the composite antioxidant and zein particles in ethanol with a mass percentage of 80% to 92%; S2, injecting anti-solvent: injecting the ethanol solution containing the composite antioxidant and the zein particles into water or carbon dioxide supercritical fluid to form nanoparticles, and spray drying to form the zein nanoparticles coated with the composite antioxidant.

7. A shortening with high antioxidant properties as claimed in claim 6, characterized in that: In step S2, the anti-solvent is one of water and supercritical carbon dioxide.

8. A process for producing shortening with high antioxidant properties according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, mixing oils and fats capable of forming β' crystal forms to obtain an oil and fat mixture, adding immobilized Lipozyme 435 lipase to the oil and fat mixture, and performing an ester exchange reaction at a temperature range of 60-90° C. After the reaction, centrifugally separating the immobilized Lipozyme 435 lipase to obtain an ester exchange oil and fat; S2, adding the zein nanoparticles coated with the composite antioxidant, the polyglycerol fatty acid ester polyethylene glycol solid dispersion, and the water to the transesterified oil according to the formula amount, and stirring evenly; S3, through a scraper heat exchanger, through a rapid cooling process, a kneading process, and then through aging, the shortening with high oxidation resistance is produced.

9. The process for producing shortening with high oxidation resistance as claimed in claim 8, characterized in that: In step S3, the temperature of the rapid cooling process is 16.5°C, the stirring rate of the kneading process is 560r / min, and the stirring time is 6min.

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