阅读说明：本技术 一种dha功能饼干及其制备方法 (DHA functional biscuit and preparation method thereof ) 是由 刘丽萍 赵祥颖 张家祥 杨丽萍 韩墨 姚明静 刘建军 于 2021-09-06 设计创作，主要内容包括：本发明属于食品加工领域,具体涉及一种DHA功能饼干及其制备方法。所述DHA功能饼干,包括：含有DHA的微藻菌体或提取部分DHA油脂后的微藻细胞残渣5-15份,低筋粉20-30份,泡打粉0.1-0.2份,黄油3-5份,发面酵母0.3-0.5份。本发明将产DHA的微藻菌体或提取部分DHA油脂后的微藻细胞残渣用于饼干的制备,其优越性一方面实现在微藻的全资源化利用,相比目前饲料应用而言提高了附加值；另一方面采用微藻菌体或分离部分DHA油脂的细胞残渣为原料,用于人们膳食强化DHA,可以大幅降低DHA藻油原料成本,价格亲民。另外,饼干为人们生活中最常见的休闲零食,更容易被消费者接受。(The invention belongs to the field of food processing, and particularly relates to a DHA functional biscuit and a preparation method thereof. The DHA functional biscuit comprises: 5-15 parts of microalgae thallus containing DHA or microalgae cell residue after partial DHA oil extraction, 20-30 parts of low-gluten flour, 0.1-0.2 part of baking powder, 3-5 parts of butter and 0.3-0.5 part of leaven. According to the invention, the microalgae thalli for producing DHA or microalgae cell residues after partial DHA grease extraction are used for preparing biscuits, on one hand, the full resource utilization of microalgae is realized, and the added value is improved compared with the current feed application; on the other hand, microalgae thalli or cell residues for separating partial DHA oil are used as raw materials for dietary enrichment of DHA, so that the cost of DHA algae oil raw materials can be greatly reduced, and the price is compatible with the people. In addition, the biscuits are the most common leisure snacks in people's lives and are more easily accepted by consumers.)

1. A DHA functional biscuit is characterized in that: comprises 5-15 parts of microalgae thallus containing DHA or microalgae cell residue after partial DHA oil extraction, 20-30 parts of low-gluten flour, 0.1-0.2 part of baking powder, 3-5 parts of butter and 0.3-0.5 part of leaven.

2. A functional DHA biscuit according to claim 1, wherein: the DHA functional biscuit also comprises 1-3 parts of white granulated sugar or erythritol, preferably erythritol.

3. A functional DHA biscuit according to claim 2, wherein: the DHA functional biscuit further comprises one or more of vegetable oil, milk powder and starch.

4. Method for the preparation of functional DHA biscuits according to any of the claims 1-3, characterized in that:

homogenizing microalgae thallus containing DHA or microalgae cell residue after extracting part of DHA oil to emulsify, taking the obtained product as base material, adding other ingredients, blending, placing into a container, covering with a preservative film, proofing, taking out the rolled surface to discharge bubbles, and placing into a baking tray paved with oil absorbing paper or tinfoil paper for heating and baking.

5. The method of claim 4, wherein: the homogenization treatment is carried out at 200-400 bar.

6. The method of claim 4, wherein: fermenting at 40-50 deg.C for 30-50 min.

7. The method of claim 4, wherein: rolling the dough for 3-5 times until the dough is about 2-3mm thin pancake, and molding with a biscuit mold.

8. The method of claim 4, wherein: the baking temperature is 130-200 ℃, and preferably 123-150 ℃.

9. The method of claim 4, wherein: the preparation method of the microalgae thallus containing DHA comprises the following steps: suspending DHA grease-producing microalgae cells with 1-2% saline solution with the volume about 2-4 times of the wet weight of the cells as a suspension medium, uniformly mixing, centrifugally washing for 1-2 times, and suspending with 1-2% saline solution to obtain a microalgae thallus suspension containing DHA.

10. The method of claim 9, wherein: the preparation method of the microalgae cell residue after extracting partial DHA oil comprises the following steps: homogenizing the microalgae thallus suspension containing DHA under the pressure of 200-300bar, centrifuging at 8000-10000 r/min for 5-10min, and separating upper-layer grease to obtain residue;

or, remixing the materials after the first homogenization and centrifugal separation of the grease for the second homogenization, and centrifugally separating the grease on the upper layer again to obtain the residue.

Technical Field

The invention belongs to the field of food processing, and particularly relates to a DHA functional biscuit and a preparation method thereof.

Background

The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.

Docosahexaenoic acid (DHA), commonly known as "brain gold", is one of the polyunsaturated fatty acids essential to the human body. DHA is an important constituent of brain and retina, is a fatty acid necessary for the good development of visual function of animals and infants in embryonic stage and early life, and is also an important functional component for maintaining normal vision. The intake of sufficient DHA can help to delay the aging of the brain and play an obvious role in repairing the encephalocyte atrophy and death caused by age and other factors. Meanwhile, DHA also has the effects of preventing cardiovascular diseases, resisting thrombus and inflammation, inhibiting anaphylactic reaction, preventing senile dementia, preventing cancer and the like. The antithrombotic effect of DHA is to inhibit the cyclooxygenase of Arachidonic Acid (AA) and reduce the synthesis of thromboxane A2(TXA2), thereby maintaining the prostacyclin I2(PGI2)/TXA2 balance. DHA reduces blood pressure by regulating the normal metabolism of blood lipid and lipoprotein in human body, reducing blood viscosity and cholesterol level in blood, and increasing high density lipoprotein content. DHA cannot be synthesized in the human body by itself and can only be transformed by means of dietary supplementation. At present, the human dietary structure is relatively lack of DHA, so the development and utilization of DHA resources become one of the popular directions of research of grease scientists, nutriologists, biochemists, medical researchers and the like in various countries in the world, and the development of DHA-containing food with a relative price is significant.

The DHA in the deep sea fish oil is derived from marine microalgae, and the DHA is produced by the marine microalgae through a fermentation method, so that the deep sea fish oil is not limited by raw materials and production places, has no seasonal and climatic dependence, and effectively reduces environmental hazards caused by over-fishing. DHA oil produced by a microalgae fermentation method exists in cells, DHA oil extraction firstly needs wall breaking treatment on microalgae cells, then oil separation is carried out by a centrifugation or extraction method, and the separated oil is further refined to obtain the commercial DHA algae oil. The commercial DHA algae oil is expensive, and is usually added into high-value commodities such as health food, infant formula food and the like, so that the application of the DHA is limited. Therefore, providing a low-cost functional food of DHA would be of great importance to balance DHA in the dietary structure of people.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides the DHA functional biscuit and the preparation method thereof, the DHA biscuit takes microalgae thalli containing DHA or microalgae cell residues after partial DHA grease extraction as raw materials for providing DHA, and can provide a DHA supplement functional food with a price close to the people for consumers and realize the full-resource value-added processing of microalgae.

In order to achieve the above object, a first aspect of the present invention provides a DHA functional biscuit, comprising: 5-15 parts of microalgae thallus containing DHA or microalgae cell residue after partial DHA oil extraction, 20-30 parts of low-gluten flour, 0.1-0.2 part of baking powder, 3-5 parts of butter and 0.3-0.5 part of leaven;

the second aspect of the invention provides a preparation method of the DHA functional biscuit, which comprises the following specific steps:

homogenizing microalgae thallus containing DHA or microalgae cell residue after extracting part of DHA oil to emulsify, taking the obtained product as base material, adding other ingredients, blending, placing into a container, covering with a preservative film, proofing, taking out the rolled surface to discharge bubbles, and placing into a baking tray paved with oil absorbing paper or tinfoil paper for heating and baking.

One or more embodiments of the present invention have at least the following advantageous effects:

according to the invention, the microalgae thallus for producing DHA or the microalgae cell residue after partial DHA grease extraction is used for preparing biscuits, on one hand, the full resource utilization of microalgae is realized, and compared with the application of the residue as feed at present, the added value is improved; on the other hand, microalgae thalli or cell residues for separating partial DHA grease are used as raw materials for dietary enrichment of DHA, so that the raw material cost of DHA food can be greatly reduced, and the price is compatible with the people.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.

Fig. 1 is a photograph of a cooked DHA functional biscuit.

Detailed Description

It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

As described in the background art, commercial DHA algal oil is expensive, and is generally added to high-value goods such as health food and infant formula food, and the application of DHA is limited, and the addition of DHA to low-value food cannot be realized.

In order to solve the above technical problems, a first aspect of the present invention provides a DHA functional biscuit, comprising: 5-15 parts of microalgae thallus containing DHA or microalgae cell residue after partial DHA oil extraction, 20-30 parts of low-gluten flour, 0.1-0.2 part of baking powder, 3-5 parts of butter and 0.3-0.5 part of leaven.

Part of DHA oil still remains in the microalgae residue after extraction of the DHA oil, and meanwhile, the residue also contains rich nutrient substances such as protein, trace elements, vitamins, polysaccharide and the like. At present, the microalgae cell residues after DHA oil extraction are mainly used for feed production at present, the price is low, and in fact, the residues can provide a certain amount of DHA components in a food formula and can also be used as a source of macronutrients and micronutrients to endow food with more comprehensive nutrition and functions.

Therefore, the microalgae thallus or the microalgae cell residue after partial DHA oil extraction is used as a DHA source of the biscuit to replace expensive commodity DHA algae oil in the traditional process, so that the microalgae cell residue after DHA oil extraction, which is originally used as a low-value raw material, can be effectively recycled, and the added value of the microalgae cell residue is improved; the DHA is provided by taking microalgae thalli or microalgae cell residues after partial DHA grease extraction as raw materials, and the preparation of DHA functional food can greatly reduce the raw material cost and realize that the DHA is widely added into common low-value food.

In one or more embodiments of the invention, the DHA functional biscuit further comprises 1-3 parts of white granulated sugar or erythritol, preferably erythritol. The white granulated sugar and the erythritol serve as sweeteners to improve the taste of the biscuit, and the erythritol is preferably used because the erythritol can serve as a sweetener, has a certain antioxidation effect and can have a certain protection effect on DHA.

Furthermore, the DHA functional biscuit also comprises other common auxiliary materials for biscuit processing, such as vegetable oil, milk powder, starch and the like.

The second aspect of the invention provides a preparation method of the DHA functional biscuit, which comprises the following specific steps:

homogenizing microalgae thallus containing DHA or microalgae cell residue after extracting part of DHA oil to emulsify, taking the obtained product as base material, adding other ingredients, blending, placing into a container, covering with a preservative film, proofing, taking out the rolled surface to discharge bubbles, and placing into a baking tray paved with oil absorbing paper or tinfoil paper for heating and baking.

Further, the homogenization treatment is carried out at 200-400 bar.

Further, fermenting at 40-50 deg.C for 30-50 min.

Further, after rolling, folding and rolling for 3-5 times until the thickness of the thin pancake is about 2-3mm, and molding by using a biscuit mold.

Further, the baking temperature is 130-200 ℃, preferably 123-150 ℃;

the homogenizing treatment process specifically comprises the following steps:

the preparation method of the microalgae thallus containing DHA comprises the following steps: suspending DHA grease-producing microalgae cells with 1-2% saline solution with the volume about 2-4 times of the wet weight of the cells as a suspension medium, uniformly mixing, centrifugally washing for 1-2 times, and suspending with 1-2% saline solution to obtain a microalgae thallus suspension containing DHA;

the preparation method of the microalgae cell residue after extracting partial DHA oil comprises the following steps: homogenizing the microalgae thallus suspension containing DHA under 200bar pressure, centrifuging at 8000-10000 r/min for 5-10min, and separating upper layer oil to obtain residue;

or, remixing the materials after the first homogenization and centrifugal separation of the grease for the second homogenization, and centrifugally separating the grease on the upper layer again to obtain the residue.

In order to make the technical solutions of the present invention more clearly understood by those skilled in the art, the technical solutions of the present invention will be described in detail below with reference to specific embodiments.

1 materials of the experiment

Taking DHA to produce schizochytrium limacinum fermentation liquid, centrifuging at 4500r/min for 5min, discarding supernatant, and collecting schizochytrium limacinum cells. Washing out residual fermentation medium of cells by using 1% saline solution, and collecting microalgae cells containing DHA oil as experimental materials. The content of total oil and fat in the cells is 58 percent and the content of DHA in the oil and fat is 43.5 percent through analysis and determination.

2 method of experiment

Preparing 1% saline: 10g of edible salt was weighed and dissolved in 1L of water.

Cell suspension preparation: the cell concentration was adjusted to 5-10% (based on dry cell weight) with saline.

Homogenizing and breaking the wall: the prepared cell suspension was homogenized by ATS AH-BASIC high pressure homogenizer. And in the homogenizing process, the temperature of the material is controlled below 30 ℃ to avoid the damage of DHA grease.

Oil separation: homogenizing the cell suspension, and centrifuging at 5000r/min for 5min to separate upper layer oil.

Preparing a DHA functional biscuit processing base material:

base material I: taking the cell suspension, and homogenizing the cell suspension by using the pressure of 200-400bar until the material liquid is emulsified.

Base material II: taking the cell suspension, homogenizing at 200-400bar once, centrifuging to separate the upper layer oil, mixing the rest part, and homogenizing until the material liquid is emulsified.

Base material III: homogenizing the cell suspension at 200-400bar once, centrifuging to separate upper-layer oil, re-mixing the rest part uniformly at 200-400bar for secondary homogenization, centrifuging to separate upper-layer oil, and mixing the rest materials for homogenization until the material liquid is emulsified.

Base material IV: homogenizing the cell suspension at 200-400bar once, centrifuging to separate upper-layer grease, re-mixing the rest part uniformly at 200-400bar for secondary homogenization, centrifuging to separate upper-layer grease, performing tertiary homogenization on the rest part at 200-400bar, centrifuging to separate upper-layer grease, and mixing the rest materials for homogenization until the material liquid is emulsified.

Base material V: taking the cell suspension, homogenizing at 200-400bar for one time, centrifugally separating the upper layer grease, removing the middle medium layer, and directly taking the residual wet cell residues as raw materials.

And (3) biscuit processing: determining a basic formula of the biscuit according to the variety of common biscuits, weighing ingredients, adding DHA base stock, uniformly blending, putting into a container, covering with a preservative film, fermenting at 45 ℃ for 40min, taking out rolled noodles to discharge bubbles, rolling the rolled noodles to about 3mm thin cakes by 3 times of folding, modeling by using the biscuit, and putting into a baking tray paved with oil absorbing paper or tinfoil paper to heat and bake.

And (3) measuring grease and DHA in the biscuit: the determination is carried out according to GB 5008.168-2016 (determination of fatty acid in food safety national standard food).

Determination of acid value of biscuits: the determination is carried out according to GB 5009.229-2016 (determination of acid value in national food safety standard).

Determination of the peroxide value of the biscuit: the determination is carried out according to GB 5009.227-2016 (determination of peroxide value in national food safety standard).

Sensory evaluation of algae oil DHA biscuit products: 11 sensory evaluators with relevant professional levels were selected and the prepared biscuits were scored with reference to colour (20%), morphology (30%), texture (20%), flavour and taste (30%) of the biscuits, the scoring criteria being shown in table 1.

TABLE 1 algal oil DHA biscuit sensory evaluation criteria

And (3) investigating the shelf life of the algae oil DHA biscuit: dividing the algae oil DHA biscuit products into 7 groups, respectively placing in a constant temperature incubator at 45 ℃, measuring the acid value and the peroxide value once every 7 days, and observing the change of the products.

Effect of algal oil DHA cookie packaging format on shelf life: the algae oil DHA biscuits are randomly divided into 3 groups and are treated as follows: (1) common packaging; (2) vacuum packaging; (3) and (5) modified atmosphere packaging (filling nitrogen), periodically measuring the acid value and the peroxide value of the product, and analyzing the influence of the packaging form on the quality of the algae oil DHA biscuit.

3 results of the experiment

1) Biscuit prepared from four matrixes and having sensory evaluation score and DHA content

Weighing 100g of low-gluten flour, 10g of white granulated sugar, 0.5g of baking powder, 15g of butter and 1.5g of leaven, respectively adding 50g of four base materials I, II, III and IV, uniformly mixing, proofing, molding by biscuit, putting into a baking tray paved with oil-absorbing paper or tin foil paper, and heating and baking for 15min at 170 ℃ in an upper and lower tube. Taking out, cooling to room temperature, performing sensory evaluation, and determining the DHA content in the biscuit, wherein the results are shown in Table 2.

TABLE 2 comparison of biscuits made with four bases

2) Effect of baking temperature on DHA

Weighing 100g of low-gluten flour, 10g of white granulated sugar, 0.5g of baking powder, 15g of butter and 1.5g of leaven, adding 50g of base material, uniformly blending, proofing, modeling by using biscuits, putting into a baking tray paved with oil-absorbing paper or tin foil paper, respectively selecting different baking temperatures (heating the upper and lower tubes of the baking tray), and observing the influence of the baking temperature on DHA by using the surface color change of the biscuits as the baking finish time. Taking out, cooling to room temperature, performing sensory evaluation, and determining the DHA content in the biscuit, wherein the results are shown in Table 2.

TABLE 3 Effect of baking temperature on biscuit DHA

DHA is polyunsaturated fatty acid and is relatively easy to oxidize, and the oxidized DHA not only loses the original nutrition and medical value, but also is harmful to human bodies. The baking temperature is therefore a critical factor affecting the oxidative stability of DHA throughout the processing of the baked product. The baking temperature of the microalgae DHA biscuit is not too high.

3) Effect of erythritol addition on biscuit DHA

Weighing 100g of low-gluten flour, 0.5g of baking powder, 15g of butter and 1.5g of leaven, adding 50g of base material I, then respectively adding different amounts of erythritol, uniformly blending, fermenting, shaping, putting into a baking tray paved with oil absorption paper or tin foil paper, baking at 130 ℃ for 10min, then baking at 150 ℃ for 15min, and investigating the influence of erythritol addition on DHA.

TABLE 4 Effect of erythritol addition on biscuit DHA

Erythritol is a sweetener with zero calorific value, does not participate in sugar metabolism, is suitable for people with diabetes and obesity, and has sweetness of about 70% of that of sucrose. The erythritol is adopted to replace white granulated sugar, and the result shows that the erythritol not only can be used as a sweetener, but also has a certain antioxidation effect and a certain protection effect on DHA. The erythritol has certain moisture retention property, and is suitable for biscuits with crisp mouthfeel, such as tough biscuits, wafers and the like.

4) Inspection of shelf life of algae oil DHA biscuits

Weighing 1000g of low-gluten flour, 100g of erythritol (dissolved in a base material), 5g of baking powder, 150g of butter and 15g of leaven, adding 500g of a base material II, uniformly mixing, kneading into dough, rolling into a thin cake with the thickness of 3mm after proofing, modeling with a biscuit, spreading in a baking tray paved with oil absorption paper, and baking at 150 ℃ for 15min after 10min at 130 ℃. Dividing the cooled biscuits into 21 groups, wherein seven groups are sealed by food bags in a heat sealing mode, seven groups of packaging bags are sealed after vacuum air exhaust, 7 groups of packaging bags are sealed after nitrogen gas is filled in the packaging bags, and the packaging bags are respectively placed in a constant-temperature incubator at 45 ℃. And taking out three packages every 7 days, respectively taking out one package, measuring peroxide value and acid value, and performing sensory evaluation.

TABLE 5 survey of shelf life of algal oil DHA biscuits

The results show that the sensory score of the biscuit is reduced along with the increase of time when the biscuit is stored at the temperature of 45 ℃, and the smell of the dried fish appears at the later stage, but the eating is not influenced.

In order to prevent the oxidation of polyunsaturated fatty acids (PUFA), such as DHA, during storage, oxygen is sequestered by evacuation and nitrogen charging. The peroxide number reflects the degree of oxidation of PUFAs, and the oxygen barrier packaging has been shown to reduce the oxidation of PUFAs such as DHA. The oxygen barrier package can also slow down the hydrolysis rancidity speed of the grease in the product.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.