Plant-based protein bar containing grape seed extract and preparation method thereof

Abstract

The invention belongs to the technical field of food processing, and particularly relates to a plant-based protein bar containing a grape seed extract and a preparation method of the plant-based protein bar. In order to solve the problems that an existing plant-based protein bar is poor in flavor, high in hardness, insufficient in storage stability and the like, the invention discloses a plant-based protein bar containing a grape seed extract (GSE) and a preparation method of the plant-based protein bar. And compounding the plant-based protein with chickpea protein powder, konjaku flour and other raw materials according to an optimized formula system, mixing, kneading, forming and baking to prepare the plant-based protein bar. The hardness of the protein bar can be remarkably reduced, the flavor is improved, the oxidation resistance of GSE is reserved to prolong the shelf life, the process is simple and convenient, the cost is controllable, the method is suitable for standardized production, and a new path is provided for quality optimization of the plant-based protein bar.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, specifically relating to a plant-based protein bar containing grape seed extract and its preparation method. Background Technology

[0002] Modern research shows that grape skins and seeds are not only important sources of vitamins and dietary fiber, but also rich in polyphenolic compounds, especially proanthocyanidins. These bioactive components can play a positive role in regulating bodily physiological functions. It is noteworthy that grape seeds are considered a highly valuable raw material in the food industry; at the same time, as a major byproduct of the wine industry, they are highly available, which facilitates their large-scale development and application.

[0003] Grape seed extract (GSE) possesses multiple biological activities, including anti-inflammatory, anti-apoptotic, anti-cellular necrosis, cardiovascular protection, and anti-tumor effects, and can play a positive regulatory role in various diseases such as skin aging. Simultaneously, GSE contains unique volatile aroma components such as alcohols, phenols, and terpenes, which can form covalent or non-covalent bonds with plant proteins, thus affecting the flavor characteristics of products. It is worth noting that most products in the food industry rely on chemically synthesized pigments. Although these pigments are inexpensive, they possess certain toxicity, posing a threat to consumer health. With the improvement of people's living standards and quality of life, the demand for healthy foods continues to rise. GSE can enhance the color of food, and its development based on natural products aligns with the concept of safe and natural health while also offering cost advantages, making it a promising candidate for a significant position in the future health industry. The polyphenols and flavonoids in GSE exhibit significant antioxidant activity and free radical scavenging capabilities, with advantages of safety, reliability, and high stability. Their antioxidant properties are even superior to vitamin C and vitamin E, with polyphenols showing particularly outstanding antioxidant performance. The total polyphenol content in GSE (Gross Sediment) is typically 80%-95%, with proanthocyanidins being the most abundant polyphenol component, accounting for over 70% of the total. Furthermore, proanthocyanidins can also act as preservatives, extending the shelf life of food and effectively reducing food safety issues. Against this backdrop, high-proanthocyanidin GSE has ushered in a broad development opportunity.

[0004] Chickpea protein ingredients have wide applications in the food industry. In grain products, its partial substitution of wheat flour can increase the protein content and nutritional value of pasta, bread, and other products, enhance rheological, functional, and sensory properties, and can also be used to prepare low-glycemic index pasta, catering to the needs of diabetic patients. In the meat products sector, adding chickpea protein concentrate to cooked sausages can improve product sensory characteristics, reduce lipid oxidation, enhance color stability during storage, and impart antioxidant properties. Its excellent gelling properties, emulsification stability, and foam stability make it a superior alternative to soy protein in sausage-like meat products. Compared to soy protein, chickpea protein has lower allergenicity and, due to its balanced amino acid composition and cost-effectiveness, is considered a potential alternative source of animal protein. Studies have shown that chickpea protein has better bioavailability and digestibility than soy protein, while also possessing superior solubility; well-soluble proteins are less prone to aggregation, a characteristic that helps alleviate the hardening problem during the storage of protein bars.

[0005] Currently, the most commonly used proteins in protein bars are milk protein and soy protein, while the application of chickpea protein is relatively limited. Protein bar manufacturers are also looking to develop products with different textures. Compared to milk protein, chickpea protein is more environmentally friendly and sustainable—it does not rely on animal feed, significantly reducing carbon emissions and water consumption. This core advantage of plant-based protein aligns perfectly with human health needs, driving a sustained surge in consumer demand for animal protein alternatives. However, the application of adding GSE (glucanase-hydrolyzed protein) treated with cellulase and pectinase in chickpea protein bars is extremely limited, especially in terms of systematic research on flavor control, texture optimization, and functional enhancement. Existing research indicates that the application of GSE in the food industry can not only improve product flavor, enhance storage stability, and reduce oxidative spoilage, but may also demonstrate unique advantages in the structural optimization of baked goods.

[0006] High-protein nutrition bars are high-protein, medium-moisture foods with a water activity between 0.5 and 0.9 and a moisture content of 10%-40%. They are mainly composed of protein, carbohydrates, sugar alcohols, glycerol, and water. These products are popular with consumers because they can effectively increase muscle mass, reduce the risk of muscle atrophy, and are convenient to eat, have a sweet taste, and high nutritional value. However, protein bars are prone to hardening during storage, leading to deterioration in texture and affecting storage stability.

[0007] Different processing methods significantly affect the firmness of protein bars. Some researchers have prepared high-protein nutrition bars using concentrated milk protein (MPC) with varying degrees of decalcification to reduce product firmness and improve texture. Other studies have focused on reducing firmness and improving texture by adding whey protein isolate and sodium caseinate at different extrusion temperatures, or by using air jet milling technology to prepare protein particles of different sizes. However, these processing techniques are complex and require significant investment of human and material resources, hindering industrial-scale production by suppliers.

[0008] In summary, how to prepare a plant-based protein bar that can reduce hardness, improve flavor, and enhance storage stability is an important issue that urgently needs to be explored. This research has significant positive implications for promoting the production, application, and promotion of plant-based protein bars. Summary of the Invention

[0009] To address the shortcomings of existing technologies and solve the problems of bland flavor and hard texture in plant-based protein bars, this invention provides a method for preparing plant-based protein bars containing GSE enzymatic hydrolysate. By optimizing the formulation system of the plant-based protein bars and precisely controlling the process parameters and reaction time of GSE enzymatic hydrolysis, the protein bars are given better softness and palatable flavor. Moreover, this processing technology is simple to operate, easy to standardize, and can meet the needs of deep processing applications in baked goods.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of the present invention provides a plant-based protein bar containing grape seed extract, wherein the raw materials used in the plant-based protein bar include chickpea protein powder, grape seed extract (GSE) hydrolysate, konjac powder, glycerin, corn syrup, maltitol, and corn oil.

[0011] Preferably, the plant-based protein bar comprises the following raw materials in parts by weight: 10-20 parts chickpea protein powder, 20-25 parts grape seed extract (GSE) hydrolysate, 3-5 parts konjac powder, 2-4 parts glycerin, 8-12 parts corn syrup, 8-12 parts maltitol, and 5-8 parts corn oil.

[0012] More preferably, the plant-based protein bar comprises the following ingredients in parts by weight: 15 parts chickpea protein powder, 20-25 parts grape seed extract (GSE) hydrolysate, 4 parts konjac powder, 3 parts glycerin, 10 parts corn syrup, 10 parts maltitol, and 6.5 parts corn oil.

[0013] Preferably, the preparation method of the grape seed extract (GSE) enzymatic hydrolysate is as follows: dissolve grape seed extract (GSE) in water, adjust the pH value to 4-5, add pectinase and cellulase, inactivate the enzymes after enzymatic hydrolysis, and collect the supernatant by centrifugation to obtain the enzymatic hydrolysate.

[0014] More preferably, the enzymatic hydrolysis is performed at 40-50 °C and 300-500 r / min for 7-10 h.

[0015] More preferably, the mass ratio of grape seed extract (GSE), pectinase and cellulase is 30:0.077-0.117:0.043-0.065.

[0016] A second aspect of the present invention also provides a method for preparing the plant-based protein bars described in the first aspect, the method comprising the following steps: S1. Prepare the dough: Mix chickpea protein powder with konjac powder, then mix grape seed extract (GSE) hydrolysate with glycerin, corn syrup, maltitol and corn oil. Combine the two mixtures and knead to form a uniform dough. S2. Shaping the raw dough: Press the dough from S1 into the mold, press it firmly to shape it, then take it out and divide it into equal squares; S3. Baking and Packaging: The formed protein bar blanks are baked, removed and cooled to room temperature, and then sealed and stored in vacuum packaging bags.

[0017] Preferably, in step S2, before pressing the dough, a layer of silicone paper is laid on the surface of the dough to prevent sticking.

[0018] Preferably, in step S3, the baking temperature is 110-130 ℃ and the baking time is 25-40 min.

[0019] Compared with the prior art, the beneficial effects of the present invention are: To address the issues of poor flavor, high hardness, and insufficient storage stability in existing plant-based protein bars, this invention discloses a plant-based protein bar containing grape seed extract (GSE) and its preparation method. First, GSE is enzymatically hydrolyzed using pectinase and cellulase to prepare a GSE hydrolysate. Then, this hydrolysate is compounded with chickpea protein powder, konjac flour, and other raw materials using an optimized formulation system. The mixture is then kneaded, shaped, and baked to produce the plant-based protein bar. This invention significantly reduces the hardness of the protein bar, improves its flavor, and retains the antioxidant properties of GSE to extend shelf life. The process is simple, cost-controllable, and suitable for standardized production, providing a new pathway for optimizing the quality of plant-based protein bars.

[0020] Specifically, the present invention has the following advantages: (1) High softness and cost-saving: This invention improves the texture of plant protein bars by adding GSE enzymatic hydrolysate. Texture test results show that GSE enzymatic hydrolysate can effectively reduce the hardness of protein bars; the effect of improving product texture and taste is best when the addition amount is 20-25 parts. In terms of mass production adaptability, based on formula conversion: with a formula of 25 parts GSE enzymatic hydrolysate, since each 25 parts of raw dough can be further divided into 8 protein bars; based on this, 360 parts GSE enzymatic hydrolysate can prepare about 115 protein bars, which has a significant advantage in mass production. Compared with untreated powdered GSE: although the addition amount of 5-10 parts can also reduce hardness, the amount of raw materials required to achieve the same improvement effect is larger, and the raw material loss is higher. It can be seen that adding GSE after enzymatic hydrolysis can effectively reduce raw material consumption and achieve reasonable control of production costs.

[0021] (2) Significantly improved flavor: When the amount of GSE hydrolysate added is 20-25 parts, sensory evaluation verified that the protein bars can present a pleasant and palatable flavor and obtain a high sensory score.

[0022] (3) Improved storage resistance: GSE itself has excellent antioxidant properties, and enzymatic hydrolysis does not destroy its proanthocyanidin components and antioxidant activity. This characteristic can significantly improve the storage resistance of protein bars. The product's functional attributes can precisely meet consumers' health needs and have broad market development prospects.

[0023] (4) The process is simple and suitable for standardized production: The raw materials used in this invention are readily available and inexpensive, and the process flow is simple and clear. It does not require expensive special equipment and can be completed using conventional laboratory equipment. This technical solution can provide manufacturers with a practical technical reference for creating plant protein bar products that meet market trends and consumer preferences. Detailed Implementation

[0024] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0026] Example 1: A plant-based protein bar based on GSE and its preparation method By weight, the GSE-based plant-based protein bar is composed of the following ingredients: Chickpea protein powder (purchased from Shandong Jianyuan Bioengineering Co., Ltd.) 15 parts, GSE enzymatic hydrolysate 5 parts, konjac powder 4 parts, glycerin 3 parts, corn syrup 10 parts, maltitol 10 parts, corn oil 6.5 parts.

[0027] Its preparation method includes the following steps: (1) Preparing the dough: First, thoroughly mix the dry ingredients, chickpea protein powder and konjac powder, at 100 rpm for 30 seconds. Then, mix the wet ingredients, GSE hydrolysate, glycerol, corn syrup, maltitol, and corn oil or water, at 200 rpm for 1 minute. Next, combine these two pretreated ingredient mixtures together and knead for about 2 minutes to form a uniform dough.

[0028] (2) Shaping the raw dough: Weigh out 25 g of dough and press it evenly into a mold measuring 8 cm × 3 cm × 2 cm. Before covering the mold and pressing the dough down, cover the surface of the dough with parchment paper to prevent sticking. After the dough is formed, take it out and cut it into four equal square pieces. These square pieces can be divided into a total of 8 meringue bars.

[0029] (3) Baking and packaging: Arrange the shaped meringue bars evenly on a baking tray and bake in a preheated oven for 30 minutes (preheat the oven to 120°C). After baking, remove the meringue bars and let them cool to room temperature. Then, pack them into vacuum-sealed bags for storage to reduce moisture loss.

[0030] The enzymatic hydrolysis of GSE is as follows: (1) The extraction method of GSE (purchased from Shandong Jinsheng Biotechnology Co., Ltd.) is as follows: Add purified water of a preset ratio (the ratio of grape seed to water is 1 mg: 5 mL) to the equipment containing grape seeds, and boil twice. Filter the mixture after the two boilings through a filter to remove grape seed residue and collect the filtrate. Transfer the filtered water extract to a temporary storage tank and cool it for later use. Pump the cooled water extract into a chromatography column containing non-polar adsorption resin (D101) for adsorption and desorption. After adsorption, use a desorption agent (70% ethanol-water solution). The solution is analyzed and collected; the collected solution is transferred to a special temporary storage container to ensure its stability for subsequent concentration; the temporary storage solution is sent to a vacuum concentration device to obtain a concentrated solution; the concentrated solution is sent to a spray drying device for spray drying to obtain grape seed extract powder; the collected powder is sent to a pulverizing and sieving device, and pulverized and sieved using an 80-120 mesh sieve to obtain grape seed extract powder with uniform particle size; after packaging, the product is subjected to metal detection, and the presence of metal impurities is detected using metal detection equipment. Qualified products are GSE finished products.

[0031] (2) Accurately weigh 30 parts of GSE, add 360 mL of deionized water, and stir magnetically until completely dissolved; then adjust the pH of the system to 4.6 with citric acid solution, and then add 0.09 parts of pectinase (enzyme activity ≥30000 U / g, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.) and 0.05 parts of cellulase (enzyme activity ≥10000 U / g, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.) to the GSE solution, and place the mixed solution in a magnetic stirrer for enzymatic hydrolysis at 45 ℃ and 400 r / min for 8 h; after the enzymatic hydrolysis is completed, inactivate the enzyme in a constant temperature water bath at 75 ℃ for 20 min to terminate the enzymatic reaction. Transfer the enzyme-inactivated solution to a centrifuge tube, centrifuge at 5000 r / min for 15 min, collect the supernatant, and prepare 340 parts of GSE enzymatic hydrolysate for later use. All parts mentioned above are by weight.

[0032] Example 2: A plant-based protein bar based on GSE and its preparation method The preparation method is the same as in Example 1, but the formulation is slightly different. Specifically, by weight, the GSE-based plant-based protein bar described in this example consists of the following raw materials: 15 parts chickpea protein powder, 10 parts GSE hydrolysate, 4 parts konjac powder, 3 parts glycerin, 10 parts corn syrup, 10 parts maltitol, and 6.5 parts corn oil.

[0033] Example 3: A plant-based protein bar based on GSE and its preparation method The preparation method is the same as in Example 1, but the formulation is slightly different. Specifically, by weight, the GSE-based plant-based protein bar described in this example consists of the following raw materials: 15 parts chickpea protein powder, 15 parts GSE hydrolysate, 4 parts konjac powder, 3 parts glycerin, 10 parts corn syrup, 10 parts maltitol, and 6.5 parts corn oil.

[0034] Example 4: A plant-based protein bar based on GSE and its preparation method The preparation method is the same as in Example 1, but the formulation is slightly different. Specifically, by weight, the GSE-based plant-based protein bar described in this example consists of the following raw materials: 15 parts chickpea protein powder, 20 parts GSE hydrolysate, 4 parts konjac powder, 3 parts glycerin, 10 parts corn syrup, 10 parts maltitol, and 6.5 parts corn oil.

[0035] Example 5: A plant-based protein bar based on GSE and its preparation method The preparation method is the same as in Example 1, but the formulation is slightly different. Specifically, by weight, the GSE-based plant-based protein bar described in this example consists of the following raw materials: 15 parts chickpea protein powder, 25 parts GSE hydrolysate, 4 parts konjac powder, 3 parts glycerin, 10 parts corn syrup, 10 parts maltitol, and 6.5 parts corn oil.

[0036] Comparative Example 1: The preparation method is the same as in Example 1, but the formulation is slightly different. Specifically, by weight, the plant-based protein bar described in this comparative example is composed of the following raw materials: 15 parts chickpea protein powder, 4 parts konjac powder, 3 parts glycerin, 10 parts corn syrup, 10 parts maltitol, and 6.5 parts corn oil.

[0037] Comparative Example 2: The preparation method is the same as in Example 1, but the formulation is slightly different. Specifically, by weight, the plant-based protein bar described in this comparative example is composed of the following raw materials: Ingredients: 15 parts chickpea protein powder, 4 parts konjac powder, 3 parts glycerin, 10 parts corn syrup, 10 parts maltitol, 6.5 parts corn oil, and 10 parts water.

[0038] Comparative Example 3: The preparation method is the same as in Example 1, but the formulation is slightly different. Specifically, by weight, the GSE-based plant-based protein bar described in this comparative example consists of the following raw materials: 15 parts chickpea protein powder, 5 parts unhydrolyzed GSE, 4 parts konjac powder, 3 parts glycerin, 10 parts corn syrup, 10 parts maltitol, 6.5 parts corn oil, and 10 parts water.

[0039] Comparative Example 4: The preparation method is the same as in Example 1, but the formulation is slightly different. Specifically, by weight, the GSE-based plant-based protein bar described in this comparative example consists of the following raw materials: 15 parts chickpea protein powder, 10 parts unhydrolyzed GSE, 4 parts konjac powder, 3 parts glycerin, 10 parts corn syrup, 10 parts maltitol, 6.5 parts corn oil, and 10 parts water.

[0040] Experimental examples: texture testing and sensory evaluation 1. Test method: (1) Hardness and chewiness (texture test): The physical properties of the plant-based protein bars of Examples 1-5 and Comparative Examples 1-4 were tested using a texture analyzer. The samples were compressed by the probe to obtain texture indicators such as hardness (unit: g) and chewiness.

[0041] (2) Sensory evaluation: Professional sensory evaluators will subjectively rate the flavor, texture, etc. of the protein bars (using a 1-10 scale, as shown in Table 1). Subjects must be from non-special populations, i.e., not pregnant or lactating, not engaged in heavy physical labor or high-intensity exercise, in good health, without metabolic diseases or hypoglycemia symptoms, without allergic reactions to the tested food, and with regular eating habits, including three meals a day. In addition to meeting the above conditions, the evaluation criteria must be referenced during the scoring process. After each tasting, the subject must rinse their mouth with water to avoid misjudgment. The final score is the average of the four scores.

[0042] Table 1 Sensory Evaluation Criteria for Chickpea Protein Bars Continued from the previous table: 2. Experimental Results: Regarding hardness and chewiness (Table 2), from Example 1 to Example 5, as the amount of GSE hydrolysate added gradually increased, the hardness decreased from 15292.50 g to 2247.83 g, and the chewiness decreased from 4083.53 g to 606.48 g, indicating that the addition of GSE hydrolysate effectively reduced the hardness and chewiness of the protein bars; especially when the amount added was 20-25 parts, the texture improvement effect was more prominent. In contrast, the hardness of Comparative Example 1 without GSE was as high as 26936.74 g, indicating that the addition of GSE itself can improve the texture; the hardness of Comparative Example 2 (without GSE) was 7247.12 g, while the hardness of Example 4 containing GSE hydrolysate was only 3244.78 g, and the hardness of Example 5 was 2247.83 g. It can be seen that GSE hydrolysate can achieve a better hardness reduction effect at a more optimal dosage. Meanwhile, 5-10 parts of unhydrolyzed GSE are needed to achieve a certain reduction in hardness (e.g., the hardness of Comparative Examples 3-4 is 5918.82-6661.74 g), while only 20-25 parts of GSE hydrolysate are needed to achieve better results, with less raw material consumption, lower loss, and more controllable costs. Taking Example 5 and Comparative Example 4 as examples, Example 5 only requires approximately 2.21 parts of GSE raw material (30 parts of GSE make 340 parts of hydrolysate, and the amount of GSE corresponding to each part of hydrolysate is 30 ÷ 340 ≈ 0.0735 parts; therefore, using 25 parts of hydrolysate requires approximately 0.0735 × 25 ≈ 2.21 parts of GSE raw material) to reduce the hardness of 8 protein bars to 2247.83 g; while in Comparative Example 4, 10 parts of unhydrolyzed GSE powder can only reduce the hardness to 5918.82 g, which is far from achieving the same level of softness.

[0043] In terms of sensory evaluation (Table 2), Examples 4 and 5 achieved sensory scores of 8.4 and 8.9, respectively, which are not only significantly higher than Comparative Example 1 (which does not contain GSE, only 4.0) but also superior to Comparative Examples 3-4 (which contain unhydrolyzed GSE, 7.3 and 8.0). This indicates that adding appropriate GSE hydrolysate can result in protein bars with a more pleasant flavor, better meeting consumer taste preferences.

[0044] Table 2. Hardness data and sensory scores of plant-based protein bars with different formulations. The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A plant-based protein bar comprising grape seed extract, characterized in that, The raw materials used in the plant-based protein bar include chickpea protein powder, grape seed extract enzymatic solution, konjac powder, glycerol, corn syrup, maltitol, and corn oil.

2. The plant-based protein bar containing grape seed extract according to claim 1, characterized in that, The plant-based protein bar includes the following raw materials by weight: Chickpea protein powder 10-20 parts, grape seed extract enzymatic solution 20-25 parts, konjac powder 3-5 parts, glycerol 2-4 parts, corn syrup 8-12 parts, maltitol 8-12 parts, and corn oil 5-8 parts.

3. The plant-based protein bar comprising grape seed extract of claim 2, wherein, The plant-based protein bar includes the following raw materials by weight: Chickpea protein powder 10-20 parts, grape seed extract enzymatic solution 20-25 parts, konjac powder 3-5 parts, glycerol 2-4 parts, corn syrup 8-12 parts, maltitol 8-12 parts, and corn oil 5-8 parts.

4. A plant-based protein bar comprising grape seed extract according to any one of claims 1-3, characterized in that, The grape seed extract enzymatic solution is prepared by dissolving grape seed extract in water, adjusting the pH value to 4-5, adding pectinase and cellulase, enzyme hydrolysis, enzyme inactivation, and centrifugal collection of the supernatant.

5. The plant-based protein bar comprising grape seed extract of claim 4, wherein, The enzyme hydrolysis is carried out at 40-50 ℃ and 300-500 r / min for 7-10 h.

6. The plant-based protein bar comprising grape seed extract of claim 4, wherein, The mass ratio of grape seed extract, pectinase, and cellulase is 30:0.077-0.117:0.043-0.

065.

7. The method of making a plant-based protein bar according to any one of claims 1-6, characterized in that, The method includes the following steps: S1, dough preparation: mix chickpea protein powder with konjac powder, mix grape seed extract enzymatic solution with glycerol, corn syrup, maltitol, and corn oil, then combine the two raw material mixtures, knead, and form a uniform dough; S2, dough shaping: press the dough of S1 into a mold, take it out after compression and shaping, and divide it into equal cubes; S3, baking and packaging: bake the shaped protein bar blank, take it out and cool it to room temperature, then immediately seal it in a vacuum packaging bag for storage.

8. The method of making a plant-based protein bar according to claim 7, wherein, In S2, before compressing the dough, first lay a layer of silicone oil paper on the surface of the dough to prevent sticking.

9. The method of making a plant-based protein bar of claim 7, wherein, In S3, the baking temperature is 110-130 ℃, and the time is 25-40 min.

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