A method for reducing the oil absorption and improving the crispness of deep-fried batter-coated peanuts

Abstract

The application discloses a method for reducing the oil absorption of deep-fried batter-coated peanuts and improving the crispness of the deep-fried batter-coated peanuts, which mainly comprises the following steps: (1) adjusting the batter formula by adding a certain amount of a resistant starch-rose seed gum mixture; (2) increasing a pre-drying treatment, i.e. carrying out hot air drying on the batter-coated peanuts prepared according to the batter formula in step (1) before deep frying; and (3) increasing a post-frying heat preservation treatment, i.e. immediately carrying out microwave heating on the deep-fried batter-coated peanuts for a certain time after deep frying. The deep-fried batter-coated peanuts produced by the method have an oil absorption reduced by 23.68%, and the crispness is improved by 28.85%, and the method is simple to operate, does not need complex processing equipment and is easy to be industrialized.

Description

Technical Field

[0001] This invention relates to a method for reducing the oil absorption of fried peanuts coated in batter and improving their crispness, belonging to the field of food processing technology. Background Technology

[0002] Peanuts are rich in unsaturated fatty acids and trace elements essential for the human body, making them highly nutritious. The batter (usually composed of wheat flour, starch, colloids, salt, and leavening agents) is often combined with frying to give the product a crispy outer shell. Fried batter-coated peanuts are particularly popular due to their unique flavor and texture. However, the batter in fried batter-coated peanuts easily absorbs moisture and softens, and has a high oil content; excessive intake can lead to cardiovascular disease, high blood pressure, and other health problems. Furthermore, excessive oil content is detrimental to long-term food preservation, and lipid oxidation can cause off-flavors and quality deterioration. Currently, many methods are used to control the oil absorption of fried foods and improve product quality, such as improving frying techniques, using coating methods, and pre-treating raw materials. Therefore, this invention combines batter formulation, raw material pre-treatment, and post-treatment to provide a method for reducing the oil absorption of fried batter-coated peanuts and improving their crispness.

[0003] 1. Optimize the batter formulation: The continuous high temperature and rapid evaporation of moisture during frying cause a series of changes in the physicochemical properties and microstructure of starch, such as starch gelatinization and changes in starch crystal form, which in turn affect product quality. Starch with higher water content is more easily gelatinized, which in turn affects the decomposition process of triglycerides. This causes polar compounds such as diglycerides and monoglycerides to prolong the residence time of water vapor on the surface of the oil phase, thereby enhancing the contact between the oil and the product and ultimately increasing the oil content of the product. On the other hand, the starch film can, to some extent, block the "water-oil replacement" process, thus effectively reducing oil penetration. Wheat flour can provide better adhesion for coated foods, but the crispness of the coating is lower. In addition, natural corn starch has an unstable structure and poor solubility. Therefore, people tend to add modified starch to the batter formulation. RS3 resistant starch is a physically modified starch formed by gelatinization and retrogradation of starch. In addition to its physiological functions such as increasing satiety, reducing the risk of obesity, and improving postprandial blood glucose levels, it also has sensory characteristics such as fine particles, mild taste, and good palatability. Using pregelatinized corn starch, obtained by pregelatinizing corn starch, can improve the expansion and crispness of the coating. Studies have shown that using it in the coating of fried chicken cutlets, adding 20% ​​resistant starch effectively reduces the oil content of fried foods, while also resulting in a golden-brown crust, denser batter, and increased crispness. Besides modified starch, hydrocolloids are also commonly used in coatings to reduce the oil absorption of fried foods. The hydrophilic groups in hydrocolloids can interact with macromolecules such as starch and protein to form a barrier, preventing oil penetration. Furthermore, using hydrocolloids to reduce the oil content of fried products can effectively increase the body's intake of dietary fiber, which has a positive effect on human health. Basil seed gum (BSG) can be used as an emulsifier, foamer, thickener, gelling agent, fat substitute, and stabilizer. Studies have shown that heating BSG gel at high temperatures (121°C) not only does not damage BSG but even produces a dense gel network with high strength and hardness, which is beneficial for improving the textural properties of products. Furthermore, studies have found that zucchini slices coated with a 1.0% basil seed gum film exhibit significantly reduced oil absorption after frying, demonstrating the application potential of basil seed gum in fried products. For coated fried products, polysaccharides can also work synergistically with starch and gluten in the batter system to form a spatial network structure, binding more water, reducing the water-oil exchange ratio, and thus reducing oil absorption. They also act as viscosity control agents for the outer coating, altering the coating ratio, promoting the formation of a uniform and dense outer coating, and improving the crispness of the fried product's outer shell. Therefore, combining basil seed gum and resistant starch to form a mixture and adding it to the coating layer will quickly form an oil-blocking layer during frying, reducing the product's oil absorption and helping to improve the sensory quality of fried products.

[0004] 2. Pre-drying treatment: The initial moisture content of food is closely related to its oil content. Based on the water-oil displacement effect, in the initial stage of food contact with high-temperature frying oil, the huge temperature difference causes water molecules to collide and move violently, vaporizing. As frying continues, a large amount of water vapor escapes, and the number of bubbles on the surface of the frying oil gradually increases. Simultaneously, numerous pores are formed inside the food, becoming "channels" connecting the internal particles of the fried product to the external heat source, providing pathways for heat and oil to enter. Therefore, reducing the initial moisture content of food helps reduce the final oil absorption of fried products. Pre-drying treatment also improves the crispness of the product and mitigates the tendency of coated peanuts to absorb moisture and soften. Hot air drying, microwave drying, and infrared drying are common drying methods; however, microwave drying easily causes the product to become soft and moist inside, while infrared drying is more expensive. Therefore, hot air drying is a lower-cost, simpler method that best preserves the product's quality.

[0005] 3. Post-frying heat preservation: When food leaves the high-temperature frying environment, the sudden temperature change causes the water vapor inside the food to condense rapidly, resulting in a sharp change in pressure. At this time, the interfacial tension between the food surface and the oil cannot balance the generated pressure. Therefore, a large amount of oil adhering to the food surface is forced into the surface pore structure under pressure, while another portion of oil continues to adhere to the food surface. Therefore, using post-frying heat preservation to reduce the temperature difference between the food and the environment after frying may help reduce the oil absorption of fried products. In addition, post-frying heat preservation can maintain the porous structure of food and preserve its crispness. Some studies have found that placing French fries under a heat lamp can reduce their oil content and improve their crispness; however, heat lamp heat preservation time is too long and heating is uneven. Microwave heating can make full use of high-frequency electromagnetic waves to heat food from the inside, with high heating efficiency, thus achieving better heat preservation effect. Summary of the Invention

[0006] This invention aims to provide a method for reducing the oil absorption of fried peanuts coated in batter and improving their crispness. This method significantly reduces the oil absorption of fried peanuts coated in batter and noticeably improves their crispness. At the same time, the operation method is simple and easy to industrialize.

[0007] This invention provides a method for reducing the oil absorption of fried coated peanuts and improving their crispness. By optimizing the coating formula with the addition of RS3 resistant starch and basil seed gum, and by adding hot air pre-drying treatment and microwave heat preservation treatment after frying, the fried coated peanuts produced have lower oil absorption and higher crispness.

[0008] The present invention provides a method for reducing the oil absorption of fried peanuts coated in batter and improving their crispness, comprising the following steps:

[0009] Step 1: Select peanuts that are free from pests, mold, and shriveling, and wash them under running water. Weigh out all-purpose wheat flour, pregelatinized corn starch, resistant starch-basil seed gum mixture, salt, and baking soda, and mix them well to make a coating.

[0010] Step 2: Place the peanuts and the coating powder obtained in Step 1 into an automatic coating machine. Use sugar water as an adhesive to ensure that the surface of each peanut is evenly covered with the coating powder. Repeat this operation until the coating powder is used up to make coated peanuts.

[0011] Step 3: Place the coated peanuts obtained in Step 2 into a hot air drying oven and pre-dry at 60℃ for 20-100 minutes before deep-frying;

[0012] Step 4: Immediately after frying, place the peanuts coated in the batter obtained in Step 3 into a microwave oven (450W) and keep them warm for 60-120 seconds before removing them.

[0013] In step 1, the coating powder consists of the following components by mass percentage: 55% medium-gluten wheat flour, 18% pregelatinized corn starch, 24% resistant starch-basil seed gum mixture, 2% salt, and 1% baking soda.

[0014] In step 1, the mass ratio of resistant starch to basil seed gum in the resistant starch-basil seed gum mixture is (1-5):1.

[0015] In step 2, the sugar water is obtained by mixing granulated sugar and purified water, wherein the mass ratio of granulated sugar, purified water and peanut kernels is 3:6:4.

[0016] In step 3, the frying is done using palm oil at 170°C for 2 minutes.

[0017] Compared with existing technologies, the beneficial effects of this invention are reflected in:

[0018] 1. This invention adds RS3 resistant starch-basil seed gum mixture to the basic coating formula, which can reduce the oil absorption of the product and improve the crispness of fried products.

[0019] 2. Hot air pre-drying can protect the product's appearance from damage to the greatest extent, while significantly improving the crispness of fried peanuts and significantly reducing oil absorption.

[0020] 3. Microwave insulation after frying preserves the porous structure of the fried peanuts, significantly improving their crispness.

[0021] 4. The method provided by this invention is simple to operate, requires no complex processing equipment, and is easy to industrialize. Attached Figure Description

[0022] Figure 1This compares the oil content and crispness of the fried batter-coated peanuts obtained in Examples 1, 2, and 3. Figure 1 It can be seen that the oil content and crispness of the fried peanuts produced in the comparative example were 59.67% and 2529.83 g·sec, respectively; the oil content and crispness of the fried peanuts produced in Example 1 were 52.45% and 2745.11 g·sec, respectively; the oil content and crispness of the fried peanuts produced in Example 2 were 45.54% and 3258.69 g·sec, respectively; and the oil content and crispness of the fried peanuts produced in Example 3 were 49.42% and 3311.63 g·sec, respectively.

[0023] Figure 2 This describes the oil content and crispness of the fried batter-coated peanuts obtained in Examples 4, 5, and 6. Figure 2 It can be seen that the oil content and crispness of the fried peanuts produced in the comparative example were 59.67% and 2529.83 g·sec, respectively; the oil content and crispness of the fried peanuts produced in Example 4 were 57.63% and 3409.19 g·sec, respectively; the oil content and crispness of the fried peanuts produced in Example 5 were 51.59% and 3058.62 g·sec, respectively; and the oil content and crispness of the fried peanuts produced in Example 6 were 48.74% and 2981.57 g·sec, respectively. Compared with the comparative example, the oil content of the fried peanuts produced in Examples 4, 5, and 6 was reduced, while the crispness was increased. This indicates that the addition of the resistant starch-basil seed gum mixture, pre-drying, and microwave insulation treatment are beneficial to reducing the oil absorption of fried peanuts and improving their crispness. Compared with Example 2, the fried peanuts produced in Example 4 had the highest oil content, followed by those produced in Example 5, while the fried peanuts produced in Example 6 had the lowest oil content. Compared to Example 2, the fried peanuts coated with batter produced in Example 4 had the highest crispness, followed by the fried peanuts coated with batter produced in Example 5, while the fried peanuts coated with batter produced in Example 6 had the lowest crispness.

[0024] The production method of this invention includes adding a resistant starch-basil seed gum mixture to the coating formula, adding a pre-drying treatment, and microwave heat preservation treatment. The oil content of the fried coated peanuts produced by the three methods, from low to high, is as follows: adding the resistant starch-basil seed gum mixture to the coating, pre-drying treatment, and microwave heat preservation treatment; the crispness, from high to low, is as follows: pre-drying treatment, microwave heat preservation treatment, and adding the resistant starch-basil seed gum mixture to the coating. Adding the resistant starch-basil seed gum mixture to the coating formula, along with pre-drying and microwave heat preservation treatment after frying, significantly reduces the oil absorption of the fried coated peanuts and improves their crispness. Detailed Implementation

[0025] Non-limiting embodiments are described below:

[0026] Example 1:

[0027] 1. Basil seed gum extraction: Basil seeds and ultrapure water were mixed at a ratio of 1:65 (w / v) (pH 8.0, 68℃) and stirred for 20 min. After centrifugation, filtration, purification, and freeze-drying, basil seed gum powder was obtained.

[0028] 2. Determination of coating formula: Weigh out different amounts of medium-gluten wheat flour (45-65%), pregelatinized corn starch (14-24%), resistant starch-basil seed gum mixture (18-26%, 1:1), and 2% salt and 1% baking soda, mix them evenly to make coating powder, and make coated peanuts by coating process. After frying, determine the final coating formula based on the oil absorption and crispness of the fried coated peanuts.

[0029] 3. Select peanuts free from pests, mold, and shriveling, and wash them under running water. According to the coating formula obtained in step 2, weigh out 55% medium-gluten wheat flour, 18% pregelatinized corn starch, 24% resistant starch-basil seed gum mixture (1:1), 2% salt, and 1% baking soda, and mix them well to make coating powder. Place the peanuts and coating powder into an automatic coating machine, using sugar water as a binder. The weight ratio of white sugar, purified water, and peanuts is 3:6:4 (w / w / w), so that the surface of each peanut is evenly covered with coating powder. Repeat this operation until the coating powder is used up to make coated peanuts.

[0030] 4. Place the coated peanuts obtained in step 1 into a hot air drying oven at 60℃ for 20 minutes to pre-dry, then deep-fry. Pour palm oil into a deep fryer and heat to 170℃, then deep-fry for 2 minutes.

[0031] 5. Immediately after frying, place the peanuts coated in the batter obtained in step 2 in a microwave oven (450W) for 30 seconds to keep warm before removing them.

[0032] The oil content of the fried peanuts coated in batter was measured to be 52.45%, and the crispness was 2745.11 g·sec.

[0033] Example 2:

[0034] Steps 1 and 2 are the same as in Example 1.

[0035] 3. Select peanuts free from pests, mold, and shriveling, and wash them under running water. According to the coating formula obtained in step 2, weigh out 55% medium-gluten wheat flour, 18% pregelatinized corn starch, 24% resistant starch-basil seed gum mixture (3:1), 2% salt, and 1% baking soda, and mix them well to make coating powder. Put the peanuts and coating powder into an automatic coating machine, using sugar water as a binder. The weight ratio of white sugar, purified water, and peanuts is 3:6:4 (w / w / w), so that the surface of each peanut is evenly covered with coating powder. Repeat this operation until the coating powder is used up to make coated peanuts.

[0036] 4. Place the peanuts coated in batter obtained in step 1 into a hot air drying oven at 60℃ for 60 minutes to pre-dry, then deep-fry. Pour palm oil into a deep fryer and heat to 170℃, then deep-fry for 2 minutes.

[0037] 5. Immediately after frying, place the peanuts coated in the batter obtained in step 2 into a microwave oven (450W) and keep them warm for 60 seconds before removing them.

[0038] The oil content of the fried peanuts was measured to be 45.54%, and the crispness was 3258.69 g·sec.

[0039] Example 3:

[0040] Steps 1 and 2 are the same as in Example 1.

[0041] 3. Select peanuts free from pests, mold, and shriveling, and wash them under running water. According to the coating formula obtained in step 2, weigh out 55% medium-gluten wheat flour, 18% pregelatinized corn starch, 24% resistant starch-basil seed gum mixture (5:1), 2% salt, and 1% baking soda, and mix them well to make coating powder. Put the peanuts and coating powder into an automatic coating machine, using sugar water as a binder. The weight ratio of white sugar, purified water, and peanuts is 3:6:4 (w / w / w), so that the surface of each peanut is evenly covered with coating powder. Repeat this operation until the coating powder is used up to make coated peanuts.

[0042] 4. Place the peanuts coated in batter obtained in step 1 into a hot air drying oven at 60℃ for 100 minutes to pre-dry, then deep-fry. Pour palm oil into a deep fryer and heat to 170℃, then deep-fry for 2 minutes.

[0043] 5. Immediately after frying, place the peanuts coated in the batter obtained in step 2 into a microwave oven (450W) and keep them warm for 90 seconds before removing them.

[0044] The oil content of the fried peanuts was measured to be 49.42%, and the crispness was 3311.63 g·sec.

[0045] Example 4:

[0046] Steps 1 and 2 are the same as in Example 1.

[0047] 3. Select peanuts free from pests, mold, and shriveling, and wash them under running water. According to the coating formula obtained in step 2, weigh out 55% medium-gluten wheat flour, 42% pregelatinized corn starch, 2% salt, and 1% baking soda, and mix them well to make coating powder. Put the peanuts and coating powder into an automatic coating machine, using sugar water as a binder. The weight ratio of white sugar, purified water, and peanuts is 3:6:4 (w / w / w), so that the surface of each peanut is evenly covered with coating powder. Repeat this operation until the coating powder is used up to make coated peanuts.

[0048] 4. Place the peanuts coated in batter obtained in step 1 into a hot air drying oven at 60℃ for 60 minutes to pre-dry, then deep-fry. Pour palm oil into a deep fryer and heat to 170℃, then deep-fry for 2 minutes.

[0049] 5. Immediately after frying, place the peanuts coated in the batter obtained in step 2 into a microwave oven (450W) and keep them warm for 60 seconds before removing them.

[0050] The oil content of the fried peanuts coated in batter was measured to be 57.63%, and the crispness was 3409.19 g·sec.

[0051] Example 5:

[0052] Steps 1 and 2 are the same as in Example 1.

[0053] 3. Select peanuts free from pests, mold, and shriveling, and wash them under running water. According to the coating formula obtained in step 2, weigh out 55% medium-gluten wheat flour, 18% pregelatinized corn starch, 24% resistant starch-basil seed gum mixture (3:1), 2% salt, and 1% baking soda, and mix them well to make coating powder. Put the peanuts and coating powder into an automatic coating machine, using sugar water as a binder. The weight ratio of white sugar, purified water, and peanuts is 3:6:4 (w / w / w), so that the surface of each peanut is evenly covered with coating powder. Repeat this operation until the coating powder is used up to make coated peanuts.

[0054] 4. Pour palm oil into a deep fryer and heat it to 170°C. Place the coated peanuts prepared in step 1 into the deep fryer and fry for 2 minutes.

[0055] 5. Immediately after frying, place the peanuts coated in the batter obtained in step 2 into a microwave oven (450W) and keep them warm for 60 seconds before removing them.

[0056] The oil content of the fried peanuts coated in batter was measured to be 51.59%, and the crispness was 3058.62 g·sec.

[0057] Example 6:

[0058] Steps 1 and 2 are the same as in Example 1.

[0059] 3. Select peanuts free from pests, mold, and shriveling, and wash them under running water. According to the coating formula obtained in step 2, weigh out 55% medium-gluten wheat flour, 18% pregelatinized corn starch, 24% resistant starch-basil seed gum mixture (3:1), 2% salt, and 1% baking soda, and mix them well to make coating powder. Put the peanuts and coating powder into an automatic coating machine, using sugar water as a binder. The weight ratio of white sugar, purified water, and peanuts is 3:6:4 (w / w / w), so that the surface of each peanut is evenly covered with coating powder. Repeat this operation until the coating powder is used up to make coated peanuts.

[0060] 3. Place the coated peanuts obtained in step 1 into a hot air drying oven at 60℃ for 60 minutes to pre-dry, then deep-fry. Pour palm oil into a deep fryer and heat to 170℃, then deep-fry for 2 minutes.

[0061] 4. After frying, allow the peanuts coated in the batter obtained in step 2 to cool naturally to room temperature.

[0062] The oil content of the fried peanuts was measured to be 48.74%, and the crispness was 2981.57 g·sec.

[0063] Comparative example:

[0064] 1. Select peanuts free from pests, mold, and shriveling, and wash them under running water. Weigh out 55% medium-gluten wheat flour, 42% pregelatinized corn starch, 2% salt, and 1% baking soda, and mix them well to make a coating powder. Place the peanuts and coating powder into an automatic coating machine, using sugar water as a binder. The weight ratio of white sugar, purified water, and peanuts is 3:6:4 (w / w / w). Ensure that the surface of each peanut is evenly covered with the coating powder. Repeat this process until the coating powder is used up to make coated peanuts.

[0065] 2. Pour palm oil into a deep fryer and heat it to 170°C. Fry the peanuts coated in batter prepared in step 1 for 2 minutes.

[0066] 3. After frying, allow the peanuts coated in the batter obtained in step 2 to cool naturally to room temperature.

[0067] The oil content of the fried peanuts coated in batter was measured to be 59.67%, and the crispness was 2529.83 g·sec.

Claims

1. A method for reducing the oil absorption of fried peanuts coated in batter and improving their crispness, characterized in that... Includes the following steps: Step 1: Select peanuts that are free from pests, mold, and shriveling, and wash them under running water. Weigh out all-purpose wheat flour, pregelatinized corn starch, resistant starch-basil seed gum mixture, salt, and baking soda, and mix them well to make a coating. Step 2: Place the peanuts and the coating powder obtained in Step 1 into an automatic coating machine. Use sugar water as an adhesive to ensure that the surface of each peanut is evenly covered with the coating powder. Repeat this operation until the coating powder is used up to make coated peanuts. Step 3: Place the peanuts coated in batter obtained in Step 2 into a hot air drying oven to dry them, and then deep-fry them; Step 4: Immediately after frying, place the peanuts coated in the batter obtained in Step 3 in a microwave oven to keep them warm; In step 1, the coating powder consists of the following components by weight percentage: 55% medium-gluten wheat flour, 18% pregelatinized corn starch, 24% resistant starch-basil seed gum mixture, 2% salt, and 1% baking soda; In step 1, the mass ratio of resistant starch to basil seed gum in the resistant starch-basil seed gum mixture is (1-5):1; In step 3, the hot air drying temperature is 60℃ and the time is 20-100 min; In step 4, the microwave power is 450W and the heat preservation time is 60-180 seconds.

2. The method according to claim 1, characterized in that: In step 2, the sugar water is obtained by mixing granulated sugar and purified water, wherein the mass ratio of granulated sugar, purified water and peanut kernels is 3:6:

4.

3. The method according to claim 1, characterized in that: In step 3, the frying is done using palm oil at 170°C for 2 minutes.

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