Lotus paste stuffing with function of reducing blood sugar as well as preparation method and application of lotus paste stuffing

Abstract

The embodiment of the invention discloses lotus paste stuffing with a blood sugar reducing function as well as a preparation method and application of the lotus paste stuffing, relates to the technical field of foods, and aims to fill the vacancy of lack of functional foods for reducing blood sugar in the market. The preparation method of the lotus seed paste stuffing with the function of reducing blood sugar comprises the following steps: extracting to obtain lotus seed starch; preparing a lotus seed starch-procyanidine compound based on the lotus seed starch; based on the lotus seed starch-procyanidine compound, the high-resistance lotus paste stuffing is prepared.

Description

Technical Field

[0001] The present application relates to the field of food technology, and in particular to a lotus seed paste filling with blood sugar lowering function, and a preparation method and application thereof. Background Art

[0002] Cantonese mooncakes are widely loved by consumers for their unique flavor and delicate texture. However, mooncakes are high in sugar and have a high glycemic index (GI). Long-term consumption may increase the risk of metabolic diseases such as diabetes and obesity. Lotus seed paste, a key ingredient in mooncakes, is typically made from lotus seeds that are steamed, homogenized with oil, water, and sugar, and then stir-fried at high temperatures. This filling is high in sugar. With the rising prevalence of diabetes, the mooncake industry urgently needs to develop functional fillings with a low glycemic index (GI). Summary of the Invention

[0003] The main purpose of this application is to provide a lotus seed paste filling with blood sugar lowering function and its preparation method and application, aiming to fill the gap in the market for functional foods that lower blood sugar.

[0004] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows:

[0005] In a first aspect, the present invention provides a method for preparing a lotus seed paste filling having a blood sugar-lowering function, comprising the following steps:

[0006] Extracting lotus seed starch;

[0007] Based on the lotus seed starch, a lotus seed starch-proanthocyanidin complex is prepared;

[0008] Based on the lotus seed starch-proanthocyanidin complex, a high-resistance lotus seed paste filling is prepared.

[0009] As some optional embodiments of the present application, the extraction to obtain lotus seed starch includes:

[0010] After removing the residual film on the surface of the Xiangtan ground lotus seeds, the pre-treated Xiangtan ground lotus seeds are obtained;

[0011] adding the pre-treated Xiangtan ground lotus seeds to distilled water, performing wall breaking and sieving to obtain a filtrate;

[0012] After the filtrate is allowed to stand, a yellow impurity layer is discarded to obtain a white starch layer; the white starch precipitate is washed with distilled water, the washed white starch precipitate is vacuum-dried to a constant weight, and pulverized to obtain lotus seed starch.

[0013] As some optional embodiments of the present application, the solid-liquid ratio of the Xiangtan ground lotus seeds after repeated washing of the residual film on the surface and the distilled water is 1g-3g:4mL-6mL;

[0014] The mesh size of the sieve after the wall breaking treatment and the sieve after the crushing treatment is 100 mesh to 120 mesh;

[0015] The filtrate is allowed to stand for 6-8 hours.

[0016] The temperature of the vacuum drying treatment is 45°C-50°C.

[0017] As some optional embodiments of the present application, the lotus seed starch-proanthocyanidin complex is prepared based on the lotus seed starch, comprising:

[0018] The lotus seed starch is evenly dispersed in distilled water, stirred to obtain a second pregelatinized starch, and cooled to 55° C.-65° C. for insulation;

[0019] Weighing a preset proportion of proanthocyanidins, dissolving the proanthocyanidins in anhydrous ethanol, and pouring the mixture into the cooled second pregelatinized starch and mixing thoroughly to obtain a lotus seed starch milk-polyphenol compound composite paste;

[0020] homogenizing and dispersing the lotus seed starch milk-polyphenol compound composite paste to obtain a homogeneous mixture;

[0021] After the homogenous mixture is subjected to centrifugation, the precipitate is washed and recovered by centrifugation to obtain the complex;

[0022] The complex is frozen at -20°C and then freeze-dried, and ground through a 100-mesh sieve to obtain high-pressure homogenized lotus seed starch and lotus seed starch-proanthocyanidins.

[0023] As some optional embodiments of the present application, the material ratio of the lotus seed starch to the distilled water is 10g-12g:200mL-220mL;

[0024] The stirring temperature is 90-95°C, and the stirring time is 28-32 minutes;

[0025] The material ratio of the lotus seed starch, the proanthocyanidins and the anhydrous ethanol is 1:0.05-0.1:45mL-55mL;

[0026] The homogenization and dispersion treatment includes sequentially using a homogenizer and a nano ultra-high pressure homogenizer for homogenization and dispersion treatment; the treatment time using the homogenizer is 4 minutes to 6 minutes; the treatment pressure using the nano ultra-high pressure homogenizer is 150 MPa, and the number of treatments is 5 to 6 times;

[0027] The parameters of the centrifugation treatment are: 8000×g for 5 min;

[0028] The washing of the precipitate refers to washing the precipitate three times with a 50% ethanol solution.

[0029] As some optional embodiments of the present application, the highly resistant lotus seed paste filling is prepared based on the lotus seed starch-proanthocyanidin complex, comprising:

[0030] Select Xiangtan dried lotus seeds with a starch content of 45%;

[0031] The dried Xiangtan lotus seeds with a starch content of 45% are peeled and cored, and then steamed. After the steaming, peanut oil, water, sucrose, and lotus seed starch-proanthocyanidin complex are added, and the mixture is poured into a colloid mill for grinding to obtain lotus seed paste. The lotus seed paste is fried to obtain a high-resistance lotus seed paste filling.

[0032] As some optional embodiments of the present application, the temperature of the steaming treatment is 95°C-105°C;

[0033] The temperature of the refining treatment is room temperature, the pressure is 0.08MPa to 0.09MPa, and the time is 4min to 6min;

[0034] The frying temperature is 195° C. and the frying time is 45 min-55 min.

[0035] As some optional embodiments of the present application, the replacement amount of resistant starch in the high-resistant lotus seed paste filling is 10wt%-30wt%;

[0036] After the steaming process is completed, 60g-65g of peanut oil, 2g-4g of glycerol, 45g-55g of sucrose, 130g-150g of water and 8g-10g of lotus seed starch-proanthocyanidin complex are added to every 80g of Xiangtan dried lotus seeds with a starch content of 45%.

[0037] In a second aspect, the embodiments of the present application also provide a lotus seed paste filling with blood sugar lowering function, which is obtained by the preparation method as described above.

[0038] In a third aspect, an embodiment of the present application further provides an application of the lotus seed paste filling having the blood sugar lowering function as described above, namely, applying it to the preparation of moon cakes.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] 1. Establish a high-quality resistant lotus seed paste processing model: obtain the optimal dosage formula and processing conditions (peanut oil addition amount 63g, glycerin addition amount 3g, frying time 45min) to make the product both resistant to digestion and excellent palatability (sensory score of 90.56 points, hardness of 35N).

[0041] 2. Improving the blood sugar-lowering activity of lotus seed paste filling: By adding RS3 (10%-30%) and RS5 (10%-30%), the resistant starch content of the filling was increased compared with the traditional lotus seed paste filling. The resistant starch content of the RS3 group was 6.25%-11.94% higher than that of the RS5 group. The degree of starch digestion in the resistant starch lotus seed paste filling was reduced, indicating that the addition of resistant starch can lower the glycemic index of lotus seed paste.

[0042] 3. Improve the quality of lotus seed paste filling: The results of the measurement of oil and water holding capacity, sensory, texture and other factors showed that the water holding capacity of the RS5 lotus seed paste filling with a 20% addition amount was improved (A22 increased by 11.23%), and the sensory quality was basically the same as that of the traditional filling. The lowest hardness increase was 19.68%, and the RS content reached 32.92% of the traditional group. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a graph showing the effect of the resistant starch involved in the examples of the present application on the moisture and fat content and water and oil holding capacity of lotus seed paste filling;

[0044] Figure 2 This is a distribution diagram of the resistant starch content of the resistant starch lotus seed paste filling involved in the examples of this application;

[0045] Figure 3 This is a graph showing the effect of the amount of peanut oil added on the sensory score and hardness of the resistant lotus seed paste filling involved in the examples of the present application;

[0046] Figure 4 This is a graph showing the effect of the amount of glycerol added on the sensory score and hardness of the resistant lotus seed paste filling involved in the examples of the present application;

[0047] Figure 5 This is a graph showing the effect of frying time on the sensory score and hardness of resistant lotus seed paste fillings involved in the embodiments of the present application;

[0048] Figure 6 The response surface and contour plots of the effects of the pairwise interaction of factors on the sensory score of lotus seed paste involved in the examples of the present application are as follows;

[0049] Figure 7 The response surface and contour diagrams are shown for the effects of the pairwise interaction of factors on the hardness of lotus seed paste according to the embodiments of the present application. DETAILED DESCRIPTION

[0050] It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0051] Resistant starch (RS) refers to starch and its hydrolysis products that cannot be digested and absorbed in the small intestine of healthy individuals. It is widely used in foods and dietary fiber-fortified products. Among them, retrograded starch (RS3) and complex starch (RS5) have attracted widespread attention due to their unique properties. In recent years, with the increasing popularity of healthy diets and low-sugar foods, resistant starch has been used in food production as a healthy ingredient. RS3 and RS5 not only improve blood sugar control but also help enhance the nutritional value of food.

[0052] However, there are still some urgent problems to be solved in the food application of resistant starch. These include poor processing stability, interaction with other ingredients leading to a decrease in food sensory quality, and insufficient adaptability in different food processes. These problems limit the widespread application of resistant starch, especially in traditional pastries and filling products, where consumers have high requirements for taste and texture. Currently, foods with added resistant starch mostly use simple physical mixing, which results in a hardened texture and rough taste, making it difficult to balance functionality and sensory quality. The use of a combined method to prepare resistant starch can break through the limitations of a single preparation method through synergistic effects, meet the sustainable development needs of the food industry, and improve the digestive resistance and processing adaptability of the product. At the same time, the addition of resistant starch will affect the texture quality of the filling. The strong hygroscopicity and moisturizing properties of glycerol (propylene glycol) play a significant role in improving the quality of baked and filling foods. It can effectively regulate the water activity of food and delay starch retrogradation, thereby maintaining the soft texture and sensory quality of the filling.

[0053] Based on this, this application prepares lotus seed resistant starch RS3 through ultra-high pressure enzymatic hydrolysis synergistic technology, and combines high-pressure homogenization method to construct lotus seed starch-proanthocyanidin complex RS5. The lotus seed paste filling prepared with RS3 and RS5 as substitutes for lotus seed starch has both excellent sensory quality and blood sugar-lowering function, which can provide a theoretical basis for the development of healthy traditional foods with low GI and dietary fiber, and provide technical support for the subsequent production of moon cakes.

[0054] Specifically, the method for preparing a lotus seed paste filling with blood sugar-lowering function described in the present application comprises the following steps:

[0055] Step S10: extracting and obtaining lotus seed starch.

[0056] In one optional embodiment, the step S10 of extracting and obtaining lotus seed starch includes:

[0057] After removing the residual film on the surface of the Xiangtan de-peeled lotus seeds, pre-treated Xiangtan de-peeled lotus seeds are obtained; the pre-treated Xiangtan de-peeled lotus seeds are added to distilled water, subjected to wall breaking treatment and sieving treatment, and a filtrate is obtained; after the filtrate is allowed to stand, a yellow impurity layer is discarded to obtain a white starch layer; the white starch precipitate is washed with distilled water, the washed white starch precipitate is vacuum-dried to a constant weight, and pulverized to obtain lotus seed starch.

[0058] It should be noted that the material-liquid ratio of the Xiangtan ground lotus seeds after repeated washing of the residual film on the surface and the distilled water is 1g-3g:4mL-6mL; the mesh size of the sieve after the wall breaking treatment and the sieve after the crushing treatment are both 100-120 mesh; the standing time of the filtrate is 6h-8h; and the temperature of the vacuum drying treatment is 45℃-50℃.

[0059] Step S20: preparing a lotus seed starch-proanthocyanidin complex based on the lotus seed starch.

[0060] In one optional embodiment, the step S20 of preparing a lotus seed starch-proanthocyanidin complex based on the lotus seed starch comprises:

[0061] The lotus seed starch is uniformly dispersed in distilled water, stirred to obtain a second pregelatinized starch, and cooled to 55° C.-65° C. for insulation; a preset proportion of proanthocyanidins is weighed and dissolved in anhydrous ethanol, and the mixture is poured into the cooled second pregelatinized starch and thoroughly mixed to obtain a lotus seed starch milk-polyphenol compound composite paste; the lotus seed starch milk-polyphenol compound composite paste is homogenized and dispersed to obtain a homogeneous mixture; the homogeneous mixture is centrifuged, the precipitate is washed, and the composite is recovered by centrifugation to obtain a composite; the composite is frozen at -20° C., freeze-dried, and ground through a 100-mesh sieve to obtain high-pressure homogenized lotus seed starch and lotus seed starch-proanthocyanidins.

[0062] It should be noted that the material ratio of the lotus seed starch and the distilled water is 10g-12g:200mL-220mL; the temperature of the stirring treatment is 90°C-95°C, and the stirring time is 28min-32min; the material ratio of the lotus seed starch, the proanthocyanidins and the anhydrous ethanol is 1:0.05-0.1:45mL-55mL; the homogenizing and dispersing treatment includes sequentially using a homogenizing disperser and a nano ultra-high pressure homogenizer for homogenizing and dispersing; the treatment time using the homogenizing disperser is 4min-6min; the treatment pressure using the nano ultra-high pressure homogenizer is 150MPa, and the number of treatments is 5 to 6 times; the parameters of the centrifugal treatment are: 8000×g centrifugation for 5min; and washing the precipitate refers to washing the precipitate 3 times with a 50% ethanol solution.

[0063] Step S30: preparing a high-resistance lotus seed paste filling based on the lotus seed starch-proanthocyanidin complex.

[0064] In one optional embodiment, the step S30 of preparing a high-resistance lotus seed paste filling based on the lotus seed starch-proanthocyanidin complex comprises:

[0065] The method comprises the following steps: selecting dried lotus seeds from Xiangtan with a starch content of 45%; removing the skin and core of the dried lotus seeds from Xiangtan with a starch content of 45% and then steaming the seeds; adding peanut oil, water, sucrose and a lotus seed starch-proanthocyanidin complex after the steaming; and pouring the mixture into a colloid mill for grinding to obtain lotus seed paste; and frying the lotus seed paste to prepare a high-resistance lotus seed paste filling.

[0066] It should be noted that the temperature of the steaming treatment is 95°C-105°C; the temperature of the refining treatment is room temperature, the pressure is 0.08MPa-0.09MPa, and the time is 4min-6min; the temperature of the frying treatment is 195°C, and the time is 45min-55min; the replacement amount of resistant starch in the high-resistant lotus seed paste filling is 10wt%-30wt%; after the steaming treatment is completed, 60g-65g of peanut oil, 2g-4g of glycerol, 45g-55g of sucrose, 130g-150g of water, and 8g-10g of lotus seed starch-proanthocyanidin complex are added to every 80g of Xiangtan dried lotus seeds with a starch content of 45%.

[0067] To facilitate understanding by those skilled in the art, the technical solutions described in this application will be described in detail below with reference to the following embodiments:

[0068] Example 1

[0069] 1. Preparation of lotus seed paste filling containing ultra-high pressure enzymatically modified lotus seed starch and lotus seed starch-proanthocyanidin complex, comprising the following steps:

[0070] (1) Extraction of lotus seed starch: Soak the peeled lotus seeds from Xiangtan in distilled water overnight, repeatedly wash the residual film on the surface, add 4 mL of distilled water per gram of washed lotus seed starch, break the wall with a juicer and sieve, and let the filtrate stand for 6 hours. Discard the yellow impurity layer above the white starch layer, wash the starch precipitate three times, dry the washed starch in a vacuum drying oven at 45°C to constant weight, crush and sieve 100 mesh, and obtain lotus seed starch, which is LS.

[0071] (2) Preparation of ultrahigh pressure enzymatically modified lotus seed starch: The lotus seed starch extracted in (1) was weighed and prepared into a 30% (m / V) starch suspension. The mixture was stirred in a water bath at 80°C for 20 minutes to prepare pregelatinized starch. After cooling to 55°C, 0.05 mol / L hydrochloric acid solution was added to adjust the pH value to 5.5. 20 U / g pullulanase was added and the mixture was shaken in a constant temperature incubator at 55°C for 12 hours for debranching treatment. The enzyme was inactivated in a water bath at 100°C for 15 minutes and then placed in a polyethylene bag and vacuum sealed. After ultrahigh pressure treatment at 600 MPa and room temperature for 30 minutes, the mixture was taken out and refrigerated at 4°C for 24 hours. The mixture was then frozen in a refrigerator at -18°C overnight. After freeze drying, the mixture was ground and passed through an 80-mesh sieve to obtain ultrahigh pressure modified lotus seed starch, which is U-PLRS.

[0072] (3) Preparation of lotus seed starch-proanthocyanidin complex: Lotus seed starch was extracted according to the method (1), 10 g of lotus seed starch was weighed and uniformly dispersed in 200 mL of distilled water, stirred in a 95°C water bath for pre-gelatinization for 30 min, and cooled to 60°C for insulation. Proanthocyanidins were weighed at a ratio of 10% (w / w, based on the dry basis of starch), dissolved in 50 mL of anhydrous ethanol, and poured into the lotus seed starch milk and mixed thoroughly. The lotus seed starch milk-polyphenol compound composite paste was dispersed in a homogenizer for 5 min, and immediately homogenized using a nano ultra-high pressure homogenizer at a pressure of 150 MPa for 5 to 6 times. The homogenized mixture was centrifuged at 8000 × g for 5 min. The precipitate was washed 3 to 4 times with 50% ethanol solution and recovered by centrifugation to obtain the complex. After freezing at -20°C, it was freeze-dried and ground through a 100-mesh sieve to obtain high-pressure homogenized lotus seed starch and lotus seed starch-proanthocyanidin, namely HPHLS-PC.

[0073] (4) Preparation of Highly Resistant Lotus Seed Paste: Commercially available Xiangtan dried lotus seeds with a starch content of 45% were used, i.e., 100g of lotus seeds contained 45g of lotus seed starch. Based on the lotus seed starch content, the resistant starch replacement amounts were 10%, 20%, and 30%, respectively, i.e., the added amounts of resistant starch were 4.5g, 9g, and 13.5g, respectively. Equivalent to lotus seed masses of 10g, 20g, and 30g, the corresponding dried lotus seed masses added to the recipe were 90g, 80g, and 70g, respectively.

[0074] That is, lotus seeds with a starch content of 45% were selected, i.e., 45g of starch was contained in 100g of lotus seeds, and this was used as the basis for calculating the content of resistant starch replacing conventional starch. The replacement amounts of resistant starch were: 10%, 20%, and 30%, respectively. In other words, the mass of resistant starch added to 45g of starch calculated according to 10%, 20%, and 30% was: 4.5g, 9g, and 13.5g. That is, the composition of the starch in the filling according to the replacement amount was: 40.5g conventional starch + 4.5g resistant starch, 36g conventional starch + 9g resistant starch, and 31.5g conventional starch + 13.5g.

[0075] Since conventional starch accounts for 45% of dried lotus seeds, the weight of dried lotus seeds added in sequence is:

[0076] 40.5g / 0.45=90g, 36g / 0.45=80g, 31.5g / 0.45=70g

[0077] The resulting formula is:

[0078] 90g dried lotus seeds (containing 40.5g regular starch) + 4.5g resistant starch;

[0079] 80g dried lotus seeds (containing 36g regular starch) + 9g resistant starch;

[0080] 70g dried lotus seeds (containing 31.5g regular starch) + 13.5g resistant starch.

[0081] According to the recipe in Table 1, dried lotus seeds were peeled and cored, then steamed at 100°C for 60 min. After the tissue softened, peanut oil, water, sucrose, ultrahigh pressure enzymatically modified lotus seed starch, and lotus seed starch-proanthocyanidin complex were added. The mixture was then ground in a colloid mill (room temperature, 0.08-0.09 MPa) for 5 min. The lotus seed paste was then stir-fried at 200°C for 50 min to obtain a high-resistance lotus seed paste filling. The mixture was cooled in a cold water bath for 30 min, vacuumized, and stored in a cool, dark place.

[0082] Table 1 Resistant lotus seed paste filling formula / g

[0083]

[0084] 2. Sensory Evaluation Method

[0085] According to the requirements of GB / T 16291.1-2012, 15 food professionals were recruited and trained in sensory evaluation to form an expert evaluation panel. They conducted sensory evaluations of the color, texture, flavor, density, and oil permeation of lotus seed paste fillings. The sensory evaluation criteria are shown in Table 2.

[0086] Table 2 Sensory evaluation scoring criteria for lotus seed paste filling

[0087]

[0088]

[0089] 3. Texture determination method

[0090] Lotus seed paste was tested using a texture analyzer at room temperature. A 30g sample of lotus seed paste filling was extruded through a die to ensure a uniform shape. The sample was then placed on the stage below the probe area for measurement. Test conditions were as follows: a P / 36 cylindrical probe was selected, with a pre-test speed of 1.00mm / s, a test speed of 5mm / s, and a post-test speed of 5mm / s. The target mode was set to Strain. The sample was compressed to 40% of its original height twice, with a dwell time of 5s. A trigger force of 5.0g was used.

[0091] Each texture index corresponds to a specific sensory attribute, and the definitions of each index are shown in Table 3.

[0092] Table 3 Definition and characteristics of texture indicators

[0093]

[0094] 4. Moisture distribution determination method

[0095] The moisture distribution of lotus seed paste was determined using a low-field nuclear magnetic resonance imaging (LF-NMR) analyzer. A 3g sample of lotus seed paste was weighed and placed in a 10mm NMR tube, which was then sealed with polytetrafluoroethylene tape. The measurement was performed using a CPMG pulse sequence. The experimental parameters included a sampling interval (TW) of 1000ms, an echo time interval (TE) of 0.50ms, an echo number (NECH) of 2000, and a scan count of 8.

[0096] 5. Determination of moisture content, fat content and oil and water holding capacity

[0097] (1) Moisture content: Determined according to the reduced pressure drying method in GB 5009.3-2016 “Determination of moisture in foods”.

[0098] (2) Fat content: Determined according to the acid hydrolysis method in GB 5009.6-2016 “Determination of fat in foods”.

[0099] (3) Determination of oil and water holding capacity: Weigh a certain amount of sample, record it as W1, and place it in a 2 mL centrifuge tube. The mass of the centrifuge tube is recorded as W2. Centrifuge at 10,000 r / min for 15 min. After removal, invert it on filter paper and let it stand for 24 h. Then weigh the total mass of the centrifuge tube and sample, record it as W3. The oil and water holding capacity is calculated as follows:

[0100]

[0101] 6. Determination of Resistant Starch Content

[0102] The resistant starch content was determined using the Megazyme resistant starch kit. Accurately weigh 100 mg of lotus seed paste filling sample and place it in a centrifuge tube. Add 4 ml of pancreatic α-amylase (containing 3 U / mL of α-amyloglucosidase) and shake continuously at 37°C for 16 h. Remove the sample and add 4 mL of anhydrous ethanol. Centrifuge at 4000 rpm for 10 min. Pour out the supernatant and wash the precipitate with 50% ethanol 2-3 times. Combine the supernatants and add 2 mL of 2 mol / L KOH to each tube. Stir magnetically in an ice-water bath for 20 min. Then, add 8 mL of 1.2 mol / L sodium acetate buffer (pH 3.8) and mix thoroughly. Immediately add 0.1 mL of α-amyloglucosidase (3300 U / mL) and mix thoroughly. Place the tube in a 50°C water bath for 30 min. Centrifuge at 4000 rpm for 10 minutes. Transfer 0.1 mL of the supernatant to a test tube. Add 3 mL of GOPOD reagent. Incubate in a 50°C water bath for 20 minutes. Measure absorbance at 510 nm relative to a blank. Calculate the resistant starch content (RS%, dry basis) in the sample using the following formula:

[0103]

[0104] Where: ΔE is the absorbance value relative to the blank sample; F is the conversion between absorbance value and micrograms; W is the dry weight of the sample, mg.

[0105] 7. Test Results

[0106] 1. Sensory evaluation results

[0107] The sensory evaluation results of each lotus seed paste filling are shown in Table 4.

[0108] In terms of color, the RS5 group can still maintain a relatively high score when the addition amount reaches 10% and 20%.

[0109] In terms of taste, the taste score of the RS3 group filling decreased linearly with the increase in the addition amount, while the RS5 type showed a trend of first increasing and then decreasing, reaching a peak at an addition amount of 20%, and the taste score was 8.72% higher than that of the traditional group filling.

[0110] In terms of density, the two resistant starches can improve the density of lotus seed paste filling when added at a rate of 10%.

[0111] In terms of oil seepage, when the resistant starch in the RS5 group increased to 20%, the oil seepage score increased to 15.57%, which was basically consistent with the filling of the traditional group.

[0112] Comprehensive sensory evaluation showed that the negative impact of RS3 type on quality indicators was more significant, while RS5 type remained acceptable when added at a dosage of <30%, and there was no significant difference in the total sensory score compared with the traditional lotus seed paste group (P<0.05), indicating that the 10% and 20% RS5-LP groups can ensure that the sensory quality of lotus seed paste is maintained at a better level.

[0113] Table 4 Effects of different resistant starches on the sensory quality of lotus seed paste fillings

[0114]

[0115] Note: Different letters indicate significant differences at P < 0.05.

[0116] 2. Texture measurement results

[0117] As shown in Table 5, compared with the traditional lotus seed paste filling, the lotus seed paste filling with 10% to 30% resistant starch showed a significant increase in hardness and chewiness. The hardness of the RS3 group increased by 55.38%, significantly higher than the 19.68% of the RS5 group, while the chewiness index increased from 17.61N to 35.07N and 23.32N respectively.

[0118] Adhesion decreased with increasing amounts of RS3 and RS5, resulting in a less sticky and more palatable lotus seed paste. Elasticity decreased by 2.13% to 27.66%, indicating that both resistant starches can mitigate the staling of lotus seed paste to varying degrees.

[0119] Table 5 Effect of resistant starch on the texture characteristics of lotus seed paste filling

[0120]

[0121] Note: Different letters indicate significant differences at P < 0.05.

[0122] 3. Moisture distribution measurement results

[0123] The results of water distribution are shown in Table 6. Compared with the traditional lotus seed paste, the resistant starch group T 22 Down and A 22 The increase indicates that the degree of water molecule binding is enhanced and the water holding capacity is improved. Among them, the RS5 group (addition amount 20%) showed the best effect. Its T 22 (17.92ms) was reduced by 52.40% compared with the traditional group. 22 It increased by 11.23%, indicating that the addition of resistant starch can reduce water migration in lotus seed paste filling and delay aging.

[0124] Table 6 Effects of different resistant starches on the moisture distribution of lotus seed paste filling

[0125]

[0126] Note: Different letters indicate significant differences at P < 0.05.

[0127] 4. Test results of moisture, fat content and water and oil holding capacity

[0128] Depend on Figure 1 The results showed that the moisture content of the lotus seed paste in the resistant starch group was significantly higher than that of the traditional lotus seed paste (P < 0.05). When the resistant starch addition reached 30%, the fat content in the lotus seed paste group reached its lowest value, a 19.29% decrease compared to the traditional group. At 20% addition, the water and oil holding capacity of the RS5 group reached a maximum of 30.18%, indicating that the RS5 group has a stronger ability to absorb oil.

[0129] Note: Different letters indicate significant differences at P < 0.05.

[0130] 5. Determination of resistant starch content

[0131] The results of resistant starch content determination were as follows Figure 2 As shown, at the same addition ratio, the crystallization characteristics of RS3 resistant starch exhibited superior thermal stability. The resistant starch content of the RS3 group was 6.25% to 11.94% higher than that of the RS5 group. The resistant starch content of both the RS3 and RS5 groups was significantly higher than that of the traditional group, demonstrating a certain degree of resistance to digestion.

[0132] Note: Different letters indicate significant differences at P < 0.05.

[0133] Through comprehensive analysis of sensory and anti-digestive properties, it was finally determined that a 20% addition of RS5 resistant starch was the optimal process parameter for subsequent formula optimization. This solution not only ensured the sensory acceptance of the product, but also increased the resistant starch content to 32.92% of traditional lotus seed paste filling.

[0134] Example 2 Optimization of processing conditions for highly resistant lotus seed paste filling

[0135] 1. Basic formula and production process of resistant lotus seed paste filling

[0136] Prepare 80g lotus seeds, 9g resistant starch (20% lotus seed starch replacement), 70g peanut oil, 50g sucrose, and 140g water. Peel and core the dried lotus seeds, then steam at 100°C for 60 minutes. Once the seeds are soft, add peanut oil, glycerin, water, sucrose, and modified starch. Grind in a colloid mill for 5 minutes to obtain the lotus seed paste, stir-fry at 200°C for 50 minutes, cool in a cold water bath for 30 minutes, evacuate, and store in a cool, dark place.

[0137] 2. Single-factor experiment on resistant lotus seed paste filling

[0138] The effects of peanut oil addition, glycerol addition and frying time on the quality of resistant lotus seed paste filling were investigated.

[0139] (1) Effect of peanut oil addition on filling quality

[0140] Lotus seed paste filling was prepared according to the ratio of peanut oil 40, 50, 60, 70, 80 g; dried lotus seeds 80 g; RS5 resistant starch 9 g; sucrose 50 g; water 140 g, and then sensory and hardness tests were performed.

[0141] (2) Effect of glycerol addition on filling quality

[0142] The lotus seed paste filling was prepared according to the ratio of 0, 1, 2, 3, 4 g of glycerol; 80 g of dried lotus seeds; 9 g of RS5 resistant starch; 70 g of peanut oil; 50 g of sucrose; and 140 g of water, and then sensory and hardness tests were performed.

[0143] (3) Effect of frying time on filling quality

[0144] Lotus seed paste filling was prepared according to the following ratios: frying time 30, 40, 50, 60, 70 min; dried lotus seeds 80 g; RS5 resistant starch 9 g; peanut oil 70 g; sucrose 50 g; water 140 g, and then sensory and hardness tests were performed.

[0145] 3. Response Surface Experimental Design

[0146] According to the Box-Behnken central composite design principle, a three-factor three-level response surface experiment was designed with the addition amount of peanut oil, glycerol and sucrose as independent variables. The hardness and sensory score of lotus seed paste were used as response values to explore the optimal formula, dosage and process parameters of resistant lotus seed paste filling.

[0147] 4. Test Results

[0148] 1. Single-factor experimental results and analysis

[0149] (1) Effect of peanut oil addition on lotus seed paste filling

[0150] Effects of peanut oil addition on sensory scores and hardness of high resistant starch lotus seed paste fillings Figure 2 .

[0151] according to Figure 3 The results show that the sensory score gradually increased to 84.3 points in the addition range of 40g to 60g. When the addition amount exceeded the critical value of 60g, the decline in texture characteristics slowed down and eventually stabilized at 46N. Based on the combined results of sensory scores and hardness, the optimal addition amount of peanut oil is between 50g and 70g.

[0152] (2) Effect of glycerol addition on lotus seed paste filling

[0153] Effects of glycerol addition on sensory scores and hardness of high-resistant starch lotus seed paste fillings Figure 4 .

[0154] Compared to the group without glycerol, adding glycerol significantly reduced the hardness of the resistant lotus seed paste filling. As the amount of glycerol added increased, the hardness decreased, making the filling softer. Based on the combined results of sensory scores and hardness, the optimal amount of glycerol added was between 2 and 4 grams.

[0155] (3) Effect of frying time on lotus seed paste filling

[0156] Effects of glycerol addition on sensory scores and hardness of high-resistant starch lotus seed paste fillings Figure 5 .

[0157] according to Figure 5 It shows that as the frying time increases, the sensory score shows an upward and then downward trend, rising from 71.33±1.11 to a peak of 85.50±1.66 in the 30-50min range; the hardness value increases linearly with the frying time. According to the comprehensive results of sensory score and hardness, the optimal frying time range is between 30 and 50 minutes.

[0158] 2. Analysis of response surface optimization results

[0159] (1) Response surface optimization scheme and experimental results

[0160] Based on the results of the single-factor experiment, a three-factor, three-level response surface optimization experiment was designed, using the addition amounts of peanut oil (A), glycerin (B), and stir-frying time (C) as independent variables and the sensory scores and firmness of the lotus seed paste as responses. This experiment investigated the interaction between the three factors and determined the optimal addition amounts and process parameters. The design factors and levels are shown in Table 7, and the experimental design and results are shown in Table 8.

[0161] Table 7 Box-Behnken test factors and levels

[0162]

[0163] Table 8 Box-Behnken test design and results

[0164]

[0165] (2) Response surface regression equation and variance analysis

[0166] Use Design Expert 8.0.6 software to fit the results in Table 3.12 into a quadratic multiple regression equation, as shown in the following example: Figure 6As shown in the figure, it is the response surface and contour map of the effect of the interaction between two factors on the sensory score of lotus seed paste filling. Based on the figure, the functional relationship between the sensory score (Y1) and the three factors can be obtained as follows:

[0167] Y1=89.8+2.625A+3.25B+3.125C-0.25AB-0.75BC-5.9A 2 -4.65B 2 -4.4C 2 ;

[0168] like Figure 7 As shown in the figure, it is the response surface and contour map of the effect of the interaction between two factors on the hardness of lotus seed paste. Based on the figure, the functional relationship between hardness (Y2) and the three factors can be obtained as follows:

[0169] Y2=38.66-5.46A-6.99B+0.65C+4.63AB+1.99AC-1.65BC+4.55A 2 -5.57B 2 +

[0170] 1.61C 2 .

[0171] in, Figure 6 Middle: Part (a) shows the response surface for the interaction between A peanut oil addition and B glycerol addition on the sensory score of lotus seed paste filling, and part (b) shows the contour map corresponding to part (a); Part (c) shows the response surface for the interaction between A peanut oil addition and C frying time on the sensory score of lotus seed paste filling, and part (d) shows the contour map corresponding to part (c); Part (e) shows the response surface for the interaction between B glycerol addition and C frying time on the sensory score of lotus seed paste filling, and part (f) shows the contour map corresponding to part (e).

[0172] in, Figure 7 middle:

[0173] Part (a) shows the response surface of the interaction between A peanut oil addition and B glycerol addition on the hardness of lotus seed paste filling, and part (b) shows the contour map corresponding to part (a); part (c) shows the response surface of the interaction between A peanut oil addition and C frying time on the hardness of lotus seed paste filling, and part (d) shows the contour map corresponding to part (c); part (e) shows the response surface of the interaction between B glycerol addition and C frying time on the hardness of lotus seed paste filling, and part (f) shows the contour map corresponding to part (e).

[0174] The experimental results in Table 8 were subjected to variance analysis, and the results are shown in Tables 9 and 10 respectively.

[0175] Table 9 Box-Behnken test regression model and variance analysis (sensory scores)

[0176]

[0177]

[0178] Table 10 Box-Behnken test regression model and variance analysis (hardness)

[0179]

[0180] (3) Response surface and contour analysis

[0181] Determination and verification of the optimal formula and processing conditions for high-resistance lotus seed paste filling

[0182] Using Design Expert 8.0.6 software, the first-order partial derivative of the sensory score fitting equation (Y1) was calculated. The optimal recipe and processing conditions for the maximum sensory score were: peanut oil 63.22g, glycerin 3.37g, and frying time 44.57min. The predicted maximum sensory score was 91.21, and the hardness was 27.35N. The first-order partial derivative of the hardness fitting equation (Y2) was calculated. The optimal recipe and processing conditions for the minimum hardness were: peanut oil 61.73g, glycerin 3.93g, and frying time 44.09min. The predicted minimum hardness was 27.41N, and the sensory score was 89.89. Taking into account the peanut oil and glycerin additions and frying time, with sensory evaluation as the priority, the optimal recipe and processing conditions for the highly resistant lotus seed paste filling were: peanut oil 63.22g, glycerin 3.37g, and frying time 44.57min.

[0183] To verify the accuracy of response surface analysis, and taking practical considerations into account, the recipe and processing conditions were adjusted to 63g peanut oil, 3g glycerin, and a frying time of 45 minutes. The predicted maximum sensory score was 90.21 points and the hardness was 34.33N. Three parallel validation tests under these conditions yielded a hardness of 35N and a sensory score of 90.56, both of which were not significantly different from the theoretical values (P>0.05). These results demonstrate that the response surface methodology closely matches the experimental values and the values predicted by the regression equation, indicating that the model-optimized response surface methodology is stable and reliable.

[0184] Based on the above embodiments, it can be seen that the present application provides a novel lotus seed paste filling containing resistant starch (RS3 or RS5) and clarifies its preparation method. By optimizing the addition ratio of resistant starch and the filling processing technology, the problems faced by existing resistant starch in food applications, such as poor processing stability, decreased sensory quality of food after addition, and insufficient process adaptability, are solved. A method for preparing a resistant starch lotus seed paste filling with good sensory quality and a certain blood sugar-lowering function is provided. At the same time, the lotus seed paste production process (frying time, amount of peanut oil added, amount of glycerol added) is optimized to make it better adapted to the characteristics of resistant starch, so as to provide a reference for the development of moon cake lotus seed paste filling related products using lotus seed resistant starch.

[0185] Compared with the existing technology, it has the following technical advances:

[0186] 1. Improve the processing adaptability of resistant starch: prepare lotus seed resistant starch by adopting the ultra-high pressure enzymatic hydrolysis combined method, and prepare a complex with proanthocyanidins and lotus seed starch to achieve the preparation of green and efficient resistant starch.

[0187] 2. Improve the quality and blood sugar-lowering function of the filling: By measuring the filling's oil and water holding capacity, sensory properties, texture characteristics, and resistant starch content, the amount of resistant starch added is adjusted to make its taste closer to the traditional sugar and oil formula, thereby preparing a healthy mooncake filling that has both good edible quality and blood sugar-lowering function.

[0188] 3. Optimize the quality of high-resistant lotus seed paste filling: By comparing the application effects of different formulas and considering process efficiency factors, the amount of peanut oil and glycerin added and the frying time were selected to determine the formula of high-resistant starch lotus seed paste filling with excellent processing and functional properties.

[0189] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A method for preparing lotus seed paste filling with blood sugar lowering function, characterized in that: The following steps are involved: Extracting lotus seed starch; Based on the lotus seed starch, a lotus seed starch-proanthocyanidin complex is prepared; Based on the lotus seed starch-proanthocyanidin complex, a high-resistance lotus seed paste filling is prepared.

2. The method for preparing the lotus seed paste filling with blood sugar lowering function according to claim 1, characterized in that: The extraction method for obtaining lotus seed starch comprises: After removing the residual film on the surface of the Xiangtan ground lotus seeds, the pre-treated Xiangtan ground lotus seeds are obtained; adding the pre-treated Xiangtan ground lotus seeds to distilled water, performing wall breaking and sieving to obtain a filtrate; After the filtrate is allowed to stand, a yellow impurity layer is discarded to obtain a white starch layer; the white starch precipitate is washed with distilled water, the washed white starch precipitate is vacuum-dried to a constant weight, and pulverized to obtain lotus seed starch.

3. The method for preparing the lotus seed paste filling with blood sugar lowering function according to claim 2, characterized in that: The solid-liquid ratio of the Xiangtan ground lotus seeds after repeated washing of the residual film on the surface and the distilled water is 1g-3g:4mL-6mL; The mesh size of the sieve after the wall breaking treatment and the sieve after the crushing treatment is 100 mesh to 120 mesh; The filtrate is allowed to stand for 6-8 hours. The temperature of the vacuum drying treatment is 45°C-50°C.

4. The method for preparing the lotus seed paste filling with blood sugar lowering function according to claim 1, characterized in that: The lotus seed starch-proanthocyanidin complex is prepared based on the lotus seed starch, comprising: The lotus seed starch is evenly dispersed in distilled water, stirred to obtain a second pregelatinized starch, and cooled to 55° C.-65° C. for insulation; Weighing a preset proportion of proanthocyanidins, dissolving the proanthocyanidins in anhydrous ethanol, and pouring the mixture into the cooled second pregelatinized starch and mixing thoroughly to obtain a lotus seed starch milk-polyphenol compound composite paste; homogenizing and dispersing the lotus seed starch milk-polyphenol compound composite paste to obtain a homogeneous mixture; After the homogenous mixture is subjected to centrifugation, the precipitate is washed and recovered by centrifugation to obtain the complex; The complex is frozen at -20°C and then freeze-dried, and ground through a 100-mesh sieve to obtain high-pressure homogenized lotus seed starch and lotus seed starch-proanthocyanidins.

5. The method for preparing the lotus seed paste filling with blood sugar lowering function according to claim 4, characterized in that: The material ratio of the lotus seed starch to the distilled water is 10g-12g: 200mL-220mL; The stirring temperature is 90-95°C, and the stirring time is 28-32 minutes; The material ratio of the lotus seed starch, the proanthocyanidins and the anhydrous ethanol is 1:0.05-0.1:45mL-55mL; The homogenization and dispersion treatment includes sequentially using a homogenizer and a nano ultra-high pressure homogenizer for homogenization and dispersion treatment; the treatment time using the homogenizer is 4 minutes to 6 minutes; the treatment pressure using the nano ultra-high pressure homogenizer is 150 MPa, and the number of treatments is 5 to 6 times; The parameters of the centrifugation treatment are: 8000×g for 5 min; The washing of the precipitate refers to washing the precipitate three times with a 50% ethanol solution.

6. The method for preparing the lotus seed paste filling with blood sugar lowering function according to claim 1, characterized in that: The method for preparing a high-resistance lotus seed paste filling based on the lotus seed starch-proanthocyanidin complex comprises: Select Xiangtan dried lotus seeds with a starch content of 45%; The dried Xiangtan lotus seeds with a starch content of 45% are peeled and cored, and then steamed. After the steaming, peanut oil, water, sucrose, and lotus seed starch-proanthocyanidin complex are added, and the mixture is poured into a colloid mill for grinding to obtain lotus seed paste. The lotus seed paste is fried to obtain a high-resistance lotus seed paste filling.

7. The method for preparing the lotus seed paste filling with blood sugar lowering function according to claim 6, characterized in that: The temperature of the steaming treatment is 95°C-105°C; The temperature of the refining treatment is room temperature, the pressure is 0.08MPa to 0.09MPa, and the time is 4min to 6min; The frying temperature is 195° C. and the frying time is 45 min-55 min.

8. The method for preparing the lotus seed paste filling with blood sugar lowering function according to claim 6, characterized in that: The replacement amount of resistant starch in the high-resistant lotus seed paste filling is 10wt%-30wt%; After the steaming process is completed, 60g-65g of peanut oil, 2g-4g of glycerol, 45g-55g of sucrose, 130g-150g of water and 8g-10g of lotus seed starch-proanthocyanidin complex are added to every 80g of Xiangtan dried lotus seeds with a starch content of 45%.

9. A lotus seed paste filling with blood sugar lowering function, characterized in that: The method is obtained by the preparation method according to any one of claims 1 to 8.

10. An application of the lotus seed paste filling with blood sugar lowering function as claimed in claim 9, characterized in that: It is used in the preparation of mooncakes.

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