Preparation method of high-activity probiotic embedded low-fat fruit and vegetable crisp chips

Abstract

The invention discloses a preparation method of high-activity probiotic embedded low-fat fruit and vegetable crisp chips, and relates to the field of food processing. The preparation method of the high-activity probiotic embedded low-fat fruit and vegetable crisp chips comprises the steps of fruit and vegetable chip preparation, probiotic embedding and fusion molding. According to the preparation method of the high-activity probiotic embedded low-fat fruit and vegetable crisp chips, a double-layer embedding and outer wall coating triple probiotic protection system is constructed, the first layer of embedding forms a primary barrier, the second layer of embedding further enhances the stability of thalli, and the outer layer is provided with a composite film, so that the triple protection synergistic effect is achieved, and the high-activity probiotic embedded low-fat fruit and vegetable crisp chips are prepared. The tolerance of the probiotics to a dry environment and forming pressure in the processing process of the fruit and vegetable crisp chips is remarkably improved, the activity loss in the processing and subsequent storage processes is greatly reduced, and the activity of the probiotics in a finished product is ensured to reach the standard.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of food processing, in particular to a preparation method of low-fat fruit and vegetable crisp pieces embedded with high-activity probiotics. BACKGROUND

[0002] As a new type of snack food, fruit and vegetable crisp pieces are favored by consumers due to their nutritional properties and crispy taste. With the popularization of healthy eating concepts, low-fat and functional fruit and vegetable crisp pieces have become a development trend in the industry. Fruit and vegetable crisp pieces with added probiotics have a growing market demand due to their health benefits such as intestinal regulation.

[0003] However, probiotics, especially lactic acid bacteria, are extremely sensitive to environmental factors such as temperature, humidity, and oxygen during processing. During the preparation of fruit and vegetable crisp pieces (such as blanching, drying, and molding) and subsequent storage, the activity is easily lost, making it difficult to ensure that the final product meets the probiotic activity standards.

[0004] In the prior art, although attempts have been made to protect the activity of probiotics using embedding technology, conventional embedding methods are mostly single-layer embedding, which lacks sufficient stability and is prone to rupture under the mild conditions of fruit and vegetable crisp piece processing, leading to inactivation of probiotics. At the same time, some embedding agents have poor compatibility with fruit and vegetable crisp pieces, which can affect the taste and flavor of the product. SUMMARY

[0005] The present application aims to provide a preparation method of low-fat fruit and vegetable crisp pieces embedded with high-activity probiotics to solve the problems raised in the background.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solution: a preparation method of low-fat fruit and vegetable crisp pieces embedded with high-activity probiotics, comprising the following steps: Step S1, fruit and vegetable piece preparation: pretreating fresh fruits and vegetables to obtain fruit and vegetable pieces, blanching the fruit and vegetable pieces, adding a penetrating agent after cooling, stirring until solid penetration, and then draining; Step S2, probiotic embedding: S2.1, culturing probiotic strains in a fermentation tank, and obtaining first bacterial bodies by high-speed centrifugation when the total number of lactic acid bacteria in the fermentation broth reaches a preset amount; S2.2, uniformly mixing the first bacterial bodies with a first layer of embedding agent to obtain second bacterial bodies, mixing the second bacterial bodies with a second layer of embedding agent, adding water, mixing, and cold storage and standing to obtain third bacterial bodies; S2.3, prepare the emulsified solution, add modified sodium alginate and whey protein into deionized water, disperse by ultrasonic, obtain the outer wall solution after sterilization, mix the third bacteria and the outer wall solution according to the preset ratio, stir uniformly, add calcium chloride solution by extrusion method, form gel after standing, stir the gel in modified carboxymethyl chitosan solution, obtain the probiotic microcapsule after washing and drying; Step S3, fusion molding: the fruit and vegetable pieces are fused and molded with the probiotic microcapsules.

[0007] Preferably, the pretreatment in step S1 includes cleaning, peeling, pitting and cutting, and the thickness of the cut fruit and vegetable pieces is set to 1-3 mm.

[0008] Preferably, the blanching temperature in step S1 is 80-95℃, the time is 1-5 min, the penetrating agent is one of sucrose and maltitol or a mixture of the two, the addition amount of the penetrating agent is 5%-15% of the mass of the fruit and vegetable pieces, the temperature of the solid-state penetration process is 20-30℃, and the time is 2-6 h.

[0009] Preferably, the total number of lactic acid bacteria in the fermentation broth in step S2.1 is ≥10^9 CFU / mL, the speed of the high-speed centrifugation process is 8000-12000 r / min, the time is 5-15 min, the centrifugation temperature is 4-10℃, and after centrifugation, the supernatant is discarded, the bottom bacteria are collected and precipitated to form the first bacteria.

[0010] Preferably, the first layer of embedding agent in step S2.2 is set to one of maltodextrin and β-cyclodextrin or a mixture of the two, the mass ratio of the first bacteria to the first layer of embedding agent is 1:2-1:5, the second layer of embedding agent is set to one of pectin and gelatin or a mixture of the two, the mass ratio of the second bacteria to the second layer of embedding agent is 1:3-1:6, the temperature of the refrigerated standing is set to 2-8℃, and the time is set to 12-24 h.

[0011] Preferably, the mass ratio of the modified sodium alginate to the whey protein in step S2.3 is set to 1:1-1:3, the solid content of the outer wall solution is set to 5%-15%, the power of the ultrasonic dispersion is set to 200-400 W, the time is set to 5-15 min, the sterilization temperature is set to 121℃, and the sterilization temperature time is set to 15-20 min.

[0012] Preferably, the mass ratio of the third bacteria to the outer wall solution in step 2.3 is set to 1:5-1:10, the mass fraction of the calcium chloride solution is set to 2%-5%, the standing time of the gel is set to 1-3 h, the mass fraction of the modified carboxymethyl chitosan solution is set to 1%-3%, and the stirring time is set to 30-60 min.

[0013] Preferably, the drying method in step 2.3 is vacuum freeze-drying, the drying temperature is -40 to -20 DEG C, the drying time is 12-24h, and the particle size of the probiotic microcapsule is 5-50 mu m.

[0014] Preferably, the fusion forming in step S3 is specifically: the probiotic microcapsule is mixed with fruit and vegetable powder, starch and erythritol, water is added to adjust the moisture content to 15%-20%, and is pressed into shape under the condition of pressure 0.5-1.0 MPa and temperature 40-60 DEG C.

[0015] Preferably, the fusion forming in step S3 is specifically: the fruit and vegetable slices after draining in step S1 are prepared into fruit and vegetable crisp chips by vacuum freeze-drying or low-temperature frying process, the probiotic microcapsule is mixed with 0.5%-1% sodium carboxymethyl cellulose to form a spraying liquid, which is uniformly sprayed on the surface of the crisp chips, the spraying amount is 5%-10% of the mass of the crisp chips, and the crisp chips are dried at 40-50 DEG C for 5-10 min for solidification.

[0016] The technical effects and advantages of the present application are as follows: The high-activity probiotic-embedded low-fat fruit and vegetable crisp chip preparation method constructs a three-layer probiotic protection system of double embedding and outer wall coating, the first layer of malt dextrin / beta-cyclodextrin embedding forms a preliminary barrier, the second layer of pectin / gelatin embedding further enhances the stability of the bacteria, and the outer layer is provided with a modified sodium alginate-whey protein / modified carboxymethyl chitosan composite film, the three-layer protection synergistically improves the tolerance of the probiotic to the drying environment and the forming pressure in the fruit and vegetable crisp chip processing process, greatly reduces the activity loss in the processing and subsequent storage process, and ensures that the probiotic activity in the finished product meets the standard.

[0017] The high-activity probiotic-embedded low-fat fruit and vegetable crisp chip preparation method can not only improve the dehydration efficiency of the fruit and vegetable chips and enhance the crispness of the final product, but also improve the surface properties of the fruit and vegetable chips and enhance the interfacial compatibility thereof with the probiotic microcapsule, whether it is pressed into shape or sprayed into shape, which can ensure that the probiotic microcapsule is tightly combined with the fruit and vegetable matrix, avoids the falling off of the microcapsule, and at the same time does not damage the nutritional ingredients and flavor of the fruit and vegetable itself.

[0018] The high-activity probiotic-embedded low-fat fruit and vegetable crisp chip preparation method avoids high-temperature and high-pressure treatment throughout the whole process, the fruit and vegetable crisp chip preparation adopts vacuum freeze-drying or low-temperature frying process, and the forming stage adopts low-temperature pressing or low-temperature solidification, so as to control the oil intake from the source and ensure the low-fat characteristics of the product; meanwhile, the selected embedding agents (malt dextrin, pectin, etc.) and auxiliary materials (erythritol, sodium carboxymethyl cellulose) all have good edible safety and taste adaptability, and will not produce odor or roughness, combined with the precise control of the thickness of the fruit and vegetable chips and the particle size of the microcapsule, the finished product has both the crisp taste and the health benefits of probiotics, which meets the current consumer demand for healthy leisure food. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall process of the present invention; Figure 2 This is a schematic diagram of the process for preparing fruit and vegetable slices according to the present invention; Figure 3 This is a schematic diagram of the probiotic encapsulation process of the present invention; Figure 4 This is a schematic diagram of the fusion molding process of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention provides, for example Figures 1-4 The method for preparing low-fat fruit and vegetable crisps encapsulated with highly active probiotics, as shown, includes the following steps: Step S1, Preparation of fruit and vegetable slices: Fresh fruits and vegetables are pretreated to obtain fruit and vegetable slices. The fruit and vegetable slices are blanched and blanched, cooled and then a penetrant is added and stirred until solid penetration is achieved. The slices are then removed and drained. Step S2, Probiotic Encapsulation: S2.1. Cultivate the probiotic strains in a fermenter. When the total number of lactic acid bacteria in the fermentation liquid reaches the preset amount, centrifuge at high speed to obtain the first bacterial cell. S2.2. Mix the first bacterial cell with the first layer of embedding agent evenly to obtain the second bacterial cell. Mix the second bacterial cell with the second layer of embedding agent, add water, mix, and refrigerate to obtain the third bacterial cell. S2.3. Prepare an emulsion solution by adding modified sodium alginate and whey protein to deionized water and dispersing them by ultrasound. After sterilization, an outer wall solution is obtained. The third bacterial cell and the outer wall solution are mixed in a preset ratio and stirred evenly. Calcium chloride solution is added by extrusion and allowed to stand to form a gel. The gel is then added to a modified carboxymethyl chitosan solution and stirred. After washing and drying, probiotic microcapsules are obtained. Step S3, Fusion Molding: The fruit and vegetable tablets and probiotic microcapsules are fused together and molded.

[0022] Through the solid state infiltration treatment of specific parameters, not only the dehydration efficiency of fruit and vegetable slices can be improved, the brittleness of the final product can be enhanced, but also the surface properties of fruit and vegetable slices can be improved, the interface compatibility of fruit and vegetable slices with probiotic microcapsules can be improved, whether it is pressed into shape or sprayed into shape, probiotic microcapsules can be tightly combined with fruit and vegetable matrix, microcapsules can be prevented from falling off, and the nutritional ingredients and flavor of fruit and vegetable itself can be prevented from being damaged.

[0023] Further, the pretreatment in step S1 includes cleaning, peeling, pitting and cutting, and the thickness of the cut fruit and vegetable slices is set to 1-3 mm.

[0024] Further, the temperature of the blanching in step S1 is 80-95℃, the time is 1-5 min, the infiltrating agent is one of sucrose and maltitol or a mixture of the two, the addition amount of the infiltrating agent is 5%-15% of the mass of the fruit and vegetable slices, the temperature of the solid state infiltration process is 20-30℃, and the time is 2-6 h.

[0025] Further, the total number of lactic acid bacteria in the fermentation broth in step S2.1 is ≥10^9 CFU / mL, the speed of the high-speed centrifugation process is 8000-12000 r / min, the time is 5-15 min, the centrifugation temperature is 4-10℃, and after centrifugation, the supernatant is discarded, the bottom bacterial body is collected, and the first bacterial body is formed by precipitation.

[0026] Further, the first layer of embedding agent in step S2.2 is set to one of maltodextrin and β-cyclodextrin or a mixture of the two, the mass ratio of the first bacterial body to the first layer of embedding agent is 1:2-1:5, the second layer of embedding agent is set to one of pectin and gelatin or a mixture of the two, the mass ratio of the second bacterial body to the second layer of embedding agent is 1:3-1:6, the temperature of the refrigeration and standing is set to 2-8℃, and the time is set to 12-24 h.

[0027] Further, the mass ratio of the modified sodium alginate to whey protein in step S2.3 is set to 1:1-1:3, the solid content of the outer wall solution is set to 5%-15%, the power of the ultrasonic dispersion is set to 200-400 W, the time is set to 5-15 min, the sterilization temperature is set to 121℃, and the sterilization temperature time is set to 15-20 min.

[0028] Further, the mass ratio of the third bacterial body to the outer wall solution in step 2.3 is set to 1:5-1:10, the mass fraction of the calcium chloride solution is set to 2%-5%, the standing time of the gel is set to 1-3 h, the mass fraction of the modified carboxymethyl chitosan solution is set to 1%-3%, and the stirring time is set to 30-60 min.

[0029] Further, the drying method in step 2.3 is vacuum freeze-drying, the drying temperature is -40 to -20℃, the drying time is 12-24h, and the particle size of the probiotic microcapsule is 5-50μm.

[0030] Further, the fusion molding in step S3 is specifically: mixing the probiotic microcapsule with fruit and vegetable powder, starch, erythritol, adding water to adjust the moisture content to 15%-20%, and molding under the conditions of pressure 0.5-1.0MPa and temperature 40-60℃.

[0031] Further, the fusion molding in step S3 is specifically: first, using vacuum freeze-drying or low-temperature frying process to prepare fruit and vegetable chips from the fruit and vegetable slices after draining in step S1, then mixing the probiotic microcapsule with 0.5%-1% sodium carboxymethyl cellulose to prepare a spraying liquid, uniformly spraying it on the surface of the chips, the spraying amount is 5%-10% of the mass of the chips, and low-temperature drying at 40-50℃ for 5-10min for solidification.

[0032] The whole process avoids high temperature and high pressure treatment, fruit and vegetable chips are prepared by vacuum freeze-drying or low-temperature frying process, and molding stage adopts low-temperature pressing or low-temperature solidification, which controls the intake of oil from the source and ensures the low-fat characteristics of the product; at the same time, the selected embedding agents (malt dextrin, pectin, etc.) and auxiliary materials (erythritol, sodium carboxymethyl cellulose) have good edible safety and taste adaptability, and will not produce odor or roughness, combined with the precise control of the thickness of fruit and vegetable slices and the particle size of microcapsules, the finished product has both crisp taste and probiotic health benefits, which meets the current consumer demand for healthy snack foods.

[0033] A triple probiotic protection system of double embedding and outer wall coating is constructed, the first layer of malt dextrin / β-cyclodextrin embedding forms a preliminary barrier, the second layer of pectin / gelatin embedding further enhances the stability of the bacteria, and the outer layer of modified sodium alginate-whey protein / modified carboxymethyl chitosan composite film is set, the triple protection synergistic effect significantly improves the resistance of probiotics to drying environment and molding pressure in the process of fruit and vegetable chip processing, greatly reduces the loss of activity in the process of processing and subsequent storage, and ensures that the activity of probiotics in the finished product meets the standard.

[0034] The overall workflow is as follows: Fresh fruits and vegetables are selected, washed, peeled, cored, and cut into slices with a thickness of 1-3mm, then the fruit and vegetable slices are blanched at 80-95℃ for 1-5min, cooled, and then 5%-15% of the fresh weight of the fruit and vegetable slices is added with sucrose or maltitol osmotic agent, stirred uniformly, and then subjected to solid-state penetration treatment at 20-30℃ for 2-6h, and then taken out and drained for standby use.

[0035] The probiotic strain is inoculated into a fermenter for expansion culture, and when the total number of lactic acid bacteria in the fermentation broth is ≥10^9 CFU / mL, high-speed centrifugation is performed at 4-10°C and 8000-12000 r / min for 5-15 min, the supernatant is discarded, and the first bacterial body is collected; the first bacterial body is mixed with malt dextrin / β-cyclodextrin type first layer embedding agent at a mass ratio of 1:2-1:5 to obtain a second bacterial body; then the second bacterial body is mixed with pectin / gelatin type second layer embedding agent at a mass ratio of 1:3-1:6, deionized water is added to adjust to a thick paste, and the mixture is stored at 2-8°C for 12-24 h to obtain a third bacterial body; deionized water is added to modified sodium alginate and whey protein at a mass ratio of 1:1-1:3, ultrasonic dispersion is performed at 200-400 W for 5-15 min, and high-pressure steam sterilization is performed at 121°C for 15-20 min to prepare an outer wall solution; the third bacterial body is mixed with the outer wall solution at a mass ratio of 1:5-1:10, and stirring is performed to obtain a uniform mixture; the mixture is dropped into a 2%-5% calcium chloride solution by extrusion method, and the mixture is allowed to stand for 1-3 h to form gel particles. The gel particles are added to a 1%-3% modified carboxymethyl chitosan solution, stirring is performed at 100-200 r / min for 30-60 min, and after washing, vacuum freeze-drying is performed at -40 to -20°C and 0.08-0.1 MPa for 12-24 h to obtain probiotic microcapsules with a particle size of 5-50 μm.

[0036] One of the following two methods is used to complete the molding: The probiotic microcapsules are mixed with fruit and vegetable powder, starch, erythritol, and deionized water is added to adjust the moisture content to 15%-20%, and the mixture is pressed at a pressure of 0.5-1.0 MPa and a temperature of 40-60°C for 2-5 min to form a shape. First, fruit and vegetable chips after draining are prepared by vacuum freeze-drying or low-temperature frying, and then the probiotic microcapsules are mixed with a 0.5%-1% sodium carboxymethyl cellulose solution to prepare a spraying solution, and the spraying solution is uniformly sprayed on the surface of the chips at a mass ratio of 5%-10%, and the chips are dried at a temperature of 40-50°C and a relative humidity of ≤60% for 5-10 min to solidify, and finally high-activity probiotic-embedded low-fat fruit and vegetable chips are obtained.

[0037] Finally, it should be noted that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features, as long as they are within the spirit and principles of the present application. Any modification, equivalent replacement, improvement, etc. made within the scope of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing low-fat fruit and vegetable crisps encapsulated with highly active probiotics, characterized in that, Includes the following steps: Step S1, Preparation of fruit and vegetable slices: Fresh fruits and vegetables are pretreated to obtain fruit and vegetable slices. The fruit and vegetable slices are blanched and blanched, cooled and then a penetrant is added and stirred until solid penetration is achieved. The slices are then removed and drained. Step S2, Probiotic Encapsulation: S2.

1. Cultivate the probiotic strains in a fermenter. When the total number of lactic acid bacteria in the fermentation liquid reaches the preset amount, centrifuge at high speed to obtain the first bacterial cell. S2.

2. Mix the first bacterial cell with the first layer of embedding agent evenly to obtain the second bacterial cell. Mix the second bacterial cell with the second layer of embedding agent, add water, mix, and refrigerate to obtain the third bacterial cell. S2.

3. Prepare an emulsion solution by adding modified sodium alginate and whey protein to deionized water and dispersing them by ultrasound. After sterilization, an outer wall solution is obtained. The third bacterial cell and the outer wall solution are mixed in a preset ratio and stirred evenly. Calcium chloride solution is added by extrusion and allowed to stand to form a gel. The gel is then added to a modified carboxymethyl chitosan solution and stirred. After washing and drying, probiotic microcapsules are obtained. Step S3, Fusion Molding: The fruit and vegetable tablets and probiotic microcapsules are fused together and molded.

2. The method for preparing low-fat fruit and vegetable crisps encapsulated with highly active probiotics according to claim 1, characterized in that, The pretreatment in step S1 includes washing, peeling, pitting, and cutting, and the thickness of the cut fruit and vegetable slices is set at 1-3 mm.

3. The method for preparing low-fat fruit and vegetable crisps encapsulated with highly active probiotics according to claim 1, characterized in that, The temperature for blanching and sterilization in step S1 is 80-95℃, the time is 1-5 minutes, and the penetrant is one or a mixture of sucrose and maltitol. The amount of penetrant added is 5%-15% of the weight of the fruit and vegetable slices. The temperature for the solid-state penetrant process is 20-30℃, and the time is 2-6 hours.

4. The method for preparing low-fat fruit and vegetable crisps encapsulated with highly active probiotics according to claim 1, characterized in that, In step S2.1, the total number of lactic acid bacteria in the fermentation broth is ≥10^9 CFU / mL. The high-speed centrifugation process is carried out at a speed of 8000-12000 r / min for 5-15 min, at a centrifugation temperature of 4-10℃, and the supernatant is discarded after centrifugation. The bottom cells are collected and precipitated to form the first cell.

5. The method for preparing low-fat fruit and vegetable crisps encapsulated with highly active probiotics according to claim 1, characterized in that, In step S2.2, the first layer embedding agent is set to one or a mixture of maltodextrin and β-cyclodextrin, and the mass ratio of the first bacterial cell to the first layer embedding agent is 1:2-1:

5. The second layer embedding agent is set to one or a mixture of pectin and gelatin, and the mass ratio of the second bacterial cell to the second layer embedding agent is 1:3-1:

6. The refrigerated standing temperature is set to 2-8℃ and the time is set to 12-24h.

6. The method for preparing low-fat fruit and vegetable crisps encapsulated with highly active probiotics according to claim 1, characterized in that, In step S2.3, the mass ratio of modified sodium alginate to whey protein is set to 1:1-1:3, the solid content of the outer wall solution is set to 5%-15%, the ultrasonic dispersion power is set to 200-400W, the time is set to 5-15min, the sterilization temperature is set to 121℃, and the sterilization time is set to 15-20min.

7. The method for preparing low-fat fruit and vegetable crisps encapsulated with highly active probiotics according to claim 1, characterized in that, In step 2.3, the mass ratio of the third bacterial cell to the outer wall solution is set to 1:5-1:10, the mass fraction of the calcium chloride solution is set to 2%-5%, the standing time of the gel is set to 1-3 hours, the mass fraction of the modified carboxymethyl chitosan solution is set to 1%-3%, and the stirring time is set to 30-60 minutes.

8. The method for preparing low-fat fruit and vegetable crisps encapsulated with highly active probiotics according to claim 1, characterized in that, The drying method described in step 2.3 is vacuum freeze drying, with a drying temperature of -40 to -20°C and a drying time of 12-24 hours. The particle size of the probiotic microcapsules is 5-50 μm.

9. The method for preparing low-fat fruit and vegetable crisps encapsulated with highly active probiotics according to claim 1, characterized in that, Step S3, fusion molding, specifically involves mixing probiotic microcapsules with fruit and vegetable powder, starch, and erythritol, adding water to adjust the moisture content to 15%-20%, and pressing the mixture into shape under a pressure of 0.5-1.0 MPa and a temperature of 40-60℃.

10. The method for preparing low-fat fruit and vegetable crisps encapsulated with highly active probiotics according to claim 1, characterized in that, Step S3, the fusion molding process, is as follows: First, the fruit and vegetable slices drained in step S1 are prepared into fruit and vegetable crisps using vacuum freeze-drying or low-temperature frying. Then, probiotic microcapsules are mixed with sodium carboxymethyl cellulose at a mass fraction of 0.5%-1% to prepare a spraying liquid, which is then evenly sprayed onto the surface of the crisps. The spraying amount is 5%-10% of the crisps' mass. The crisps are then cured by low-temperature drying at 40-50℃ for 5-10 minutes.

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