Fermented fruit and vegetable paste as well as preparation method and application thereof

Abstract

The invention relates to the technical field of food processing, in particular to fermented fruit and vegetable paste, a preparation method and application. The fermented fruit and vegetable paste is prepared by the method. The method comprises a first scheme and a second scheme. The first scheme comprises the following steps: mixing a first fermentation mother solution, a second fermentation mother solution and a third fermentation mother solution according to a volume ratio of (0.5-2): (0.5-2): (1-4) to obtain a compound bacteria solution; inoculating the fruit and vegetable puree with the compound bacteria liquid, and fermenting to obtain fermented fruit and vegetable puree; the scheme II comprises the following steps: mixing the first fermentation mother liquor and the third fermentation mother liquor according to the volume ratio of (0.5-2): (1-4) to obtain a compound bacteria solution; inoculating the fruit and vegetable puree with the compound bacteria liquid, and fermenting to obtain the fermented fruit and vegetable puree. The application is the application of the fermented fruit and vegetable puree in preparation of nutritional fruit and vegetable puree for infants. The problem that vegetable puree in the prior art is not suitable for infants to eat in taste is solved, and the problem that existing fruit puree is relatively single in component and cannot meet diversified nutritional requirements is also solved.

Description

Technical Field

[0001] The present invention relates to the technical field of food processing, and in particular to a fermented fruit and vegetable puree, a preparation method and an application thereof. Background Art

[0002] With the change of people's consumption concept and the improvement of scientific feeding awareness, infant food supplement has gradually become a "must-have", and parents have also put forward more demands on the healthy nutrition and raw material ingredients of infant food supplement, and the market of infant food supplement has continued to develop. Since the microbial flora in infants and young children will change rapidly from birth to 3 years old, the metabolism of food by infants and young children under 3 years old is different from that of normal people. This stage is an important window period for intestinal microbial colonization and immunity formation. The beneficial bacteria in breast milk and complementary foods are an important source of such microorganisms for infants and young children.

[0003] Fruits and vegetables are important sources of nutrients that infants and young children need on a daily basis, such as vitamins, minerals, and dietary fiber. However, infants and young children do not have perfect oral development, so they need to be mashed or pureed to be easier to eat. Vegetable purees, such as carrots or pumpkins, are relatively unpopular because of their earthy smell. After fermentation, the earthy smell will be relatively weakened, but after fermentation, they will become too acidic during refrigerated storage, and the taste is not suitable for infants and young children.

[0004] During the critical period of infant growth and development, nutritional supplements need to be diversified and additive-free in order to better connect with breast milk to effectively protect the gastrointestinal tract. Although there are many fruit purees or rice flour products on the market, the ingredients are relatively simple and cannot meet diverse nutritional needs. Therefore, it is technically difficult and challenging to develop a healthy fruit and vegetable puree that is tailored to the growth characteristics of infants, has clean ingredients, and meets the nutritional needs of infants aged 1 to 3 years old.

[0005] In summary, there is a need to develop a fermented fruit and vegetable puree, a preparation method and an application to solve the problem in the prior art that the taste of vegetable puree is not suitable for infants and young children and that the fruit puree ingredients are relatively single and cannot meet the diverse nutritional needs. Summary of the invention

[0006] The present invention aims to provide a fermented fruit and vegetable puree, a preparation method and an application thereof. The specific technical scheme is as follows:

[0007] In a first aspect, the present invention provides a method for preparing fermented fruit and vegetable puree, comprising:

[0008] Step S1, subjecting the fruit puree to enzymatic hydrolysis, centrifugation, filtration to obtain the supernatant, and sterilization treatment to obtain the juice;

[0009] Step S2, dividing the juice into three portions, which are respectively recorded as a first portion of juice, a second portion of juice and a third portion of juice; wherein activated Lactobacillus rhamnosus fermentation liquid is added to the first portion of juice to obtain a first yeast liquid after fermentation; activated Lactobacillus acidophilus fermentation liquid is added to the second portion of juice to obtain a second yeast liquid after fermentation; activated Bifidobacterium animalis subsp. lactis fermentation liquid is added to the third portion of juice to obtain a third yeast liquid after fermentation;

[0010] Step S3, mixing the first yeast solution, the second yeast solution and the third yeast solution at a volume ratio of 0.5-2:0.5-2:1-4 to obtain a composite bacterial solution; adding the composite bacterial solution to fruit and vegetable puree to obtain fermented fruit and vegetable puree through fermentation.

[0011] In a second aspect, the present invention provides a method for preparing fermented fruit and vegetable puree, comprising:

[0012] Step S1, subjecting the fruit puree to enzymatic hydrolysis, centrifugation, filtration to obtain the supernatant, and sterilization treatment to obtain the juice;

[0013] Step S2, dividing the juice into two portions, which are respectively recorded as the first portion of juice and the third portion of juice; adding activated Lactobacillus rhamnosus fermentation liquid to the first portion of juice, and obtaining a first yeast liquid after fermentation; adding activated Bifidobacterium animalis subsp. lactis fermentation liquid to the third portion of juice, and obtaining a third yeast liquid after fermentation;

[0014] Step S3, mixing the first yeast solution and the third yeast solution at a volume ratio of 0.5-2:1-4 to obtain a composite bacterial solution; inoculating the composite bacterial solution into fruit and vegetable puree to obtain fermented fruit and vegetable puree through fermentation.

[0015] Optionally, the method for obtaining the activated Lactobacillus rhamnosus fermentation broth comprises:

[0016] Weigh 0.01-0.03 g of Lactobacillus rhamnosus powder and dissolve it in 5-10 mL of sterile saline, shake it evenly, and activate it at a constant temperature of 35-39°C for 15-30 minutes;

[0017] Inoculate the activated Lactobacillus rhamnosus into a sterile MRS liquid culture medium at 2% to 3% of the volume of the culture medium; culture at a constant temperature of 35 to 39° C. for 16 to 24 hours in a static anaerobic manner; perform continuous subculturing for 2 to 3 times to obtain a fermentation culture liquid of the activated Lactobacillus rhamnosus;

[0018] The number of viable bacteria in the fermented bacterial liquid of Lactobacillus rhamnosus is ≥10 9 CFU / mL;

[0019] The method for obtaining the activated animal Bifidobacterium lactis subsp. fermented bacterial liquid comprises:

[0020] Weigh 0.01-0.03 g of animal Bifidobacterium lactis powder and dissolve it in 5-10 mL of sterile saline, shake it evenly, and activate it at a constant temperature of 35-41°C for 15-30 minutes;

[0021] Inoculate the activated animal Bifidobacterium lactis subspecies into a sterile bifidobacterium liquid culture medium at 3% to 5% of the culture medium volume; culture at a constant temperature of 35 to 41° C. for 16 to 30 hours in a static anaerobic manner; perform continuous subculturing for 2 to 3 times to obtain the activated animal Bifidobacterium lactis subspecies fermentation culture liquid;

[0022] The number of live bacteria in the fermented bacterial liquid of Bifidobacterium lactis subspecies animalis is ≥ 10 9 CFU / mL.

[0023] Optionally, the method for obtaining the activated Lactobacillus acidophilus fermentation liquid comprises:

[0024] Weigh 0-0.03 g of Lactobacillus acidophilus powder and dissolve it in 5-10 mL of sterile saline, shake it evenly, and activate it at a constant temperature of 35-39°C for 15-30 minutes;

[0025] Inoculate the activated Lactobacillus acidophilus into a sterile MRS liquid culture medium at 2% to 3% of the volume of the culture medium; culture at a constant temperature of 35 to 39° C. for 16 to 24 hours in a static anaerobic manner; perform continuous subculturing for 2 to 3 times to obtain the activated Lactobacillus acidophilus fermentation liquid;

[0026] The viable bacterial count of the Lactobacillus acidophilus fermentation liquid is ≥109 CFU / mL;

[0027] The volume ratio of the Lactobacillus acidophilus fermented liquid added to the second juice is 5% to 10%;

[0028] Before inoculation, the Lactobacillus acidophilus fermentation liquid is centrifuged and resuspended.

[0029] Optionally, the volume ratio of the fermented bacterial liquid of Lactobacillus rhamnosus added to the first juice is 5% to 10%;

[0030] The volume ratio of the fermented bacterial liquid of Bifidobacterium animalis subsp. lactis added to the third portion of juice is 5% to 10%;

[0031] Before inoculation, the Lactobacillus rhamnosus fermentation liquid and the Bifidobacterium animalis subsp. lactis fermentation liquid are centrifuged and resuspended respectively.

[0032] Optionally, the enzymatic hydrolysis treatment comprises adding an enzyme preparation to the fruit puree, and performing enzymatic hydrolysis at 40-45° C. for 30-90 min; wherein the mass ratio of the enzyme preparation to the fruit puree is 0.1-0.5:100; the enzyme preparation comprises at least one of pectinase, cellulase and hemicellulase; and the fruit puree comprises any one of apple puree, pear puree, pumpkin puree, prune puree, banana puree, fruit corn puree and hawthorn puree;

[0033] The sterilization treatment adopts pasteurization treatment, the treatment temperature is 85-95° C., and the treatment time is 10-15 minutes.

[0034] Optionally, the volume of the composite bacterial liquid added to every 100g of the fruit and vegetable puree is 1-3mL; the composite bacterial liquid ferments the fruit and vegetable puree in a constant temperature anaerobic static fermentation manner, the fermentation temperature adopted is 35-39°C, and the fermentation time is 12-48h.

[0035] Optionally, the fruit and vegetable puree includes one or more of apple puree, pear puree, banana puree, carrot puree and pumpkin puree.

[0036] In a third aspect, the present invention provides a fermented fruit and vegetable puree, which is prepared by the method for preparing the fermented fruit and vegetable puree.

[0037] In a fourth aspect, the present invention provides an application of the fermented fruit and vegetable puree in preparing nutritious fruit and vegetable puree for infants and young children, wherein the fermented fruit and vegetable puree is mixed and homogenized with rice flour in a mass ratio of 20 to 50:1 to obtain nutritious fruit and vegetable puree for infants and young children; the rice flour is rice flour that has been subjected to wet enzymatic hydrolysis and drying treatment in sequence.

[0038] The application of the technical solution of the present invention has at least the following beneficial effects:

[0039] (1) The present invention provides a method for preparing fermented fruit and vegetable puree. The prepared fermented fruit and vegetable puree is rich in multiple nutrients such as probiotics, dietary fiber, vitamins and polyphenols, and combines the unique fermented flavor of fruits and vegetables. The puree has a delicate taste, is sweet and sour, and is nutritious and healthy. The problem that the taste of vegetable puree in the prior art is not suitable for infants and young children is solved. Specifically, the present invention adopts specific composite bacteria for fermentation and limits the volume ratio of fermented yeast liquid, which not only effectively shortens the fermentation cycle, but also increases the abundance of fermented flavor; after mild fermentation by probiotics, the original nutrients such as protein and sugar in fruits and vegetables are effectively converted into small molecules such as lactic acid and amino acids, which are easier to absorb; the content of polyphenols, organic acids, minerals and amino acids is increased, the flavor of fruits and vegetables is improved, and the shelf life of foods is extended; the fruit and vegetable puree can effectively improve the special earthy smell of pumpkin / carrot through fermentation, retain the unique aroma of fruits and vegetables, and at the same time, weaken the "traditional Chinese medicine taste" of the two vegetable purees; it can effectively regulate intestinal microecology; polyphenols are increased, SOD is accumulated, antioxidant activity is improved, and the body's immunity is enhanced; the present invention can prepare two types of fermented fruit and vegetable puree products, refrigerated and room temperature, the refrigerated product retains the probiotic activity in the fermented fruit and vegetable puree, and the room temperature product has low requirements for the storage environment, infants and young children can enjoy delicious fruit and vegetable puree at any time, enriching the category of nutritious complementary foods for infants and young children.

[0040] (2) The fermented fruit and vegetable puree prepared by the present invention is a combination of multiple fruits and vegetables, which solves the problem that the existing puree ingredients are relatively single and cannot meet the diversified nutritional needs. The present invention combines fruit juice with fruit and vegetable purees of multiple different flavors such as banana, pear, pumpkin and carrot as complementary food for infants and young children. It has strong instant edibility and can meet the diversified needs of infants and young children for adding complementary food. It is rich in multiple vitamins, dietary fiber and polyphenols, has high antioxidant activity, is beneficial to physical health, and has a promoting effect on the intestinal health of infants and young children.

[0041] (3) The present invention combines fermented fruit and vegetable puree with rice flour in the preparation of nutritious fruit and vegetable puree for infants and young children, and perfectly integrates the dietary fiber, vitamins and trace elements in the fermented fruit and vegetable puree with easily absorbed carbohydrates, thereby providing rich nutrition for the development of infants and young children. At the same time, it contains the unique aroma of fermented fruits and vegetables and the flavor of rice flour, and has a three-dimensional aftertaste. In addition, it can also improve the stability of the fermented fruit and vegetable puree system, avoid the occurrence of stratification or water separation, and improve the overall quality of the product.

[0042] (4) The fermented fruit and vegetable puree and infant nutritional fruit and vegetable puree products prepared by the present invention do not contain any pigments, sweeteners, thickeners, stabilizers, preservatives, etc., effectively ensuring the safety of infant consumption.

[0043] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0045] Figure 1 is the moisture content of the fruit and vegetable puree samples in Examples 1 to 3, Comparative Examples 1 to 3 and Control Groups 1 to 3;

[0046] Figure 2 is the TPA test curve of the fruit and vegetable puree samples in Examples 1 to 3 and Comparative Examples 1 to 3;

[0047] Figure 3 is a comparison chart of the total acid content of the fruit and vegetable puree samples in Examples 1 to 3, Comparative Examples 1 to 3 and Control Groups 1 to 3;

[0048] Figure 4 is a comparison chart of soluble sugar content of fruit and vegetable puree samples in Examples 1 to 3, Comparative Examples 1 to 3 and Control Groups 1 to 3;

[0049] Figure 5 is a comparison chart of the total phenol content of the fruit and vegetable puree samples in Examples 1 to 3, Comparative Examples 1 to 3 and Control Groups 1 to 3;

[0050] Figure 6 is a comparison chart of the total flavonoid content of the fruit and vegetable puree samples in Examples 1 to 3, Comparative Examples 1 to 3 and Control Groups 1 to 3;

[0051] Figure 7 is a comparison chart of the total antioxidant capacity of the fruit and vegetable puree samples in Examples 1 to 3, Comparative Examples 1 to 3 and Control Groups 1 to 3;

[0052] Among them, Figure 3 to Figure 6 In the table, “*” indicates p<0.05, “**” indicates p<0.01, and “***” indicates p<0.001. DETAILED DESCRIPTION

[0053] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0054] Example 1 (preparation of nutritious applesauce):

[0055] A method for preparing fermented fruit and vegetable puree (specifically fermented apple puree), comprising:

[0056] Step S1, enzymatically hydrolyzing the apple puree, centrifuging it, filtering out the supernatant, and sterilizing the supernatant to obtain apple juice;

[0057] Step S2, dividing the apple juice into three portions of apple juice, which are respectively recorded as a first portion of apple juice, a second portion of apple juice and a third portion of apple juice; wherein, the first portion of apple juice is inoculated with an activated fermentation bacterial liquid of Lactobacillus rhamnosus (specifically Lactobacillus rhamnosus GG), and a first yeast liquid is obtained after fermentation; the second portion of apple juice is inoculated with an activated fermentation bacterial liquid of Lactobacillus acidophilus (specifically Lactobacillus acidophilus NCFM), and a second yeast liquid is obtained after fermentation; the third portion of apple juice is inoculated with an activated fermentation bacterial liquid of Bifidobacterium animalis subsp. lactis (specifically Bifidobacterium animalis subsp. lactis Bb-12), and a third yeast liquid is obtained after fermentation;

[0058] Step S3, mixing the first yeast solution, the second yeast solution and the third yeast solution in a volume ratio of 0.5-2:0-2:1-4 (specifically 1:2:3) to obtain a composite bacterial solution; inoculating the composite bacterial solution into fruit and vegetable puree (specifically apple puree) to obtain fermented fruit and vegetable puree through fermentation.

[0059] The method for obtaining the activated Lactobacillus rhamnosus fermentation liquid comprises:

[0060] Weigh 0.01 g of Lactobacillus rhamnosus powder and dissolve it in 5 mL of sterile saline, shake it evenly, and activate it at 37°C for 30 min.

[0061] The activated Lactobacillus rhamnosus was inoculated into 10 mL of sterile MRS liquid culture medium at 2% of the volume of the culture medium; the culture was statically anaerobically cultured at a constant temperature of 37° C. for 18 hours; and the culture was continuously subcultured twice to obtain the activated Lactobacillus rhamnosus fermentation culture liquid;

[0062] The number of viable bacteria in the fermented bacterial liquid of Lactobacillus rhamnosus is ≥10 9 CFU / mL.

[0063] The method for obtaining the activated Lactobacillus acidophilus fermented bacterial liquid comprises:

[0064] Weigh 0.02 g of Lactobacillus acidophilus powder and dissolve it in 5 mL of sterile saline, shake it evenly, and activate it at 37°C for 30 min.

[0065] The activated Lactobacillus acidophilus is inoculated into 10 mL of sterile MRS liquid culture medium at 2% of the volume of the culture medium; the culture is statically anaerobically cultured at a constant temperature of 37° C. for 24 hours; and the culture is continuously subcultured twice to obtain the activated Lactobacillus acidophilus fermentation liquid;

[0066] The number of live bacteria in the Lactobacillus acidophilus fermented liquid is ≥10 9CFU / mL.

[0067] The method for obtaining the activated animal Bifidobacterium lactis subsp. fermented bacterial liquid comprises:

[0068] Weigh 0.03 g of Bifidobacterium animalis subsp. lactis powder and dissolve it in 10 mL of sterile saline, shake it evenly, and activate it at 37°C for 30 min.

[0069] Inoculate the activated animal Bifidobacterium lactis subsp. into 10 mL of sterile bifidobacterium liquid culture medium at 5% of the culture medium volume; culture at 37° C. for 24 hours in a static anaerobic manner; perform continuous subculturing twice to obtain the activated animal Bifidobacterium lactis subsp. fermentation liquid;

[0070] The number of live bacteria in the fermented bacterial liquid of Bifidobacterium lactis subspecies animalis is ≥ 10 9 CFU / mL.

[0071] The volume ratio of the fermentation liquid of Lactobacillus rhamnosus added to the first portion of apple juice is 5%;

[0072] The volume ratio of the Lactobacillus acidophilus fermentation liquid added to the second portion of apple juice is 10%;

[0073] The volume ratio of the fermented bacterial liquid of Bifidobacterium animalis subsp. lactis to the third portion of apple juice is 10%;

[0074] Before inoculation, the fermentation liquid of Lactobacillus rhamnosus, the fermentation liquid of Lactobacillus acidophilus and the fermentation liquid of Bifidobacterium animalis subsp. lactis are centrifuged and resuspended respectively; wherein the centrifugation is used to remove the culture medium components; and the resuspending is used to resuspend the concentrated bacterial bodies obtained by the centrifugation in physiological saline for 3 times.

[0075] The enzymatic hydrolysis treatment includes adding pectinase to the apple puree and performing enzymatic hydrolysis at 45° C. for 40 minutes; wherein the mass ratio of the pectinase to the apple puree is 0.1:100; and the enzyme activity of the pectinase is 10,000 U / g;

[0076] The sterilization treatment adopts pasteurization treatment, and the treatment temperature is 90° C. and the treatment time is 10 minutes.

[0077] The volume of the composite bacterial liquid added to every 100g of the fruit and vegetable puree is 1-3mL (specifically 2mL); the composite bacterial liquid ferments the fruit and vegetable puree in a constant temperature anaerobic static fermentation manner, the fermentation temperature used is 37°C, and the fermentation time is 24h.

[0078] The fermented applesauce prepared in Example 1 and rice flour were mixed and homogenized in a mass ratio of 25:1, aseptically packaged to obtain nutritious applesauce, and refrigerated at 0-4° C.; the rice flour was sequentially treated with wet enzymatic hydrolysis (which is a prior art, specifically, soaking rice into rice slurry and enzymolyzing it with α-amylase) and drum drying.

[0079] Embodiment 2 (nutritional banana mud):

[0080] The difference from Example 1 is that in step S2, the apple juice is divided into two portions of apple juice, which are respectively recorded as the first portion of apple juice and the third portion of apple juice; activated Lactobacillus rhamnosus (specifically Lactobacillus rhamnosus GG) fermentation liquid is added to the first portion of apple juice to obtain a first yeast liquid after fermentation; activated Bifidobacterium animalis subsp. lactis (specifically Bifidobacterium animalis subsp. lactis Bb-12) fermentation liquid is added to the third portion of apple juice to obtain a third yeast liquid after fermentation;

[0081] Step S3, mixing the first yeast solution and the third yeast solution in a volume ratio of 0.5-2:1-4 (specifically 1:1) to obtain a composite bacterial solution; inoculating the composite bacterial solution into fruit and vegetable puree (specifically banana puree), and fermenting to obtain fermented fruit and vegetable puree (specifically fermented banana puree).

[0082] The volume of the composite bacterial liquid added to every 100 g of the fruit and vegetable puree is 3 mL; the composite bacterial liquid is used to ferment the fruit and vegetable puree for 36 hours.

[0083] The fermented banana puree prepared in Example 1 and rice flour were mixed and homogenized in a mass ratio of 25:1, aseptically packaged to obtain nutritious banana puree, and stored in a refrigerator at 0-4°C.

[0084] Embodiment 3 (nutritional pumpkin puree):

[0085] The difference from Example 1 is that the fruit and vegetable puree is pumpkin puree; and the fermentation time of the fruit and vegetable puree by the composite bacterial liquid is 18 hours.

[0086] The fermented pumpkin puree prepared in Example 1 was mixed with rice flour in a mass ratio of 20:1 and homogenized, and the nutritious pumpkin puree was obtained after aseptic packaging. The puree was sterilized at 90° C. for 10 min and then stored at room temperature.

[0087] Comparative Example 1:

[0088] Different from Example 1, rice flour was not added, and only fermented applesauce was prepared.

[0089] Comparative Example 2:

[0090] Different from Example 2, no rice flour was added, and only fermented banana puree was prepared.

[0091] Comparative Example 3:

[0092] Different from Example 3, no rice flour was added, and only fermented pumpkin puree was prepared.

[0093] The present invention also sets up control groups 1 to 3, wherein control group 1 is conventional apple puree, control group 2 is conventional banana puree, and control group 3 is conventional pumpkin puree.

[0094] The fruit and vegetable puree products in Examples 1 to 3, Comparative Examples 1 to 3 and Control Groups 1 to 3 were subjected to sensory scoring, respectively. The scoring basis is shown in Table 1, and the scoring results are shown in Table 2. The sensory scoring method is as follows: 9 adult volunteers with normal taste were invited to try the fruit and vegetable puree products in Examples 1 to 3, Comparative Examples 1 to 3 and Control Groups 1 to 3, respectively, and score each item according to the scoring basis in Table 1, and take the average value.

[0095] Table 1 Sensory scoring standards

[0096]

[0097] Table 2 Sensory rating table

[0098]

[0099]

[0100] From the data in Table 2, it can be seen that the overall scores of the fruit and vegetable puree products in Examples 1 to 3, Comparative Examples 1 to 3 and Control Groups 1 to 3 are all good, especially Example 1 has the highest comprehensive score.

[0101] Furthermore, the present invention weighs samples of the fruit and vegetable puree products in Examples 1 to 3, Comparative Examples 1 to 3 and / or Control Groups 1 to 3 for physical and chemical quality analysis. The changes in the moisture content, texture characteristics, color difference, total acid, soluble sugar, total phenol, total flavonoids and total antioxidant capacity of the fruit and vegetable puree products under corresponding storage conditions are mainly investigated.

[0102] (I) Determination of moisture content

[0103] The moisture content of the samples was determined using the first method of GB 5009.3-2016. Each sample was tested three times and the results were expressed as mean ± standard deviation. Figure 1 .exist Figure 1 The a and b in the table indicate significant differences (p < 0.05).

[0104] Depend on Figure 1It can be seen that the moisture content of the fruit and vegetable puree samples in Comparative Examples 1 to 3 is higher than that in the corresponding control group, mainly because a small amount of water is produced during the fermentation process; while the moisture content of Examples 1 to 3 is closer to the fruit and vegetable puree samples before fermentation in the corresponding control group, indicating that adding an appropriate amount of rice flour after fermentation can effectively improve the moisture content of the fermented samples.

[0105] (II) Determination of texture characteristics

[0106] The fruit and vegetable puree samples in Examples 1 to 3 and Comparative Examples 1 to 3 were subjected to full texture testing (i.e., Texture Profile Analysis, TPA) using a CT3 texture analyzer. A 25.4 mm cylindrical extrusion probe TA11 / 1000 was used; the probe test speed before the test was 2.0 mm / s; the probe return speed after the test was 1.0 mm / s; the test distance was 20.0 mm; the trigger load was 4.0 g, the deformation was 75%, the cycle was repeated 2 times, and the test was conducted 6 times in parallel. The results are expressed as mean ± standard deviation. See the test results for details. Figure 2 and Table 3. In the data of Table 3, the superscript letters with different letters indicate significant differences (p < 0.05).

[0107] Table 3 TPA characteristic measurement results

[0108] project Hardness / N Elasticity / mm Viscosity / mJ Cohesion Adhesion / N Chewability / mJ Example 1 <![CDATA[0.57±0.01 ab ]]> <![CDATA[6.63±0.25 a ]]> <![CDATA[1.56±0.04 a ]]> <![CDATA[0.90±0.07 a ]]> <![CDATA[0.47±0.02 ab ]]> <![CDATA[3.15±0.23 ab ]]> Comparative Example 1 <![CDATA[0.60±0.05 a ]]> <![CDATA[6.44±0.10 ab ]]> <![CDATA[1.52±0.18 ab ]]> <![CDATA[0.78±0.012 ab ]]> <![CDATA[0.50±0.06 ab ]]> <![CDATA[3.23±0.38 a ]]> Control group 1 <![CDATA[0.60±0.04 a ]]> <![CDATA[6.46±0.31 ab ]]> <![CDATA[1.25±0.05 c ]]> <![CDATA[0.85±0.07 ab ]]> <![CDATA[0.52±0.01 a ]]> <![CDATA[3.22±0.38 a ]]> Example 2 <![CDATA[0.61±0.03 a ]]> <![CDATA[7.01±0.36 ab ]]> <![CDATA[2.04±0.21 ab ]]> <![CDATA[0.85±0.06 ab ]]> <![CDATA[0.55±0.03 ab ]]> <![CDATA[4.01±0.21 ab ]]> Comparative Example 2 <![CDATA[0.47±0.04 c ]]> <![CDATA[7.02±0.30 ab ]]> <![CDATA[1.30±0.18 c ]]> <![CDATA[0.88±0.04 a ]]> <![CDATA[0.41±0.02 c ]]> <![CDATA[2.88±0.07 c ]]> Control group 2 <![CDATA[0.57±0.05 ab ]]> <![CDATA[7.07±0.52 a ]]> <![CDATA[2.17±0.10 a ]]> <![CDATA[0.81±0.01 ab ]]> <![CDATA[0.57±0.05 a ]]> <![CDATA[4.04±0.52 a ]]> Example 3 <![CDATA[0.31±0.01 b ]]> <![CDATA[7.51±0.38 a ]]> <![CDATA[0.59±0.03 ab ]]> <![CDATA[0.92±0.01 ab ]]> <![CDATA[0.28±0.02 ab ]]> <![CDATA[2.13±0.22 ab ]]> Comparative Example 3 <![CDATA[0.30±0.01 b ]]> <![CDATA[7.41±0.28 ab ]]> <![CDATA[0.52±0.09 b ]]> <![CDATA[0.93±0.08 a ]]> <![CDATA[0.27±0.02 ab ]]> <![CDATA[1.90±0.05 bc ]]> Control group 3 <![CDATA[0.34±0.01 a ]]> <![CDATA[7.38±0.29 ab ]]> <![CDATA[0.68±0.03 a ]]> <![CDATA[0.89±0.03 b ]]> <![CDATA[0.30±0.02 a ]]> <![CDATA[2.20±0.20 a ]]>

[0109] Depend on Figure 2 It can be seen that Example 2 has the largest first compression work and the largest hardness, followed by Comparative Example 2, while Comparative Example 3 has the lowest hardness. The TPA texture characteristics of Example 2 and Comparative Example 2 are significantly different.

[0110] As can be seen from Table 3, for the same TPA texture properties, the differences between different fruit and vegetable puree samples are different. Compared with Comparative Example 2, the hardness, viscosity, adhesiveness and chewiness of the fermented banana puree in Example 2 are significantly different (p < 0.05). Overall, hardness, viscosity and chewiness are related to the differences in fruit and vegetable puree raw materials. Different categories of fruit and vegetable purees are different, while the elasticity and cohesion of each embodiment and the corresponding comparative example are relatively small.

[0111] (III) Determination of color difference

[0112] The fruit and vegetable puree samples in Examples 1 to 3, Comparative Examples 1 to 3 and Control Groups 1 to 3 were measured using a ColorQuest XE colorimeter. L* represents brightness (0 to 100), a* represents red-green value (+ red-green), and b* represents yellow-blue value (+ yellow-blue). The overall color change (ΔE) was calculated using the following formula:

[0113]

[0114] The color difference measurement results are shown in Table 4. The data in Table 4 are expressed in the form of mean ± standard deviation; different superscript letters appearing in the data in Table 4 indicate significant differences (p < 0.05); ΔE in Table 4 is the value of color change comparison between the embodiment and the comparative example and the control group, which is calculated by subtracting the L0, a0 and b0 values ​​of the control group from the embodiment and the comparative example, respectively; wherein, the ΔE in the control groups 1 to 3 is all 0.

[0115] Table 4 Color difference measurement results

[0116] L* a* b* ΔE Example 1 <![CDATA[38.97±0.21 a ]]> <![CDATA[-0.63±0.12 c ]]> <![CDATA[6.02±0.08 a ]]> 0.85±0.22 Comparative Example 1 <![CDATA[37.61±0.30 c ]]> <![CDATA[-0.29±0.10 a ]]> <![CDATA[5.61±0.32 c ]]> 0.75±0.43 Control group 1 <![CDATA[38.16±0.13 b ]]> <![CDATA[-0.43±0.10 ab ]]> <![CDATA[5.99±0.03 ab ]]> 0 Example 2 <![CDATA[49.10±0.61 ab ]]> <![CDATA[2.63±0.27 b ]]> <![CDATA[8.01±0.46 a ]]> 1.26±0.10 Comparative Example 2 <![CDATA[48.88±0.16 abc ]]> <![CDATA[2.59±0.12 bc ]]> <![CDATA[7.06±0.07 bc ]]> 1.00±0.11 Control group 2 <![CDATA[49.28±0.64 a ]]> <![CDATA[3.45±0.33 a ]]> <![CDATA[7.34±0.40 b ]]> 0 Example 3 <![CDATA[40.67±0.11 a ]]> <![CDATA[6.96±0.06 a ]]> <![CDATA[17.66±0.11 a ]]> 6.24±0.14 Comparative Example 3 <![CDATA[39.05±0.07 b ]]> <![CDATA[6.60±0.08 b ]]> <![CDATA[16.61±0.09 b ]]> 4.35±0.09 Control group 3 <![CDATA[36.42±0.32 c ]]> <![CDATA[5.10±0.39 c ]]> <![CDATA[13.89±0.77 c ]]> 0

[0117] As can be seen from Table 4, the banana puree group has the highest brightness L*, and the main chromaticity of Example 2 changes the most; the total color difference ΔE of Example 3 changes the most, and the difference with the control group 3 when ΔE>3 is discernible by the naked eye, indicating that the pumpkin group has the largest color difference change after fermentation; the brightness L* increases most significantly, and the a* value and b* value also differ significantly, indicating that the color of Example 3 and Comparative Example 3 is improved the most, which is consistent with the results of the sensory evaluation.

[0118] (IV) Determination of total acid content and soluble sugar content

[0119] ① Determination of total acid content: Refer to GB 5009.239-2016, use 0.01M standard NaOH solution for acid-base titration to determine the total acid, and use the lactic acid conversion coefficient (k=0.090) to calculate the result. Figure 3 .

[0120] ② Determination of soluble sugar content: refer to NY / T2742-2015, 3,5-dinitrosalicylic acid colorimetric method. Figure 4 .

[0121] Depend on Figure 3 and Figure 4 It can be seen that in the pumpkin group and the banana group, the total acid content of each embodiment and the corresponding comparative example increased significantly compared with the corresponding control group, and the soluble sugar content decreased significantly; among them, the total acid content of the pumpkin group increased the most and the soluble sugar content was the lowest, and the overall acceptability of the comparative example was the lowest; in the banana group, the soluble sugar of the embodiment and the corresponding comparative example decreased the most compared with the corresponding control group, and the total acid content increased significantly, so that the sugar-acid ratio of the embodiment and the corresponding comparative example in the banana group decreased more, and the comparative example was more significant than the embodiment, and the taste decreased; the sugar-acid ratio of the apple group changed less, showing a suitable sugar-acid ratio (20-60), which would improve the taste of the fruit and vegetable puree to a certain extent, and the taste was suitable; overall, the embodiment is better than the comparative example, which is consistent with the taste score result in the sensory score.

[0122] (V) Determination of total phenolic content, total flavonoid content and total antioxidant capacity

[0123] ① Determination of total phenols: Determine the total phenol content by referring to the Folin-Ciocalteu method and make slight improvements. Take 1g of fruit and vegetable puree sample, add 25mL of 80% methanol, perform ultrasonic-assisted extraction for 1h, reflux oscillation for 1h, and centrifuge at 5000r / min for 20min to obtain the supernatant, which is the methanol extract. Take a 10mL graduated test tube, add 1mL of methanol extract, 4mL of water, 1mL of Folin-phenol reagent and 4mL of 12.5% ​​sodium carbonate solution, react at room temperature in the dark for 2h, measure the absorbance of the sample at a wavelength of 760nm, and use the reagent blank as a reference. Results A standard curve was drawn using gallic acid as the standard (y=1.7235x-0.0297, R 2 =0.9922), calculate the total phenolic content in the sample, and the result is expressed as mgGEA / 100g fresh weight. Figure 5 .

[0124] ② Determination of total flavonoids: The NaNO2-Al(NO3)3 colorimetric method was used to determine the content of total flavonoids in fruit and vegetable puree samples. A standard curve was prepared using rutin as the standard. Take 5g of fruit and vegetable puree sample and add 50mL of 80% methanol. Ultrasonic-assisted extraction was performed for 1h. The supernatant was taken and 1.00mL of the extract was placed in a 10mL test tube. The ethanol (volume fraction 30%) was added to 5mL. 0.3mL of NaNO2 solution (mass fraction 5%) was added, shaken, and allowed to stand for 8min. 0.3mL of Al(NO3)3 solution (mass fraction 10%) was added, shaken, and allowed to stand for 8min. 4mL of NaOH solution (mass fraction 4%) was added, and the volume was made up with distilled water. The absorbance of the sample was measured at a wavelength of 510nm, and the reagent blank was used as a reference. A standard curve was drawn using rutin as the standard (y=0.9346x-0.0102, R 2 =0.9942), calculate the total flavonoid content in the sample, and the result is expressed as rutin equivalent mgRE / 100g fresh weight. The total flavonoid content determination results refer to Figure 6 .

[0125] ③ Determination of total antioxidant capacity: Determination by DPPH method, ABTS method and FRAP method, total antioxidant capacity is expressed as Trolox equivalent μmol / g fresh weight. Figure 7 .exist Figure 7 The a, b and c in the table indicate significant differences (p < 0.05).

[0126] Depend on Figure 5-6It can be seen that the total flavonoids content in Example 1 and Comparative Example 1 of the apple group was significantly lower than that in the control group 1, while the total phenol content was significantly increased, and the total phenol content of Example 1 was the highest; the total flavonoids content in Example 2 and Comparative Example 2 of the banana group was higher than that in the control group 2, while the total phenol content was lower; the total flavonoids and total phenols in Example 3 and Comparative Example 3 of the pumpkin group were significantly higher than those in the control group 3.

[0127] Depend on Figure 7 It can be seen that the total antioxidant capacity of the embodiments and comparative examples of the apple group, banana group and pumpkin group was significantly higher than that of the control group; among them, the three antioxidant capacities of the embodiments and comparative examples of the banana group were higher than those of the other two groups, which was proportional to the high total phenol content; the DPPH and ABTS free radical scavenging capacity of the embodiment 1 and comparative example 1 of the apple group was significantly higher than that of the control group 1, and the ABTS free radical scavenging capacity was the highest; the pumpkin group had the lowest overall antioxidant capacity. Figure 5 and Figure 7 It can be seen that the antioxidant capacity is positively correlated with the total phenol content. Overall, the embodiment is better than the comparative example.

[0128] From the above data, it can be seen that Examples 1 to 3 are better than Comparative Examples 1 to 3, and the total flavonoids, total phenols and antioxidant activity are significantly better than the corresponding original fruit and vegetable purees. The present invention uses the method of mixing fermented fruit and vegetable purees with rice flour for the first time to improve product stability, and combines the flavor of fermented fruit and vegetable purees with the taste and aroma of rice flour. The product is rich in probiotics, dietary fiber, vitamins, polyphenols, etc., has a delicate taste, is sweet and sour, and is nutritious and healthy.

[0129] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing fermented fruit and vegetable puree, characterized in that: include: Step S1, subjecting the fruit puree to enzymatic hydrolysis, centrifugation, filtration to obtain the supernatant, and sterilization treatment to obtain the juice; Step S2, dividing the juice into three portions, which are respectively recorded as a first portion of juice, a second portion of juice and a third portion of juice; wherein activated Lactobacillus rhamnosus fermentation liquid is added to the first portion of juice to obtain a first yeast liquid after fermentation; activated Lactobacillus acidophilus fermentation liquid is added to the second portion of juice to obtain a second yeast liquid after fermentation; activated Bifidobacterium animalis subsp. lactis fermentation liquid is added to the third portion of juice to obtain a third yeast liquid after fermentation; Step S3, mixing the first yeast solution, the second yeast solution and the third yeast solution at a volume ratio of 0.5-2:0.5-2:1-4 to obtain a composite bacterial solution; adding the composite bacterial solution to fruit and vegetable puree to obtain fermented fruit and vegetable puree through fermentation.

2. A method for preparing fermented fruit and vegetable puree, characterized in that: include: Step S1, subjecting the fruit puree to enzymatic hydrolysis, centrifugation, filtration to obtain the supernatant, and sterilization treatment to obtain the juice; Step S2, dividing the juice into two portions, which are respectively recorded as the first portion of juice and the third portion of juice; adding activated Lactobacillus rhamnosus fermentation liquid to the first portion of juice, and obtaining a first yeast liquid after fermentation; adding activated Bifidobacterium animalis subsp. lactis fermentation liquid to the third portion of juice, and obtaining a third yeast liquid after fermentation; Step S3, mixing the first yeast solution and the third yeast solution at a volume ratio of 0.5-2:1-4 to obtain a composite bacterial solution; inoculating the composite bacterial solution into fruit and vegetable puree to obtain fermented fruit and vegetable puree through fermentation.

3. The method for preparing fermented fruit and vegetable puree according to claim 1 or 2, characterized in that: The method for obtaining the activated Lactobacillus rhamnosus fermentation liquid comprises: Weigh 0.01-0.03 g of Lactobacillus rhamnosus powder and dissolve it in 5-10 mL of sterile saline, shake it evenly, and activate it at a constant temperature of 35-39°C for 15-30 minutes; Inoculate the activated Lactobacillus rhamnosus into a sterile MRS liquid culture medium at 2% to 3% of the volume of the culture medium; culture at a constant temperature of 35 to 39° C. for 16 to 24 hours in a static anaerobic manner; perform continuous subculturing for 2 to 3 times to obtain a fermentation culture liquid of the activated Lactobacillus rhamnosus; The number of viable bacteria in the fermented bacterial liquid of Lactobacillus rhamnosus is ≥10 9 CFU / mL; The method for obtaining the activated animal Bifidobacterium lactis subsp. fermented bacterial liquid comprises: Weigh 0.01-0.03 g of animal Bifidobacterium lactis powder and dissolve it in 5-10 mL of sterile saline, shake it evenly, and activate it at a constant temperature of 35-41°C for 15-30 minutes; Inoculate the activated animal Bifidobacterium lactis subspecies into a sterile bifidobacterium liquid culture medium at 3% to 5% of the culture medium volume; culture at a constant temperature of 35 to 41° C. for 16 to 30 hours in a static anaerobic manner; perform continuous subculturing for 2 to 3 times to obtain the activated animal Bifidobacterium lactis subspecies fermentation culture liquid; The number of viable bacteria in the fermented bacterial liquid of Bifidobacterium lactis subspecies animalis ≥ 10 9 CFU / mL.

4. The method for preparing fermented fruit and vegetable puree according to claim 1, characterized in that: The method for obtaining the activated Lactobacillus acidophilus fermentation liquid comprises: Weigh 0-0.03 g of Lactobacillus acidophilus powder and dissolve it in 5-10 mL of sterile saline, shake it evenly, and activate it at a constant temperature of 35-39°C for 15-30 minutes; Inoculate the activated Lactobacillus acidophilus into a sterile MRS liquid culture medium at 2% to 3% of the volume of the culture medium; culture at a constant temperature of 35 to 39° C. for 16 to 24 hours in a static anaerobic manner; perform continuous subculturing for 2 to 3 times to obtain the activated Lactobacillus acidophilus fermentation liquid; The number of live bacteria in the Lactobacillus acidophilus fermented liquid is ≥10 9 CFU / mL; The volume ratio of the Lactobacillus acidophilus fermented liquid added to the second juice is 5% to 10%; Before inoculation, the Lactobacillus acidophilus fermentation liquid is centrifuged and resuspended.

5. The method for preparing fermented fruit and vegetable puree according to claim 1 or 2, characterized in that: The volume ratio of the fermented bacterial liquid of Lactobacillus rhamnosus added to the first juice is 5% to 10%; The volume ratio of the fermented bacterial liquid of Bifidobacterium animalis subsp. lactis added to the third portion of juice is 5% to 10%; Before inoculation, the Lactobacillus rhamnosus fermentation liquid and the Bifidobacterium animalis subsp. lactis fermentation liquid are centrifuged and resuspended respectively.

6. The method for preparing fermented fruit and vegetable puree according to claim 1 or 2, characterized in that: The enzymatic hydrolysis treatment comprises adding an enzyme preparation to the fruit puree, and performing enzymatic hydrolysis at 40-45° C. for 30-90 minutes; wherein the mass ratio of the enzyme preparation to the fruit puree is 0.1-0.5:100; the enzyme preparation comprises at least one of pectinase, cellulase and hemicellulase; and the fruit puree comprises any one of apple puree, pear puree, pumpkin puree, prune puree, banana puree, fruit corn puree and hawthorn puree; The sterilization treatment adopts pasteurization treatment, the treatment temperature is 85-95° C., and the treatment time is 10-15 minutes.

7. The method for preparing fermented fruit and vegetable puree according to claim 1 or 2, characterized in that: The volume of the composite bacterial liquid added to every 100g of the fruit and vegetable puree is 1-3mL; the composite bacterial liquid ferments the fruit and vegetable puree in a constant temperature anaerobic static fermentation manner, the fermentation temperature used is 35-39°C, and the fermentation time is 12-48h.

8. The method for preparing fermented fruit and vegetable puree according to claim 1 or 2, characterized in that: The fruit and vegetable puree includes one or more of apple puree, pear puree, banana puree, carrot puree and pumpkin puree.

9. A fermented fruit and vegetable puree, characterized in that: The fermented fruit and vegetable puree is prepared by the method for preparing the fermented fruit and vegetable puree as claimed in claim 1 or 2.

10. Use of the fermented fruit and vegetable puree as claimed in claim 9 in preparing nutritious fruit and vegetable puree for infants and young children, characterized in that: The fermented fruit and vegetable puree and rice flour are mixed and homogenized in a mass ratio of 20 to 50:1 to obtain nutritious fruit and vegetable puree for infants and young children; the rice flour is rice flour that has been subjected to wet enzymatic hydrolysis and drying treatments in sequence.

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