Normal-temperature nut-based fermented yoghurt and preparation method thereof

Abstract

The invention provides normal-temperature nut-based fermented yoghurt and a preparation method thereof, and the yoghurt comprises the following raw materials in 1000 parts by weight: 28-100 parts of nuts, 50-120 parts of white granulated sugar, 3-8 parts of an emulsifier, 3-85 parts of a stabilizer and / or a thickener, and 0.002-0.006 part of a leavening agent. The method comprises the following steps: baking nut raw materials twice, grinding, and mixing with water to obtain nut feed liquid; mixing white granulated sugar and an emulsifier, putting the mixture into the nut feed liquid, stirring, filtering, homogenizing, pasteurizing, cooling, adding a leavening agent, performing constant-temperature fermentation to obtain fermented milk, and demulsifying and stirring; uniformly mixing white granulated sugar and a stabilizer, and putting the mixture into water to obtain a second mixed solution; mixing the demulsified fermented milk with the second mixed solution, and homogenizing twice according to the protein content in the mixed feed liquid; and sterilizing and cooling to obtain the product. The obtained yoghurt product is free of preservatives and essence, meanwhile, the nut fragrance is sufficient, and the shelf life is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of plant protein fermentation, and particularly relates to a room-temperature nut-based fermented yogurt and a preparation method thereof. Background Art

[0002] So far, although there are many kinds of plant-based fermented yogurts, they are all fermented with soybeans as the base. Due to the uniqueness of soybeans, fermentation to produce yogurt is more feasible. However, current technologies rarely involve how to pre-treat nuts to improve product flavor and use nuts to ferment yogurt. Therefore, completing the technical development of a room temperature nut-based fermented yogurt is an urgent problem that needs to be solved. Summary of the invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide a room temperature nut-based fermented yogurt and a preparation method thereof, through which the aroma of the nuts can be enhanced while extending the shelf life of the nuts, and the product can maintain a good texture, flavor and smoothness.

[0004] In order to achieve the above object, the present invention provides a method for preparing room temperature nut-based fermented yogurt, wherein the raw material composition of the yogurt includes: 28-100 parts of nuts, 50-120 parts of white sugar, 3-8 parts of emulsifier, 3-85 parts of stabilizer and / or thickener, and 0.002-0.006 parts of starter, based on 1000 parts by weight; the preparation method of the yogurt includes:

[0005] (1) roasting the nut raw materials twice to obtain roasted nuts;

[0006] (2) grinding the roasted nuts to obtain nut paste;

[0007] (3) mixing the nut paste with water to obtain a nut paste liquid;

[0008] (4) mixing a portion of white sugar and an emulsifier evenly, and adding the mixture into the nut liquid to obtain a first mixed liquid;

[0009] (5) stirring, filtering, homogenizing, and pasteurizing the first mixed liquid to obtain a sterilized first mixed liquid;

[0010] (6) cooling the sterilized first mixed liquid, adding a fermentation agent to perform constant temperature fermentation, and obtaining fermented milk;

[0011] (7) breaking the fermented milk and stirring it to obtain the fermented milk after breaking the milk;

[0012] (8) After mixing the remaining white sugar and the stabilizer, add them into water and stir at a constant temperature until they are completely dissolved to obtain a second mixed solution;

[0013] (9) uniformly mixing the fermented milk after demulsification with the second mixed solution to obtain a mixed feed liquid;

[0014] (10) homogenizing the mixed liquid twice, wherein the homogenization pressure is set according to the protein content in the mixed liquid to obtain a homogenized liquid;

[0015] (11) sterilizing and cooling the homogenized liquid to obtain the room temperature nut-based fermented yogurt.

[0016] According to a specific embodiment of the present invention, preferably, the raw materials for preparing the yogurt consist of the following ingredients: 28-100 parts of nuts, 50-120 parts of white sugar, 3-8 parts of emulsifier, 3-85 parts of stabilizer and / or thickener, 0.002-0.006 parts of leavening agent, and the rest is supplemented with water to 1000 parts.

[0017] According to a specific embodiment of the present invention, preferably, the raw materials for preparing the yogurt consist of the following ingredients: 40-80 parts of nuts, 50-90 parts of white sugar, 3-8 parts of emulsifier, 3-75 parts of stabilizer and / or thickener, 0.002-0.006 parts of leavening agent, and the rest is supplemented with water to 1000 parts.

[0018] According to a specific embodiment of the present invention, preferably, the raw materials for preparing the yogurt consist of the following ingredients: 45-80 parts of nuts, 60-90 parts of white sugar, 3-8 parts of emulsifier, 3-75 parts of stabilizer and / or thickener, 0.002-0.006 parts of leavening agent, and the rest is supplemented with water to 1000 parts.

[0019] According to a specific embodiment of the present invention, preferably, the nuts include one or a combination of two or more of almonds, almonds, peanuts, pistachios, walnuts, hazelnuts and cashews.

[0020] According to a specific embodiment of the present invention, preferably, the nuts include one or a combination of two or more of almonds, walnuts and almonds.

[0021] According to a specific embodiment of the present invention, preferably, the almonds are debittered almonds.

[0022] According to a specific embodiment of the present invention, preferably, the emulsifier includes one or a combination of two or more of polyglycerol fatty acid esters, pectin, and mono- and di-glycerol fatty acid esters.

[0023] According to a specific embodiment of the present invention, preferably, the emulsifier comprises polyglycerol fatty acid ester and pectin.

[0024] According to a specific embodiment of the present invention, preferably, the weight ratio of the polyglycerol fatty acid ester to the pectin is (1-5):(1-3), more preferably (3-5):(1-3).

[0025] According to a specific embodiment of the present invention, preferably, the emulsifier comprises mono- and di-glycerol fatty acid esters and pectin.

[0026] According to a specific embodiment of the present invention, preferably, the weight ratio of the mono- and di-glycerol fatty acid esters to the pectin is (1-5):(1-3), more preferably (3-5):(1-3).

[0027] According to a specific embodiment of the present invention, preferably, the stabilizer and / or thickener comprises one or a combination of two or more of sodium carboxymethyl cellulose, agar, hydroxypropyl distarch phosphate, xanthan gum, and glutinous rice starch. According to a specific embodiment of the present invention, preferably, the stabilizer and / or thickener comprises hydroxypropyl distarch phosphate and sodium carboxymethyl cellulose.

[0028] According to a specific embodiment of the present invention, preferably, the weight ratio of the hydroxypropyl distarch phosphate to the sodium carboxymethyl cellulose is (10-70):(1-15), more preferably (15-60):(1-8), and further preferably (20-40):(4-8).

[0029] According to a specific embodiment of the present invention, preferably, the stabilizer and / or thickener comprises hydroxypropyl distarch phosphate, sodium carboxymethyl cellulose and agar.

[0030] According to a specific embodiment of the present invention, preferably, the weight ratio of hydroxypropyl distarch phosphate, sodium carboxymethyl cellulose and agar is (10-70):(1-12):(0.1-3), more preferably (15-60):(1-8):(0.5-3), and further preferably (20-40):(4-8):(0.5-2).

[0031] According to a specific embodiment of the present invention, preferably, the stabilizer and / or thickener comprises glutinous rice starch, sodium carboxymethyl cellulose and agar.

[0032] According to a specific embodiment of the present invention, preferably, the weight ratio of glutinous rice starch, sodium carboxymethyl cellulose and agar is (10-70):(1-12):(0.1-3), more preferably (15-60):(1-8):(0.5-3), and further preferably (20-40):(4-8):(0.5-2).

[0033] According to a specific embodiment of the present invention, preferably, the stabilizer and / or thickener comprises glutinous rice starch, sodium carboxymethyl cellulose and xanthan gum.

[0034] According to a specific embodiment of the present invention, preferably, the weight ratio of glutinous rice starch, sodium carboxymethyl cellulose and xanthan gum is (10-70):(1-12):(0.1-3), more preferably (15-60):(1-8):(0.5-3), and further preferably (20-40):(4-8):(0.5-2).

[0035] According to a specific embodiment of the present invention, preferably, the heating method for the two bakings is a tunnel-type electric heating furnace method.

[0036] According to a specific embodiment of the present invention, preferably, the first baking temperature of the two bakings is 150-250° C., and the baking time is 2-15 min.

[0037] According to a specific embodiment of the present invention, preferably, the first baking temperature of the two bakings is 150-230° C., and the baking time is 2-10 min.

[0038] According to a specific embodiment of the present invention, preferably, the first baking temperature of the two bakings is 150-200°C, and the baking time is 2-8 minutes. According to a specific embodiment of the present invention, preferably, the first baking temperature of the two bakings is 175-200°C, and the baking time is 2-5 minutes.

[0039] According to a specific embodiment of the present invention, preferably, the second baking temperature of the two bakings is 65-90° C., and the baking time is 5-35 min.

[0040] According to a specific embodiment of the present invention, preferably, the second baking temperature of the two bakings is 70-90° C., and the baking time is 5-30 min.

[0041] According to a specific embodiment of the present invention, preferably, the second baking temperature of the two bakings is 75-90° C., and the baking time is 10-25 min.

[0042] According to a specific embodiment of the present invention, preferably, the second baking temperature of the two bakings is 75-85° C., and the baking time is 10-18 min.

[0043] According to a specific embodiment of the present invention, preferably, in step (2), a dry grinding process using a stone roller is used to make the particle size of the ground nut butter material ≤80 μm.

[0044] According to a specific embodiment of the present invention, preferably, in the step of mixing the nut butter with water, the temperature of the water is 60-80°C, preferably 70-75°C, and the water may be purified water.

[0045] According to a specific embodiment of the present invention, preferably, the stirring time is 5-20 min.

[0046] According to a specific embodiment of the present invention, preferably, in step (5), the homogenization pressure is 10-35 MPa.

[0047] According to a specific embodiment of the present invention, preferably, the pasteurization temperature is 75-95° C. and the pasteurization time is 100-300 s.

[0048] According to a specific embodiment of the present invention, preferably, in step (6), the temperature after cooling is 43±1°C.

[0049] According to a specific embodiment of the present invention, preferably, the bacterial species contained in the fermentation agent include Streptococcus salivarius subsp. thermophilus and / or Lactobacillus delbrueckii subsp. bulgaricus; preferably, the lactic acid bacteria strain model during fermentation is YoFIexPremiun 6.0.

[0050] According to a specific embodiment of the present invention, preferably, the fermentation endpoint of the constant temperature fermentation is pH ≤ 4.5.

[0051] According to a specific embodiment of the present invention, preferably, in step (8), the temperature of the water is 50-55° C., and the water may be RO water.

[0052] According to a specific embodiment of the present invention, preferably, the constant temperature stirring time is 10-35 min.

[0053] According to a specific embodiment of the present invention, preferably, in step (10), the homogenization pressure is set according to the protein content (Pro) in the mixed liquid.

[0054] According to a specific embodiment of the present invention, preferably, the protein content in the mixed liquid can be obtained according to the amount of nuts added.

[0055] According to a specific embodiment of the present invention, preferably, Pro<1.0 g / 100 mL, and the homogenization pressure ≤20 MPa.

[0056] According to a specific embodiment of the present invention, preferably, 1.0 g / 100 mL ≤ Pro < 1.5 g / 100 mL, 20 MPa < homogenization pressure ≤ 25 MPa.

[0057] According to a specific embodiment of the present invention, preferably, 1.5 g / 100 mL ≤ Pro ≤ 2.0 g / 100 mL, and 25 MPa < homogenization pressure < 30 MPa.

[0058] According to a specific embodiment of the present invention, preferably, Pro>2.0g / 100mL, and the homogenization pressure≥30MPa.

[0059] According to a specific embodiment of the present invention, preferably, in step (10), the homogenized liquid can be filled before proceeding to subsequent steps.

[0060] According to a specific embodiment of the present invention, preferably, in step (11), the sterilization temperature is 75-95° C., and the sterilization time is 10-30 min.

[0061] According to a specific embodiment of the present invention, preferably, the method for preparing room temperature nut-based fermented yogurt provided by the present invention comprises the following steps:

[0062] (1) subjecting the nut raw material to two baking processes, wherein the first baking temperature is 150-250° C. and the baking time is 2-15 min; the second baking temperature is 65-90° C. and the baking time is 5-35 min;

[0063] (2) grinding the raw material obtained in step (1) by dry grinding with a stone roller so that the particle size of the ground nut paste is ≤80 μm;

[0064] (3) putting the ground sauce from step (2) into water preheated to 70-75° C. and stirring for 5-20 minutes to fully dissolve;

[0065] (4) mixing part of the white sugar with the emulsifier to obtain a first mixed liquid, and adding the first mixed liquid to the nut liquid dissolved in step (3) and stirring the mixture thoroughly;

[0066] (5) filtering the nut liquid in step (4);

[0067] (6) homogenizing the filtrate obtained in step (5) at a homogenization pressure of 10-35 MPa;

[0068] (7) pasteurizing the homogenized liquid obtained in step (6) at a temperature of 75-95° C. and a time of 100-300 seconds;

[0069] (8) cooling the sterilized liquid obtained in step (7) to 43±1° C., adding a fermentation agent, stirring evenly, and fermenting at a constant temperature until the pH at the fermentation end point is ≤4.5;

[0070] (9) breaking and stirring the fermented milk obtained in step (8);

[0071] (10) Mix the remaining white sugar with the stabilizer, put it into water at 50-55° C., and stir at a constant temperature for 10-35 minutes until it is completely dissolved to obtain a second mixed liquid;

[0072] (11) Mix the solutions obtained in step (9) and step (10), and stir for 20 min until the mixture is uniform;

[0073] (12) The solution obtained in step (11) is homogenized in two passes, and the homogenization pressure is set according to the protein content in the mixed liquid; the protein content of the product can be calculated according to the amount of nuts added; when the protein content is less than 1.0 g / 100 mL, the homogenization pressure is ≤20 MPa; when the protein content is 1.0 g / 100 mL≤ and the protein content is less than 1.5 g / 100 mL, the homogenization pressure is 20 MPa<and the homogenization pressure is ≤25 MPa; when the protein content is 1.5 g / 100 mL≤ and the protein content is less than 2.0 g / 100 mL, the homogenization pressure is 25 MPa<and the homogenization pressure is less than 30 MPa; when the protein content is greater than 2.0 g / 100 mL, the homogenization pressure is ≥30 MPa;

[0074] (13) filling the homogenized solution obtained in step (12);

[0075] (14) sterilizing the product after filling in step (13), the sterilization temperature and time are 75-95° C. and 10-30 min respectively;

[0076] (15) The product sterilized in step (14) is cooled to obtain the room temperature nut-based fermented yogurt.

[0077] The present invention also provides a room temperature nut-based fermented yogurt, the raw materials of which include: 28-100 parts of nuts, 50-120 parts of white sugar, 3-8 parts of emulsifier, 3-85 parts of stabilizer, 0.002-0.006 parts of fermentation agent, and the rest is supplemented with water to 1000 parts.

[0078] According to a specific embodiment of the present invention, preferably, the yogurt is prepared by the above-mentioned preparation method.

[0079] The beneficial effects of the present invention are:

[0080] The present invention provides a method for preparing a room temperature nut-based fermented yogurt without preservatives and flavors. The present invention develops a method for preparing a nut yogurt that can achieve a product without adding preservatives and flavors through a double baking process of nuts and a post-homogenization process, and can ensure that the product maintains a good stability system during a room temperature shelf life of 9 months. The method for preparing a room temperature nut-based fermented yogurt provided by the present invention solves the problems related to poor flavor, inharmoniousness, rough taste, and poor product stability during the shelf life of nut-based fermented yogurt.

[0081] In the present invention, nuts are processed by different processes, which prolong the shelf life of the nuts and enhance the aroma of the nuts, and make the flavor of the product more harmonious after fermentation; during production, a homogenization process is performed based on the protein content of the product, so that the product can maintain a good tissue state, flavor and smoothness within a room temperature shelf life of 9 months.

[0082] The yogurt obtained by the preparation method of the present invention has a white appearance, a uniform texture, and no stratification, water separation, or precipitation. The product has a sufficient nut flavor, a smooth mouthfeel, and a harmonious sour-sweet ratio, which brings better taste enjoyment to consumers. It creates a new category of nut-based fermented products, enriches the diversity of beverages on the market, and provides better protection for people with lactose intolerance. DETAILED DESCRIPTION

[0083] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be construed as limiting the applicable scope of the present invention.

[0084] In actual production, those skilled in the art will understand that some relevant process steps may be adjusted or increased or decreased, provided that qualified products can be obtained.

[0085] In some specific embodiments of the present invention, the present invention provides a method for preparing room temperature nut-based fermented yogurt, wherein the raw material composition of the yogurt, based on 1000 parts by weight, includes: 28-100 parts of nuts, 50-120 parts of white sugar, 3-8 parts of emulsifier, 3-85 parts of stabilizer and / or thickener, and 0.002-0.006 parts of starter; the preparation method of the yogurt includes:

[0086] (1) roasting the nut raw materials twice to obtain roasted nuts;

[0087] (2) grinding the roasted nuts to obtain nut paste;

[0088] (3) mixing the nut paste with water to obtain a nut paste liquid;

[0089] (4) mixing a portion of white sugar and an emulsifier evenly, and adding the mixture into the nut liquid to obtain a first mixed liquid;

[0090] (5) stirring, filtering, homogenizing, and pasteurizing the first mixed liquid to obtain a sterilized first mixed liquid;

[0091] (6) cooling the sterilized first mixed liquid, adding a fermentation agent to perform constant temperature fermentation, and obtaining fermented milk;

[0092] (7) breaking the fermented milk and stirring it to obtain the fermented milk after breaking the milk;

[0093] (8) After mixing the remaining white sugar and the stabilizer, add them into water and stir at a constant temperature until they are completely dissolved to obtain a second mixed solution;

[0094] (9) uniformly mixing the fermented milk after demulsification with the second mixed solution to obtain a mixed feed liquid;

[0095] (10) homogenizing the mixed liquid twice, wherein the homogenization pressure is set according to the protein content in the mixed liquid to obtain a homogenized liquid;

[0096] (11) sterilizing and cooling the homogenized liquid to obtain the room temperature nut-based fermented yogurt.

[0097] In some specific embodiments of the present invention, in the above preparation method, the raw materials for preparing the yogurt include: 28-100 parts of nuts, 50-120 parts of white sugar, 3-8 parts of emulsifier, 3-85 parts of stabilizer, 0.002-0.006 parts of fermentation agent, and the remaining materials are supplemented with water to 1000 parts.

[0098] In some specific embodiments of the present invention, in the above-mentioned preparation method, the heating method of the two bakings is a tunnel electric heating furnace method; the first baking temperature of the two bakings is 150-250°C, and the baking time is 2-15min; the second baking temperature of the two bakings is 65-90°C, and the baking time is 5-35min.

[0099] In some specific embodiments of the present invention, in the above-mentioned preparation method, when the mixed liquid is homogenized in two passes, the homogenization pressure is set according to the protein content in the mixed liquid; when Pro<1.0g / 100mL, the homogenization pressure ≤20MPa; when 1.0g / 100mL≤Pro<1.5g / 100mL, 20MPa<homogenization pressure≤25MPa; when 1.5g / 100mL≤Pro≤2.0g / 100mL, 25MPa<homogenization pressure<30MPa; when Pro>2.0g / 100mL, the homogenization pressure ≥30MPa.

[0100] Example 1

[0101] 1. Formula (per 1000kg raw material):

[0102] raw material Addition amount (kg) Debittered almonds 45 white sugar 70 Polyglycerol fatty acid esters 3 Hydroxypropyl distarch phosphate 25 Pectin 2 Sodium Carboxymethyl Cellulose 4 Fermentation Agents 0.003

[0103] 2. Preparation method:

[0104] (1) 45 kg of almond raw material was subjected to two baking processes, the first baking process was 175° C. / 4.5 min, and the second baking process was 75° C. / 15 min;

[0105] (2) grinding the raw material obtained in step (1) by dry grinding with a stone roller, so that the particle size of the ground nut paste is ≤80 μm;

[0106] (3) putting the sauce ground in step (2) into purified water preheated to 75° C. and stirring for 10 minutes to fully dissolve;

[0107] (4) 35 kg of white sugar and an emulsifier are mixed to obtain a first mixed liquid, which is added to the almond liquid dissolved in step (3) and stirred for 25 min;

[0108] (5) filtering the liquid in step (4);

[0109] (6) homogenizing the filtrate obtained in step (5) at a homogenization pressure of 35 MPa;

[0110] (7) The homogenized liquid obtained in step (6) is pasteurized at a temperature of 95° C. and a time of 300 seconds;

[0111] (8) cooling the sterilized liquid obtained in step (7) to 43±1° C., adding a fermentation agent, stirring evenly, and fermenting at a constant temperature until the pH at the fermentation end point is ≤4.5;

[0112] (9) breaking the fermented milk obtained in step (8) and stirring for 5 minutes;

[0113] (10) 35 kg of white sugar and stabilizer were mixed, added into RO water at 55° C., and stirred at constant temperature for 25 min until completely dissolved to obtain a second mixed liquid;

[0114] (11) Mix the solutions obtained in step (9) and step (10), and stir for 20 min until the mixture is uniform;

[0115] (12) The solution obtained in step (11) was homogenized in two passes, with the homogenization pressure being 20 MPa;

[0116] (13) filling the homogenized solution obtained in step (12);

[0117] (14) sterilizing the product after filling in step (13), the sterilization temperature and time are 85° C. and 20 min respectively;

[0118] (15) The product sterilized in step (14) is cooled to obtain a yogurt product.

[0119] Example 2

[0120] 1. Formula (per 1000kg raw material):

[0121] raw material Addition amount (kg) Almonds 50 Walnut 10 white sugar 80 Polyglycerol fatty acid esters 4 Hydroxypropyl distarch phosphate 23 Pectin 1 Sodium Carboxymethyl Cellulose 4.5 Agar 0.8 Fermentation Agents 0.004

[0122] 2. Preparation method:

[0123] (1) 50 kg of almonds and 10 kg of walnuts are subjected to two baking processes, the first baking process is 200° C. / 3 min, and the second baking process is 75° C. / 15 min;

[0124] (2) grinding the raw material obtained in step (1) by dry grinding with a stone roller, so that the particle size of the ground nut paste is ≤80 μm;

[0125] (3) putting the sauce ground in step (2) into purified water preheated to 75° C. and stirring for 10 minutes to fully dissolve;

[0126] (4) 40 kg of white sugar and an emulsifier are mixed to obtain a first mixed liquid, which is added to the almond and walnut liquid dissolved in step (3), and stirred for 25 minutes;

[0127] (5) filtering the liquid in step (4);

[0128] (6) homogenizing the filtrate obtained in step (5) at a homogenization pressure of 35 MPa;

[0129] (7) pasteurizing the homogenized liquid obtained in step (6) at a temperature of 95° C. and a time of 300 s;

[0130] (8) cooling the sterilized liquid obtained in step (7) to 43±1° C., adding a fermentation agent, stirring evenly, and fermenting at a constant temperature until the pH at the fermentation end point is ≤4.5;

[0131] (9) breaking the fermented milk obtained in step (8) and stirring for 5 minutes;

[0132] (10) 40 kg of white sugar and stabilizer were mixed, added into RO water at 55° C., and stirred at constant temperature for 25 min until completely dissolved to obtain a second mixed liquid;

[0133] (11) Mix the solutions obtained in step (9) and step (10), and stir for 20 min until the mixture is uniform;

[0134] (12) The solution obtained in step (11) was homogenized in two passes, and the homogenization pressure was 25 MPa;

[0135] (13) filling the homogenized solution obtained in step (12);

[0136] (14) sterilizing the product after filling in step (13), the sterilization temperature and time are 85° C. and 20 min respectively;

[0137] (15) The product sterilized in step (14) is cooled to obtain a yogurt product.

[0138] Example 3

[0139] 1. Formula (per 1000kg raw material):

[0140] raw material Addition amount (kg) Walnut 55 white sugar 65 Mono- and di-glycerol fatty acid esters 3.5 Glutinous rice starch 23 Pectin 2.5 Sodium Carboxymethyl Cellulose 5 Xanthan gum 0.6 Fermentation Agents 0.005

[0141] 2. Preparation method:

[0142] (1) 55 kg of walnut raw material was subjected to two baking processes, the first baking process was 185° C. / 4 min, and the second baking process was 83° C. / 12 min;

[0143] (2) grinding the raw material obtained in step (1) by dry grinding with a stone roller, so that the particle size of the ground nut paste is ≤80 μm;

[0144] (3) putting the sauce ground in step (2) into purified water preheated to 75° C. and stirring for 10 minutes to fully dissolve;

[0145] (4) 35 kg of white sugar and an emulsifier are mixed to obtain a first mixed liquid, which is added to the walnut liquid dissolved in step (3) and stirred for 25 min;

[0146] (5) filtering the liquid in step (4);

[0147] (6) homogenizing the filtrate obtained in step (5) at a homogenization pressure of 35 MPa;

[0148] (7) pasteurizing the homogenized liquid obtained in step (6) at a temperature of 95° C. and a time of 300 s;

[0149] (8) cooling the sterilized liquid obtained in step (7) to 43±1° C., adding a fermentation agent, stirring evenly, and fermenting at a constant temperature until the pH at the fermentation end point is ≤4.5;

[0150] (9) breaking the fermented milk obtained in step (8) and stirring for 5 minutes;

[0151] (10) 30 kg of white sugar and stabilizer were mixed, added into RO water at 55° C., and stirred at constant temperature for 25 min until completely dissolved to obtain a second mixed liquid;

[0152] (11) Mix the solutions obtained in step (9) and step (10), and stir for 20 min until the mixture is uniform;

[0153] (12) The solution obtained in step (11) was homogenized in two passes, with the homogenization pressure being 20 MPa;

[0154] (13) filling the homogenized solution obtained in step (12);

[0155] (14) sterilizing the product after filling in step (13), wherein the sterilization temperature and time are 85° C. and 20 min respectively; (15) cooling the product after sterilization in step (14) to obtain a finished yogurt product.

[0156] Comparative Example 1

[0157] 1. Formula (per 1000kg raw material):

[0158]

[0159]

[0160] 2. Preparation method:

[0161] (1) 50 kg of walnut raw material was subjected to a baking process at 112° C. / 4 min;

[0162] (2) grinding the raw material obtained in step (1) by dry grinding with a stone roller, so that the particle size of the ground nut paste is ≤80 μm;

[0163] (3) putting the sauce ground in step (2) into purified water preheated to 75° C. and stirring for 10 minutes to fully dissolve;

[0164] (4) 35 kg of white sugar and an emulsifier are mixed to obtain a first mixed liquid, which is added to the walnut liquid dissolved in step (3) and stirred for 25 min;

[0165] (5) filtering the liquid in step (4);

[0166] (6) homogenizing the filtrate obtained in step (5) at a homogenization pressure of 35 MPa;

[0167] (7) pasteurizing the homogenized liquid obtained in step (6) at a temperature of 95° C. and a time of 300 s;

[0168] (8) cooling the sterilized liquid obtained in step (7) to 43±1° C., adding a fermentation agent, stirring evenly, and fermenting at a constant temperature until the pH at the fermentation end point is ≤4.5;

[0169] (9) breaking the fermented milk obtained in step (8) and stirring for 5 minutes;

[0170] (10) 35 kg of white sugar and stabilizer were mixed, added into RO water at 55° C., and stirred at constant temperature for 25 min until completely dissolved to obtain a second mixed liquid;

[0171] (11) Mix the solutions obtained in step (9) and step (10), and stir for 20 min until the mixture is uniform;

[0172] (12) The solution obtained in step (11) was homogenized in two passes, and the homogenization pressure was 25 MPa;

[0173] (13) filling the homogenized solution obtained in step (12);

[0174] (14) sterilizing the product after filling in step (13), wherein the sterilization temperature and time are 85° C. and 20 min respectively; (15) cooling the product after sterilization in step (14) to obtain a finished yogurt product.

[0175] Comparative Example 2

[0176] 1. Formula (per 1000kg raw material):

[0177] raw material Addition amount (kg) Debittered almonds 45 white sugar 70 Mono- and di-glycerol fatty acid esters 3 Glutinous rice starch 20 Pectin 3 Sodium Carboxymethyl Cellulose 3 Agar 0.5 Fermentation Agents 0.005

[0178] 2. Preparation method:

[0179] (1) 45 kg of almond raw material was subjected to two baking processes, the first baking process was 175° C. / 5 min, and the second baking process was 75° C. / 15 min;

[0180] (2) grinding the raw material obtained in step (1) by dry grinding with a stone roller, so that the particle size of the ground nut paste is ≤80 μm;

[0181] (3) putting the sauce ground in step (2) into purified water preheated to 75° C. and stirring for 10 minutes to fully dissolve;

[0182] (4) 35 kg of white sugar and an emulsifier are mixed to obtain a first mixed liquid, which is added to the almond liquid dissolved in step (3) and stirred for 25 min;

[0183] (5) filtering the liquid in step (4);

[0184] (6) homogenizing the filtrate obtained in step (5) at a homogenization pressure of 35 MPa;

[0185] (7) pasteurizing the homogenized liquid obtained in step (6) at a temperature of 95° C. and a time of 300 s;

[0186] (8) cooling the sterilized liquid obtained in step (7) to 43±1° C., adding a fermentation agent, stirring evenly, and fermenting at a constant temperature until the pH at the fermentation end point is ≤4.5;

[0187] (9) breaking the fermented milk obtained in step (8) and stirring for 5 minutes;

[0188] (10) 35 kg of white sugar and stabilizer were mixed, added into RO water at 55° C., and stirred at constant temperature for 25 min until completely dissolved to obtain a second mixed liquid;

[0189] (11) Mix the solutions obtained in step (9) and step (10), and stir for 20 min until the mixture is uniform;

[0190] (12) The solution obtained in step (11) was homogenized in two passes, with the homogenization pressure being 5 MPa;

[0191] (13) filling the solution obtained in step (12);

[0192] (14) sterilizing the product after filling in step (13), wherein the sterilization temperature and time are 85° C. and 20 min respectively; (15) cooling the product after sterilization in step (14) to obtain a finished yogurt product.

[0193] Comparative Example 3

[0194] 1. Formula (per 1000kg raw material):

[0195] raw material Addition amount (kg) Debittered almonds 50 white sugar 70 Polyglycerol fatty acid esters 4 Hydroxypropyl distarch phosphate 18 Pectin 2.5 Sodium Carboxymethyl Cellulose 3.5 Fermentation Agents 0.003

[0196] 2. Preparation method:

[0197] (1) 50 kg of almond raw material was subjected to two baking processes, the first baking process was 75° C. / 20 min, and the second baking process was 150° C. / 3 min;

[0198] (2) grinding the raw material obtained in step (1) by dry grinding with a stone roller, so that the particle size of the ground nut paste is ≤80 μm;

[0199] (3) putting the sauce ground in step (2) into purified water preheated to 75° C. and stirring for 10 minutes to fully dissolve;

[0200] (4) 35 kg of white sugar and an emulsifier are mixed to obtain a first mixed liquid, which is added to the almond liquid dissolved in step (3) and stirred for 25 min;

[0201] (5) filtering the liquid in step (4);

[0202] (6) homogenizing the filtrate obtained in step (5) at a homogenization pressure of 35 MPa;

[0203] (7) pasteurizing the homogenized liquid obtained in step (6) at a temperature of 95° C. and a time of 300 s;

[0204] (8) cooling the sterilized liquid obtained in step (7) to 43±1° C., adding a fermentation agent, stirring evenly, and fermenting at a constant temperature until the pH at the fermentation end point is ≤4.5;

[0205] (9) breaking the fermented milk obtained in step (8) and stirring for 5 minutes;

[0206] (10) 35 kg of white sugar and stabilizer were mixed, added into RO water at 55° C., and stirred at constant temperature for 25 min until completely dissolved to obtain a second mixed liquid;

[0207] (11) Mix the solutions obtained in step (9) and step (10), and stir for 20 min until the mixture is uniform;

[0208] (12) The solution obtained in step (11) was homogenized in two passes, and the homogenization pressure was 25 MPa;

[0209] (13) filling the homogenized solution obtained in step (12);

[0210] (14) sterilizing the product after filling in step (13), the sterilization temperature and time are 85° C. and 20 min respectively;

[0211] (15) The product sterilized in step (14) is cooled to obtain a yogurt product.

[0212] Experimental results detection

[0213] 1. Product acidity

[0214] Before the product is formulated, the yogurt obtained is fermented with lactic acid bacteria and the pH value thereof is tested. After the fermentation is completed, the product is formulated and the pH value thereof is tested.

[0215] The product is fermented with lactic acid bacteria before blending, and the pH of the resulting yogurt is ≤4.5. After the fermentation is completed, the product is blended and the pH of the finished product is 4.52±0.3.

[0216] 2. Product status and stability

[0217] The state and structure of the products of the experimental examples and comparative examples were observed, and the samples were tasted to check their flavor and other conditions. The stability evaluation criteria are shown in Table 1.

[0218] Table 1 Stability evaluation criteria

[0219]

[0220] According to the stability evaluation criteria in Table 2, the products of the embodiments and comparative examples were evaluated, and the results are shown in Table 2:

[0221] Table 2 Stability evaluation results

[0222] product Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 7d 96 94 92 84 82 85 30d 93 91 89 79 75 76 60d 91 88 87 73 70 70 120d 88 86 84 66 64 63 180d 85 84 80 61 54 54 210d 83 82 78 57 47 48

[0223] According to the stability evaluation results in Table 2, the products of Examples 1-3 all scored high after stability evaluation, indicating that the product tissue state was maintained well without stratification, water separation, or precipitation. However, the products of Comparative Examples 1-3 scored low after stability evaluation, indicating that the nut pretreatment method, product formula, and processing technology had a significant impact on the product tissue state, thereby affecting the product taste and shelf life, lowering the overall evaluation of the product.

[0224] After being placed for a period of time, the products of comparative examples 1-3 showed stratification, water separation, precipitation, and granularity in terms of sensory perception. The flavor of the products was not harmonious, and there was no unique aroma of nuts, sourness, rough taste, and other problems. This shows that the products of Examples 1-3 have good stability, can maintain a good organizational state, and will not affect the product quality; the samples of comparative examples 1 and 3 are poor, indicating that the nuts are not fully roasted, so that the enzymes in the nuts are not completely inactivated, so that the nut paste is contaminated by microorganisms, and the aroma of the nuts cannot be emitted, which has a great impact on the organizational morphology and aroma of the product; comparative example 2 changes the production process of the product, and the pressure of the post-homogenization process is not carried out according to different protein contents. The aroma of the product is guaranteed, but its organizational state is poor, and the product cannot be made uniform and stable. The preparation method of the above products verifies the influence of different pre-treatment processes of nuts and post-homogenization processes based on the protein content of the product on the organizational state and taste of the product. The product formed by the preparation method of room temperature nut-based fermented yogurt provided by the present invention is stable in state, has the characteristics of yogurt, does not have the phenomenon of stratification, precipitation and water separation of nut-based yogurt, has a harmonious flavor, has no other peculiar smell, has a delicate and soft taste, and has no graininess.

[0225] 3. Sensory evaluation

[0226] For the samples of Examples 1-3 and Comparative Examples 1-3, 30 professional tasters (male to female ratio of 1:1) were selected to evaluate the products according to the five aspects of smoothness, consistency, sour-sweet ratio, aroma and overall preference of the products. The evaluation criteria are shown in Table 3, and the full score for each indicator is 10. The results of the sensory evaluation are the average of the scores of the 30 people, and the sensory evaluation results are shown in Table 4.

[0227] Table 3 Sensory evaluation standards

[0228] project Scoring Criteria Points Smoothness Delicate and smooth taste 10 Thin consistency Moderate consistency 10 Sweet and sour ratio Moderate sweet-sour taste 10 aroma Aroma Coordination 10 Overall likeability Rating based on personal preference 10

[0229] Table 4 Sensory evaluation results

[0230] sample Smoothness Thin consistency Sweet and sour ratio aroma Overall likeability Total score Example 1 8.5 9.1 8.3 8.5 8.6 43.0 Example 2 8.3 8.9 8.4 8.1 8.5 42.2 Example 3 8.4 9.0 8.3 8.4 8.5 42.6 Comparative Example 1 8.3 8.1 8.1 7.3 7.6 39.4 Comparative Example 2 7.1 7.7 7.6 8.1 7.6 38.1 Comparative Example 3 6.8 7.5 7.8 7.9 7.5 37.5

[0231] It can be seen from the sensory evaluation results in Table 4 that the total evaluation scores of the products of Examples 1-3 according to the present invention are higher than those of Comparative Examples 1-3. Example 1 has the highest score for product smoothness, while Comparative Example 3 has the lowest score. Comparative Example 3 has poor smoothness, and its product state is poorer than that of Examples 1-3, resulting in a relatively low sensory score for the product. In terms of consistency, there is not much difference between Examples 1-3 and Comparative Example 1, while there is a very obvious difference between Comparative Example 3. In the sour-sweet ratio of the product, there is not much difference between Examples 1-3 and Comparative Example 1, while Comparative Example 2 has the lowest score. Products that are too sour or too sweet will affect the consumer's experience, thereby affecting the overall score of the product. When comparing the aroma of the products, Comparative Example 1 has the lowest score, and the differences between the other products are small. Among the products of Examples 1-3 and Comparative Examples 1-3, Example 1 has the highest overall preference score, which is superior to other products not only in terms of tissue sensory state and taste.

[0232] Sensory evaluation shows that when the nut raw materials are processed by different pre-processing techniques, they have a certain impact on the flavor and texture of the product, resulting in a lower overall product evaluation; and different stabilizer ratios and different processing techniques have a greater impact on the taste and texture of the product, resulting in uneven consistency, precipitation, rough taste, etc.

[0233] 4. Shelf life verification

[0234] The products of Example 1-2 and Comparative Example 1-2 were selected to observe the stability, taste, consistency, sour-sweet ratio and flavor of the products during the shelf life. Table 5 shows the status of the products during the shelf life.

[0235] Table 5 Shelf life verification results

[0236]

[0237]

[0238] It can be seen from the shelf life verification results shown in Table 5 that the performance of the embodiment and the comparative example during the shelf life is quite different. The organizational state of the comparative example product is poor. At 30 days, the comparative example product is not only poor in sensory perception, but also its taste is not very harmonious; while the embodiment can still maintain a good state and taste. At 60 days, the comparative example not only changes in sensory perception, but also changes in taste accordingly. The flavor of the comparative example No. 1 product changes, and the comparative example No. 2 product has water separation and precipitation; while the embodiment still maintains a good state. At 120 days, the organizational state, taste and flavor of the comparative example product have all changed, while the sour-sweet ratio of the embodiment product has only changed slightly, but the overall state and flavor are better. At 180 days, the organizational state of the comparative example is poor, with water separation, precipitation, unharmonious flavor, rough taste and other phenomena, while the embodiment has only changed slightly, and the overall state and flavor have not changed much. At 210 days, the comparative product showed serious changes, with obvious stratification, precipitation and water separation in the organizational state, and a rough and granular taste. The example product showed only slight changes, and the overall state and flavor were still within an acceptable range.

[0239] It can be seen that the room temperature nut-based fermented yogurt product according to the embodiment of the present invention is milky white, has a uniform and stable tissue state, a delicate and smooth taste, and an appropriate sour-sweet ratio, which ensures the shelf life of the product.

Claims

1. A method for preparing room temperature nut-based fermented yogurt, wherein: The raw material composition of the yogurt includes, based on 1000 parts by weight, 28-100 parts of nuts, 50-120 parts of white sugar, 3-8 parts of emulsifier, 3-85 parts of stabilizer and / or thickener, and 0.002-0.006 parts of starter. The preparation method of the yogurt includes: (1) roasting the nut raw materials twice to obtain roasted nuts; (2) grinding the roasted nuts to obtain nut paste; (3) mixing the nut paste with water to obtain a nut paste liquid; (4) mixing a portion of white sugar and an emulsifier evenly, and adding the mixture into the nut liquid to obtain a first mixed liquid; (5) stirring, filtering, homogenizing, and pasteurizing the first mixed liquid to obtain a sterilized first mixed liquid; (6) cooling the sterilized first mixed liquid, adding a fermentation agent to perform constant temperature fermentation, and obtaining fermented milk; (7) breaking the fermented milk and stirring it to obtain the fermented milk after breaking the milk; (8) After mixing the remaining white sugar and the stabilizer, add them into water and stir at a constant temperature until they are completely dissolved to obtain a second mixed solution; (9) uniformly mixing the fermented milk after demulsification with the second mixed solution to obtain a mixed feed liquid; (10) homogenizing the mixed liquid twice, wherein the homogenization pressure is set according to the protein content in the mixed liquid to obtain a homogenized liquid; (11) sterilizing and cooling the homogenized liquid to obtain the room temperature nut-based fermented yogurt.

2. The preparation method according to claim 1, wherein The raw materials for preparing the yogurt are composed of the following ingredients: 28-100 parts of nuts, 50-120 parts of white sugar, 3-8 parts of emulsifier, 3-85 parts of stabilizer and / or thickener, 0.002-0.006 parts of starter, and the rest is supplemented with water to 1000 parts; Preferably, the nuts include one or a combination of two or more of almonds, almonds, peanuts, pistachios, walnuts, hazelnuts and cashews; Preferably, the emulsifier comprises one or a combination of two or more of polyglycerol fatty acid esters, pectin, and mono- and di-glycerol fatty acid esters; Preferably, the stabilizer and / or thickener comprises one or a combination of two or more of sodium carboxymethyl cellulose, agar, hydroxypropyl distarch phosphate, xanthan gum, and glutinous rice starch.

3. The preparation method according to claim 1, wherein The heating method for the two bakings is a tunnel-type electric heating furnace method; Preferably, the first baking temperature of the two bakings is 150-250° C., and the baking time is 2-15 min; Preferably, the second baking temperature of the two bakings is 65-90° C., and the baking time is 5-35 min.

4. The preparation method according to claim 1, wherein In the step of mixing the nut paste with water, the temperature of the water is 70-75° C.; Preferably, the stirring time is 5-20 min.

5. The preparation method according to claim 1, wherein In step (5), the homogenization pressure is 10-35 MPa; Preferably, the pasteurization temperature is 75-95° C. and the pasteurization time is 100-300 s.

6. The preparation method according to claim 1, wherein In step (6), the temperature after cooling is 43±1°C; Preferably, the bacterial species contained in the fermentation agent include Streptococcus salivarius subspecies thermophilic and / or Lactobacillus delbrueckii subspecies bulgaricus; Preferably, the fermentation endpoint of the constant temperature fermentation is pH ≤ 4.

5.

7. The preparation method according to claim 1, wherein In step (8), the temperature of the water is 50-55°C; Preferably, the constant temperature stirring time is 10-35 min.

8. The preparation method according to claim 1, wherein In step (10), the homogenization pressure is set according to the protein content in the mixed liquid; Preferably, when the protein content is less than 1.0 g / 100 mL, the homogenization pressure is ≤ 20 MPa; Preferably, when the protein content is 1.0 g / 100 mL ≤ 1.5 g / 100 mL, the homogenization pressure is 20 MPa ≤ 25 MPa; Preferably, when the protein content is 1.5 g / 100 mL ≤ ≤ 2.0 g / 100 mL, the homogenization pressure is 25 MPa < 30 MPa; Preferably, when the protein content is greater than 2.0 g / 100 mL, the homogenization pressure is greater than or equal to 30 MPa.

9. The preparation method according to claim 1, wherein In step (11), the sterilization temperature is 75-95°C and the sterilization time is 10-30 minutes.

10. A room temperature nut-based fermented yogurt, the raw materials of which include: 28-100 parts of nuts, 50-120 parts of white sugar, 3-8 parts of emulsifier, 3-85 parts of stabilizer, 0.002-0.006 parts of leavening agent, and the rest is supplemented with water to 1000 parts; Preferably, the yogurt is prepared by the preparation method according to any one of claims 1-9.

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