Freeze-dried yoghourt block and preparation method thereof

Abstract

The invention belongs to the technical field of food processing, and particularly relates to a freeze-dried yoghourt block and a preparation method thereof. According to the invention, rhizoma polygonati extract liquid is used as a main material, traditional Chinese medicine extract liquid with homology of medicine and food is used as an auxiliary material, the rhizoma polygonati extract liquid and milk are mixed and fermented in proportion, and the mixture is frozen by adopting a vacuum freeze-drying technology, so that common light health-preserving food of rhizoma polygonati series freeze-dried yoghurt is developed; the series of products comprise rhizoma polygonati freeze-dried yoghurt blocks, rhizoma polygonati-chaenomeles speciosa freeze-dried yoghurt blocks, rhizoma polygonati-cortex moutan freeze-dried yoghurt blocks, rhizoma polygonati-poria cocos freeze-dried yoghurt blocks, rhizoma polygonati-platycodon grandiflorum freeze-dried yoghurt blocks and rhizoma polygonati-chrysanthemum freeze-dried yoghurt blocks. Results of the embodiment show that the prepared rhizoma polygonati series freeze-dried yoghurt blocks are crisp in taste, rich in milk fragrance, regular in block appearance, natural in color and luster, free of additives and nutritional and healthy to eat.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and in particular relates to a freeze-dried yogurt block and a preparation method thereof. Background Art

[0002] Yogurt is a nutritious fermented dairy product. Through milk fermentation, lactic acid bacteria break down lactose into lactic acid, retaining the original nutrients while allowing lactose intolerant patients to eat it with confidence. With the rise of the healthy diet trend, yogurt, as a dairy product rich in probiotics and nutrients, has been favored by consumers. It has a refreshing and crispy taste, is convenient and ready to eat, and is suitable for all ages.

[0003] Polygonatum sibiricum is a food ingredient of the genus Polygonatum in the Liliaceae family. It is rich in polysaccharides, steroidal saponins, amino acids, flavonoids, minerals and other active ingredients. It has the effects of tonifying qi, strengthening kidneys and bones, strengthening spleen and lungs, enhancing immune function, delaying aging, regulating blood lipids, and lowering blood sugar. The Chinese Pharmacopoeia records Yunnan Polygonatum, Polygonatum sibiricum, and Polygonatum multiflorum, which have the effects of tonifying qi, strengthening spleen, and tonifying kidneys.

[0004] Chaenomeles speciosa S.Nakai is the dried nearly mature fruit of the Rosaceae plant Chaenomeles speciosa S.Nakai. According to the Compendium of Materia Medica, "papaya is everywhere, but the one in Xuancheng is the best", so it is called Xuan papaya. Xuan papaya contains active ingredients such as polysaccharides, flavonoids, organic acids, triterpenes, phenols, essential oils, alkaloids, and nutrients such as amino acids, vitamins, and mineral trace elements. It has pharmacological activities such as analgesia, anti-inflammatory, anti-tumor, antibacterial, antioxidant, hypoglycemic, hypolipidemic, and gastrointestinal protection. The combination of Polygonatum sibiricum and Xuan papaya can better warm the spleen essence, warm the liver blood, and remove dampness and strengthen the spleen.

[0005] Peony bark is the dried root bark of the Ranunculaceae plant Paeonia sutfruticosaAndr, referred to as Peony Bark, bitter in taste, with the effects of clearing heat and cooling blood, promoting blood circulation and removing blood stasis, etc. It is clinically used to treat symptoms such as fever and rash, night heat and morning chill, etc. In the Diju Taohong Decoction, Polygonatum sibiricum and Peony Bark are used together. Polygonatum sibiricum nourishes the liver and kidneys, benefits the essence and blood, and Peony Bark nourishes yin and clears heat. Both nourish the liver and kidneys, promote blood circulation and remove blood stasis, and clear the meridians and improve eyesight.

[0006] Poria cocos is the dried sclerotium of the Polyporaceae fungus Poria cocos (Schw.) Wolf, which has the effects of dispelling dampness and promoting diuresis, calming the mind and strengthening the spleen. The chemical components isolated and identified from Poria cocos include triterpenes, diterpenes, sterols, other classes and polysaccharides. Modern pharmacological studies have shown that Poria cocos has multiple biological activities such as anti-liver fibrosis, diuresis, immunomodulation, regulation of intestinal flora, anti-inflammatory, anti-tumor, enhancement of body immunity, anti-aging, and anti-diabetes. Both Polygonatum sibiricum and Poria cocos have the effects of enhancing immunity, anti-oxidation, and anti-aging. Their combination can greatly improve their synergistic effects.

[0007] Platycodon grandiflorus (Jacq.) A.DC. is a perennial herbaceous plant of the genus Platycodon in the family Campanulaceae. It is a traditional Chinese medicine that is both a medicine and food. It is bitter, pungent and flat in nature and flavor. It belongs to the lung meridian and has the effects of clearing the lungs, relieving throat pain, removing phlegm and draining pus. Studies have shown that Platycodon grandiflorus contains triterpenoid saponins, polysaccharides, flavonoids, polyacetylene, steroids, phenolic acids, fatty acids and other types of compounds, and the main pharmacologically active ingredients are saponins. The results also show that the water extracts of Polygonatum sibiricum and Platycodon grandiflorum have certain antioxidant and metabolic regulation effects.

[0008] Chrysanthemum is the dried head inflorescence of the Asteraceae plant. It is also known as female chrysanthemum, regeneration, and yincheng. It is a Chinese medicine that can be used as both medicine and food. The "Compendium of Materia Medica" says that "bitterness can relieve heat, sweetness can benefit blood, sweetness can detoxify, and neutrality is pungent, so it can also disperse knots. Bitterness enters the heart and small intestine, sweetness enters the spleen and stomach, neutrality and pungentness go to the liver and gallbladder, and enters the lungs and large intestine. Bitterness can relieve stagnant heat, sweetness can benefit blood vessels, and neutrality can disperse deficiency heat." "Compendium of Materia Medica Seeking Truth" says that "sweet chamomile specifically enters the liver, lungs, and kidneys. Its pungent taste can dispel wind and brighten the eyes; its sweet taste can protect the lungs to nourish water; its bitter taste can relieve heat and eliminate restlessness." Professor Zheng Yanlin, based on the theory of the five wheels of ophthalmology in traditional Chinese medicine, selected four Chinese medicinal materials, namely wolfberry, chrysanthemum, polygonatum, and northern adenophora, and developed the Qingrun Yangmu oral liquid after years of experience summary. It is used to treat patients with liver and kidney yin deficiency, dry eyes and visual fatigue caused by residual evil. Therefore, the combination of Polygonatum sibiricum and Chrysanthemum can promote blood circulation, nourish the liver and improve eyesight.

[0009] As consumers pay more and more attention to the health attributes of beverages, the market for freshly made yogurt has entered a peak period of development. The cross-border integration trend of "traditional Chinese medicine + diet" has not only brought new development opportunities to the traditional Chinese medicine industry, but also provided consumers with more diversified and personalized health choices. The continuous expansion of the industry scale is a strong support for the development of the medicinal diet business.

[0010] Therefore, there is an urgent need for a freeze-dried yogurt product that is both medicinal and edible and that is prepared using Chinese medicinal materials such as Polygonatum sibiricum. Summary of the invention

[0011] The purpose of the present invention is to provide a freeze-dried yogurt block. The freeze-dried yogurt block product provided by the present invention not only retains the nutrition of yogurt, but also contains natural herbal essences of traditional Chinese medicines such as polygonatum and the like, and has a crisp taste and rich nutrition.

[0012] In order to achieve the above object, the present invention provides the following technical solutions:

[0013] The invention provides a freeze-dried yogurt block, which is prepared by mixed fermentation of polygonatum sibiricum water extract and milk.

[0014] Preferably, the freeze-dried yogurt block also includes water extract of Rhizoma Cibotii, Cortex Moutan, Poria, Platycodon grandiflorum or Chrysanthemum.

[0015] The present invention also provides a method for preparing the freeze-dried yogurt block, which specifically comprises the following steps:

[0016] S1. Raw material pretreatment: drying and grinding the Chinese medicinal materials into powder, and then boiling them in water to obtain water extract;

[0017] S2, sterilizing the water extract and milk at high temperature, mixing them in proportion, inoculating yogurt fermentation bacteria powder, fermenting, and post-ripening to obtain a yogurt product;

[0018] S3. Add skimmed high-calcium high-protein milk powder, low-fat pectin, white sugar and compound coloring agent to the finished yogurt, mix well, put into a mold plate, and obtain the freeze-dried yogurt block product through the process of pre-freezing, freezing and freeze-drying.

[0019] Preferably, the water extract in step S1 is obtained by mixing powdered medicinal materials and ultrapure water in a mass ratio of 1:10, stirring and soaking for 30 minutes, heating in a water bath at 80° C. and then keeping it slightly boiling for 30 minutes, and cooling and filtering.

[0020] Preferably, the amount of the water extract added in step S2 is 20% of the volume of the milk; 1 g of yogurt fermentation bacteria powder is added to every 100 ml of milk.

[0021] Preferably, in step S2, the fermentation temperature is 43° C. and the fermentation time is 10 to 12 hours.

[0022] Preferably, the post-ripening process in step S2 is to refrigerate the fermented yogurt at 4° C. for one week.

[0023] Preferably, in step S3, the amount of skimmed high-calcium high-protein milk powder added is 5-9 g, the amount of low-fat pectin added is 0.3-0.7 g, the amount of white sugar added is 10.5-14.5 g, and the amount of compound colorant added is 0.5-1.5 ml.

[0024] 9. The preparation method according to claim 3 is characterized in that the pre-freezing process in step S3 is pre-freezing at -20°C for 4 hours; the freezing process is freezing at -80°C for 24 hours, the vacuum freeze-drying time is 40 to 48 hours, and the temperature is -50°C.

[0025] The present invention also provides the application of the preparation method in preparing freeze-dried yogurt blocks. When preparing the polygonatum series freeze-dried yogurt blocks, the amount of the Chinese medicinal material water extract added is 20% of the amount of milk added; the volume ratio of polygonatum to other Chinese medicinal material water extracts is 3: (1-9).

[0026] Beneficial effects of the present invention:

[0027] 1. The present invention mainly uses polygonatum sibiricum extract and other Chinese medicine extracts as supplementary ingredients, mixes and ferments them with milk in a certain proportion, and freezes them using vacuum freeze drying technology to develop a series of common light health foods such as polygonatum sibiricum freeze-dried yogurt blocks, retains the nutritional components of yogurt and the natural herbal essence of Chinese medicines such as polygonatum sibiricum, adds Chinese medicine and other active ingredients to yogurt, and provides more flavors and effects. Promote the development of Chinese medicine culture, in order to provide reference significance for the future development model of "Chinese medicine + diet", the research and development of products related to Chinese medicines such as polygonatum sibiricum and the research and development of yogurt block flavors.

[0028] 2. The polygonatum series freeze-dried yogurt block products prepared by the present invention are suitable for people of all ages to eat. In particular, as a convenient nutritional supplement in outdoor travel, office overtime and other occasions, it can meet the human body's needs for nutrients such as yogurt.

[0029] 3. The present invention adopts solid freeze-drying technology to increase the possibility of long-term storage of yogurt. This technology removes moisture from yogurt and reduces the conditions for microbial growth, thereby greatly extending the shelf life of the product. In addition, solid freeze-dried yogurt does not require refrigeration, which is more convenient in storage and transportation, and extends the sales time.

[0030] 4. The polygonatum series freeze-dried yogurt blocks prepared by the present invention have a crisp taste, a rich milky aroma, a regular block appearance, a natural color, no additives, and are healthy to eat. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0032] Figure 1 This is the finished product packaging picture of the Huangjing series freeze-dried yogurt blocks;

[0033] Figure 2 The present invention is a flow chart for the preparation of a series of freeze-dried yogurt blocks of polygonatum;

[0034] Figure 3 This is the finished product picture of Polygonatum freeze-dried yogurt cubes;

[0035] Figure 4 Sensory evaluation standard for Polygonatum freeze-dried yogurt cubes;

[0036] Figure 5 This is the sensory scoring curve of Polygonatum odoratum freeze-dried yogurt cubes;

[0037] Figure 6 This is the finished product picture of Huangjing-Xuan papaya freeze-dried yogurt cubes;

[0038] Figure 7 The sensory evaluation standard for Polygonatum sibiricum-Xuan papaya freeze-dried yogurt cubes;

[0039] Figure 8 This is a sensory scoring curve of Polygonatum sibiricum-Xuan papaya freeze-dried yogurt cubes;

[0040] Fig. 9 It is the sensory evaluation standard of Polygonatum sibiricum-Cortex Moutan freeze-dried yogurt cubes;

[0041] Fig.10 This is a sensory scoring curve of Polygonatum sibiricum-Cortex Moutan freeze-dried yogurt cubes;

[0042] Fig.11 It is the sensory evaluation standard of Polygonatum sibiricum-Poria cocos freeze-dried yogurt cubes;

[0043] Fig.12 This is a sensory scoring curve of Polygonatum sibiricum-Poria cocos freeze-dried yogurt cubes;

[0044] Fig.13 This is the finished product picture of Polygonatum-Planthodium freeze-dried yogurt cubes;

[0045] Fig.14 The sensory evaluation standard for Polygonatum sibiricum-Planthoceras freeze-dried yogurt cubes;

[0046] Fig.15 This is a sensory scoring curve of Polygonatum sibiricum-Planthoceras grandiflora freeze-dried yogurt cubes;

[0047] Fig.16 This is the finished product picture of Polygonatum-Chrysanthemum freeze-dried yogurt cubes;

[0048] Fig.17 Sensory evaluation standard for polygonatum-chrysanthemum freeze-dried yogurt cubes;

[0049] Fig.18 This is a sensory scoring curve of Polygonatum sibiricum-Chrysanthemum freeze-dried yogurt cubes;

[0050] Fig.19This is the error analysis of the amount of extract added and the volume ratio of each freeze-dried yogurt block. DETAILED DESCRIPTION

[0051] The present invention provides a freeze-dried yogurt block, which is mainly made of polygonatum sibiricum extract and supplemented with other Chinese medicinal and edible herbal extracts, which are mixed and fermented with milk in a certain proportion, and freeze-dried by vacuum freeze-drying technology to develop a series of common light health food such as polygonatum sibiricum freeze-dried yogurt blocks. Chinese medicinal materials with medicinal and edible properties include but are not limited to polygonatum sibiricum, papaya, moutan bark, tuckahoe, platycodon or chrysanthemum.

[0052] In the present application, the dried and powdered Chinese medicinal materials are boiled in water to obtain a water extract, which is sterilized and then mixed with milk and inoculated with yogurt fermentation bacteria powder for fermentation and post-ripening to obtain a yogurt product. A certain proportion of skim high-calcium high-protein milk powder, low-fat pectin and white sugar are added to the fermented yogurt, and a certain amount of compound colorant is added to distinguish different types of products, and a freeze-dried yogurt block product is obtained through a pre-freezing, freezing and freeze-drying process.

[0053] The present invention utilizes the preparation method to prepare polygonatum freeze-dried yogurt blocks, polygonatum-Xuan papaya freeze-dried yogurt blocks, polygonatum-Mountain bark freeze-dried yogurt blocks, polygonatum-Poria freeze-dried yogurt blocks, polygonatum-Planthophyllum freeze-dried yogurt blocks and polygonatum-Chrysanthemum freeze-dried yogurt blocks. When preparing the polygonatum freeze-dried yogurt blocks, the addition amount of polygonatum water extract is 16%-24%; when preparing other freeze-dried yogurt blocks of polygonatum series, the addition amount of the Chinese medicinal material water extract is 20% of the addition amount of milk; the volume ratio of polygonatum to other Chinese medicinal material water extracts is 3:(1-9). When preparing freeze-dried yogurt blocks of polygonatum and papaya, the volume ratio of polygonatum and papaya water extract is preferably 3:1; when preparing freeze-dried yogurt blocks of polygonatum and moutan bark, the volume ratio of polygonatum and moutan bark water extract is preferably 2:1; when preparing freeze-dried yogurt blocks of polygonatum and poria, the volume ratio of polygonatum and poria water extract is preferably 1:1; when preparing freeze-dried yogurt blocks of polygonatum and platycodon, the volume ratio of polygonatum and platycodon water extract is preferably 1:1; when preparing freeze-dried yogurt blocks of polygonatum and chrysanthemum, the volume ratio of polygonatum and chrysanthemum water extract is preferably 2:1.

[0054] The added amount of skimmed high-calcium high-protein milk powder is 5-9g, preferably 7g; the added amount of low-fat pectin is 0.3-0.7g, preferably 0.5g; the added amount of white sugar is 10.5-14.5g, preferably 12.5g.

[0055] In order to further illustrate the present invention, the technical solution provided by the present invention is described in detail below in conjunction with the accompanying drawings and embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0056] The white sugar of the present invention was purchased from Kunming Chan Xiaoya Food Co., Ltd.; low-fat pectin was purchased from Guangdong Zhida Biotechnology; yogurt fermentation bacteria powder was purchased from Qingdao Youbit Fermentation Engineering Co., Ltd.; the 12-piece pigment set was purchased from Lianyungang Xinai Food Technology Co., Ltd.; Yili pure milk was purchased from Hefei Yili Dairy Co., Ltd.; and skimmed high-calcium and high-protein milk powder was purchased from Inner Mongolia Jinhetao Dairy Co., Ltd.

[0057] The production processes, experimental methods or detection methods involved in the embodiments of the present invention, unless otherwise specified, are all conventional methods in the prior art, and their names and / or abbreviations are all conventional names in the field, and are very clear and unambiguous in the relevant application fields. Technical personnel in the field can understand the conventional process steps based on the names and apply the corresponding equipment, and implement them according to conventional conditions or the conditions recommended by the manufacturer.

[0058] The various instruments, equipment, raw materials or reagents used in the embodiments of the present invention are not particularly limited in terms of their sources, and are all conventional products that can be purchased through regular commercial channels, or can be prepared according to conventional methods well known to those skilled in the art.

[0059] Example 1 Preparation process of freeze-dried yogurt blocks

[0060] 1. Raw material pretreatment

[0061] Drying of medicinal materials: Place the medicinal materials in an oven and dry them until they are easily broken into pieces.

[0062] Powdering: Place the dried medicinal materials in a powdering machine for powdering and sifting.

[0063] Water extraction: Weigh a certain mass of medicinal powder and add ten times the mass of ultrapure water. Stir and soak for 30 minutes, heat in a water bath at 80 degrees and boil for 30 minutes. Take it out and cool to room temperature. Filter 1-2 times to obtain a crude extract, centrifuge it, and obtain the extract.

[0064] 2. Raw Materials Preparation

[0065] Sterilization: Place the obtained water extract and milk in 80-90 degree water for high temperature sterilization for half an hour to one hour, then take them out, cool them and place them in the cell room for ultraviolet sterilization for half an hour.

[0066] Mixed emulsion: Mix the sterilized water extract and sterilized milk, with the amount of water extract added being 20% ​​of the volume of the milk.

[0067] Inoculation: Add yogurt fermentation bacteria powder into the emulsion, add 1g yogurt fermentation bacteria powder to every 100ml milk, stir evenly to prevent contamination by miscellaneous bacteria.

[0068] Fermentation: Place the inoculated emulsion in a constant temperature incubator at 43 degrees Celsius and ferment for 10 to 12 hours.

[0069] Post-ripening: Move the fermented yogurt to a 4-degree refrigerated environment and the finished product will be obtained after one week of post-ripening.

[0070] 3. Dissolution of auxiliary materials and molding

[0071] Dissolution of auxiliary materials: Add 5-9g of skimmed high-calcium and high-protein milk powder, 0.3-0.7g of low-fat pectin, 10.5-14.5g of white sugar to the fermented yogurt, and add 0.5-1.5ml of a compound colorant to distinguish different types of products.

[0072] Liquid homogenization: After stirring the liquid evenly, let it stand for 10 minutes and wait for the bubbles to disappear.

[0073] Put into mold and tray: put the homogenized liquid into the mold and then put it into the tray.

[0074] 4. Pre-freezing and vacuum freeze drying

[0075] Prefreeze: Prefreeze at -20 degrees for 4 hours.

[0076] Freezing: Freeze at -80 degrees for 24 hours.

[0077] Freeze drying: After the frozen yogurt blocks are demolded, they are placed on a vacuum freeze dryer tray for vacuum drying and dehydration. The vacuum freeze drying time is 40 to 48 hours, and the temperature is -50°C. After completion, the freeze-dried yogurt blocks are obtained and finally demolded and packaged. The packaging of the freeze-dried yogurt blocks is shown in the figure below. Figure 1 shown.

[0078] The preparation process of Huangjing series freeze-dried yogurt blocks is as follows Figure 2 shown.

[0079] Example 2 Preparation of Polygonatum freeze-dried yogurt blocks

[0080] Under the conditions of 100ml milk, 12.5g white sugar, 1g yogurt fermentation powder, 7g skimmed high calcium and high protein milk powder, 0.5g low fat pectin, 0.5ml each of compound colorants lemon yellow, brown and orange yellow, fermentation temperature 43℃, fermentation time 12h, the amount of polygonatum extract added was 16, 18, 20, 22 and 24ml respectively, and the finished product of polygonatum freeze-dried yogurt block was as shown in the figure Figure 3 The finished product is subjected to sensory evaluation, and the sensory evaluation method is as follows Figure 4 shown.

[0081] like Figure 5 As shown, it can be seen that with the increase in the amount of Polygonatum sibiricum extract added, the product sensory score first increased and then decreased. When the amount of Polygonatum sibiricum extract added was 20ml, the sensory score was the highest. When the amount added was 24ml, the product taste was not obvious and the comprehensive score was low.

[0082] Example 3 Preparation of Polygonatum sibiricum-Xuan papaya freeze-dried yogurt blocks

[0083] Under the conditions of 100ml milk, 12.5g white sugar, 1g yogurt fermentation bacteria powder, 7g skim high calcium high protein milk powder, 0.5g low fat pectin, 1.5ml compound colorant cherry red, fermentation temperature 43℃, fermentation time 12h, total addition of polygonatum and papaya extracts 20%, the volume ratios of polygonatum and papaya extracts were 3:1, 2:1, 1:1, 1:2 and 1:3 respectively, and the polygonatum-papaya freeze-dried yogurt blocks were as follows Figure 5 As shown, and sensory evaluation is performed on it. The sensory evaluation method is as follows Figure 6 shown.

[0084] The addition amount of polygonatum and papaya extract was fixed at 20%, and the effect of the volume ratio of polygonatum and papaya extract on the polygonatum-papaya freeze-dried yogurt cubes was investigated. The results are shown in Figure 7 .Depend on Figure 8 It can be seen that as the volume ratio of polygonatum and papaya extract increases, the sensory score of freeze-dried yogurt blocks decreases; when the volume ratio of polygonatum and papaya extract is 3:1, the sensory score is the highest, which is 90.6 points. Under this condition, the appearance of the tissue state of the polygonatum-papaya freeze-dried yogurt block is free of particles and cracks, with appropriate hardness and small ice crystals; the color is uniform, shiny, and pink; the flavor of polygonatum-papaya is coordinated with the milk flavor and has no peculiar smell; the yogurt block has a delicate and crisp taste and appropriate sweetness and sourness. When the volume ratio of polygonatum-papaya extract continues to increase, the sensory score gradually decreases. The reason may be that with the increase in the amount of papaya, the papaya flavor is too heavy, which covers up the unique milk flavor of the yogurt block, and the taste experience is not good. In summary, the optimal volume ratio of polygonatum and papaya extract is 3:1.

[0085] Example 4 Preparation of Polygonatum sibiricum-Paeonia lactiflora freeze-dried yogurt blocks

[0086] Under the conditions of 100 ml of milk, 12.5 g of white sugar, 1 g of yogurt fermentation powder, 7 g of defatted high-calcium and high-protein milk powder, 0.5 g of low-fat pectin, 0.5 ml of compound colorants, bright red and brown, 43 °C of fermentation temperature, 12 h of fermentation time, and 20% of the total amount of polygonatum and moutan bark extracts, the volume ratios of polygonatum and moutan bark extracts were 3:1, 2:1, 1:1, 1:2 and 1:3, respectively, and sensory evaluation was carried out. The sensory evaluation method is as follows: Fig. 9 shown.

[0087] The addition amount of Polygonatum sibiricum and Cortex Moutan was fixed at 20%, and the effect of the volume ratio of Polygonatum sibiricum and Cortex Moutan on the freeze-dried yogurt cubes of Polygonatum sibiricum and Cortex Moutan was investigated. Fig.10 .Depend on Fig.10It can be seen that with the increase of the volume ratio of the extract of polygonatum and moutan bark, the sensory score of the freeze-dried yogurt blocks first increased and then decreased; when the volume ratio of the extract of polygonatum and moutan bark was 2:1, the sensory score was the highest, which was 90.3 points. Under this condition, the appearance of the tissue state of the polygonatum-moutan bark freeze-dried yogurt block was free of particles and cracks, with appropriate hardness and small ice crystals; the color was uniform, shiny, and red; the flavor of polygonatum-moutan bark and the milky flavor were coordinated and had no peculiar smell; the yogurt blocks had a delicate and crisp taste and appropriate sourness and sweetness. When the volume ratio of the polygonatum-moutan bark extract continued to increase, the sensory score first increased and decreased. The reason may be that with the increase of the amount of moutan bark, the taste of moutan bark was too heavy, the color was dark red, which covered the unique milky flavor of the yogurt block and the taste experience was not good. In summary, the optimal volume ratio of polygonatum and moutan bark extract was selected as 2:1.

[0088] Example 5 Preparation of Polygonatum sibiricum-Poria cocos freeze-dried yogurt blocks

[0089] Under the conditions of 100 ml milk, 12.5 g white sugar, 1 g yogurt fermentation bacteria powder, 7 g skimmed high calcium and high protein milk powder, 0.5 g low fat pectin, fermentation temperature 43 ° C, fermentation time 12 h, total addition of polygonatum and poria extracts 20%, the volume ratios of polygonatum and poria extracts were 3:1, 2:1, 1:1, 1:2 and 1:3 respectively, and sensory evaluation was carried out. The sensory evaluation method is as follows: Fig.11 shown.

[0090] The addition amount of Polygonatum sibiricum and Poria cocos extract was fixed at 20%, and the effect of the volume ratio of Polygonatum sibiricum and Poria cocos extract on the freeze-dried yogurt cubes of Polygonatum sibiricum and Poria cocos was investigated. Fig.12 .Depend on Fig.12 It can be seen that with the increase of the volume ratio of polygonatum and tuckahoe extract, the sensory score of freeze-dried yogurt blocks first increases and then decreases; when the volume ratio of polygonatum and tuckahoe extract is 1:1, the sensory score is the highest, which is 90.1 points. Under this condition, the appearance of the tissue state of polygonatum-tuckahoe freeze-dried yogurt blocks is free of particles and cracks, with appropriate hardness and small ice crystals; the color is uniform and shiny, white or light yellow; the flavor of polygonatum-tuckahoe and milk flavor are coordinated and have no peculiar smell; the yogurt blocks have a delicate and crisp taste and appropriate sweetness and sourness. When the volume ratio of polygonatum-tuckahoe extract continues to increase, the sensory score first increases and decreases. The reason may be that with the increase of the amount of tuckahoe, the tuckahoe flavor is too heavy, which masks the unique milk flavor of the yogurt blocks, and the taste experience is not good. In summary, the optimal volume ratio of polygonatum and tuckahoe extract is 1:1.

[0091] Example 6 Preparation of Polygonatum sibiricum-Planthoceras freeze-dried yogurt blocks

[0092] Under the conditions of 100ml milk, 12.5g white sugar, 1g yogurt fermentation bacteria powder, 7g skimmed high-calcium high-protein milk powder, 0.5g low-fat pectin, 1.5ml compound colorant taro purple, fermentation temperature 43℃, fermentation time 12h, total addition amount of polygonatum and platycodon extracts 20%, the volume ratios of polygonatum and platycodon extracts are 3:1, 2:1, 1:1, 1:2 and 1:3 respectively, and the finished product of polygonatum-platycodon freeze-dried yogurt blocks is shown in the figure Fig.13 As shown. And sensory evaluation is carried out on it. The sensory evaluation method is as follows Fig.14 shown.

[0093] The addition amount of Polygonatum sibiricum and Poria cocos extract was fixed at 20%, and the effect of the volume ratio of Polygonatum sibiricum and Poria cocos extract on the freeze-dried yogurt cubes of Polygonatum sibiricum and Poria cocos was investigated. Fig.15 .Depend on Fig.15 It can be seen that with the increase of the volume ratio of polygonatum and tuckahoe extract, the sensory score of freeze-dried yogurt blocks first increases and then decreases; when the volume ratio of polygonatum and tuckahoe extract is 1:1, the sensory score is the highest, which is 90.1 points. Under this condition, the appearance of the tissue state of polygonatum-tuckahoe freeze-dried yogurt blocks is free of particles and cracks, with appropriate hardness and small ice crystals; the color is uniform and shiny, white or light yellow; the flavor of polygonatum-tuckahoe and milk flavor are coordinated and have no peculiar smell; the yogurt blocks have a delicate and crisp taste and appropriate sweetness and sourness. When the volume ratio of polygonatum-tuckahoe extract continues to increase, the sensory score first increases and decreases. The reason may be that with the increase of the amount of tuckahoe, the tuckahoe flavor is too heavy, which masks the unique milk flavor of the yogurt blocks, and the taste experience is not good. In summary, the optimal volume ratio of polygonatum and tuckahoe extract is 1:1.

[0094] Example 7 Preparation of Polygonatum sibiricum-Chrysanthemum Freeze-dried Yogurt Blocks

[0095] Under the conditions of 100ml milk, 12.5g white sugar, 1g yogurt fermentation bacteria powder, 7g skimmed high calcium and high protein milk powder, 0.5g low fat pectin, 0.5ml compound colorant lemon yellow, fermentation temperature 43°C, fermentation time 12h, total addition amount of polygonatum and chrysanthemum extracts 20%, the volume ratios of polygonatum and chrysanthemum extracts were 3:1, 2:1, 1:1, 1:2 and 1:3 respectively, and the finished product of polygonatum-chrysanthemum freeze-dried yogurt block was as follows Fig.16 As shown, and sensory evaluation is performed on it. The sensory evaluation method is as follows Fig.17 shown.

[0096] The addition amount of polygonatum and chrysanthemum extract was fixed at 20%, and the effect of the volume ratio of polygonatum and chrysanthemum extract on the polygonatum-chrysanthemum freeze-dried yogurt cubes was investigated. The results are shown in Fig.18 .Depend on Fig.18It can be seen that with the increase of the volume ratio of polygonatum and chrysanthemum extract, the sensory score of freeze-dried yogurt blocks first increases and then decreases; when the volume ratio of polygonatum and chrysanthemum extract is 2:1, the sensory score is the highest, which is 91.4 points. Under this condition, the appearance of the tissue state of polygonatum-chrysanthemum freeze-dried yogurt blocks is free of particles and cracks, with appropriate hardness and small ice crystals; the color is uniform, shiny, and light yellow; the polygonatum-chrysanthemum flavor and milk flavor are coordinated and have no peculiar smell; the yogurt blocks have a delicate and crisp taste and appropriate sweetness and sourness. When the volume ratio of polygonatum-chrysanthemum extract continues to increase, the sensory score first increases and decreases. The reason may be that with the increase in the amount of chrysanthemum, the chrysanthemum flavor is too heavy, the color is orange-yellow, which covers up the unique milk flavor of the yogurt blocks, and the taste experience is not good. In summary, the optimal volume ratio of polygonatum and moutan bark extract is 2:1.

[0097] Example 8 Error Analysis

[0098] In order to further verify the accuracy of each addition amount and volume ratio obtained by the single factor experiment, the sensory scores of various types of freeze-dried yogurt blocks in Examples 2-7 were analyzed for errors. Fig.19 It can be seen that the error bar is smaller, that is, the smaller the range of variation between the observations, the smaller the discreteness of the data, the relatively concentrated observations, and the more accurate the data.

[0099] Example 9 Optimization Test

[0100] 1. Single factor test of excipients

[0101] Under the conditions of determining the ratio of each Chinese medicine extract of the series of Huangjing yogurt blocks, the ratio parameters with better sensory evaluation were selected by taking Huangjing freeze-dried yogurt blocks as an example. These parameters were floated up and down by 2 points each. When other factors remained unchanged, a single factor was changed. Taking sensory evaluation as an indicator, the effects of three factors on the sensory quality of Huangjing series yogurt blocks, namely, the addition of skim high calcium and high protein milk powder (3, 5, 7, 9 and 11g), the addition of low fat pectin (0.1, 0.3, 0.5, 0.7 and 0.9g) and the addition of white sugar (8.5, 10.5, 12.5, 14.5 and 16.5g) were investigated. The sensory evaluation table is shown in Table 1. When the addition of skim high calcium and high protein milk powder was 7g, the addition of low fat pectin was 0.5g and the addition of white sugar was 12.5g, the corresponding single factor test had the highest sensory score. Therefore, 5-9g of skimmed high-calcium and high-protein milk powder, 0.3-0.7g of low-fat pectin, and 10.5-14.5g of white sugar were selected for orthogonal optimization.

[0102] Table 1 Sensory evaluation table of excipients single factor test

[0103]

[0104] 2. Determination of the formula of main and auxiliary materials

[0105] Taking Polygonatum sibiricum freeze-dried yogurt cubes as an example, based on the single-factor experiment of auxiliary materials, the amount of Polygonatum sibiricum extract, the amount of skimmed high-calcium high-protein milk powder, the amount of low-fat pectin and the amount of white sugar were used as the investigation factors. The L9(34) orthogonal table was used to design a four-factor three-level experiment, and the sensory evaluation score was used as the indicator. The results of intuitive analysis and variance analysis are shown in Table 2.

[0106] Table 2 Orthogonal test results and intuitive analysis

[0107]

[0108]

[0109] It can be seen from Table 2 that the influence of each factor on the sensory evaluation is B>A>C>D, that is, the amount of skimmed high calcium and high protein milk powder added is the main factor affecting the sensory score, followed by the amount of polygonatum sibiricum extract added, the amount of low fat pectin added, and the amount of white sugar added. Through the analysis of the orthogonal test results, it can be seen that the A2B2C2D2 combination is the optimal combination. The optimal combination was verified and tested, and its comprehensive sensory score was 89 points, so the orthogonal test results are relatively reliable. Therefore, the ratio of the main and auxiliary materials is 20.0ml of polygonatum sibiricum extract, 7.0g of skimmed high calcium and high protein milk powder, 0.5g of low fat pectin and 12.5g of white sugar.

[0110] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A freeze-dried yogurt block, characterized in that: The freeze-dried yogurt block is prepared by mixed fermentation of polygonatum water extract and milk.

2. The freeze-dried yogurt block according to claim 1, characterized in that: The freeze-dried yogurt block also includes water extract of papaya, moutan bark, tuckahoe, platycodon or chrysanthemum.

3. The method for preparing the freeze-dried yogurt block according to claim 1, characterized in that: The specific steps include: S1. Raw material pretreatment: drying and grinding the Chinese medicinal materials into powder, and then boiling them in water to obtain water extract; S2, sterilizing the water extract and milk at high temperature, mixing them in proportion, inoculating yogurt fermentation bacteria powder, fermenting, and post-ripening to obtain a yogurt product; S3. Add skimmed high-calcium high-protein milk powder, low-fat pectin, white sugar and compound coloring agent to the finished yogurt, mix well, put into a mold plate, and obtain the freeze-dried yogurt block product through the process of pre-freezing, freezing and freeze-drying.

4. The preparation method according to claim 3, characterized in that: The water extract in step S1 is obtained by mixing powdered medicinal materials and ultrapure water in a mass ratio of 1:10, stirring and soaking for 30 minutes, heating in a water bath at 80° C. and then keeping it slightly boiling for 30 minutes, and cooling and filtering.

5. The preparation method according to claim 3, characterized in that: The amount of the water extract added in step S2 is 20% of the volume of the milk; 1 g of yogurt fermentation bacteria powder is added to every 100 ml of milk.

6. The preparation method according to claim 3, characterized in that: In step S2, the fermentation temperature is 43° C. and the fermentation time is 10 to 12 hours.

7. The preparation method according to claim 3, characterized in that: The post-ripening process in step S2 is to refrigerate the fermented yogurt at 4° C. for one week.

8. The preparation method according to claim 3, characterized in that: In step S3, the added amount of skimmed high-calcium high-protein milk powder is 5-9g, the added amount of low-fat pectin is 0.3-0.7g, the added amount of white sugar is 10.5-14.5g, and the added amount of the compound colorant is 0.5-1.5ml.

9. The preparation method according to claim 3, characterized in that: In step S3, the pre-freezing process is -20°C pre-freezing for 4 hours; the freezing process is -80°C freezing for 24 hours, the vacuum freeze drying time is 40 to 48 hours, and the temperature is -50°C.

10. Application of the preparation method according to claim 3 in preparing freeze-dried yogurt blocks, characterized in that: When preparing the polygonatum series freeze-dried yogurt blocks, the amount of the Chinese medicinal material water extract added is 20% of the amount of milk added; the volume ratio of polygonatum to other Chinese medicinal material water extracts is 3: (1-9).

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