Pure pear syrup capable of moistening lung to arrest cough and processing technology of pure pear syrup

Abstract

The invention belongs to the technical field of food and food processing, and relates to pure pear syrup for moistening lung to arrest cough and a processing technology thereof. The processing technology of the pure pear syrup comprises the steps of pretreatment, repeated freezing and thawing, pH gradient enzymolysis, vacuum concentration and the like, the bitter taste of the pear syrup is reduced by optimizing the technology, and the freshness and sweetness of the pure pear syrup are improved. The pure pear syrup is not added with preservatives, pigments, sweeteners and other additives, so that the risk that human bodies take in the chemical substances is reduced, and the pure pear syrup is safer and more reliable to eat.

Description

Technical Field

[0001] The invention belongs to the technical field of food and food processing, and specifically relates to pure pear paste for moistening lungs and relieving cough and a processing technology thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] As a common fruit, pears have always been considered to have the effects of moistening the lungs and relieving coughs, clearing away heat and reducing phlegm. Modern medical research has also shown that pears are rich in water, vitamins, minerals and dietary fiber, and have good health care effects. In traditional medicine, pears are believed to have the effects of moistening the lungs and relieving coughs, clearing away heat and reducing fire, and promoting body fluid and quenching thirst. Pears are sweet, slightly sour, cold in nature, non-toxic, and belong to the lung and stomach meridians. "Compendium of Materia Medica" records: "Pears are beneficial, and their nature is downward and smooth." Pears can cure wind-heat, moisten the lungs, cool the heart, eliminate phlegm, reduce fire, and detoxify. Modern medical research has also shown that pears contain a variety of vitamins and minerals, such as vitamin C, B vitamins, potassium, etc., and have antioxidant, anti-inflammatory, and immune-enhancing effects. However, despite the numerous health benefits of pears, in daily life, the way to eat pears is relatively single, and for some cough symptoms that require long-term treatment or relief, simply eating pears cannot meet their needs for fast and efficient treatment. Therefore, how to effectively retain and utilize the health benefits of pears has become an important research topic in the field of food and health products.

[0004] The Chinese patent with publication number CN 108719902 A discloses a cough-relieving pear paste and a preparation method thereof, comprising peeling and core-removing pears to obtain pear flesh, squeezing the pear flesh to obtain pear juice and pear residue, then mashing the pear residue with the pear skin and pear core to obtain pear juice, concentrating the squeezed pear juice and the extracted pear juice respectively and mixing them, and then mixing them with carrageenan to obtain pear paste. Studies have shown that excessive or long-term intake of carrageenan may have adverse effects on the stomach, the immune system, etc. The Chinese patent with publication number CN 110250469 A discloses a preparation method of pear paste, comprising the following steps: crushing the washed pears, squeezing them, and filtering them to obtain pear juice; boiling the concentrated pear juice, and the obtained concentrated liquid is centrifuged and filtered to remove impurities in turn to obtain a semi-finished product; using a four-effect downstream evaporator to evaporate and concentrate the semi-finished product to obtain a semi-finished pear paste; adding reduced glutathione to the semi-finished pear paste, mixing and stirring to obtain the pear paste. A Chinese patent with publication number CN 117044911A discloses a micro-fermented golden pear paste and a preparation method thereof, which uses enzymatic hydrolysis and probiotic micro-fermentation technology to increase the types of organic acids and the content of flavor substances while retaining antioxidant substances without adding sulfur-containing color preservatives.

[0005] However, the prior art of pear paste and preparation technology still has the following problems: (1) Complex ingredients: Many pear paste products contain a large amount of other ingredients, such as sugars and additives. Although these ingredients enhance the taste of the pear paste to a certain extent, they pose many problems in terms of food safety.

[0006] (2) Outdated processing technology: Traditional pear paste processing technology usually adopts the method of heating and concentration. This method is not only energy-intensive and time-consuming, but also easily destroys the nutrients and active substances in the pears, reducing the quality and efficacy of the pear paste. At the same time, the taste of bitter amino acids will be more obvious, affecting the taste and flavor of the product. Summary of the invention

[0007] It is currently known that tryptophan and phenylalanine are bitter amino acids in pears, which have a bitter effect on the overall taste. To overcome the deficiencies of the prior art, the present invention provides a pure pear paste with safe ingredients, no additives, good taste, and lung-moistening and cough-relieving effects, and its processing technology.

[0008] Specifically, the processing technology of the pure pear paste includes the following steps: (1) Peel and core the pears, cut the pear flesh into strips or cubes, and set aside; (2) After the processed pear flesh is repeatedly frozen and thawed, the thawed pear juice is collected; (3) extracting juice from the frozen and thawed pear pulp, subjecting it to pH gradient enzymatic hydrolysis, filtering it, and collecting the enzymatic hydrolyzed pear juice; (4) Mix the thawed pear juice and the enzymatically hydrolyzed pear juice, concentrate under reduced pressure, and filter to obtain pear paste.

[0009] Furthermore, the processing technology of the pure pear paste comprises the following steps: (1) Peel and core the pears, cut the pear flesh into strips or cubes, and set aside; (2) The processed pear flesh is frozen at -40℃±5℃ for 6~10h, thawed at 15℃±5℃ for 6~10h, frozen at -20℃±5℃ for 10~15h, thawed at 10℃±5℃ for 5~10h, frozen at -10℃±5℃ for 8~12h, thawed at 10℃±5℃ for 8~12h, and the thawed pear juice is collected and refrigerated at 2~8℃ for later use; (3) After the pear pulp is frozen and thawed, the juice is squeezed, and 2 to 4 times the volume of a cellulase hydrolyzing solution with a concentration of 5 to 15 U / ml is added to perform pH gradient hydrolysis for 4 to 8 hours, and then the hydrolyzed pear juice is filtered and collected; (4) Mix the thawed pear juice and the enzymatically hydrolyzed pear juice, concentrate under reduced pressure to a relative density of 1.25-1.35 (45°C), and filter to obtain pear paste.

[0010] Furthermore, the pH gradient enzymatic hydrolysis is adjusted with citric acid and water to: pH=3.0-4.0, enzymatic hydrolysis for 1-2 hours, pH=4.0-5.0, enzymatic hydrolysis for 1-2 hours, pH=5.0-6.0, enzymatic hydrolysis for 1-2 hours, pH=6.0-7.0, enzymatic hydrolysis for 1-2 hours.

[0011] The present invention also provides a pure pear paste prepared by the processing technology and use of the pure pear paste in preparing food with lung moistening and cough relieving effects.

[0012] Compared with the prior art, the technical effects of the present invention are: The pure pear paste of the present invention does not add preservatives, sweeteners, or pigments throughout the process, and only improves the taste through process control, which is in line with the trend of natural food. It also reduces the risk of human body ingestion of these chemicals, and is safer and more reliable for children, pregnant women, the elderly, and people with weak bodies to eat.

[0013] The invention improves the sweetness of the pear paste by reducing the bitter taste, breaking through the limitation of the traditional single enzymatic hydrolysis or boiling process. Specifically, through the synergistic effect of the repeated freeze-thaw pear juice collection method and the gradient pH enzymatic hydrolysis method, the tryptophan and phenylalanine contents in the pears are significantly reduced, and the conversion of arginine to bitter compounds is inhibited, thereby improving the freshness and sweetness of the pure pear paste. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The tryptophan content in the pure pear paste of Examples 1 to 3 and the pure pear paste of Comparative Examples 1 to 5.

[0015] Figure 2 The content of phenylalanine in the pure pear paste of Examples 1 to 3 and the pure pear paste of Comparative Examples 1 to 5.

[0016] Figure 3 It is the urea content in the pure pear paste of Example 1 to Example 3 and the pure pear paste of Comparative Example 1 to Comparative Example 5.

[0017] Figure 4 The taste scores of the pure pear pastes of Examples 1 to 3 and Comparative Examples 1 to 5 are shown.

[0018] Figure 5 This is a statistical chart of the number of coughs before and after taking pear paste. DETAILED DESCRIPTION

[0019] In order to make the purpose and technical solution of the present invention clearer, the present invention is further described below in conjunction with embodiments, but the protection scope of the present invention is not limited to these embodiments, and the embodiments are only used to explain the present invention. It should be understood by those skilled in the art that any changes or equivalent substitutions that do not deviate from the concept of the present invention are included in the protection scope of the present invention.

[0020] Embodiment 1 Pure pear paste and processing technology (1) Peel and core 1 kg of pears, cut the pear flesh into strips or cubes, and set aside; (2) The processed pear flesh was frozen at -40°C for 8 h, thawed at 15°C for 8 h, frozen at -20°C for 12 h, thawed at 10°C for 8 h, frozen at -10°C for 10 h, and thawed at 10°C for 10 h. All thawed pear juice was collected and refrigerated at 4°C for later use; (3) After the pear pulp was squeezed after freezing and thawing, 3 volumes of 10U / ml cellulase enzymatic hydrolysis solution were added to perform pH gradient enzymatic hydrolysis using citric acid, pH = 3.5, enzymatic hydrolysis for 1.5 h, add appropriate amount of water to adjust pH = 4.5, enzymatic hydrolysis for 1.5 h, add appropriate amount of water to adjust pH = 5.5, enzymatic hydrolysis for 1.5 h, add appropriate amount of water to adjust pH = 6.5, enzymatic hydrolysis for 1.5 h, filter and collect the enzymatic hydrolyzed pear juice; (4) Mix the thawed pear juice and the enzymatically hydrolyzed pear juice, concentrate under reduced pressure to a relative density of 1.3, and filter to obtain 260 g of pear paste.

[0021] Embodiment 2 Pure pear paste and processing technology (1) Peel and core 1 kg of pears, cut the pear flesh into strips or cubes, and set aside; (2) The processed pear flesh was frozen at -45°C for 6 h, thawed at 10°C for 6 h, frozen at -25°C for 10 h, thawed at 5°C for 5 h, frozen at -5°C for 8 h, and thawed at 5°C for 8 h. All thawed pear juice was collected and refrigerated at 2°C for later use; (3) After the pear pulp was squeezed after freezing and thawing, 2 volumes of 15 U / ml cellulase enzymatic hydrolysis solution were added to perform pH gradient enzymatic hydrolysis using citric acid, pH = 3.0, enzymatic hydrolysis for 1 hour, adding appropriate amount of water to adjust pH = 4.0, enzymatic hydrolysis for 1 hour, adding appropriate amount of water to adjust pH = 5.0, enzymatic hydrolysis for 1 hour, adding appropriate amount of water to adjust pH = 6.0, enzymatic hydrolysis for 1 hour, filtering, and collecting the enzymatic hydrolyzed pear juice; (4) Mix the thawed pear juice and the enzymatically hydrolyzed pear juice, concentrate under reduced pressure to a relative density of 1.25, and filter to obtain 242 g of pear paste.

[0022] Embodiment 3 Pure pear paste and processing technology (1) Peel and core 1 kg of pears, cut the pear flesh into strips or cubes, and set aside; (2) The processed pear flesh was frozen at -35°C for 10 h, thawed at 20°C for 10 h, frozen at -15°C for 15 h, thawed at 5°C for 10 h, frozen at -5°C for 12 h, and thawed at 15°C for 12 h. All thawed pear juice was collected and refrigerated at 8°C for later use; (3) After the pear pulp was squeezed after freezing and thawing, 4 times the volume of 5U / ml cellulase enzymatic solution was added to perform pH gradient enzymatic hydrolysis using citric acid, pH = 4.0, enzymatic hydrolysis for 2 h, adding appropriate amount of water to adjust pH = 5.0, enzymatic hydrolysis for 2 h, adding appropriate amount of water to adjust pH = 6.0, enzymatic hydrolysis for 2 h, adding appropriate amount of water to adjust pH = 7.0, enzymatic hydrolysis for 2 h, filtering, and collecting the enzymatic hydrolyzed pear juice; (4) Mix the thawed pear juice and the enzymatically hydrolyzed pear juice, concentrate under reduced pressure to a relative density of 1.35, and filter to obtain 253 g of pear paste.

[0023] Comparative Example 1 Pure pear paste and processing technology (1) Peel and core 1 kg of pears, cut the pear flesh into strips or cubes, and set aside; (2) After the pear pulp is squeezed, 3 volumes of 10U / ml cellulase hydrolyzate are added to perform pH gradient hydrolysis using citric acid, pH = 3.5, hydrolyze for 1.5 h, add appropriate amount of water to adjust pH = 4.5, hydrolyze for 1.5 h, add appropriate amount of water to adjust pH = 5.5, hydrolyze for 1.5 h, add appropriate amount of water to adjust pH = 6.5, hydrolyze for 1.5 h, filter and collect the hydrolyzed pear juice; (3) Mix the thawed pear juice and the enzymatically hydrolyzed pear juice, concentrate under reduced pressure to a relative density of 1.3, and filter to obtain 179 g of pear paste.

[0024] Comparative Example 2 Pure pear paste and processing technology (1) Peel and core 1 kg of pears, cut the pear flesh into strips or cubes, and set aside; (2) The processed pear flesh was frozen at -20°C for 12 h, thawed at 10°C for 8 h, and frozen at -10°C for 10 h. The thawed pear juice was collected and refrigerated at 4°C for later use; (3) After the pear pulp was squeezed after freezing and thawing, 3 volumes of 10U / ml cellulase enzymatic hydrolysis solution were added to perform pH gradient enzymatic hydrolysis using citric acid, pH = 3.5, enzymatic hydrolysis for 1.5 h, add appropriate amount of water to adjust pH = 4.5, enzymatic hydrolysis for 1.5 h, add appropriate amount of water to adjust pH = 5.5, enzymatic hydrolysis for 1.5 h, add appropriate amount of water to adjust pH = 6.5, enzymatic hydrolysis for 1.5 h, filter and collect the enzymatic hydrolyzed pear juice; (4) Mix the thawed pear juice and the enzymatically hydrolyzed pear juice, concentrate under reduced pressure to a relative density of 1.3, and filter to obtain 203 g of pear paste.

[0025] Comparative Example 3: Pure pear paste and processing technology (1) Peel and core 1 kg of pears, cut the pear flesh into strips or cubes, and set aside; (2) The processed pear flesh was frozen at -40°C for 8 h, thawed at 15°C for 8 h, frozen at -20°C for 12 h, thawed at 10°C for 8 h, frozen at -10°C for 10 h, and thawed at 10°C for 10 h. All thawed pear juice was collected and refrigerated at 4°C for later use; (3) After the pear pulp is frozen and thawed, juice is squeezed, and 3 times the volume of 10U / ml cellulase enzymatic solution is added, and the pH is adjusted to 4.5 by citric acid for enzymatic hydrolysis, and then the enzymatic hydrolyzed pear juice is filtered and collected; (4) Mix the thawed pear juice and the enzymatically hydrolyzed pear juice, concentrate under reduced pressure to a relative density of 1.3, and filter to obtain 210 g of pear paste.

[0026] Comparative Example 4 Pure pear paste and processing technology (1) Peel and core 1 kg of pears, cut the pear flesh into strips or cubes, and set aside; (2) The processed pear flesh was frozen at -40°C for 8 h, thawed at 15°C for 8 h, frozen at -20°C for 12 h, thawed at 10°C for 8 h, frozen at -10°C for 10 h, and thawed at 10°C for 10 h. All thawed pear juice was collected and refrigerated at 4°C for later use; (3) After the pear pulp was squeezed after freezing and thawing, 3 volumes of 10 U / ml cellulase hydrolyzate were added and pH gradient hydrolysis was performed using citric acid: pH = 6.5, hydrolysis for 1.5 h, pH = 5.5, hydrolysis for 1.5 h, pH = 4.5, hydrolysis for 1.5 h, pH = 3.5, hydrolysis for 1.5 h, filtration, collection of hydrolyzed pear juice and adjustment of pH to neutral; (4) Mix the thawed pear juice and the enzymatically hydrolyzed pear juice, concentrate under reduced pressure to a relative density of 1.3, and filter to obtain 185 g of pear paste.

[0027] Comparative Example 5 Pure pear paste and processing technology (1) Peel and core 1 kg of pears, cut the pear flesh into strips or cubes, and set aside; (2) Squeeze the processed pear juice, add appropriate amount of water, simmer at 80°C until the relative density is 1.3, filter, and obtain 167g of pear paste.

[0028] The contents of tryptophan, phenylalanine and urea in pure pear paste were determined by HPLC.

[0029] Figure 1 The tryptophan content in the pure pear paste of Examples 1 to 3 and the pure pear paste of Comparative Examples 1 to 5, Figure 2 The content of phenylalanine in the pure pear paste of Examples 1 to 3 and the pure pear paste of Comparative Examples 1 to 5 is shown in Table 1. Since the pure pear paste of the present invention does not contain any flavoring agent or additive, it is difficult to cover up the bitter taste by adding sugar. When the content of tryptophan and phenylalanine in the pear paste is high, it will bring bitterness and affect the taste. Figure 1~Figure 2 The data show that the repeated freeze-thaw and gradient pH enzymatic hydrolysis process of the present invention has a great influence on the content of tryptophan and phenylalanine in pure pear paste, and can effectively reduce the content of tryptophan and phenylalanine in pure pear paste, and restore the sweet taste of fresh pears themselves.

[0030] Arginine generally does not have a noticeable bitter taste. In terms of taste, it usually does not cause a noticeable bitter taste due to the high arginine content. However, studies have found that during the processing process, the arginine in pears will degrade or transform itself due to factors such as high temperature and pH changes. For example, arginine may be converted into ornithine and urea under certain conditions. Urea will produce a bitter taste, which will affect the taste. Figure 3 The urea content in the pure pear paste of Example 1 to Example 3 and the pure pear paste of Comparative Example 1 to Comparative Example 5 shows that the present invention optimizes the preparation process, avoids the high temperature process, effectively inhibits the conversion of arginine to urea through repeated freeze-thaw and gradient pH enzymatic hydrolysis process, avoids the formation of bitter substances, and improves the taste of the pure pear paste.

[0031] Sensory quality evaluation 5.0 g of pure pear paste of Examples 1 to 3 and pure pear paste of Comparative Examples 1 to 5 were taken respectively, placed in each evaluation cup, and 300 ml of water at a temperature of 45° C. was added for brewing. 20 volunteers were asked to taste the pear paste beverages, score them between 0 and 10 points, and statistical analysis was performed. Figure 4 The taste scores of the pure pear pastes of Examples 1 to 3 and Comparative Examples 1 to 5 are shown. Through SPSS analysis, the taste scores of the pure pear pastes of Examples 1 to 3 and any one of the pure pear pastes of Comparative Examples 1 to 5 are significantly different, P < 0.01.

[0032] Pure pear paste has the effect of moistening the lungs and relieving cough For the subjects suffering from pharyngitis and cough, the number of coughs in a fixed period of time was counted. After SPSS analysis, 20 subjects with no significant difference were selected. Among them, 10 subjects brewed 5.0g of pure pear paste of Example 1 twice a day, and the other 10 subjects brewed 5.0g of pure pear paste of Comparative Example 5 twice a day for 3 consecutive days. The number of coughs in the same period was counted and compared. Figure 5 The statistical graph of the number of coughs before and after taking the pear paste proves that the pure pear paste of the present invention has a significant effect of relieving cough and moistening the lungs.

Claims

1. A processing technology for pure pear paste, characterized in that: The processing technology of the pure pear paste comprises the following steps: (1) Peel and core the pears, cut the pear flesh into strips or cubes, and set aside; (2) After the processed pear flesh is repeatedly frozen and thawed, the thawed pear juice is collected; (3) extracting juice from the frozen and thawed pear pulp, subjecting it to pH gradient enzymatic hydrolysis, filtering it, and collecting the enzymatic hydrolyzed pear juice; (4) Mix the thawed pear juice and the enzymatically hydrolyzed pear juice, concentrate under reduced pressure, and filter to obtain pear paste.

2. The processing technology of pure pear paste according to claim 1, characterized in that: The processing technology of the pure pear paste comprises the following steps: (1) Peel and core the pears, cut the pear flesh into strips or cubes, and set aside; (2) The processed pear flesh is frozen at -40℃±5℃ for 6~10h, thawed at 15℃±5℃ for 6~10h, frozen at -20℃±5℃ for 10~15h, thawed at 10℃±5℃ for 5~10h, frozen at -10℃±5℃ for 8~12h, thawed at 10℃±5℃ for 8~12h, and the thawed pear juice is collected and refrigerated at 2~8℃ for later use; (3) After the pear pulp is frozen and thawed, juice is squeezed, and 2 to 4 times the volume of a cellulase hydrolyzing solution with a concentration of 5 to 15 U / ml is added for pH gradient enzymatic hydrolysis, and then the enzymatic hydrolyzed pear juice is collected by filtering; (4) Mix the thawed pear juice and the enzymatically hydrolyzed pear juice, concentrate under reduced pressure, and filter to obtain pear paste.

3. The processing technology of pure pear paste according to claim 1 or 2, characterized in that: The pH gradient enzymolysis is as follows: pH=3.0-4.0, enzymolysis for 1-2 hours, pH=4.0-5.0, enzymolysis for 1-2 hours, pH=5.0-6.0, enzymolysis for 1-2 hours, pH=6.0-7.0, enzymolysis for 1-2 hours.

4. The processing technology of pure pear paste according to claim 3, characterized in that: The pH gradient enzymatic hydrolysis is as follows: pH=3.5, enzymatic hydrolysis for 1.5 h, pH=4.5, enzymatic hydrolysis for 1.5 h, pH=5.5, enzymatic hydrolysis for 1.5 h, pH=6.5, enzymatic hydrolysis for 1.5 h.

5. The processing technology of pure pear paste according to claim 1, characterized in that: The pH gradient enzymatic hydrolysis was adjusted using citric acid and water.

6. The processing technology of pure pear paste according to claim 2, characterized in that: The concentration of cellulase in the enzymatic hydrolysis solution is 10 U / ml.

7. The processing technology of pure pear paste according to claim 1, characterized in that: The repeated freezing and thawing program is: freezing at -40°C for 8 hours, thawing at 15°C for 8 hours, freezing at -20°C for 12 hours, thawing at 10°C for 8 hours, freezing at -10°C for 10 hours, and thawing at 10°C for 10 hours.

8. The processing technology of pure pear paste according to claim 1, characterized in that: The reduced pressure concentration is to a relative density of 1.25 to 1.

35.

9. A pure pear paste, characterized in that: The pure pear paste is prepared according to the processing technology of pure pear paste according to any one of claims 1 to 8.

10. Use of the pure pear paste according to claim 9 in preparing food having lung-moistening and cough-relieving effects.

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