Evaluation method for processing quality grade of fresh rhizome of edible polygonatum cyrtonema

Abstract

The invention relates to a polygonatum cyrtonema fresh rhizome processing quality grade evaluation method, which is characterized in that a production enterprise only needs to detect seven content values of polysaccharides, total saponins, total phenols, total flavonoids, reducing sugar, crude protein and crude fat of processed polygonatum cyrtonema rhizomes by themselves or entrusting a third-party mechanism, and then can calculate and evaluate by themselves; the method is simple and easy to learn, convenient to operate, high in precision, high in efficiency and low in cost, can be widely applied to quality self-evaluation of edible polygonatum cyrtonema production enterprises and separation of superior and inferior products, is beneficial to grading sales of edible polygonatum cyrtonema products, improves the added value of the products, and meets the demand of consumers for purchase according to needs.

Description

Technical Field

[0001] The invention belongs to the technical field of determination and evaluation of agricultural product processing components, and specifically relates to a method for evaluating the processing quality grade of fresh rhizomes of edible Polygonatum cyrtonema. Background Art

[0002] Polygonatum multiflorum is one of the three original plants of Chinese medicinal material Polygonatum sibiricum. It has the effects of replenishing qi and nourishing yin, strengthening the spleen, moistening the lungs, and benefiting the kidneys. It is used to treat spleen and stomach qi deficiency, fatigue, insufficient stomach yin, dry mouth and poor appetite, lung deficiency and dry cough, insufficient essence and blood, soreness of waist and knees, premature graying of hair, internal heat and thirst, etc. Modern pharmacological research shows that Polygonatum sibiricum has pharmacological effects such as anti-aging, anti-fatigue, antioxidant, anti-tumor, anti-inflammatory, antibacterial, hypoglycemic, hypolipidemic, anti-atherosclerosis, and memory enhancement and improvement. In ancient times, people were very particular about processing rhizomes of Polygonatum sibiricum, and the processing (processing) methods were also very rich, including one steaming and one drying method, nine steaming and nine drying methods, de-mesh and double steaming method, black bean co-cooking method, Vitex rotundifolia co-steaming method, etc. At present, the processing of edible rhizomes of Polygonatum cyrtonema in the domestic market mostly adopts the method of steaming or steaming and baking. The number of steaming (baking) varies from 1 to 9 times, and the quality of processed products is uneven. The quality indicators of processed rhizomes mainly refer to the indicators of ordinary foods, such as ash content, moisture, energy, vitamins and main mineral elements, etc., which do not reflect the characteristics that edible rhizomes of Polygonatum cyrtonema should have as superfoods (longevity foods), and lack the corresponding evaluation standards for the processing quality of edible rhizomes of Polygonatum cyrtonema. Polygonatum cyrtonema has been used as a food for health and longevity since ancient times. In addition to polysaccharides, its health and longevity ingredients also include total saponins, total phenols, total flavonoids, reducing sugars, crude protein and other effective ingredients. At present, the industry still lacks a reasonable evaluation method for the processing quality grade of edible rhizomes of Polygonatum cyrtonema from multiple effective ingredients, taste, color and other aspects, so as to effectively distinguish the superior and inferior products of edible Polygonatum cyrtonema. Summary of the invention

[0003] The patent of the present invention provides a method for evaluating the processing quality grade of fresh rhizomes of Polygonatum cyrtonema after multiple steaming and drying (drying), which solves the problem of the lack of a comprehensive evaluation method for the processing quality of edible rhizomes of Polygonatum cyrtonema.

[0004] The method for evaluating the processing quality grade of fresh rhizomes of Polygonatum cyrtonema adopts the following technical scheme:

[0005] The preparation method of fresh rhizomes of Polygonatum cyrtonema by multiple steaming and drying or steaming and sun-drying comprises the following steps:

[0006] S11. Rhizome selection: fresh rhizomes of Polygonatum cyrtonema planted for two years or more are selected as processing raw materials;

[0007] S12. rhizome processing: washing the fresh rhizome of Polygonatum cyrtonema once or twice using a washing device, removing sand and roots to obtain fresh rhizome with skin; or washing the fresh rhizome of Polygonatum cyrtonema once or three times using a washing device, removing sand, roots and skin to obtain fresh rhizome with skin removed;

[0008] S13. Number of times of rhizome processing: using a steamer and oven to repeatedly steam and dry the rhizome 1 to 9 times, with one steaming and drying being counted as one time; or using a wooden steamer and drying room to repeatedly steam and dry the rhizome 1 to 9 times, with one steaming and drying being counted as one time;

[0009] S14. Sorting: According to the size of the rhizomes of Polygonatum cyrtonema, sieves with different aperture diameters are selected for sorting and classification packaging;

[0010] S15. Quality evaluation: After the products are classified, they are self-inspected or sent for inspection, and the quality level is evaluated according to the following steps;

[0011] The method for evaluating the processing quality grade of fresh rhizomes of Polygonatum cyrtonema comprises the following steps:

[0012] S21. Select the fresh rhizomes of Polygonatum cyrtonema that have been steamed or dried for 1 to 9 times and processed into finished products;

[0013] S22. The evaluation indicators include at least polygonatum polysaccharide, total saponin, total phenol, total flavonoids, reducing sugar, protein and crude fat;

[0014] S23. Evaluation index determination methods include:

[0015] The anthrone-sulfuric acid method was used to determine the content of polygonatum polysaccharide, and glucose was used as a reference substance to determine the content of polygonatum polysaccharide (%);

[0016] The total saponins were determined by the vanillin glacial acetic acid method, and the total saponins content (mg·g-1) was determined using ginsenoside Rb1 as a reference;

[0017] The total phenols were determined by the Folin-phenol method, and the total phenol content (mg·g-1) was determined using gallic acid as a reference;

[0018] The total flavonoids were determined by aluminum chloride colorimetric method, and the total flavonoids content (mg·g-1) was determined using rutin as reference substance;

[0019] The reducing sugar content (%) was determined by the DNS method using glucose as the reference substance;

[0020] Protein (%) was determined by Kjeldahl method using H2SO4 standard acid titration solution;

[0021] Crude fat was determined by Soxhlet extraction, and crude fat content (%) was determined by gravimetric method;

[0022] S24. Evaluation methods include:

[0023] The first step is to calculate the rhizome mass value; substitute the test values ​​of polysaccharides, total saponins, total phenols, total flavonoids, reducing sugars, proteins and crude fats into the formula to calculate the rhizome mass value (Y). The calculation formula is:

[0024] Y=13.3253+0.5533X2+0.0782X3+1.3453X4+30.4549X5+0.2654X6+1.0778X7+6.1582X8. Among them: X2 is polysaccharide content, X3 is total saponin content, X4 is total phenol content, X5 is total flavonoid content, X6 is reducing sugar content, X7 is crude protein content, and X8 is crude fat content;

[0025] The second step is to conduct quality evaluation. According to the calculated rhizome quality value and the sensory requirements of the processed rhizome, the quality of the processed product is evaluated as superior, qualified or unqualified.

[0026] The product grade is superior, and the quality value is required to be greater than or equal to 75.0; the product sensory requirements are that the root is sweet, has no throat irritation, no raw taste, and the surface and cross section are black or bright black;

[0027] The product grade is qualified, and the quality value is required to be greater than or equal to 65.0 and less than 75.0; the product sensory requirements are that the root is sweet, has no throat irritation, no raw taste, and the surface and cross section are black;

[0028] The product grade is unqualified, and the quality value requirement is less than 65.0; the product sensory requirements are that the rhizome is sweet, has a pungent or raw taste, and the cross-section is black-brown, yellow-brown, or brown-yellow.

[0029] 1) Evaluation object: products of fresh rhizomes of Polygonatum cyrtonema that have been steamed and dried or steamed and sun-dried for 1 to 9 times.

[0030] 2) Evaluation indicators: Polygonatum sibiricum polysaccharide, total saponins, total phenols, total flavonoids, reducing sugar, protein, and crude fat, a total of 7.

[0031] 3) Determination method: The content of polygonatum polysaccharide was determined by the anthrone-sulfuric acid method in the 2020 edition of the Chinese Pharmacopoeia, with glucose as the reference substance. The total saponin content was determined by the vanillin-glacial acetic acid method, with ginsenoside Rb1 as the reference substance. The total phenol content was determined by the Folin phenol colorimetric method, with gallic acid as the reference substance. The total flavonoid content was determined by the aluminum chloride colorimetric method, with rutin as the reference substance. The reducing sugar content was determined by referring to GB / T 5009.7-2003 Determination of reducing sugar in food. The protein content was determined by referring to GB / T 6432-2018 Determination of crude protein in feed. The crude fat content was determined by referring to GB / T 14772-2008 Determination of crude fat in food.

[0032] 4) Evaluation level: According to the quality value and product taste and appearance of fresh rhizomes of Polygonatum cyrtonema after processing, it is divided into three levels: superior, qualified, and unqualified (see Table 1). Evaluation criteria: It must meet the requirements of both quality value and product appearance.

[0033] Table 1 Quality grades of fresh rhizomes of Polygonatum cyrtonema

[0034]

[0035] 5) Evaluation method: Substitute the relevant test data into the rhizome quality value calculation formula to obtain the rhizome quality value, and then evaluate the quality of the processed rhizome as superior, qualified or unqualified according to the requirements of Table 1. Rhizome quality value Y = 13.3253 + 0.5533X2 + 0.0782X3 + 1.3453X4 + 30.4549X5 + 0.2654X 6+ 1.0778X 7+ 6.1582X8. Among them, X2 is the polysaccharide content, X3 is the total saponin content, X4 is the total phenol content, X5 is the total flavonoid content, X6 is the reducing sugar content, X7 is the crude protein content, and X8 is the crude fat content.

[0036] The beneficial effects of the patent of the present invention are: the provided method for evaluating the processing quality grade of edible Polygonatum cyrtonema rhizomes, the production enterprise only needs to detect the seven content values ​​of polysaccharides, total saponins, total phenols, total flavonoids, reducing sugars, crude protein and crude fat of the processed Polygonatum cyrtonema rhizomes by itself or entrust a third-party agency to calculate and evaluate by itself; it is simple and easy to learn, easy to operate, high in precision, high in efficiency, and low in cost, and can be widely used for self-evaluation of quality of edible Polygonatum production enterprises to distinguish good and bad products; it is conducive to the sales of edible Polygonatum cyrtonema products by grade, providing product added value, and meeting the needs of consumers to purchase on demand. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below in conjunction with tests and examples.

[0038] Experimental study 1

[0039] 1.1 Test materials

[0040] The rhizomes of Polygonatum cyrtonema were from the field planting base of Hezhuang Village, Biaoxi Township, Jingning County, Zhejiang Province, at an altitude of 780m, and the planting time was 4 years. Glucose standard (batch number: P-012-180222, HPLC ≥ 98%, Chengdu Ruifensi Biotechnology Co., Ltd.); rutin reference (batch number: 19010202, UV ≥ 98%), gallic acid reference (batch number: 18032801, HPLC ≥ 99.04%), were purchased from Chengdu Institute of Biology, Chinese Academy of Sciences; ginsenoside Rb1 reference (batch number: 129K024, HPLC ≥ 98%, Beijing Solaibao Technology Co., Ltd.). Anthrone, vanillin, sodium carbonate, aluminum chloride, potassium acetate, ferric chloride, sodium acetate, potassium sodium tartrate, redistilled phenol, sodium sulfite, sodium hydroxide, boric acid, ammonium sulfate, copper sulfate pentahydrate, sodium sulfate, sucrose, bromocresol green, methyl red, 30% hydrogen peroxide, hydrochloric acid, concentrated sulfuric acid, glacial acetic acid, perchloric acid, folin phenol, petroleum ether, methanol, ethanol and other reagents were all domestically produced analytical grade.

[0041] 1.2 Instruments and Equipment

[0042] ME204 electronic analytical balance; DK-8D three-temperature three-control water tank; DKS electric constant temperature water bath; DLSB-5L / 20 low temperature cooling circulation pump; DHG-9140A electric blast drying oven; KQ-500VDE three-frequency digital control ultrasonic cleaner; Cary60 ultraviolet spectrophotometer; XB70 ice maker; TF-IFD single-person single-sided fume hood; ME204 electronic analytical balance; FOSS digester; KjeltecTM 8100 FOSS automatic Kjeldahl nitrogen analyzer; ST 243Soxtec TM Soxhlet Extractor.

[0043] 1.3 Test methods

[0044] A three-factor completely randomized block experiment with three repetitions was designed. The first experimental factor was the treatment method of rhizome bark (A), with two experimental levels: root and bark removed (A1) and root and bark removed (A2); the second experimental factor was the processing equipment (B), with two experimental levels: modern processing equipment (B1) and traditional processing equipment (B2); the third experimental factor was the number of processing times (C), with one steaming and one drying (drying) as one time, and a total of 9 processing times (C1-C9). It can be classified into 4 different processing methods, namely, modern processing equipment peeling processing method (A1B1C), traditional processing equipment peeling processing method (A1B2C), modern processing equipment with bark processing method (A2B1C), and traditional processing equipment with bark processing method (A2B2C).

[0045] Among them: A1B1C, first use automatic cleaning equipment to clean the rhizomes of Polygonatum cyrtonema, remove sand, roots and skin, and then use stainless steel steaming cabinet and oven to steam and dry the rhizomes of Polygonatum cyrtonema, one steaming and one drying is one time, steaming for 1 to 3 hours after steaming (the time decreases with the increase of the number of times, the same below), and drying until half dry (the skin is dry and not sticky), steaming and drying for 9 times in total, and sampling 500g for component analysis after each steaming and drying, and the samples are recorded as A1B1C1 to A1B1C9 in sequence, and the control (A1B1C0) is the peeled rhizomes that have not been processed after washing;

[0046] A1B2C, first use automatic cleaning equipment to clean the rhizomes of Polygonatum cyrtonema, remove sand, roots and skin, and then use traditional wooden rice steamer and glass clean drying room to steam and dry the rhizomes of Polygonatum cyrtonema, one steaming and one drying is one time, steam for 1 to 3 hours after steaming, and dry until semi-dry (the skin is dry and not sticky), steam and dry for 9 times in total, and take 500g of samples for component analysis after each steaming and drying. The samples are recorded as A1B2C1 to A1B2C9 in sequence, and the control (A1B2C0) is the peeled rhizomes that have not been processed after washing;

[0047] A2B1C, first use automatic cleaning equipment to clean the rhizomes of Polygonatum cyrtonema, remove sand and roots, and then use stainless steel steaming cabinet and oven to repeatedly steam and dry the rhizomes with skin for 9 times, each time for 1 to 3 hours, and each time until half dry (the epidermis is dry and not sticky). After each steaming and drying, 500g of samples are taken for component analysis. The samples are recorded as A2B1C1 to A2B1C9 in sequence, and the control (A2B1C0) is the unprocessed rhizomes with skin after washing;

[0048] A2B2C, the rhizomes of Polygonatum cyrtonema were first cleaned with automatic cleaning equipment, and after removing the sand and roots, they were steamed and dried in a traditional wooden rice steamer and a glass clean drying room. A total of 9 steamings were performed, each time for 1 to 3 hours, and each time they were dried until semi-dry (the skin was dry and not sticky). After each steaming and drying, 500 g of samples were taken for component analysis. The samples were recorded as A2B2C1 to A2B2C9, and the control (A2B2C0) was the unprocessed rhizomes with skin after washing.

[0049] 1.4 Detection indicators and methods

[0050] Determine the content of extracts and Polygonatum sibiricum polysaccharides in the samples according to the relevant methods in the Chinese Pharmacopoeia (2020 edition) [1] , reducing sugar was determined according to the method in the relevant literature [8] , total saponins [9-10] , total phenol

[11] , total flavonoids

[12] ,protein

[13] and crude fat

[14] Each sample was tested 3 times.

[0051] Statistical analysis

[0052] SPSS25.0 statistical software was used to perform statistical analysis on the relevant data. The variance analysis of the rhizome mass values ​​of 20 different treatments in the de-meshing and re-steaming method (A1B1C, A1B2C) and the nine-steaming and nine-exposure method (A2B1C, A2B2C) was performed using the two-factor randomized block LSD method for multiple comparisons; the variance analysis of the rhizome mass values ​​of 40 different treatments was performed using the multi-factor randomized block LSD method for multiple comparisons. The formula for calculating the rhizome mass value of each treatment is as follows:

[0053] Among them: X1~X8 are the quality values ​​of extract, polysaccharide, total saponin, total phenol, total flavonoid, reducing sugar, protein and crude fat respectively, and the maximum score of each test index is 12.5 points. The full score of Y is 100 points.

[0054] The quality values ​​of each treatment are calculated in two groups: the de-meshing and re-steaming method (A1B1C, A1B2C) and the nine-steaming and nine-exposure method (A2B1C, A2B2C). The quality value formula is X i =X n / X 0* 12.5, where X n Refers to the detection index value of each treatment; X0 is the highest value of the same detection index in each group.

[0055] 1.5 Experimental study results

[0056] Through the dominant analysis and optimal combination analysis of the data in Table 2 and Table 3, the results show that, except for X3 which has no significant correlation with rhizome quality (p=0.8202>0.05), the other 7 variables are extremely significantly correlated with rhizome quality (p<0.01); the correlation coefficients Ra of introducing 1 variable, 2 variables, 3 variables, 4 variables, 5 variables, 6 variables, 7 variables, and 8 variables are 0.9383, 0.9552, 0.9670, 0.9746, 0.9814, 0.9888, 0.9965, and 0.9964, respectively. Among them, the regression equation introducing 7 variables is the best.

[0057] Y=13.3253+0.5533X2+0.0782X3+1.3453X4+30.4549X5+0.2654X 6+ 1.0778X 7+ 6.1582X8, the contribution rate of the six variables to the root mass is 92.38%. After inspection, the difference between the mass value of the equation and the actual mass value is only 0.0036, and the accuracy is as high as 99.99% (Table 4).

[0058] Table 2 Comparison of the quality differences of Polygonatum cyrtonema rhizomes in the two-factor experiment of “de-mesh re-steaming method”

[0059]

[0060]

[0061] Note: Capital letters indicate that there are significant differences in product quality between different treatments at the 0.01 statistical level.

[0062] Table 3 Comparison of the quality differences of Polygonatum cyrtonema rhizomes in the two-factor experiment of "nine steaming and nine exposure method"

[0063]

[0064]

[0065] Note: Capital letters indicate that there are significant differences in product quality between different treatments at the 0.01 statistical level.

[0066] Table 4. Results of the regression equation accuracy test

[0067]

[0068]

[0069] Implementation 2

[0070] 2.1 Processing method: 100 kg of four-year-old fresh rhizomes of Polygonatum cyrtonema were machine washed to remove the roots and sand, and then processed using traditional equipment such as wooden rice steamers and clean drying rooms. One steaming and one drying was counted as one time, each steaming lasted 1 to 2 hours, and a total of 6 steaming and drying times, with a cumulative steaming time of 8 to 9 hours. 500 g of the processed rhizomes were taken for inspection.

[0071] 2.2 Detection indicators: There are 8 in total, namely extract (X1), polygonatum polysaccharide (X2), total saponins (X3), total phenols (X4), total flavonoids (X5), reducing sugar (X6), protein (X7), and crude fat (X8).

[0072] 2.3 Detection method:

[0073] 2.4 Evaluation level: According to the quality value and product taste and appearance of fresh rhizomes of Polygonatum cyrtonema after processing, there are three levels: superior, qualified, and unqualified (see Table 1 below). Evaluation criteria: The quality value and product appearance requirements must be met at the same time.

[0074] 2.5 Evaluation method: Substitute the relevant test data into the rhizome quality value calculation formula to obtain the rhizome quality value, and then evaluate the quality of the processed rhizome as superior, qualified or unqualified according to the requirements of Table 1. Rhizome quality value Y = 13.3253 + 0.5533X2 + 0.0782X3 + 1.3453X4 + 30.4549X5 + 0.2654X 6+ 1.0778X7+ 6.1582X8. Among them, X2 is the polysaccharide content, X3 is the total saponin content, X4 is the total phenol content, X5 is the total flavonoid content, X6 is the reducing sugar content, X7 is the crude protein content, and X8 is the crude fat content.

[0075] 2.6 Evaluation results: There is a slight raw taste in the taste, the cross section is dark brown, not black, and the sensory appearance is unqualified; the quality value is 61.34, which is unqualified (the actual quality value is 60.54, the accuracy is 98.68%). Overall evaluation: The product of fresh rhizome of Polygonatum cyrtonema repeatedly steamed and dried 6 times by traditional equipment is an unqualified product.

[0076] Table 5 Detection values ​​and evaluation results of rhizome components

[0077]

[0078] Implementation 3

[0079] 3.1 Processing method: 200 kg of four-year-old fresh rhizomes of Polygonatum cyrtonema were machine washed to remove the roots, sand and epidermis, and then processed using modern stainless steel steaming cabinets and stainless steel drying machines. One steaming and drying is one time, each steaming takes 1 to 3 hours, a total of 8 steaming and drying times, and a cumulative steaming time of 14 hours. 500 g of the processed rhizomes were taken for inspection.

[0080] 3.2 Detection indicators: There are 8 in total, namely extract (X1), polygonatum polysaccharide (X2), total saponins (X3), total phenols (X4), total flavonoids (X5), reducing sugar (X6), protein (X7), and crude fat (X8).

[0081] 3.3 Detection method:

[0082] 3.4 Evaluation level: According to the quality value and product taste and appearance of fresh rhizomes of Polygonatum cyrtonema after processing, there are three levels: superior, qualified, and unqualified (see Table 1). Evaluation criteria: The quality value and product appearance requirements must be met at the same time.

[0083] 3.5 Evaluation method: Substitute the relevant test data into the rhizome quality value calculation formula to obtain the rhizome quality value, and then evaluate the quality of the processed rhizome as superior, qualified or unqualified according to the requirements of Table 1. Rhizome quality value Y = 13.3253 + 0.5533X2 + 0.0782X3 + 1.3453X4 + 30.4549X5 + 0.2654X 6+ 1.0778X 7+ 6.1582X8. Among them, X2 is the polysaccharide content, X3 is the total saponin content, X4 is the total phenol content, X5 is the total flavonoid content, X6 is the reducing sugar content, X7 is the crude protein content, and X8 is the crude fat content.

[0084] 3.6 Evaluation results: The processed rhizomes are sweet, without throat irritation or raw taste, the surface of the rhizomes is black (partly bright black), and the cross section of the rhizomes is black, which meets the requirements of eating and sensory perception; the quality value is 77.56, which is a superior product (the actual quality value is 78.07, and the accuracy is 99.35%). Overall evaluation: The fresh rhizomes of Polygonatum cyrtonema that are repeatedly steamed and dried 8 times using modern equipment are superior products.

[0085] Table 6 Detection values ​​and evaluation results of rhizome components

[0086]

[0087] Implementation 4

[0088] 4.1 Processing method: 200 kg of four-year-old fresh rhizomes of Polygonatum cyrtonema were machine washed to remove the roots, sand and epidermis, and then processed using traditional equipment. One steaming and one drying was counted as one time, each steaming lasted 1 to 3 hours, a total of 8 steaming and drying times, and a total steaming time of 14 hours. 500 g of the processed rhizomes were taken for inspection.

[0089] 4.2 Detection indicators: There are 8 in total, namely extract (X1), polygonatum polysaccharide (X2), total saponins (X3), total phenols (X4), total flavonoids (X5), reducing sugar (X6), protein (X7), and crude fat (X8).

[0090] 4.3 Detection method:

[0091] 4.4 Evaluation level: According to the quality value and product taste and appearance of fresh rhizomes of Polygonatum cyrtonema after processing, there are three levels: superior, qualified, and unqualified (see Table 1). Evaluation criteria: The quality value and product appearance requirements must be met at the same time.

[0092] 4.5 Evaluation method: Substitute the relevant test data into the rhizome quality value calculation formula to obtain the rhizome quality value, and then evaluate the quality of the processed rhizome as superior, qualified or unqualified according to the requirements of Table 1. Rhizome quality value Y = 13.3253 + 0.5533X2 + 0.0782X3 + 1.3453X4 + 30.4549X5 + 0.2654X 6+ 1.0778X 7+ 6.1582X8. Among them, X2 is the polysaccharide content, X3 is the total saponin content, X4 is the total phenol content, X5 is the total flavonoid content, X6 is the reducing sugar content, X7 is the crude protein content, and X8 is the crude fat content.

[0093] 4.6 Evaluation results: The processed rhizomes are sweet, without throat irritation or raw taste, the surface of the rhizomes is black (partly bright black), and the cross section of the rhizomes is black, which meets the requirements for eating and sensory perception; the quality value is 66.27, which is a qualified product (the actual quality value is 68.67, and the accuracy is 97.96%). Overall evaluation: The fresh rhizomes of Polygonatum cyrtonema that are repeatedly steamed and dried 8 times using modern equipment are qualified.

[0094] Table 7 Detection values ​​and evaluation results of rhizome components

[0095]

[0096] Although the present invention has been described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein within the scope of the claims.

Claims

1. A method for evaluating the processing quality grade of fresh rhizomes of edible Polygonatum cyrtonema, characterized in that: The preparation method of fresh rhizomes of Polygonatum cyrtonema by multiple steaming and drying or steaming and sun-drying comprises the following steps: S11. Rhizome selection: fresh rhizomes of Polygonatum cyrtonema planted for two years or more are selected as processing raw materials; S12. rhizome processing: washing the fresh rhizome of Polygonatum cyrtonema once or twice using a washing device, removing sand and roots to obtain fresh rhizome with skin; or washing the fresh rhizome of Polygonatum cyrtonema once or three times using a washing device, removing sand, roots and skin to obtain fresh rhizome with skin removed; S13. Number of times of rhizome processing: using a steamer and oven to repeatedly steam and dry the rhizome 1 to 9 times, with one steaming and drying being counted as one time; or using a wooden steamer and drying room to repeatedly steam and dry the rhizome 1 to 9 times, with one steaming and drying being counted as one time; S14. Sorting: According to the size of the rhizomes of Polygonatum cyrtonema, sieves with different aperture diameters are selected for sorting and classification packaging; S15. Quality evaluation: After the products are classified, they are self-inspected or sent for inspection, and the quality level is evaluated according to the following steps; The method for evaluating the processing quality grade of fresh rhizomes of Polygonatum cyrtonema comprises the following steps: S21. Select the fresh rhizomes of Polygonatum cyrtonema that have been steamed or dried for 1 to 9 times and processed into finished products; S22. The evaluation indicators include at least polygonatum polysaccharide, total saponin, total phenol, total flavonoids, reducing sugar, protein and crude fat; S23. Evaluation index determination methods include: The anthrone-sulfuric acid method was used to determine the content of polygonatum polysaccharide, and glucose was used as a reference substance to determine the content of polygonatum polysaccharide (%); The total saponins were determined by the vanillin glacial acetic acid method, and the total saponins content (mg·g-1) was determined using ginsenoside Rb1 as a reference; The total phenols were determined by the Folin-phenol method, and the total phenol content (mg·g-1) was determined using gallic acid as a reference; The total flavonoids were determined by aluminum chloride colorimetric method, and the total flavonoids content (mg·g-1) was determined using rutin as reference substance; The reducing sugar content (%) was determined by the DNS method using glucose as the reference substance; Protein (%) was determined by Kjeldahl method using H2SO4 standard acid titration solution; Crude fat was determined by Soxhlet extraction, and crude fat content (%) was determined by gravimetric method; S24. Evaluation methods include: The first step is to calculate the rhizome mass value; substitute the test values ​​of polysaccharides, total saponins, total phenols, total flavonoids, reducing sugars, proteins and crude fats into the formula to calculate the rhizome mass value (Y), the calculation formula is: Y=13.3253+0.5533X2+0.0782X3+1.3453X4+30.4549X5+0.2654X6+1.0778X7+6.1582X8. Among them: X2 is polysaccharide content, X3 is total saponin content, X4 is total phenol content, X5 is total flavonoid content, X6 is reducing sugar content, X7 is crude protein content, and X8 is crude fat content; The second step is to conduct quality evaluation. According to the calculated rhizome quality value and the sensory requirements of the processed rhizome, the quality of the processed product is evaluated as superior, qualified or unqualified. The product grade is superior, and the quality value is required to be greater than or equal to 75.0; the product sensory requirements are that the root is sweet, has no throat irritation, no raw taste, and the surface and cross section are black or bright black; The product grade is qualified, and the quality value is required to be greater than or equal to 65.0 and less than 75.0; the product sensory requirements are that the root is sweet, has no throat irritation, no raw taste, and the surface and cross section are black; The product grade is unqualified, and the quality value requirement is less than 65.0; the product sensory requirements are that the rhizome is sweet, has a pungent or raw taste, and the cross-section is black-brown, yellow-brown, or brown-yellow.

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