Method for rapidly detecting wheat germination rate

Abstract

The invention discloses a method for rapidly detecting the wheat germination rate. The method comprises the steps of sample selection, original sample detection, sample germination and germination and germination sample detection. The method comprises the following steps: culturing a wheat sample in an artificial incubator with the temperature of 28-30 DEG C and the humidity of 60% for 26-28 hours, adding 25 ml + / -0.2 ml of distilled water into the obtained germinated sample, crushing to obtain a uniform suspension, transferring all the suspension into a sample introduction tube, and putting the sample introduction tube into an instrument for detection. The landing numerical instrument is used for detection, operation is easy and fast, result reproducibility is good, and experimental data are reliable. When an enterprise applies the method to grain detection, the key technical problem of the grain enterprise in the raw material acceptance check process can be effectively solved. The method is especially suitable for application scenes such as large-scale grain purchasing, seed quality detection and wine brewing raw material screening.

Description

Technical Field

[0001] This invention relates to the field of brewing raw material quality testing technology, specifically to a method for rapidly detecting wheat germination rate. Background Technology

[0002] Wheat is the main raw material for making koji (fermentation starter), and the microbial, enzyme, and other biological systems in koji are crucial to the fermentation process. High-end baijiu brands have strict requirements for raw materials, and germination rate is one of the important indicators for measuring wheat quality. The germination rate of wheat effectively reflects its quality, such as whether it is fresh and plump or moldy and aged. The germination rate of wheat is significantly positively correlated with the quality of koji (microbial activity, enzyme system, flavor), and a high germination rate is one of the core indicators of high-quality brewing wheat. Wheat with a high germination rate contains abundant carbon and nitrogen sources, promoting the growth of beneficial mycelia; the germ contains natural plant hormones, stimulating microbial metabolic activity; the enzyme content is rich, enhancing the saccharification and liquefaction power of the koji; and the amino acid metabolism is vigorous, producing a variety of flavor substances. Wheat with a low germination rate may carry dead embryos or moldy bacteria, inhibiting the reproduction of functional bacteria in the koji; it may also produce aldehydes due to fat oxidation, resulting in a "stale" or "rotten" taste.

[0003] The current industry testing standard is GB / T 5520-2011 Grain and Oil Inspection - Germination Test of Cereal Seeds: 400 wheat grains are manually selected (4 × 100 parallel samples, removing other samples, damaged, moldy, etc.). Each grain is placed in one of four sterilized glass petri dishes (germination beds) lined with filter paper. A small amount of sterile water is sprayed onto the surface of the wheat grains, and then the petri dishes are covered for germination culture. The germination culture conditions are: constant temperature incubator temperature 20℃-22℃, humidity 60%-65%, and a growth time of 7 days.

[0004] This method has the following drawbacks, mainly: ① Long detection time: It takes 7 days to obtain results, delaying production decisions and exacerbating storage pressure; ② High cost: If the samples are unqualified, the costs of grain loading and unloading, logistics, and supplier scheduling will be repeatedly incurred; ③ Questionable sample representativeness: The standard requires manual screening of 400 wheat grains (4×100 parallel samples, removing other samples, damaged, moldy, etc.), but the wheat actually purchased by liquor companies is not selected by grain, resulting in a disconnect between the detection conditions and the actual purchase. To overcome the above bottlenecks, near-infrared spectroscopy (NIR) technology was explored in the early stage. Although this technology has the advantages of high efficiency, non-destructive nature, and environmental friendliness, it only uses the spectral characteristics of ungerminated wheat and the germination rate value to model the results. The accuracy of the detection results is poor because the biochemical characteristics of ungerminated wheat are significantly different from those of germinated wheat, and their spectral characteristics are also significantly different, making it impossible for the model to accurately assess the germination rate. Based on this, an innovative detection method was developed that is simple and fast (reducing the detection cycle from 7 days to less than 18 hours), requires no large amount of data modeling, objectively characterizes (avoids human screening bias), and can truly reflect the germination activity of wheat. Summary of the Invention

[0005] The purpose of this invention is to provide a rapid method for detecting wheat germination rate, thereby solving the problems of poor reproducibility and long processing time in existing wheat standard germination tests. Specifically, it provides a rapid detection method for screening wheat with high germination rates that is fast, accurate, reproducible, and objective.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for rapidly detecting wheat germination rate, comprising the following steps: S1. Sample selection: Select wheat samples with different germination rates, with 3 samples selected for each germination rate range, for a total of 9 samples; S2. Original sample detection: Take 7.00g + / - 0.05g of each of the 9 original samples selected in S1, mix them well, add 25ml + / - 0.2ml of distilled water, break them up to obtain a uniform suspension, transfer the entire suspension into the injection tube, and put it into the instrument for detection. S3, Germination Experiment: 7.00g + / - 0.05g of each of the 9 samples selected in S1 were mixed and weighed, and cultured in an artificial climate incubator with a temperature of 28~30℃ and a humidity of 60~65% for 16~18h. Four replicates were set up for each sample. S4. Germination Sample Detection: Add 25ml + / -0.2ml of distilled water to the germination sample obtained in S3, break it up to obtain a uniform suspension, transfer the entire suspension into the injection tube, and place it into the instrument for detection.

[0007] Furthermore, the wheat samples with different germination rates in S1 include samples with a germination rate of <80%, samples with a germination rate of 80% ≤ germination rate <90%, and samples with a germination rate of 90% ≤ germination rate <100%.

[0008] Furthermore, the cultivation conditions in S2 are as follows: incubation at a temperature of 28~30℃ and a humidity of 60~65% for 26~28 hours in an incubator.

[0009] Furthermore, the sample weights weighed during S2 and S3 are corrected based on a 14% moisture content.

[0010] Furthermore, when the FN value measured in the sample in S3 is ≤165, the wheat germination rate is ≥86%.

[0011] Furthermore, the cultivation conditions in S3 were obtained through a germination and sprouting pre-experiment, specifically including: (1) Select one sample with the highest germination rate and one sample with the lowest germination rate, and incubate them for 24 hours in an artificial incubator with a humidity of 60% and a temperature of 20, 25, 30 and 35℃ respectively. Four replicates were set up for each sample at different incubation temperatures.

[0012] (2) Select one sample with the highest germination rate and one sample with the lowest germination rate. Weigh 7.00g + / - 0.05g of each sample and incubate them in an artificial incubator with a humidity of 60% and a temperature of 30℃ for 8, 16, 18, 20, 22 and 24h respectively. Four replicates were set up for each sample at different incubation times.

[0013] Wheat's core enzyme system can be divided into six major categories: starch hydrolases, proteases, cellulases and hemicellulases, lipases, phytases, and polyphenol oxidases, with starch hydrolases having the highest content. International standards typically use a falling number instrument (FN) to determine the activity of α-amylase in the starch hydrolases. The FN is a specialized device for determining α-amylase activity in grains (especially wheat and rye). Its principle is that the degradation capacity of α-amylase on gelatinized starch is quantitatively related to the rate of viscosity decrease in the system. A higher FN value indicates lower α-amylase activity and better wheat quality; after germination, α-amylase activity is high, and the FN value is low. The falling number instrument offers the following advantages: ① High efficiency: a single measurement takes only 5-7 minutes; ② Standardization: conforms to international standards such as ICC 107 / 1 and ISO 3093; ③ Green testing: requires no chemical reagents, only water and samples, making it environmentally friendly and low-cost; ④ Objectivity: samples are randomly selected, requiring no human intervention.

[0014] Based on the above technical solution, the embodiments of the present invention can produce at least the following technical effects: (1) Standardization: The core advantage and value of the falling number meter is its objective and standardized assessment of grain germination damage. By measuring the rate of viscosity decrease of starch gelatinized liquid under specific conditions, it directly reflects the activity level of α-amylase. The higher the enzyme activity (the more severe the germination damage), the faster the starch is decomposed, the faster the viscosity decreases, and the lower the measured falling number. The falling number meter provides an objective, repeatable, and internationally recognized value (such as ICC 107 / 1, AACC 56-81.03, ISO 3093 standards) (FN, in seconds), replacing subjective visual judgment, and is the gold standard for assessing germination damage and predicting processing performance.

[0015] (2) High efficiency: Compared with the drawback of the standard germination test being time-consuming (requiring 7 days of cultivation), the entire testing process (including sample weighing, germination, crushing and measurement) of wheat falling values ​​can usually be completed within 16 to 18 hours for one sample. The high efficiency of this method can quickly determine the quality grade of grain entering the warehouse and prevent inferior grain from entering the warehouse.

[0016] (3) Accurate results and good repeatability: Compared with the drawback of large differences between parallel samples in the standard wheat germination experiment, the falling numerical instrument is precisely designed and strictly controls the test conditions (water bath temperature, stirring rod specifications, lifting speed, timing accuracy, etc.) and follows international standard methods, so that the results measured at different times and locations are comparable and reliable.

[0017] (4) More objective and representative: In the standard wheat germination test, the sample preparation process requires the removal of moldy, shriveled, large-area black spots, and incomplete grains to ensure the accuracy of the test results. In contrast, the determination of wheat germination and fall values ​​uses the original sample for direct testing without the need for manual selection. This method can more comprehensively reflect the actual state of the sample, and the obtained data is more objective and representative, better reflecting the overall quality characteristics of the batch.

[0018] (5) Simple operation: Although this method requires strict adherence to the procedures, the operation process is relatively standardized and simple, and can be mastered by trained technicians. Detailed Implementation

[0019] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0020] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0021] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0022] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This specification and embodiments are merely exemplary.

[0023] Example 1: Measurement of landing values ​​using original sample testing S1. Sample selection: Select wheat samples with different germination rates, with 3 samples selected from each interval, for a total of 9 samples.

[0024] S2. Original Sample Detection: Take 7.00g + / - 0.05g of each of the 9 original samples selected in S1, mix them thoroughly, add 25ml + / - 0.2ml of distilled water, break them up to obtain a uniform suspension, transfer the entire suspension into the injection tube, and place it into the instrument for detection.

[0025] Table 1. FN values ​​of original samples Sample number 1 2 3 4 5 6 7 8 9 Germination rate (%) 73 76 80 83 86 90 96 98 99 FN value 515 521 518 535 516 520 518 525 508 As shown in Table 1, the nine wheat samples were not subjected to germination culture, and their FN values ​​were all between 500 and 535, showing no significant difference or pattern. However, their actual germination rates varied greatly. Therefore, directly testing the original wheat samples cannot determine the relationship or pattern between their falling values ​​and germination rates.

[0026] Example 2: Selection of Germination Temperature Sample selection: Select wheat samples with different germination rates, with 3 samples selected from each interval, for a total of 9 samples.

[0027] To determine the optimal germination temperature, one sample each with the highest and lowest germination rates were selected and cultured for 24 hours in artificial incubators at 60% humidity and temperatures of 20, 25, 30, and 35°C, respectively. Four replicates were set up for each sample at different incubation temperatures. Under the same incubation temperature, wheat with high germination rates showed better germination than wheat with low germination rates. However, the germination behavior of the same sample varied under different incubation temperatures: at 20°C, wheat showed almost no buds; at 25°C, some short and sparse buds appeared; at 30°C, wheat buds grew well, and the culture dish retained moisture effectively; at 35°C, wheat buds grew well, but the culture dish experienced severe moisture loss, and some samples showed signs of bacterial contamination. Based on these experimental results, the optimal germination temperature was determined to be 30°C.

[0028] Example 3: Germination and Sprouting Experiment and Sample Detection S1. Sample Selection: Select wheat samples with different germination rates, selecting 3 samples from each range. A total of 9 samples are selected.

[0029] S3. Germination Experiment: Take 7.00g + / - 0.05g of each of the 9 samples selected in S1 and mix them thoroughly. Incubate them in an artificial climate incubator at 30℃ and 60% humidity for 26-28h. Each sample was tested in quadruplicate.

[0030] S4. Germination Sample Detection: Add 25ml + / -0.2ml of distilled water to the germination sample obtained in S3, break it up to obtain a uniform suspension, transfer the entire suspension into the injection tube, and place it into the instrument for detection.

[0031] The FN values ​​of the above germinating and sprouting samples are shown in Table 2: Table 2. FN values ​​of germinating and sprouting samples

[0032] As shown in Table 2, after wheat samples with different germination rates germinated and sprouted for 26-28 hours, their FN values ​​were measured. The results showed that as the germination rate increased, the FN value showed a significant decreasing trend, which was inversely correlated.

[0033] Those skilled in the art can formulate germination rate quality control standards according to their own requirements and establish falling number detection standards corresponding to germination rate indicators. Taking the table above as an example: if the germination rate of purchased wheat is set at ≥85%, this method can be used to weigh a certain amount of wheat, allow it to germinate for 26-28 hours, then crush it and measure its FN value. A value ≤165 is considered qualified grain and can be stored. This eliminates the need for a 7-day cultivation period followed by manual counting to obtain the results.

[0034] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A method for rapidly detecting wheat germination rate, characterized in that, Includes the following steps: S1. Sample selection: Select wheat samples with different germination rates; S2, Germination Experiment: The samples selected in S1 were weighed, mixed, and cultured for a certain period of time under suitable temperature and humidity conditions. S3. Germination Sample Detection: Add distilled water to the germination sample obtained in S3, break it up to obtain a uniform suspension, transfer the entire suspension into the injection tube, and place it into the instrument to detect the FN value.

2. The method for rapidly detecting wheat germination rate according to claim 1, characterized in that, The wheat samples with different germination rates in S1 include samples with a germination rate of <80%, samples with a germination rate of 80% ≤ germination rate <90%, and samples with a germination rate of 90% ≤ germination rate <100%.

3. The method for rapidly detecting wheat germination rate according to claim 1, characterized in that, The cultivation conditions in S2 are: incubation at 28~30℃ and 60~65% humidity in an incubator for 26~28 hours.

4. The method for rapidly detecting wheat germination rate according to claim 1, characterized in that, In S2, each sample needs to be set up with no less than 3 parallel groups.

5. The method for rapidly detecting wheat germination rate according to claim 1, characterized in that, The sample weight in S2 is adjusted according to a 14% moisture content standard.

6. The method for rapidly detecting wheat germination rate according to claim 1, characterized in that, When the FN value measured in the sample of S3 is ≤165, the germination rate of wheat is ≥86%.

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