A method for predicting the difficulty of sucking a liquid food sucking pipe based on a rheological test

Abstract

The application provides a kind of liquid food straw sucking difficulty prediction method based on rheological test, the characteristic flow curve of liquid food sample is measured by steady flow test, respectively Carreau-Yasuda model or Casson model (if it is yield type fluid) fitting is carried out, and the predicted flow Q of straw is calculated c , then Herschel-Bulkley model fitting is carried out, and the consistency index K h , power law index n, Herschel-Bulkley yield stress τ h (if it is yield type fluid) is obtained.According to the equation of pipe flow flow, τ R Is calculated and substituted into Herschel-Bulkley model, and the apparent viscosity corresponding to shear rate is obtained, then the prediction model is constructed to predict the liquid food straw sucking difficulty, replace the traditional sensory evaluation method, and provide new ideas for food enterprise research and development decision.

Description

Technical Field

[0001] This invention belongs to the field of food science, specifically relating to a method for predicting the difficulty of sucking liquid food through a straw based on rheological testing. Background Technology

[0002] Drinking through straws is a common method of consuming liquid foods across all age groups, and it is particularly recommended clinically for developing oral motor skills in infants and addressing drinking difficulties in the elderly. Customer-centric straw-drinking design is becoming increasingly important for improving the consumption experience of both general and specialty medical foods. In the past, there has been a growing reliance on group-based sensory evaluation to assess the sensory characteristics of foods, as sensory evaluation is inherently suitable for quantifying the intensity of sensory attributes. However, to ensure ethical compliance and reduce costs, human sensory evaluation relies on subjective human perception and is susceptible to influences such as the evaluator's mindset and the environment, leading to inherent instability in the results. Therefore, the trend of minimizing participant involvement in product innovation presents a challenge to future food innovation, necessitating alternative methods to traditional sensory evaluation to inform food companies' R&D decisions. Summary of the Invention

[0003] The technical problem to be solved: The purpose of this invention is to provide a method for predicting the difficulty of drinking liquid food through a straw based on rheological testing. By establishing a mathematical model between the perceived difficulty of drinking through a straw and the fluid properties of the liquid food, the ease or difficulty of drinking can be directly assessed through simple measurement.

[0004] Technical solution: A method for predicting the difficulty of sucking liquid food through a straw based on rheological testing, comprising the following steps: S1. Using a rotational rheometer to conduct steady-state flow tests on the liquid food, obtaining the viscosity and shear stress as a function of shear rate, fitting the Carreau-Yasuda model and the Herschel-Bulkley model to obtain the fitting parameter set A, or fitting the Casson model and the Herschel-Bulkley model to obtain the fitting parameter set B;

[0005] S2. Based on the fitted parameter group A or group B obtained in S1, calculate the predicted straw flow rate Q. c ;

[0006] S3. Based on the predicted straw flow rate Q c Calculate the pipe wall shear stress τ based on the flow equation R The shear stress τ of the pipe wall R Combined with the Herschel-Bulkley model, the shear rate was calculated. and the corresponding apparent viscosity

[0007] S4. Based on shear rate and the corresponding apparent viscosity Building a prediction model The difficulty of sucking liquid food through a straw was predicted.

[0008] Furthermore, the parameters for the steady-state flow test in step S1 are: a conical plate fixture diameter of 40 mm, flowsweep mode, and a test shear rate range of 0.01-1000 s. -1 The temperature is 24.8-25.2℃.

[0009] Furthermore, in the method for predicting the difficulty of sucking liquid food through a straw based on rheological testing, the fitting parameter set A in step S1 is the zero shear rate viscosity η0 and the infinite shear rate viscosity η ∞ Time constant λ, power law exponent n, dimensionless parameter a of the transition region between the zero shear rate region and the power law region, and consistency index K. h Herschel-Bulkley yield stress τ h The fitting parameter set B is the Carson viscosity τ. c Carson yield stress K c Herschel-Bulkley yield stress τ h The power-law exponent is n. Further, in step S2, the straw flow rate Q is predicted. c The specific steps are as follows:

[0010] If it is a non-yielding fluid, the Carreau-Yasuda model applies: Q c =11.104×η0 -0.159 ×η ∞ 0.261 ×λ -0.336 ×a 0.377 ×n 0.761 Where η0 represents the zero-shear rate viscosity, η ∞ λ represents the viscosity at infinite shear rate, λ is the time constant, n is the power law exponent, and a is a dimensionless parameter characterizing the transition region between the zero shear rate region and the power law region.

[0011] If it is a yielding fluid, the Casson model applies: Q c =1.125×K c -0.414 ×τ c -0.048 ;

[0012] Among them, K c For Carson viscosity, τ c The stress is the Carson yield stress.

[0013] Furthermore, step S3 specifically involves the following steps:

[0014] S31. Express the flow rate of the liquid in the pipette:

[0015]

[0016] In the formula, R is the radius of the straw, and τ R It is the shear stress on the inner wall of the straw, r = R. It is the shear rate through a circular cross-section with radius r;

[0017] S32. Use the simplified Herschel-Bulkley model to transform the formula in S31 above:

[0018]

[0019] S33. Q c Substituting into the equation, and through substitution and rearranging, the shear stress of the pipe wall is calculated:

[0020]

[0021] S34. The pipe wall shear stress τ calculated in conjunction with S33 R Calculating the shear rate using the Herschel-Bulkley model and the corresponding apparent viscosity

[0022] Furthermore, the Herschel-Bulkley model in step S32 is... In the formula K h Let τ be the consistency index, n be the power law index, and τ be the t. h The Herschel-Bulkley yield stress.

[0023] Furthermore, in step S4, Sp represents the predicted difficulty of sucking through the straw.

[0024] Furthermore, the method is applied to predicting the difficulty of sucking liquid food through straws.

[0025] Beneficial effects:

[0026] 1. This invention models the perceived drinking ability of a straw as a power-law equation concerning the shear viscosity of liquid food at a specific flow rate, and the established model has a coefficient of determination (R²). 2 The accuracy is 0.90, which shows very good prediction performance in existing samples. For commercial samples, the prediction success rate reaches 70%. Attached image description:

[0027] Figure 1 This is a schematic diagram of the modeling process of the present invention;

[0028] Figure 2 This is a force balance diagram of liquid flow within a straw.

[0029] Figure 3 The image shows the predicted tube suction capacity and residual histogram derived from the shear viscosity model. Different colors represent different samples, and the dashed line is used to guide the viewer's eye. Here, a represents the predicted tube suction capacity, and b represents the residual histogram. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments. The following embodiments are illustrative of the present invention, but the present invention is not limited to the following embodiments:

[0031] Example 1: Sensory rating and predicted straw sucking difficulty of 20 samples using polylactic acid straws

[0032] A method for predicting the tube suckability of liquid food based on rheological testing, characterized by comprising the following steps:

[0033] S1. Steady-state flow tests of liquid food were conducted using a 40mm diameter conical plate clamp in the flow sweep mode of a rotational rheometer. The test shear rate range was 0.01-1000s. -1 Temperature: 25±0.2℃. To minimize the impact of sample loading, each sample was placed on the rheometer platform for 30 seconds before the test structure recovered, and measurements were taken in triplicate; the data were logarithmically sampled, with 5 points per order of magnitude; the flow curves were fitted and analyzed using TRIOS software (version 4.4.0.41128, TAInstruments, USA) to obtain the viscosity and shear stress as a function of shear rate, and then fitted using the Carreau-Yasuda model and the Herschel-Bulkley model, or the Casson model and the Herschel-Bulkley model.

[0034] S2. Based on the fitting parameters obtained in S1, calculate the predicted straw flow rate Q. c ;

[0035] If it is a non-yielding fluid, the Carreau-Yasuda model applies: Q c =11.104×η0 -0.159 ×η ∞ 0.261 ×λ -0.336 ×a 0.377 ×n 0.761 Where η0 represents the zero-shear rate viscosity, η ∞λ represents the viscosity at infinite shear rate, λ is the time constant, n is the power law exponent, and a is a dimensionless parameter characterizing the transition region between the zero shear rate region and the power law region.

[0036] If it is a yielding fluid, the Casson model applies: Q c =1.125×K c -0.414 ×τ c -0.048 ;

[0037] Among them, K c For Carson viscosity, τ c The Carson yield stress;

[0038] S3. Based on the predicted straw flow rate Q c Calculate the pipe wall shear stress τ based on the flow equation R The shear stress τ of the pipe wall R Combined with the Herschel-Bulkley model, the shear rate was calculated. and the corresponding apparent viscosity

[0039] The force balance of the liquid in the straw is as follows: Figure 2 As shown:

[0040]

[0041] In the formula, ΔP is the pressure difference between the two ends along the length L of the straw, and r is the radius extending from the center of the straw.

[0042] S31. Express the flow rate of the liquid in the pipette:

[0043]

[0044] In the formula, R is the radius of the straw, and τ R It is the shear stress on the inner wall of the straw, r = R. It is the shear rate through a circular cross-section with radius r;

[0045] S32. Transform the formula in S31 above using the simplified Herschel-Bulkley model. The Herschel-Bulkley model is: In the formula K h Let τ be the consistency index, n be the power law index, and τ be the t. h Herschel-Bulkley yield stress:

[0046]

[0047] S33. Qc Substituting into the equation, and through substitution and rearranging, the shear stress of the pipe wall is calculated:

[0048]

[0049] S34. The pipe wall shear stress τ calculated in conjunction with S33 R Calculating the shear rate using the Herschel-Bulkley model and the corresponding apparent viscosity

[0050] S4. Based on shear rate and the corresponding apparent viscosity Building a prediction model Predict the difficulty of sucking liquid food through a straw;

[0051] In the formula, S p To predict the difficulty of sucking through a straw.

[0052] I. Investigation of Smoking Behavior

[0053] The straws used were made of polylactic acid (PLA), with a diameter of 3 mm and a length of 15 cm. During the experiment, samples were placed in batches into opaque white paper cups. Five participants were involved, instructed to take a sip as naturally as possible. To accurately record the time of each sip, researchers used a stopwatch and issued standardized instructions before each test: "Ready, steady, start, stop." Furthermore, to reduce the impact of oral muscle fatigue on the results, participants were required to rinse their mouths with water and rest for one minute after each sip before continuing with subsequent tests. Notably, participants were unaware that researchers were monitoring their flow during the sip tasks, and therefore were not aware of the specific objectives of the experiment. This design helps prevent participants from consciously altering their sip behavior due to awareness of being monitored. To further ensure the fairness of the experiment, the presentation order of the samples was balanced among all participants. Each sample was tested five times to enhance the reliability of the results.

[0054] II. Sensory Evaluation

[0055] In our study, straw suction was defined as the force required to draw a sample into the oral cavity through a straw, corresponding to the difficulty of sipping. The sensory panel consisted of 15 experienced and trained members. Panel members were required to drink 20 mL of a commercial sample in a natural drinking state. Furthermore, each sample was assigned a three-digit code before testing, with random numbering and random arrangement of samples. A standard reference was also provided for evaluation. Using a modified scoring method, scores were categorized on a 16-point scale (15 for very large, 12 for large, 9 for moderate, 6 for small, 3 for very small, and 0 for none). Before each sample evaluation, panel members cleaned their mouths with water and rested for one minute. Sensory testing was repeated twice.

[0056] Table 1 Actual flow rate (Q) in commercial samples II ) and predicted flow (Q c ) and sensory scores (S) for the difficulty of straw sucking in commercial samples and predicted straw sucking difficulty (S p )*

[0057]

[0058] *Data are expressed as mean ± standard deviation.

[0059] Table 2 Confusion Matrix for Commercial Sample Evaluation

[0060]

[0061] The accuracy is calculated as (9+5) / (9+5+1+5) = 0.70, meaning the success rate is 70%.

[0062] III. Sample Prediction Results

[0063] Figure 3 The predicted value of tube suction capacity derived from the shear viscosity model ( Figure 3 a) and residual histogram ( Figure 3 b) Determine the best-fit prediction model as the sensory score.

[0064] Example 2: Sensory rating and predicted straw-sucking difficulty of four samples using straws made of two different materials.

[0065] We applied this prediction model to different straw materials, and the results are as follows:

[0066] Table 3 Sensory ratings and predicted straw sucking difficulty for straws of different materials.

[0067]

[0068]

[0069] Polypropylene pipettes: Confusion matrix for commercial sample evaluation

[0070] Table 4. Confusion Matrix for Polypropylene Straw Evaluation

[0071]

[0072] Wherein, accuracy = (1+2) / (1+2+0+1) = 0.75

[0073] Kraft paper straws: Confusion matrix for evaluating commercial samples

[0074] Table 5. Confusion Matrix for Kraft Paper Straw Evaluation

[0075]

[0076] Wherein, accuracy = (1+3) / (1+3+0+0) = 1.00

[0077] The results show that the prediction model is applicable to straws of different materials and has a high prediction accuracy.

[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the spirit and technical essence of the present invention. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the technical solutions of the present invention, shall still fall within the scope of protection of the present invention.

Claims

1. A method for predicting the difficulty of sucking liquid food using straws based on rheological testing, characterized in that, Includes the following steps: S1. Steady-state flow tests were conducted on liquid food using a rotational rheometer to obtain the viscosity and shear stress as a function of shear rate. The Carreau-Yasuda model and the Herschel-Bulkley model were then fitted to obtain the fitting parameter set A, or the Casson model and the Herschel-Bulkley model were fitted to obtain the fitting parameter set B. S2. Calculate the predicted straw flow rate based on the fitted parameter group A or group B obtained in S1. Q c ; S3. Based on the predicted straw flow rate Q c Calculation of pipe wall shear stress based on flow equation τ R Shear stress on the pipe wall τ R Combined with the Herschel-Bulkley model, the shear rate was calculated. and the corresponding apparent viscosity η ( ); S4. Based on shear rate and the corresponding apparent viscosity η ( ), construct a prediction model S p = ( η ( ) / 0.206) 0.316 The difficulty of sucking liquid food through a straw was predicted. The parameters for the steady-state flow test in step S1 are: a conical plate fixture diameter of 40 mm, flow sweep mode, and a test shear rate range of 0.01-1000 s. -1 The temperature is 24.8-25.2℃; In step S1, the fitting parameter set A is zero shear rate viscosity. η 0 Infinite shear rate viscosity η ∞ time constant λ Power Law Index n Dimensionless parameters of the transition region between the zero shear rate region and the power-law region a Consistency Index K h Herschel-Bulkley yield stress τ h The fitting parameter set B is the Carson viscosity. τ c Carson yield stress K c Herschel-Bulkley yield stress τ h Power Law Index n ; In step S2, the straw flow rate is predicted. Q c The specific steps are as follows: If it is a non-yielding fluid, the Carreau-Yasuda model applies: Q c = 11.104× η 0 −0.159 × η ∞ 0.261 × λ −0.336 × a 0.377 × n 0.761 ; in, η 0 Indicates viscosity at zero shear rate. η ∞ Indicates viscosity at infinite shear rate. λ It is a time constant. n The power-law exponent, a Dimensionless parameters characterizing the transition region between the zero shear rate region and the power-law region; If it is a yielding fluid, then the Casson model applies: Q c = 1.125× K c −0.414 × τ c −0.048 ; in, K c For Carson viscosity, τ c The Carson yield stress; The specific steps of step S3 are as follows: S31. Express the flow rate of the liquid in the pipette: In the formula, R It is the radius of the straw. τ R It is the shear stress on the inner wall of the straw. r = R , ( r ) is through a radius of r The shear rate of a circular cross-section; S32. Use the simplified Herschel-Bulkley model to transform the formula in S31 above: S33. Will Q c Substituting into the equation, and through substitution and rearranging, the shear stress of the pipe wall is calculated: S34. Tube wall shear stress calculated in conjunction with S33 τ R Calculating the shear rate using the Herschel-Bulkley model and the corresponding apparent viscosity η ( ); The Herschel-Bulkley model in step S32 is... In the formula K h As a consistency index, n The power-law exponent, τ h The Herschel-Bulkley yield stress; In step S4 Sp To predict the difficulty of sucking through a straw.

2. The application of the method according to claim 1 in predicting the difficulty of drinking liquid food through a straw.

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