Method of predicting cut-time of milk coagulum in cheese-making process

• US 5,172,193 A
• Filed: 02/15/1990
• Issued: 12/15/1992
• Est. Priority Date: 02/15/1990
• Status: Expired due to Term

• Current Assignee: University Of Kentucky Research Foundation (University of Kentucky)
• Original Assignee: University Of Kentucky Research Foundation (University of Kentucky)
• Inventors: Payne, Frederick A., Hicks, Clair L.
• Primary Examiner(s): Turner, Samuel A.
• Assistant Examiner(s): Keesee, LaCharles P.
• Application Number:
  US07/480,629
• Time in Patent Office: 1,034 Days
• Field of Search: 356/445, 356/446, 356/447, 356/448, 356/39, 356/40, 356/41, 73/64.1, 73/169, 250/564, 250/574
• US Class Current: 356/445
• CPC Class Codes: G01N 2021/4769 Fluid samples, e.g. slurries, granulates; Compressible powdery of fibrous samples
• CPC Class Codes: G01N 21/4738 Diffuse reflection precedence is given to G01N21/55 - G01N21/57 if specular component is taken into consideration, e.g. also for testing fluids, fibrous materials
• CPC Class Codes: G01N 2201/084 Fibres for remote transmission
• CPC Class Codes: G01N 33/04 Dairy products

Abstract

An apparatus for predicting milk coagulum cut-time in a cheese making process includes a light source, a sensor or detector for sensing diffuse reflectance of light from said milk and a controller for analyzing the diffuse reflectance and accurately predicting the cut-time to significantly enhance overall yield. More specifically, the apparatus includes an optical probe which may be suspended over the milk or attached to a wall of a fermentation vessel in which the milk is contained. A method for predicting milk coagulum cut-time includes the steps of (a) directing light from a light source toward milk undergoing enzymatic hydrolysis; (b) sensing diffuse reflectance of that light from the milk; (c) analyzing the sensed diffuse reflectance profile and (d) signaling the cut-time. The sensing occurs at between 400 to 6000 nm. Specific mathematical formulae for the analyzing steps are also disclosed.

Claims

1. A method for predicting mild coagulum cut-time in a cheese making process, comprising the steps of:

directing light from a light source toward milk undergoing enzymatic hydrolysis;

sensing diffuse reflectances of the light from said milk at substantially 950±

5 nm;

analyzing the sensed diffuse reflectance profile of said light; and

signaling said cut-time.

2. The method as set forth in claim 1, wherein said analyzing step is completed in accordance with the following formula:

##EQU6## where;

t_c =predicted cut-time in minutes

(dv/dt)_max =maximum value of first derivative where V=output voltage of the sensor in volts and t=time in minutes

C=constant=12.11

3. The method set forth in claim 1, wherein said analyzing step is completed in accordance with the following formula:

##EQU7## where;

t_c =predicted cut-time in minutes

t_i =induction time in minutes ##STR4## a=exponent=1.95 C=constant=3.93

4. The method set forth in claim 1, wherein said analyzing step is completed in accordance with the following formula:

##EQU8## where;

R=reflectance ratio from the sensor

R.sub.∞

=theoretical reflectance ratio after an infinitely long period of coagulation

τ

=gelling time constant in minutes which is a multiple of the cut-time, t_c

t=time since enzyme addition in minutes

t_o =time since enzyme addition to end of transition period in minutes

R_o =reflectance ratio at end of transition period.

5. The method set forth in claim 1, wherein said analyzing step is completed in accordance with the following formula:

space="preserve" listing-type="equation">t=2.67t.sub.max -4.2

where;

t_max =time from enzyme addition to maximum first derivative in minutes

t_c =predicted cut-time in minutes

6. A method for predicting milk coagulum cut-time in a cheese making process, comprising the steps of:

directing light from a light source toward milk undergoing enzymatic hydrolysis;

sensing diffuse reflectance of said light from said milk;

analyzing the sensed diffuse reflectance profile of said light;

identifying induction, sigmoidal and logarithmic periods from the reflectance profile; and

signaling said cut time.

7. The method as set forth in claim 6, including utilizing characteristics of the sigmodial period of the reflectance profile to accurately predict coagulum cut-time.

8. A method for predicting mild coagulum cut-time in a cheese making process, comprising the steps of:

directing light from a light source toward milk undergoing enzymatic hydrolysis;

sensing diffuse reflectance of the light from said milk;

analyzing the sensed diffuse reflectance profile of said light; and

signaling said cut-time;

wherein said analyzing step is completed in accordance with the following formula;

space="preserve" listing-type="equation">(dV/dt).sub.max x t.sub.c =C

where;

t_c =predicted cut-time in minutes

(dV/dt)_max =maximum value of first derivative where V=output voltage of the sensor in volts and t=time in minutes

C=constant=12.11

9. A method for predicting mild coagulum cut-time in a cheese making process, comprising the steps of:

directing light from a light source toward milk undergoing enzymatic hydrolysis;

sensing diffuse reflectance of the light from said milk;

analyzing the sensed diffuse reflectance profile of said light; and

signaling said cut-time;

wherein said analyzing step is completed in accordance with the following formula;

space="preserve" listing-type="equation">(t.sub.c -t.sub.i) (dV/dt).sub.max.sup.1 =C

where;

t_c =predicted cut-time in minutes

(dV/dt)_max =maximum value of the first derivative where V=output voltage of the sensor in volts and t=time in minutes

a=exponent=1.95

c=constant=3.93

10. A method for predicting mild coagulum cut-time in a cheese making process, comprising the steps of:

directing light from a light source toward milk undergoing enzymatic hydrolysis;

sensing diffuse reflectance of the light from said milk;

analyzing the sensed diffuse reflectance profile of said light; and

signaling said cut-time;

wherein said analyzing step is completed in accordance with the following formula;

##EQU9## where;

R=reflectance ratio from the sensor

R.sub.∞

=theoretical reflectance ratio after an infinitely long period of coagulation

τ

=gelling time constant in minutes which is a multiple of the cut-time, t₃

t=time since enzyme addition in minutes

t_o =time since enzyme addition to end of transition period in minutes

R_o =reflectance ratio at end of transition period

11. A method for predicting mild coagulum cut-time in a cheese making process, comprising the steps of:

directing light from a light source toward milk undergoing enzymatic hydrolysis;

sensing diffuse reflectance of the light from said milk;

analyzing the sensed diffuse reflectance profile of said light; and

signaling said cut-time;

wherein said analyzing step is completed in accordance with the following formula;

space="preserve" listing-type="equation">t.sub.c =2.67t.sub.max -4.2

where;

t_max =time from enzyme addition to maximum first derivative in minutes

t_c =predicted cut-time in minutes.