Farinograph
Encyclopedia
In Baking
Baking
Baking is the technique of prolonged cooking of food by dry heat acting by convection, and not by radiation, normally in an oven, but also in hot ashes, or on hot stones. It is primarily used for the preparation of bread, cakes, pastries and pies, tarts, quiches, cookies and crackers. Such items...

, a Farinograph measures specific properties of flour
Flour
Flour is a powder which is made by grinding cereal grains, other seeds or roots . It is the main ingredient of bread, which is a staple food for many cultures, making the availability of adequate supplies of flour a major economic and political issue at various times throughout history...

. It was first developed and launched in 1928 Brabender History. The Farinograph is used as a tool to measure shear (fluid) and viscosity
Viscosity
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...

 of a mixture of flour and water
Dough
Dough is a paste made out of any cereals or leguminous crops by mixing flour with a small amount of water and/or other liquid. This process is a precursor to making a wide variety of foodstuffs, particularly breads and bread-based items , flatbreads, noodles, pastry, and similar items)...

. The primary units of the farinograph are Brabender Units, an arbitrary unit
Arbitrary unit
In science and technology, an arbitrary unit or procedure defined unit is a relative unit of measurement to show the ratio of amount of substance, intensity, or other quantities, to a predetermined reference measurement...

 of measuring the viscosity of a fluid. The Farinograph is a variation of the Brabender Plastograph
Brabender Plastograph
The plastograph, or Brabender plastograph, is a device for the continuous observation of torque in the shearing of a polymer with a range of temperatures and shear rates...

 that has been specialized for the baking industry, and it is used around the world as an objective measurement of a variety of flours.

A baker can formulate end products by using the Farinograph's results to determine the following:
  • Water absorption.
  • Dough viscosity, including peak water to gluten
    Gluten
    Gluten is a protein composite found in foods processed from wheat and related grain species, including barley and rye...

     ratio prior to gluten breakdown.
  • Peak mixing time to arrive at desired water/gluten ratio.
  • The stability of flour under mixing.
  • The tolerance of a flour's gluten.

Method

The farinograph is drawn on a curved graph with the vertical axis labeled in Brabender Units (BU) and the horizontal axis labeled as time in minutes. The graph is generally hockey-stick shaped, with the curve being more or less acute depending on the strength of the gluten in the flour.
The points of interest on the graph are fivefold:

1. Arrival Time (Absorption) - Absorption is the point chosen by the baking industry which represents a target water to flour ratio in bread
Bread
Bread is a staple food prepared by cooking a dough of flour and water and often additional ingredients. Doughs are usually baked, but in some cuisines breads are steamed , fried , or baked on an unoiled frying pan . It may be leavened or unleavened...

. This ratio is marked at the 500 BU line and is taken as a rule of thumb
Rule of thumb
A rule of thumb is a principle with broad application that is not intended to be strictly accurate or reliable for every situation. It is an easily learned and easily applied procedure for approximately calculating or recalling some value, or for making some determination...

 for desired taste, texture, and dough performance during proofing
Proofing (baking technique)
Proofing , as the term is used by professional bakers, is the final dough-rise step before baking, and refers to a specific rest period within the more generalized process known as fermentation...

 and baking. All other measurements are based on this 500 BU standard. (For comparison, the accepted BU is 1000 or greater for noodles.

Thus on the graph above, Arrival time is the point on the graph where the top of the curve reaches the 500 BU point and indicates the rate of absorption (minutes/BU).

2. Peak time - Peak time is reached at the highest point on the curve, and indicates when the dough has reached is maximum viscosity before gluten strands begin to break down.

3. Mixing Tolerance Index (MTI) - MTI is found by taking the difference in BU between the peak time point (on the graph above 3 minutes, 30 seconds) and 5 minutes after peak time is reached. This is used by bakers to determine the amount that a dough will soften over a period of mixing. MTI may be expressed as a value in BU or as a percentage of BU lost over time ().

4. Departure Time - Departure time is defined as the point at which the top of the curve goes below the 500 BU line. This point is generally considered the point at which gluten is breaking down and dough has become over mixed.

5. Stability - Stability is the point between arrival time and departure time and generally indicates the strength of a flour (how much gluten a flour has and how strong it is).

The graph above is a gluten rich bread flour, as its stability time is relatively long and the MTI is still above the 500 BU line. A weaker flour, such as a cake or pastry flour with a much lower gluten content would have a much steeper decline after peak time.

Applications

The Farinograph is used worldwide by bakers and food technicians in building bakery formulations. The farinograph gives the baker a good snapshot of the flour's properties and how the flour will react in different stages of baking. It assists the baker in choosing the right flour for the job they are trying to complete.

The industrial application of these 5 points is far reaching. A baker may use, for example, the arrival time as a bare minimum time when planning full product floor time for a batch of dough. A baker may also use MTI as guideline to judge the response of a dough to the addition of other ingredients. Peak time may be used as a target mix time for optimal gluten structure and resilience. Stability may be used as a method of determining desired cell structure before irreparable gluten breakdown occurs.

Sources


External links

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