RU2157991C1 - Process determining capacity of wheat flour to darkening - Google Patents

Abstract

FIELD: baking and confectionery industry. SUBSTANCE: process determining capacity of wheat flour to darkening consists in preparation of dough sample on the basis of 10.0 g of flour and 5.0 ml of water. Prepared dough sample is divided into two equal parts and is put into hollow cylinders made of fluoroplastic. Measured surface is formed by cutting of surplus dough with knife followed by compaction with the use of special fluoroplastic punch to obtain smooth surface. After it cylinders are snugly fitted to dish of whiteness meter which in its turn is put on mounting seat of instrument that is subjected to thermostating. Sample is measured in the course of one hour with interval of one minute between measurements. Measured values read from instrument are entered into personal computer. Obtained data are used to construct functional dependence of whiteness of dough on time by which coefficients a, b λ are determined per each sort of flour by method of least squares. Obtained values a, b, λ are used to predict by calculation values f of whiteness for time specified by methodology by formula: f= aexp(-tf = aexp(-tλ)+b)+b, where f is whiteness of flour at time moment t; t is time; a is initial amplitude; λ is rate of change of whiteness of dough; b is asymptotic value to which whiteness of dough tends. In this case capacity of wheat flour to darkening is calculated by formula: σ ≠ (c-f)•100/:c= /(c-f) 100/:c, where σ is capacity of wheat flour to darkening expressed as percentage; c is whiteness of sample before lying; f is whiteness of sample after lying for 6 h. Given process enables measurement time to be reduced by 6 times. EFFECT: considerably reduced time of process.

Description

 The invention relates to the baking and confectionery industry, namely, to determine the ability of wheat flour to darken.

 A known method for determining the ability of wheat flour to darken by changing the color of the surface of the dough ball in the process of determining its fuzziness (see L.Ya. Auerman "Technology of baking", Pishchepromizdat, M., 1956, S. 66-67).

 The disadvantage of this method is its duration.

A known method for determining the ability of wheat flour to darken, providing for the compaction of flour on the tray of the Pekar device or on a metal plate, which are then lowered in an inclined position into a vessel with water at a temperature of 40 ^o C and kept in water until the air bubbles cease to be released. After that they are kept in the thermostat for up to 6 hours 30 minutes, while after a certain period of time an organoleptic comparison is made of the color of the freshly prepared “wet sample” of flour with the flour aged at 40 ^o C, the numerical value of the ability of flour to darken is determined using photometers (see K. N. Chizhova and others. "Technochemical control of baking production", M .: "Food industry", 1975, p. 89).

 The disadvantage of this method is its duration and low accuracy.

The closest analogue to the claimed method is a method for determining the ability of wheat flour to darken, involving the preparation of a dough sample by kneading it with water and rolling it into a thin cake, followed by keeping it in a humidified desiccator located in a thermostat at a temperature of 40 ^o C for 6-6 , 5 hours, then using a photometer determine the color of the freshly baked cakes and the color of the cakes aged in the thermostat, the ability of wheat flour to darken is determined by the difference in the measured readings (see K.N. Chizhova et al. "Technochemical control of bakery production", M., "Food industry", 1975, p. 88).

 The disadvantage of this method is its duration.

 The technical result, to which the invention is directed, is to reduce the time for determining the ability of wheat flour to darken.

The specified technical result is achieved due to the fact that in the method for determining the ability of wheat flour to darken, involving the preparation of a test sample with subsequent determination of the ability of wheat flour to darken by changing the whiteness before and after curing, measure the whiteness of the dough with a given period of one hour, and the whiteness of the test after aging is calculated by the formula:
f = aexp (-t λ) + b. (1)
where f is the whiteness of flour at time t;
t is the time;
a is the initial amplitude;
λ is the rate of change of whiteness of the test;
b is the asymptotic value towards which the whiteness of the test tends,
the coefficients a, b, λ, are found from the measured whiteness values.

где σ - способность пшеничной муки к потемнению, выраженная в %;
c - белизна образца до отлежки;
f - белизна образца после отлежки через 6 часов.The method is as follows:
A sample is prepared by kneading a dough at the rate of 10 g of flour and 5 ml of water until a homogeneous mass is obtained (within 5-10 minutes). The resulting dough piece is divided into two equal parts and placed in hollow cylinders made of fluoroplastic. The measured surface is formed by cutting off the excess dough with a knife, followed by compaction using a special PTFE punch to obtain a smooth surface. After that, the cylinders are tightly fixed on the cuvette of the whiteness meter, which in turn is placed on the seat of the device, which is thermostated. The sample is measured for an hour at intervals of 1 minute between measurements, the measured values from the device are transferred to a personal computer. According to the data obtained, a functional dependence of the whiteness of the test on time is constructed, according to which for each type of flour the coefficients a, b, λ are determined by the least squares method. According to the obtained values of a, b, λ, they are predicted by calculating the whiteness value f for the time regulated by the method according to the formula
f = aexp (-t λ) + b,
where f is the whiteness of flour at time t;
t is the time;
a is the initial amplitude;
λ is the rate of change of whiteness of the test;
b is the asymptotic value towards which the whiteness of the test tends,
after which the ability of wheat flour to darken is calculated by the formula

where σ is the ability of wheat flour to darken, expressed in%;
c is the whiteness of the sample before draining;
f is the whiteness of the sample after curing after 6 hours.

Example 1
The method is as follows:
A sample is prepared by kneading a dough at the rate of 10 g of flour and 5 ml of water until a homogeneous mass is obtained (within 5-10 minutes). The resulting dough piece is divided into two equal parts and placed in hollow cylinders made of fluoroplastic. The measured surface is formed by cutting off the excess dough with a knife, followed by compaction using a special PTFE punch to obtain a smooth surface. After that, the cylinders are tightly fixed on the cuvette of the Blik-P3 whitometer, which, in turn, is placed on the instrument seat, which is thermostated. The sample is measured for an hour with intervals between measurements of 1 minute, the measured values from the device are transferred to a personal computer. The obtained values are smoothed by the filter of the current average with a transmission frequency of 10 minutes to eliminate the high-frequency component. According to the data obtained per hour of measurements, the coefficients a, b, λ are calculated by the least squares method. So, for example, for one batch of premium flour a = 6.8, b = 50.0, λ = 0.162, the whiteness of the dough piece after 6 hours of curing is determined by the formula (1). In our case, the predicted whiteness after 6 hours of curing after an hour of measurement = 50.01, knowing the whiteness of the dough piece before curing, which = 55.78, using formula (2), we calculate the ability of flour to darken σ = 10%.
Example 2
The method is as follows:
A sample is prepared by kneading a dough at the rate of 10 g of flour and 5 ml of water until a homogeneous mass is obtained (within 5-10 minutes). The resulting dough piece is divided into two equal parts and placed in hollow cylinders made of fluoroplastic. The measured surface is formed by cutting off the excess dough with a knife, followed by compaction using a special PTFE punch to obtain a smooth surface. After that, the cylinders are tightly fixed on the cuvette of the Blik-P3 whitometer, which, in turn, is placed on the instrument seat, which is thermostated. The sample is measured for an hour with intervals between measurements of 1 minute, the measured values from the device are transferred to a personal computer. The obtained values are smoothed by the filter of the current average with a transmission frequency of 10 minutes to eliminate the high-frequency component. According to the data obtained per hour of measurements, the coefficients a, b, λ are calculated by the least squares method. So, for example, for one batch of premium flour a = 7.8, b = 34.0, λ = 0.126, the whiteness of the dough piece after 6 hours of curing is determined by the formula (1). In our case, the predicted whiteness after 6 hours of curing after an hour of measurement = 34.08, knowing the whiteness of the dough piece before curing, which = 40.87, using formula (2), we calculate the ability of flour to darken σ = 16.6%.

Claims (1)

A method for determining the ability of wheat flour to darken, involving the preparation of a dough sample, followed by determining the ability of wheat flour to darken by changing the whiteness of the dough before and after curing, characterized in that the whiteness of the dough is measured with a predetermined period of 1 hour, and the whiteness of the test after curing is calculated according to the formula
f = aexp (-tλ) + b,
where f is the whiteness of flour at time, t;
t is the time;
a is the initial amplitude;
λ is the rate of change of whiteness of the test;
b is the asymptotic value towards which the whiteness of the test tends, at
the coefficients a, b, λ are found by the whiteness values measured per hour.