Bleaching detection in wheat flour

Principle: It is based on the comparison of the sample taken from bread by dissolving in petroleum ether and not bleaching.

Tools and Equipment: General laboratory equipment and materials, precision laboratory balance.

Chemical: Petroleum ether

Application: Bleaching with flour known to be not bleaching is taken from the sample to be determined by bleaching. 100 ml of petroleum ether were added on both and shake with closed mouth for 5 minutes. It is then allowed to crash for 12 hours. At the end of the period, both flasks are shaken for 5 minutes and allowed to settle again. The liquid remaining on the precipitated portion is filtered (avoiding as much fly as possible). The first 10 ml of the filtrate is filtered again and the filtrate colors are compared.

Calculation: The colors of the filtrate of the flours which were not bleached were darker than the ones of the bleached flours (TS4500 / April 1985).

Soybean flour is an additive used to whiten bread.

-DATEM, tartaric acid esters of mono diglycerides are an additive used for the smooth internal structure of the bread, but it is not accepted because it changes the flavor of the bread.

  • Cysteine ​​causes the bread dough to become weak and soft. more bran content and salt content in the dough dough of wheat grown in Turkey is low, there is a problem, such as weak. Adding cysteine ​​on top of this will adversely affect the structure of the bread.

Furthermore, these three additives, including food additives, are not in compliance with the food communiqué and are not suitable for use.

-The use of glucose oxidase instead of vitamin C in the production of bread adversely affects the flavor of bread and is not suitable for use. Glucose oxidase forms hydrogen peroxide using glucose and causes spoilage of taste.

  • Bread wheat modification is made hexaploid to obtain wheats more resistant to fungal infection.

ELISA or PCR approaches are used to detect all these undesirable contributions. These detect the presence / absence. If a quantitative result is desired, real-time PCR is used.

ELISA (Enzyme linked immuno sorbent assay) tests for the presence of specific proteins using the binding property between antigen and antibody. PCR (Polymerase Chain Reaction) is based on the identification of DNA sequences transferred to cereal. These methods can provide information about the quantity (percentage) in the sample. The first method approved in the EU is the PCR-based assay, in which many GMOs approved for presentation to the market can be detected (Lipp et al., 1999).

The sample from the bread is extracted; mechanic shredding, chemical application or enzymatic shredding. The extracted sample is then purified: extraction / precipitation, chromatography, centrifugation, affinity column separation (Zimmermann et al., 1998).