cereals

Wheat grain

Group members Saunyama Dorothy R11674R Sibanda Celesani. V R115706Q Ndlovu Thandi R112209R Samu Elizabeth R113014Q Kavizah Precious. A R114088G

Victoria foods Gweru

introduction Our journey to Victoria Foods was eventful however disappointing. They were very welcoming but were only forthcoming with the theoretical parts of the laboratory tests but could not show us the practical application. They did however show us the milling of wheat into flour and the equipment involved in the laboratory tests and flour production.

Physical test Hectoliter Weight test Known as weight of the grain in relation to quantity. Grain is poured into a container of known volume from a set height then weighed. Calculated and expressed as kg/hl High hectoliter weight is preferred and varieties pass a cut off level before being classed as milling quality

Grain Weight test Is a measure of grain plumpness. Using a grain counter, 1000 seeds are counted and weighed. Expressed in grams per 100 seeds High grain weight is preferred.

Protein content test 0.1-0.2g of ground wheat is weighted and placed in an Inframatic 8100 Protein Analysis. The sample is allowed to drop automatically into a hot oven and burned at 952 degrees The amount of nitrogen gas released while burning is measured and a formula is applied to convert this measurement to protein content in the sample. The results are expressed as a percentage of the total sample weight.

applicability End product attributes e.g. texture and appearance are due to the protein content. High protein content is required for crisp, tender end products e.g. snacks and cakes. Also required for end products with a chewy texture e.g. bread. Bakers use this knowledge to anticipate water absorption and dough development. High protein content requires more water and longer mixing time to achieve optimum dough consistency.

Moisture content test 2-3g of ground wheat is weighed and placed in a moisture dish. The sample is heated at 130 degrees in an air oven for 1 hour. The sample is then cooled to room temperature and the residue is weighed. the weighed of the sample after and before heating is compared. The difference in weight loss is the moisture content.

applicability Used to analyse wheat quality. Indicates grain stability. Indicates profitability in milling.

Equipment used to measure moisture content

Glutomatic test 10g of ground wheat sample is weighed and placed in the Glutomatic Washing Chamber. The sample is mixed and washed with a 2% salt solution for 5minutes. The wet gluten is removed from the washing chamber, placed in a centrifuge holder and centrifuged. The residue remains on top of the screen and is weighed.

applicability The wet gluten test provides information on the quality and quantity of gluten in the wheat samples. Gluten is required for the elasticity and extensibility characteristics of flour dough. Wet gluten reflects protein content and is a flour specification required to end users.

Falling number test 7g of wheat sample is weighted and combined with 25ml of distilled water in a Glass Falling Number Tube with a stirrer and shaken to form a shurry. As the shurry is heated at 100degrees and stirred constantly, the starch gelatinises and forms a thick paste. The time it takes the stirrer to drop through the paste is recorded as the falling number value. A falling number instrument analyses viscosity by measuring the resistance of flour and water paste to a falling stirrer.

applicability The level of alpha amylase activity measured by the falling number tests affects product quality. Too much enzyme activity results in sticky dough during processing and poor texture in the end product. Too low falling number makes it difficult to remove enzymes from the wheat resulting in unsuitable wheat. Falling number results are recorded as an index of enzyme activity in a wheat or flour sample and expressed in time as seconds.

WHEAT CONTAMINANTS

GROUP MEMBERS

HOSPITALITY