Starter – what do you know about cereals? CarbohydrateGluten Fat bran Hardputrefaction Softmalt

Cereals What you need to learn: Cereals — importance of protein content, bread making. Malting process Cereal product deterioration, influence of moisture content and pests. Resources: PPT, BNF Cereals and Bread documents, Proudlove P ,

Nutritional Value Principal nutrient is Carbohydrate. Protein in cereal grain is of Low Biological Value. The amount of fat varies in the different grains but fairly LOW. Vitamins - B group, Riboflavin, A and C. Vit E in germ but often lost through oxidation. Minerals - Iron and Calcium.

Nutritional composition Depends on variety Weather Growing conditions Moisture content is ALWAYS higher after harvesting (read link) but if properly handled the grain will reach 10-14% moisture and the grain will not germinate or rot. harvesting

Structure All cereals share the same main structure. Embryo or germ from which root and shoot sprout Endosperm – stores starch which is broken down to glucose to supply energy Bran – several protective layers which covers the grain.

Composition of wheat Germ- 2%. The embryo plant rich in protein, fat and the B vitamins. Bran - 13%. The seed coats which protect the embryo and controls the intake of water. Mainly fibre but with some minerals and B vitamins. Endosperm - 85%. The young plant's food reserve composed of starch granules mixed with protein.

Wheat protein – the mixograph The Mixograph curve provides information about protein quality. The amount of water absorption affects the placement of the curve on the paper and the peak time. Higher water absorption levels indicate higher quality wheat flour proteins. The curve peak is the highest point obtained in the Mixogram. A well-defined peak indicates proteins that are suitable for bread- making. Longer peak times of well-defined curves indicate stronger gluten proteins.

Wheat Milling Bread made from wheat (rye bread popular in N. Europe) Wheat grain milled and separated. ‘Strong’ wheats have a higher protein content than ‘weak’ wheats (cakes/biscuits). Needed for bread. Hardness relates to endosperm texture and means how easily the endosperm disintegrates during milling. In hard wheats it separates more easily whereas in soft wheats it breaks down and does not separate. Hard wheats used for breadmaking and mill to give a free-flowing flour of high water-holding capacity. Soft wheats are often used for biscuit flours, mill to give poorer flowing flour of low water-holding capacity.

The Milling Process 1. Cleaning 2. Conditioning 3. Blending / Gristing 4. Breaking 5. Sieving 6. Reducing 7. Sieving

Cleaning, conditioning and milling Stones/metal/straw/seeds removed by machine - sieving/blowing hot air Metal removed using magnets Grains are washed in moving water then in a type of centrifuge The grain is opened using break rolls process, the grains do not crush but opened so the endosperm and bran are separate. See Milling process. Milling process The moisture content affects its milling ability. As moisture increases the bran toughens but the endosperm breaks down more easily. The ideal is 25-27%. This is attained by conditioning for 48hrs at 25oC. At higher moisture levels the bran sticks to the endosperm and will not separate easily. Harder wheats are conditioned by higher temperatures than soft wheats.

Yeast bread ingredients Flour provides the structure for the product. Fat contributes flavour and colour. Sugar adds sweetness, colour and moisture. Eggs are a leavening agent and the yolks add fat and act as an emulsifier for texture. Liquid carries flavourings, forms gluten bonds, reacts with starch in protein for structure. Salt strengthens gluten and adds flavour. Yeast makes the dough rise and adds flavour.

Types of wheat used in various products Strong wheats with high protein content required for breadmaking. Weaker - lower protein content for cakes and biscuits. Pasta made from semolina or Durum wheat has harder endosperm and needs less drying.

BASIC TYPES OF FLOUR Flours vary in their composition and, broadly speaking, are defined by their rate of extraction. This refers to the percentage of whole cleaned wheat grain that is present in the flour. The three basic flour categories are: Wholemeal percent extraction, made from the whole wheatgrain with nothing added or taken away. Brown - usually contains about 85 per cent of the original grain, some bran and germ have been removed. This flour is frequently labelled as "85 per cent flour" rather than brown. White - usually 75 per cent of the wheatgrain. Most of the bran and wheatgerm have been removed during milling. Wheatgerm - white or brown flour with at least 10% added wheatgerm. Malted wheatgrain - brown or wholemeal flour with added malted grains. Stoneground-wholemeal flour ground in traditional way between two stones. Organic -flour milled from a wheat grown and processed naturally without the use of chemicals.

Bread making Chorleywood process Chorleywood process – see link. What is the role of vitamin C in this process? How does the straight dough system differ from this method?

Explain the differences in the physical appearance and nutritional composition of these 3 cereals. Rye grain

Rye Likes colder and drier conditions Rye protein contains some gluten but lacks elasticity Loaves are poor volume and very dense Higher in fibre, darker in colour Often soured with a starter culture which gives acidity and rye bread’s characteristic flavour.

Maize - Corn Popular in many poorer countries in the world Poorer nutritionally than wheat or rye Deficient in lysine and tryptophan Low in nicotinic acid Cornflour is an important product from maize and is used extensively in food processing.

Barley Barley – used in brewing industry, malt vinegar, malt whisky. Malt is made from germinating barley 1. Steeping The moisture content of the barley is raised from typically 12% to 43-46%. 2. Germinating Barley is allowed to sprout in warm moist conditions so the amylases become active and start to break down the endosperm. The endosperm loses its hard structure and becomes "modified". Starch is then hydrolysed to simple sugars (eg maltose). 3. Kilning dries the grain down to 3-6% moisture and arrests germination. Large volumes of hot air are blown through the grain. By varying air flows and kiln temperatures malts of different colour can be produced with varying flavour profiles. At the end of kilning the malt is cooled and the tiny rootlets removed. If stored correctly, malt at 3-% moisture may be stored for several months with no loss of quality.

Process of obtaining Malt Obtained from Barley. Exposed to warm and moist conditions to bring about sprouting / germination. Enzyme - amylases break down starch to maltose.

Putrefaction and Deterioration of cereals Optimum moisture content range for cereal grain is %. The moisture levels are critical. Higher levels encourage germination and mould attack.Higher levels encourage germination and mould attack. Higher moisture conditions induce germination and this leads to the conversion of starch to sugar as the grain uses up its food store. As water availability increases bacteria and moulds are able to multiply and begin to rot the grain. During storage, cereals are subject to insect and rodent attack. Without good storage practice, cereal grain can be seriously damaged by insects and other pests. Make notes on storage and care of grain post harvesting.