Description of Durum Semolina Quality Factors

Moisture % - Water content in the wheat inversely related to the amount of dry matter. Dry wheat can be kept for years if properly stored, but wet wheat may deteriorate dramatically.

Protein % (12% MB) - Ranges from 6% to 20%, depending on variety, class, environmental conditions and cultural practices during growth. Rainfall during kernel development results in low protein, whereas dry conditions during development usually results in high protein. 1 to 1.5% of protein is lost when the wheat is milled into flour.

Ash % - Mineral content in the wheat. Bran has higher ash content than flour. Small or shriveled kernels have more bran on a percentage basis and therefore more crude fiber and ash than large, plump kernels and consequently yield less flour. Wheat usually contains 1.4 to 2% ash at 14% moisture basis.

Test Weight (lb/bu) - Wheat weight per unit volume. Most widely used and simplest criteria of wheat. Rough index of flour yield.

Wheat Hardness (NIR) - A means of determining hard and soft wheat kernels. The higher the hardness the higher the absorption.

1000 Kernel Wt. (g) - Function of kernel size, shape, dryness, purities and density and also an index of potential milling yield.

HVAC (Hard Vitreous Amber Color) - Vitreousness is that characteristic which gives the wheat kernels a hard, glossy appearance, and is usually related to protein content. The best milling quality will be found in those wheats of highly vitreous kernels.

Kernel Size Dist. (g) - Percentage of large, medium, and small kernels in a durum wheat sample.

2. SEMOLINA ANALYSIS

Moisture % - Flour Moisture content is usually in the range of 12-15.

Protein % - 1 to 1.5% of protein is lost when the wheat is milled into flour.

Ash % - A highly significant correlation is found between ash content and the brightness of semolina. For any given wheat, higher extraction produces darker semolina with higher ash content.

Falling Number (Sec) - A measure of the a-amylase activity (starch liquefied enzyme). With more a-amylase, degradation of starch is greater and starch viscosity decreases, giving a decreased falling number. A falling number of 300 and above is desirable.

Wet Gluten % (14%MB) - Determined with the glutomatic instrument using 10 grams of semolina and with results expressed on a 14% moisture basis.

Dry Gluten % (14%MB) - The remainder from wet gluten test is completely dried by placing doughball in a heat press (Glutork) for 4 minutes and then weighed.

Speck - The number of bran specks per 10 sq. in. area of semolina. A test of the milling efficiency.

Color "b" Value - The intensive yellowness of pasta color. The color measured by Minolta Chromameter; the higher the value the more yellowness of the semolina or pasta.

3. EXPERIMENTAL MILLING

Total Extract - Percentage of flour and semolina from 100% tempered durum wheat.

Semolina Extract - Percentage of semolina from 100% tempered durum wheat. Must not contain more than 3% flour through a #100 US sieve.

4. PASTA ANALYSIS

Color - A spaghetti sample with a color score 9.0 or greater is good, 8.0 to 8.9 is fair, and below 8.0 is a poor sample as far as color characteristics.

Cooked Weight - This test is best used in conjunction with firmness values to determine the cooking qualities of a spaghetti sample. A 10 gm spaghetti sample (precooked weight) is used for this test. A good spaghetti sample will have a high cooked weight with a high firmness value. A poor quality spaghetti sample will have a high cooked weight with a low firmness value. Generally a cooked spaghetti sample will weigh three times (30 gm) its pre-cooked weight. AACC method 16-50.

Cooking Loss - To determine the amount of solubles lost during cooking using AACC method 16-50. A spaghetti sample with a cooking loss below 6.0 is good, 6.0 to 6.9 is fair, and 7.0 or above is a poor sample.

Firmness - AACC method 16-50 modified by using two strands of spaghetti for the firmness measurement. A spaghetti sample with firmness 6.0 and above is good, 5.0-5.9 is fair, and below 5.0 is a poor sample.

5. ALVEOGRAPH

Analysis of dough strength.

W - Surface of the recording curve linked to the energy required to rupture the dough bubble.
P/L Ratio - Measure of resistance and extensibility.