Pasta Production презентация

Pasta Production NUFS 283: Food Engineering Group 3

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Introduction Pasta is popular because it… Is nutritious Is convenient to buy and prepare Has a long shelf life

Inputs: Ingredients Semolina made from durum wheat Water Salt

Inputs: Ingredients Optional: Eggs Spinach, tomato puree, chilli, mushrooms for flavour Substitutes: Rice, corn, spelt, kamut for semolina flour Whole grain, non-grain, or soy-bean flour for semolina to make it more nutritious

Selection of Semolina Semolina preferential to other flours for its Particle size High protein content of 13-14% dwb Makes a less sticky dough during processing for easier extrusion

Combining ingredients Three steps involve Mixing Processing Extruding

Combining ingredients: Pre-mixing Ingredients flows into mixer is regulated by a volumetric or gravimetric doser 0.180mm mesh sieve sifts the flour to acquire a homogeneous dough The flour and water is sent through a high pressure pre-mixer to hydrate the mixture

Combining ingredients: Mixing Bubbles are removed by a conventional dual shaft mixer to prevent a weak and pale pasta from forming Warm water (45-60°C) is added to bring the moisture content of the dough to 28-32% Spaghetti requires 16-18 minutes in the mixing chamber

Mixing Calculation Must consider energy balance of inputs in order to achieve desired properties: ∑Mi ⋅Δhi =Mflour ⋅Δhw +M⋅Em − Qj ∆hw = 15.1 kJj/kg

Combining ingredients: Extrusion Gluten matrix develops, assuming dough was sufficiently hydrated

Extrusion An extruder ____ the dough. Convey Compacts Kneads Relaxes Extrudes

Extrusion Hydrated semolina mixture drops directly onto the extrusion screw Screw brings mixture to extrusion barrel, where it is compacted Pressure increase from to 2 MPa to form a compact dough Screw continues to move dough along to extension plate

Extrusion: Challenges yet Difficult to form uniformly kneaded dough Solution: apply a kneading plate Friction between the walls, barrel, and screw increases the temperature of dough Tremove = (TFrictional + TExtrusion screw)°C – 45°C (Specific Mechanical Energy) SME = Cp = 1.44 + 2.74Xw Ideal temperature: 45 - 50°C 50°C impedes gluten matrix formation Too cool will yield a dough with undesirable viscosity

Extrusion Long pasta, like spaghetti are allowed a brief rest before entering the die in the extension tube The pasta will be fully developed by the time taken to reach the end of the extension tube

Extrusion Die is used with an insert to shape pasta Shape of insert determines shape of pasta Circular for spaghetti Inserts are coated with Teflon to decrease friction and increase rate of extrusion Also prevents pasta from absorbing water while being cooked Extruder output = drag flow - pressure flow - leakage flow

Extrusion Long pastas are left to stand on a spreader which cuts them into uniform lengths Trims result from uneven flow out from the die Are collected and brought back to mixer via trim return system Pastas are then attached to sticks are transfer to dryer

Drying Purpose: to reduce moisture content to 12% to extend shelf life Limits bacterial growth

Drying Four factors involved: Humidity Temperature Time exposure to heat Air flow Air flow and time exposure affects humidity and temperature

Drying: Air flow Direct contact between air and the pasta enables the most efficient method of drying due to the greater surface area

Drying: Humidity Wet hot air (40-70% w/w) Prevent product from cracking at high temperatures

Drying: Exposure Time High temperatures requires shorter exposure time Rapid drying may form cracks in the dough and result in a brittle the final product Low temperatures requires longer exposure time Moulds development, especially on the inner parts

Drying: Temperature Needs to be regulated because Too high: damage product and destroy nutrients Too low: expensive and inefficient Ranges from 32-110°C Spaghetti Pre-dried with gradual increase 30-56°C Dried by gradual increasing from 56-72°C

Drying: Temperature Regulations Short pastas are regulated by: Being on a shaking pre-dryer to decrease time exposure to high temperature in drier Long pastas are regulated by: Pre-dried with blast of air for 30-60 minutes Dried at 55-82°C Cooled in a cooling chamber by indirect water contact at 28-32°C for 1.5 hours

Use of Ultra High Temperature Application of Ultra-High Temperature May cause non-enzymatic browning May result in lysine and vitamins losses Shortens drying time of spaghetti from 12 hours to 4.5 hours Result in product with better cooking properties Greater expression of yellow in product

Improper cooling? Damage the packaging Contaminated product Brittle product

Nutritional and Sensory Quality Nutritious Carbohydrates Protein Vitamin B Iron Folic acid Not fattening itself

Nutritional and Sensory Quality Ideal food for diabetics, especially whole grain products Slow digestion Maintains steady glucose levels Gradual insulin release Because of the limited surface area for α-amylase Tight protein structure Limited porosity With cooking, swelling of pasta restricted by tight gluten matrix and oligosaccharides

Nutritional and Sensory Quality Yellowness of pasta determine by Adding eggs Adding β-carotene (most times) β-carotene (vitamin A precursor) Prevents many diseases Immune function Vision Processing makes this more bioavailable

Nutritional and Sensory Quality Cooking should not exceed >50°C Damage gluten matrix Loss of lysine, vitamins, furosine Mixing and extruding under pressure Decrease beta-carotene oxidation Water increase calcium and copper slightly

Summary Mixing, extruding, and drying are required in pasta processing Extrusion process forms gluten network Useful in forming desirable structure for shaping and cooking Gluten also helps retain nutrients

Summary Drying creates a moisture gradient Reduces required drying energy, temperature, and time Drying requires attention in order to ensure safety and maintain nutrients Shelf stable product Preserve nutrients in gluten matrix

Photo References http://www.food-info.net/images/pasta/pasta.jpg https://files.nyu.edu/avl236/public/Flat%20Noodles.jpg https://files.nyu.edu/avl236/public/pasta.JPG http://bombaybazar.ie/images/semolina-19582.jpg http://thinkcommon.com/blog/wp-content/uploads/2009/05/water.jpg http://www.wholesaleitalianfood.com/media/catalog/category/file_6.JPG http://www.italgi.it/foto/extrspag1.jpg http://www.klaroudaseeds.com/wheat-Thur06.jpg http://images.google.ca/imgres?imgurl=http://www.freshpastamachines.co.uk/images/lillo_dies.jpg&imgrefurl=http://www.freshpastamachines.co.uk/lillo_due_pasta_machine.html&usg=__zGyw76D9SF_rMXa9AoGFgLEITJg=&h=302&w=320&sz=33&hl=en&start=47&itbs=1&tbnid=YToJZz90WcMP6M:&tbnh=111&tbnw=118&prev=/images%3Fq%3Dpasta%2Bextruder%26start%3D36%26hl%3Den%26client%3Dfirefox-a%26sa%3DN%26rls%3Dorg.mozilla:en-GB:official%26gbv%3D2%26ndsp%3D18%26tbs%3Disch:1