Editing Pasta (section)

==Science==

===Molecular and physical composition===
Pasta exhibits a random molecular order rather than a crystalline structure.<ref name="Roos-2010">{{cite journal |doi=10.1146/annurev.food.102308.124139 |pmid=22129345 |title=Glass Transition Temperature and its Relevance in Food Processing |journal=Annual Review of Food Science and Technology |volume=1 |pages=469–496 |year=2010 |last1=Roos |first1=Yrjö H |s2cid=23621696 }}</ref> The moisture content of dried pasta is typically around 12%,<ref>{{cite journal |doi=10.1111/j.1745-4603.2006.00079.x |title=Dynamic Viscoelastic Properties of Pasta As a Function of Temperature and Water Content |journal=Journal of Texture Studies |volume=37 |issue=6 |pages=696–710 |year=2006 |last1=Takhar |first1=Pawan Singh |last2=Kulkarni |first2=Manish V |last3=Huber |first3=Kerry }}</ref> indicating that dried pasta will remain a brittle solid until it is cooked and becomes malleable. The cooked product is, as a result, softer, more flexible, and chewy.<ref name="Roos-2010" />

Semolina flour is the ground endosperm of durum wheat,<ref name=wg/> producing granules that absorb water during heating and an increase in viscosity due to semi-reordering of starch molecules.<ref name=wg/><ref name="Sissons-2008" />

Another major component of durum wheat is protein which plays a large role in pasta dough rheology.<ref name="shewry1">{{cite journal |doi=10.1098/rstb.2001.1024 |pmid=11911770 |pmc=1692935 |title=The structure and properties of gluten: An elastic protein from wheat grain |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |volume=357 |issue=1418 |pages=133–142 |year=2002 |last1=Shewry |first1=P. R |last2=Halford |first2=N. G |last3=Belton |first3=P. S |last4=Tatham |first4=A. S }}</ref> Gluten proteins, which include monomeric gliadins and polymeric glutenin, make up the major protein component of durum wheat (about 75&ndash;80%).<ref name=shewry1/> As more water is added and shear stress is applied, gluten proteins take on an elastic characteristic and begin to form strands and sheets.<ref name=shewry1/><ref name="Kill-2001">{{Cite journal|last1=Kill|first1=R. C.|last2=Turnbull|first2=K|year=2001|title=Pasta and semolina technology}}</ref> The gluten matrix that results during forming of the dough becomes irreversibly associated during drying as the moisture content is lowered to form the dried pasta product.<ref name="De Noni-2010">{{cite journal |doi=10.1080/10408390802437154 |pmid=20373190 |title=Cooking Properties and Heat Damage of Dried Pasta as Influenced by Raw Material Characteristics and Processing Conditions |journal=Critical Reviews in Food Science and Nutrition |volume=50 |issue=5 |pages=465–472 |year=2010 |last1=De Noni |first1=Ivano |last2=Pagani |first2=Maria A |s2cid=12873153 }}</ref>

===Impact of processing on physical structure===
Before the mixing process takes place, semolina particles are irregularly shaped and present in different sizes.<ref name=wg/><ref name="Petitot-2009">{{cite journal |doi=10.1016/j.tifs.2009.06.005 |title=Structuring of pasta components during processing: Impact on starch and protein digestibility and allergenicity |journal=Trends in Food Science & Technology |volume=20 |issue=11–12 |pages=521–532 |year=2009 |last1=Petitot |first1=Maud |last2=Abecassis |first2=Joël |last3=Micard |first3=Valérie}}</ref> Semolina particles become hydrated during mixing. The amount of water added to the semolina is determined based on the initial moisture content of the flour and the desired shape of the pasta. The desired moisture content of the dough is around 32% wet basis and will vary depending on the shape of pasta being produced.<ref name="Petitot-2009" />

The forming process involves the dough entering an extruder in which the rotation of a single or double screw system pushes the dough toward a die set to a specific shape.<ref name=wg/> As the starch granules swell slightly in the presence of water and a low amount of thermal energy, they become embedded within the protein matrix and align along the direction of the shear caused by the extrusion process.<ref name="Petitot-2009" />

Starch gelatinization and protein coagulation are the major changes that take place when pasta is cooked in boiling water.<ref name=shewry1/> Protein and starch competing for water within the pasta cause a constant change in structure as the pasta cooks.<ref name="Petitot-2009" />