Food consumption of large population groups are much more often conditioned by limits due to health problems: coeliac disease, intolerances, different dismetabolisms may force consumers to reduce or to completely eliminate pasta consumption. Many times those consumers feel such a prohibition as a punishment and would be absolutely grateful to have again the possibility to eat a food that has all the good characteristics of pasta without having its problems, a food which is definitively “differently pasta”.
During last years the offer, not necessarily bound to coeliac consumers, of dry gluten free pasta has continuously developed, and at the moment the market offers goods products from the sensorial point of view, although their cost is not low. There is instead much less offer of fresh pasta – with or without eggs – and of filled pasta, frozen too; those products show moreover, at least according to my experience, unsatisfying sensorial characteristics.
The good knowledge of raw materials’ characteristics and of their production processes is the starting point to obtain good results on end products.
Gluten free flours which can be used to produce gluten free pasta are normally made by milling gluten free cereals or pseudocereals (most of all rice and corn, but also buckwheat, millet, sorghum, amaranth, teff, quinoa); also starches, obtained from rice, corn, from starchy roots (potato, sweet potato, manioc, cassava) or from some beans (mungo beans, soya), can be transformed into pasta, but generally the end product reminds the glass noodles, much more common in far East food tradition than in our dishes.
As known the manufacturing technology of gluten free pasta is based on thermoplastic properties of starch molecules, which, carefully cooked (gelatinized), can imitate with success gluten functional and sensorial properties.
Without spending too much time on starch molecular composition (amylose and amylopectine), on their different role in starch granules, on their different reologic behavior during gelatinization and on their different distribution depending on the botanical origin of the considered starch (table), it is otherwise necessary to well consider some basic information:
- the higher the amylopectin content, the faster the raw starch granules become hydrated (more porous);
- the higher the amylose content, the higher the starch gelatinization temperature and therefore a flour or a dough cooking temperature;
- the higher the amylose content, the stronger the derived gel, and therefore the higher the gumminess and the elasticity of cooked dough;
- the higher the amylose content, the deeper will be the gel, the cooked dough or the cooked pasta retrogradation (hardening by water elimination);
- retrogradation makes starches more slowly digestible and determines a lower glycemic index;
- retrogradation can be only partially reversed, and the absorption of water into a retrograded gel is difficult;
- the higher is the damaging degree of a starch (by mechanical or enzymatic action), the faster will be its hydration or rehydration and the lower the gelatinization temperature.