The researchers, who published their findings in the International Journal of Food Science & Technology, found that gluten-free spaghetti samples made with a high content of maize flour had high values of elongation and shear viscosity, and therefore a higher firmness.
Functional pasta using alternatives to wheat flour could offer and open up opportunities in the gluten-free market for pasta manufacturers.
The research team, based at the University of Foggia in Italy, claims that the appeal of pasta amongst consumers has made it a potential vehicle for highly nutritious compounds.
But pasta based on non-conventional flours needs to achieve a proper compromise between satisfactory sensorial and functional properties, they added.
Good quality pasta is defined as having high degree of firmness and elasticity, which is mainly termed as ‘al dente’. The team notes that evaluation of pasta cooking quality requires consideration of factors including elasticity, firm pasta structure, reduced adhesiveness, water absorption, and low cooking loss.
And, in order to optimise the formulation of functional and gluten-free pasta, the researchers said they experimented with different quantities of various flour types including quinoa, heat-treated maize and defatted soy flours.
They note that maize contains 7–13 g/100 g proteins, is rich in dietary fibre, vitamin B6, magnesium and it has very low fat content, while quinoa has a relatively high quantity of vitamins and minerals, iron and calcium.
Soybean flours, add the team, are used in many countries because they are a good resource of vegetable proteins, fat, lysine and other components that may be effective in reducing the risk of coronary heart diseases and several cancers.
Method
In order to prepare the non-conventional dough a portion of heat-treated maize flour was pre-gelatinised (PS). Water mixed with flour was heated at 80°C to obtain pre-gelatinised starch. Afterwards, the pre-gelatinised starch was cooled at about 40°C, and then added to the soy, quinoa and heat-treated maize flour and kneaded for 20 minutes. After kneading, the samples were extruded.
The water content of all samples was 43.65 per cent (w/w dough basis), explained the team.
Dry and fresh spaghetti samples were submitted to a panel of ten trained tasters in order to evaluate the sensorial attributes, with colour, odour, homogeneity, resistance to break and overall acceptability of non-cooked spaghetti, both dry and fresh, assessed.
Findings
Results suggest that either the absence of quinoa or low quinoa flour content and a high amount of maize flour increase the dough firmness.
And the researchers noted that pre-gelatinised maize improved the resistance to break and the taste of non-cooked and cooked spaghetti.
They also found that quinoa constituents bring about a bitter taste that affects negatively the overall acceptability of the pasta.
In terms of dry spaghetti, maximum value of overall acceptability was obtained at the maize flour PS concentration of 26.17 per cent, soy flour concentration of 4.25 per cent and at the lowest concentration of quinoa flour (0 per cent).
And, similarly, the best acceptability scores for fresh spaghetti were obtained with a high concentration of maize flour PS (30.78 per cent) and at the lowest concentration of quinoa flour (0 per cent), concluded the researchers.
The article cites financial support for the research project from the Apulia region in Italy.
Source: International Journal of Food Science & Technology
Published online ahead of print: DOI: 10.1111/j.1365-2621.2011.02613.x
Title: Formulation optimisation of gluten-free functional spaghetti based on quinoa, maize and soy flours
Authors: M. Mastromatteo, S. Chillo, M. Iannetti, V. Civica, M. Alessandro Del Nobile