Effects of red rice or buckwheat addition on nutritional and technological quality of potato-based pasta

The main objective of the present study was to investigate the effects of red rice (R) or buckwheat (B) flour addition on nutritional and technological quality of frozen potato-based pasta tailored to celiac consumers. Since pasta behavior during cooking is related to protein network, effects of R and B addition in traditional (containing gluten) products were explored for comparison. One gluten free (GF) and one traditional (T) sample without R or B addition and four samples containing 20% R (GFR and TR) or B (GFB and TB) were investigated. All samples were produced in an industrial line by a turbo-cooking technology and individual quick-freezing at -35°C. Pasta samples were evaluated in terms of proximate composition, starch digestibility, and cooking behavior. The addition of R and B increased the amount of fats and reduced starch content in both traditional and gluten-free products. The enrichment with B promoted a significant increase in dietary fiber in both the product types (4.8±0.5 versus 1.7±0.1 g/100g, respectively for TB and T; 6.0±0.5 g/100g versus 0.8±0.3 g/100g, respectively for GFB and GF), mainly represented by the insoluble fraction. However, compared to T and GF products, samples added with R or B showed an increase in the ready digestible starch fraction, thus suggesting a potential increase of the glycemic impact. The addition of R flour worsened the structure of GFR sample with respect to GF, increasing significantly (p<0.05) matter loss in cooking water (5.4±1.2 versus 4.1±0.5 g/100g pasta) and reducing significantly (p<0.05) the product resistance to shearing/extrusion (from 408±13 to 108±2 N) as evaluated using a Kramer cell. While the presence of B flour resulted in intermediate shear force values (243±8 N), despite the highest weight increase of this sample during cooking. Similar trends were found also for R and B addition in the traditional samples, indicating a better texturizing capacity of buckwheat in comparison to red rice flour. Outcomes of this research can be useful in developing new potato-based pasta for consumers focused on healthier foods and industries willing to better valorize their products. This work was supported by Lombardy Region (Linea R&S per Aggregazioni; project number 145075).