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Sweetpotato starches were characterized to understand the changes upon modification by acid and heat‐moisture treatment (HMT) in the rheological, differential scanning calorimetry (DSC), and textural characteristics of starch isolated from the sweetpotato variety PSP‐21 and to compare these findings with those of commercially available arrowroot starch. The native sweetpotato starch had a Type A pasting profile characterized by a high peak viscosity (PV) (741.5 rapid viscoanalyzer unit [rvu]), with a high breakdown (378.8 rvu) and low cold paste viscosity (CPV) (417.6 rvu). After HMT, there was a marked decrease in the PV (639.1), a very slight breakdown (113.5 rvu) and an increase in CPV (759.5 rvu), more like a Type C pasting profile. However, acid modification did not notably change the pasting profile of native sweetpotato starch. The DSC characteristics were also affected significantly after modifications. The gelatinization temperature parameter to onset (To) decreased significantly after HMT and acid modification. The gelatinization enthalpy decreased during HMT from 15.98 to 14.42 J/g. The gel strength of acid‐modified starch was the highest compared with that of HMT and native sweetpotato and arrowroot starches.

Broken pieces of three indigenous rice cultivars were utilized for the formulation of tube type pasta (Ziti-cut) using four levels each of vital gluten and guar gum. The rice flours were modified by pregelatinization and the pregelatinized flour was found suitable for pasta preparation based on instrumental and sensory texture analysis. The cooking time for pasta was reduced from 10 to 6 min by using pregelatinized rice flour. The textural quality of pasta was analyzed using texture analyzer (TAXT-2i) and descriptive sensory analysis techniques. A protein level of 16% was found suitable for production of rice pasta, which was comparable to commercial semolina sample whereas a gum level of 1.5% supplemented to pregelatinized rice flour containing 14% protein was judged the best on the basis of instrumental as well as sensory textural characteristics.

Summary Sweet potato flour was used for the development of a pasta product. The system known as response surface methodology was used to analyse the effect of sweet potato flour, soyflour, water, Arabic gum and carboxy methyl cellulose (CMC) on quality responses (sensory, solids loss and hardness) of the pasta product. A rotatable central‐composite design was used to develop models for the responses. Responses were affected most by changes in soyflour and gum levels and to a lesser extent by sweet potato flour and water levels. Individual contour plots of the different responses were superimposed and regions meeting the maximum sensory score (33.8), minimum solids loss (16.6%) and maximum texture hardness (5616 g) were identified at 674 g kg−1 sweet potato flour, 195 g kg−1 water, 110 g kg−1 soyflour, 10.6 g kg−1 Arabic gum and 10.1 g kg−1 CMC levels.