Nutritional evaluation of a high-temperature dried soft wheat pasta supplemented with cowpea (Vigna unguiculata (L) Walp).

The objective of this study was to determine the nutritional quality of the pasta described above. The work was unique in the following aspects: 1) the drying process was a nonconventional method, consisting of a high-temperature short-time (HTST) process; 2) the nutritional quality of the wheat pasta was improved by the cowpea supplementation. Cowpea was especially chosen due to it being a staple food in the diet of the people in Northeast Brazil. Benefits attributed to the HTST drying process include a reduction in bacterial counts, shorter processing time and less energy consumption. In addition, there are reports in the literature of improved pasta firmness, color intensity, and cooking characteristics, when non Triticum durum materials plus drying are used. The pasta produced in this work was made using 100% soft wheat flour (SP), and soft wheat flour (SF) mixed supplemented with 10, 20 and 30% dehulled cowpea meal (CM); referred to as 10, 20 and 30% SP, respectively. The methods utilized in this project included: AACC methods for proximate analyses and trypsin inhibitor activity determination, atomic absorption spectrophotometry for mineral determination, a dye binding procedure for measuring available lysine, HPLC for amino acid quantification., FAO/WHO amino acid scoring patterns for chemical scores and AOAC for protein digestibility. The protein content of the past as supplemented with CM ranged from 11.3 to 14.2%, while the 100% SF pasta (SP) contained 10.9%. CM supplementation resulted in 52 to 113% more total lysine, and 26 to 82% more available lysine in the CM pasta compared to the SP. Chemical scores for SP were 45 and 59% for preschool and school-age children, respectively. Adding 30% CM to SP improved the above chemical scores to 89 and 100+, respectively. However, the addition of CM compromised the in vitro protein digestibility of SP from 4 to 6%. The addition fo 30% CM provided the SP with greater calcium (Ca), iron (Fe), zinc (Zn) and copper (Cu): 44, 49, 91 and 402% respectively. Cooking the CM pasta resulted in a 50 to 90% retention of mineral content, with the greatest loss being for Cu. In the cooked 30% CM pasta, the contents of Fe, Zn and Ca were, respectively, 50, 67 and 243% greater than their content in the cooked SP. Of the cooked pasta, the only one displaying trypsin inhibitor activity was the 30% CM pasta, which had 0.8 TIU.