Rheological properties of spaghetti enriched with resistant starch

Spaghetti samples were produced with control, 5 % and 15 % as resistant starchtype III (RS3) in the formulation. Since RS3 containing spaghetti was planned tobe an alternative for bran containing spaghetti, a commercial bran containingspaghetti was included into the research. Main quality parameters of interest wereviscoelasticity, texture and thermal properties of spaghetti besides some well-defined criteria like colour, cooking loss and water absorption. Viscoelasticitywas tested by both stress relaxation and creep. The results were modelled byMaxwell, Burger and Peleg models. In general Peleg model was determined to bethe best model for both creep and stress relaxation data. Texture profile analysiswas done to better understand textural attributes and the results were comparedwith a panel test. Firmness and adhesiveness, which are the most importanttextural parameters for spaghetti cooking quality, were found to increase withincreasing RS3 amount in the formulation. Thermal properties of cooked anduncooked samples were also investigated. The onset and peak temperatures ofgelatinisation were found 58 and 64 oC, respectively. Enthalpy values of allspaghetti samples decreased with increase in cooking time. In vitro RS3determinations showed that the amount of RS3 (g/100 g dry sample) in 5 % RS3formulated spaghetti is 4.90 and in 15 % RS3, 7.57. This showed that amount ofRS3 in the end product was increased from low levels to intermediate and highlevels successfully. During cooking the amount of RS3 can be increased to highervalues.iiiCooking loss values which is an indicator of amount of dry matter lost into thecooking water increased as cooking time increased. It was a also found thatspaghetti with 15 % RS3 in the formulation gave the highest cooking loss values.However, water absorption values were highest for spaghetti produced with 5 %RS3 in the formulation also there was an increase in water absorption values withincrease in cooking time. Enrichment of spaghetti with RS3 in the formulationmade the color of spaghetti a little pale.Key words: Spaghetti, Resistant starch, Rheology, Viscoelasticity, Texture4