Effect of added sweet potato and defatted soy flour and some storage conditions on selected chemical, physical, and sensory attributes of pasta

Pasta was prepared with all-purpose wheat flour, sweet potato (SP) flour or puree, defatted soy flour (DSF), whole egg, salt, and water. The objectives of Experiment 1 were to determine the effects of SP and DSF on proximate composition, color, β-carotene, cooking loss, and sensory attributes of pasta. From Experiment 1, 2 formulations were selected for further investigation. In Experiment 2, the objective was to determine the effects of packaging atmosphere, storage temperature, and storage period on color, moisture and β-carotene contents, and sensory attributes of pasta.

From Experiment 1, the addition of SP to the control pasta decreased crude protein and carbohydrate, increased ash and total dietary fiber, and had no effect on crude fat.The DSF decreased crude fat and carbohydrate and increased crude protein, ash, and total dietary fiber of SP-containing pasta. The SP as an ingredient in pasta reduced Hunter L and increased 'a' and 'b.' The DSF reduced Hunter L and 'b' and had no effect on 'a' of SP-containing pasta. β-carotene was increased with addition of SP, but was unchanged with addition of DSF. The level of β-carotene in SP- and DSF containing pasta was sufficient to provide 57.7% of the Recommended Dietary Allowance of retinol equivalents for an adult male and 72.1% for an adult female. Cooking losses were increased by addition of SP but were affected further only slightly with addition of DSF. The SP flour at 10% increased color and overall acceptabilities, but had no effect on flavor acceptability. Puree of SP had no effect on acceptability. The DSF did not effect acceptability of the pasta. Neither SP nor DSF affected pasta tenderness. The SP puree reduced pasta stickiness while SP flour had no effect as DSF.

From Experiment 1, the 2 formulations selected were 10% DSF with 10% SP flour and 10% DSF with 15% SP puree. In Experiment 2, pasta with 10% SP flour had the higher L and 'b' values, while pasta with 15% SP puree had the higher 'a' values. Packaging atmosphere did not influence Hunter color values. During storage, L and 'b' of samples packaged under vacuum or air increased and 'a' decreased. Storage conditions had minor effects on moisture change. Overall, pasta with 15% SP puree had the greater amount of β-carotene than pasta with 10% SP flour; storage at 4.4 °C yielded pasta with a greater amount of S-carotene than did storage at 22- 30 °C. Packaging atmosphere had no effect on β-carotene level. During storage, β-carotene of samples packaged either under vacuum or under air decreased. Overall, pasta with 10% SP flour was scored as "like moderately" or higher, while the storage conditions influenced acceptability scores to a minor degree.