KAJIAN AKTIVITAS ANTIOKSIDAN, SERAT PANGAN,DAN
KADAR AMILOSA PADA NASI YANG DISUBSTITUSI DENGAN
UBI JALAR (Ipomoea batatas L.) SEBAGAI
BAHAN MAKANAN POKOK
Sweet potato is a local commodity which is potential as staple food. The
making a sweet potato rice can reduce the depence on rice because sweet potato can
substitute rice up to 40%. The purple and aranye sweet potato contain a natural
oligosaccharide fiber and also pigmen antosianin and β-carotene which is used as
antioxidants.
The aim of this study is to know the influence of the different types and the
concentration of sweet potato toward antioxidants activity, dietary fiber, and amilosa
content on sweet potato rice. The study also aims to know the exact concentration of
sweet potato in the making of sweet potato rice to be like by the consumer. The
ingredients, which is used in the making of sweet potato rice, is rice type SS-64 super
which is gotten from one of the farmer in Surakarta while oranye and purple sweet
potatoes are from Tawangmangu. The rice is mixed with sweet potato paste with the
concentration at 30%, 35%, and40% than it is mixed with water. The comparation
between the rice and the water is 1 : 1,4. Then, those ingredients are boiled until a
half cooked, or until the water is all used up. After that, then it is cooked or steamed.
The parameter which is tastedin the study is the antioxidants activity, dietary
fiber, amilosa content, and sensoric content (such as the color, the taste, the aroma,
the teksture, and the whole aspects). The result of the test is statistical analized by
using ANOVA at α = 5%.
The results of the study shows that the purple sweet potato rice has the
antioxidants activity which is higher than the oranye sweet potato rice. Thus, the
higher concentration of sweet potato which is mixed with the rice, the higher
antioxidants activity will be. Different types of sweet potato does not influence
toward sweet potato rice dietary fiber content. The higher concentration of sweet
potato, the higher sweet potato rice dietary fiber content will be. The result also
shows that the amilosa content of the oranye sweet potato is higher than the purple sweet potato rice. Based on chemical test result, the purple sweet potato rice 40% has
the highest antioxidants activity and dietary fiber and the lowest amilosa content.
From sensoric side, the purple sweet potato tends to be liked with the presentage up
to 40% eventhough the value of this evaluation does not show a real distinction.
Key words : Antioxidants activity, dietary fiber, amilosa, sweet potato, rice