Pengaruh Suhu Blanching dan Suhu Pengeringan Terhadap Mutu Fisik, Kimia dan Fungsional Tepung Ubi Jalar Ungu (Ipomea batatas L)

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ABSTRAK

MAGDALENA CRISTINA PARDEDE : Pengaruh suhu blanching dan suhu pengeringan terhadap mutu fisik, kimia, dan fungsional tepung ubi jalar ungu, dibimbing oleh ELISA JULIANTI dan RIDWANSYAH

Tujuan peneitian ini adalah untuk mengetahui pengaruh suhu blanching

dan suhu pengeringan terhadap mutu fisik, kimia, dan fungsional tepung ubi jalar ungu. Penelitian ini menggunakan rancangan acak lengkap dengan dua faktor, yaitu suhu blanching (B): (suhu blanching 60 oC, 70 oC , 80 oC and 90 oC)

suhu pengeringan (P): (50 oC, 55 oC, 60 oC, 65 oC). Parameter yang dianalisa meliputi nilai warna meliputi nilai L*, a* dan b*, densitas kamba, organoleptik warna dan aroma, indeks pencoklatan, kadar air, antosianin, daya serap air dan minyak, swelling power, kelarutan, dan baking expansion.

Hasil penelitian menunjukkan bahwa suhu blanching memberikan pengaruh berbeda nyata terhadap indeks pencoklatan dan memberikan pengaruh berbeda sangat nyata terhadap kadar air, antosianin dan daya serap air serta memberikan pengaruh berbeda tidak nyata terhadap densitas kamba, organoleptik warna dan aroma, daya serap minyak, swelling power, kelarutan, dan baking

expansion. Suhu pengeringan memberikan pengaruh berbeda nyata terhadap daya

serap minyak dan memberikan pengaruh berbeda tidak nyata terhadap nilai warna meliputi nilai L*, a* dan b*, densitas kamba, organoleptik warna dan aroma, indeks pencoklatan, kadar air, antosianin, daya serap air dan minyak, swelling

power, kelarutan, dan baking expansion. Interaksi antara kedua faktor

memberikan pengaruh berbeda sangat nyata terhadap kadar air dan memberikan pengaruh berbeda tidak nyata terhadap nilai warna meliputi nilai L*, a* dan b*, densitas kamba, organoleptik warna dan aroma, indeks pencoklatan, antosianin, daya serap air dan minyak, swelling power, kelarutan, dan baking expansion. Tepung dengan mutu terbaik diperoleh dari perlakuan suhu blanching 90°C dan suhu pengeringan 60 o_{C. Tepung dari hasil perlakuan terbaik memiliki nilai warna}

(Hue), nilai organoleptik aroma, total gula, gula reduksi dan kelarutan yang secara nyata (P<0,05) lebih tinggi dibandingkan tepung ubi jalar kontrol.

Kata kunci: suhu blanching, suhu pengeringan, tepung ubi jalar ungu

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ABSTRACT

MAGDALENA CRISTINA PARDEDE: The effect of blanching temperature and drying temperature on physical, chemical, and functional quality of purple

fleshed sweet potato flour, supervised by ELISA JULIANTI and RIDWANSYAH

The purpose of this research was to find the effect of blanching temperature and drying temperature on physical, chemical, and functional of purple flesh sweet potato flour. This research was using randomized design with two factors, namely the blanching temperature (B): (blanching temperature of 60

o_{C, 70} o_{C , 80} o_{C and 90} o_{C ) and the drying temperature (P): (50}o_{C, 55}o_{C, 60}

o_{C, 65}o_{C). The parameters analyzed were color values of L*, a* and b*, bulk}

density, organoleptic test of color and aroma, browning index, moisture content, antocianin, water and oil absorption, swelling power, solubility, and baking expansion.

The results showed that blanching temperature had significant effect on the browning index and had highly significant effect on the moisture content, antocianin and water absorption and had no significant effect on the bulk density, organoleptic test of color and aroma, oil absorption, swelling power, solubility, and baking expansion. The temperature of drying gave significant effect on the oil absorption, had no significant effect on the value of the color, bulk density, organoleptic test of color and aroma, browning index, moisture content, water and oil absorption, swelling power, solubility, and baking expansion. The interaction between the two factors had highly significant effect on moisture content and had no significant effect on the value of the color, bulk density, organoleptic test of color and aroma, browning index, water and oil absorption, swelling power, solubility, and baking expansion. The flour with the best treatment was using blanching temperature of 90°C and drying temperature of 60 °C. The flour with the best treatment had significant effect (P<0,05) on color value of hue, organoleptic test of aroma, total sugar, reducting sugar and solubility more higher than control.

Keywords: Blanching temperature, drying temperature, the purple flesh sweet potato flour