(The Use of Erpa (Aerva sanguinolenta) Leaf Extract as Colour Indicator Smart Label)

Endang Warsiki*, Rini Nofrida, Indah Yuliasih

ABSTRAK

Pewarna alami antosianin sangat mudah berubah warna karena suhu di sekitarnya berubah. Perubahan warna ini dapat dimanfaatkan sebagai indikator warna untuk memberikan informasi tentang kerusakan produk yang sensitif terhadap suhu dan cahaya yang dinamakan label cerdas indikator warna. Label film dibuat dari kitosan dan polivinil alkohol dan ekstrak warna daun erpa (Aerva sanguinolenta). Ekstraksi dilakukan dengan berbagai nisbah daun:air. Film dibuat dengan 2 cara, yaitu (i) pencampuran dan (ii) pengolesan. Ekstrak warna daun erpa memiliki pH 5,09 dengan rendemen total 116,65 mg antosianin/100 g daun segar. Pembuatan film indikator warna dengan metode pencampuran pewarna ke dalam larutan film dan kemudian dikeringkan pada suhu 50 ?C, telah menghasilkan film yang tidak berwarna. Pewarnaan film dengan metode pengolesan 1 mL pewarna per 40 cm2 film menghasilkan film yang berwarna merata dan stabil yang dapat dimanfaatkan dengan label cerdas indikator warna.

Kata kunci: ekstrak daun erpa, indikator warna, label cerdas

ABSTRACT

The colour of natural dyes, as anthocyanins, is very easily changing as he temperature changes. The color change can be used as a color indicator to provide information about product deterioration due to its sensitivity toward temperature and light. This indicator is called smart label of colour indicator. This film label can be made of chitosan and polyvinyl alcohol and extract of erpa (Aerva sanguinolenta) leaves. The extraction was done under various leaf:water ratios. The filming was done in 2 methods, i.e. (i) by mixing the extract into film solution and drying the film at 50 ?C; and (ii) by brushing the extract on the film surface. The leaf extract had a pH of 5.09 and the total yield of 116.65 mg anthocyanin/100 g leaves. Filming of color indicator in mixing method and dried at 50 ?C resulted a colorless film. Brushing method was the best method to produce smart label with quite stable property and 1 mL extract could be applied evenly per 40 cm2 film area. Thus, this film can be utilized as smart label with color indicator to detect the deterioration in temperature-sensitive products.

Keywords: colour indicator, erpa leaf extract, smart label