KARAKTERISASI LABEL KOLORIMETRIK DARI KARAGENAN/NANOFIBER SELULOSA DAN EKSTRAK UBI UNGU UNTUK INDIKATOR KERUSAKAN PANGAN

CHARACTERIZATION OF COLORIMETRIC LABELS FROM CELLULOSE CARAGENAN/NANOFIBER AND PURPLE SWEET POTATO EXTRACT FOR FOOD SPOILAGE INDICATOR. In this study, we has been used anthocyanin sources from purple sweet potato extract with carrageenan matrix and nanofiber cellulose (NFC) from pineapple leaf fiber. The materials that used are renewable natural materials and used in the food industry. One of them is the packaging industry such as active packaging and smart packaging, which can be used to monitor and inform consumers about food conditions directly. To prepare this indicator label, the carrageenan/NFC matrix was added dye extract from purple sweet potato with several concentrations (0%,1%,3%,5% v/v), then formed into a film using the casting method. Several characterizations were carried out, including testing the stability of the dye against pH, label morphology, mechanical properties, and label color response to food spoilage. The results obtained show that the label indicator is sensitive to pH changes. The color change of the label is from pink to clear greenish. From the results of the mechanical properties test, the label that has the highest tensile strength value is the label with the addition of 1% extract, which is 3.01 Mpa, while for the label with the addition of extract above 1%, the mechanical properties tend to decrease. Likewise with the results of elongation and WVTR, the addition of extract causes the label to tend to be hydrophilic, and this is needed in the mechanism of changing the color of the label. These results indicate that the addition of dye extract from purple sweet potato into the carrageenan/NFC matrix has the potential to be used as a colorimetric indicator for food spoilage detection, although some improvements must be made to improve the mechanical properties and WVTR value of the label.