Abstract. Shrimp is a type of perishable food. This study developed a simple indicator label using colorimetric method for monitoring shrimp freshness. This indicator label was made from natural dye extract of Ruellia simplex flowers which immobilized on cellulose paper by dip coating method. The indicator labels were used for examining freshness of shrimp. In this experiment, shrimp were stored in sealed bottles that have been labeled using the indicator and stored at 13 °C, 25 °C, and 40 °C for a certain range of time. Color changes of the indicator labels were observed using digital photography after shrimp storage for 0 h, 2 h, 17 h and 24 h. The color changes that occur were quantified and analyzed using the ImageJ program. The color of the indicator label when detecting the fresh shrimp was pink and after the shrimp spoilage began, the color of the label changed to purple and then became yellow when the shrimp is badly spoilage. The color change rates of label indicator increases as the shrimp storage temperature increased. These results indicate that this label indicator can be used as an indicator of the freshness of shrimps and it is not toxic and safe for food.

ABSTRAK KERTAS LABEL KOLORIMETRIK DENGAN EKSTRAK UBI UNGU SEBAGAI INDIKATOR PADA KEMASAN PINTAR UNTUK MENDETEKSI KESEGARAN SUSU.Produk susu sangat rentan terhadap penurunan kualitas yang dapat disebabkan karena faktor penyimpanan, padahal kualitas susu sangat penting untuk diperhatikan sebelum dikonsumsi. Pada penelitian ini dikembangkan label kolorimetrik sebagai indikator pada kemasan pintar yang dapat mendeteksi kualitas susu secara sederhana dan murah. Label kolorimetrik dibuat dari kertas selulosa dan ekstrak Ipomoea batatas sebagai zat warna alami untuk mendeteksi kualitas susu. Label dibuat dengan variasi pH ekstrak pH 2, pH 7, dan pH 11. Pengujian label dilakukan untuk kondisi penyimpanan suhu pada temperatur 4 o C, 23 o C dan 40 o C selama waktu 48 jam. Perubahan warna label difoto digital dan kemudian dihitung dengan analisis warna RGB. Hasil eksperimen menunjukkan label kolorimetrik dengan ekstrak zat warna pH 2 mengalami perubahan warna dari merah muda ke merah keunguan, pH 7 berubah warna dari ungu ke ungu terang agak kemerahan, dan pH 11 berubah warna dari biru keabuan menjadi terang kekuningan setelah 48 jam. Dengan demikian label kolorimetrik dengan ekstrak zat warna pH 11 paling baik untuk mendeteksi kesegaran susu, karena mengalami perubahan warna yang paling kontras. Penelitian ini menunjukkan bahwa label kolorimerik berbahan dasar ekstrak Ipomoea batatas baik untuk digunakan sebagai indikator pada kemasan pintar untuk mendeteksi kesegaran susu secara visual dan sederhana.Kata kunci : label kolorimetrik, kemasan pintar, kesegaran susu ABSTRACT PAPER-BASED COLORIMETERIC LABEL USING SWEET POTATO EXTRACT AS MILK FRESHNESS INDICATOR IN SMART PACKAGING. Dairy products are particularly susceptible to quality degradation because of storage factors, yet the milk quality is very important to be considered before being consumed. This research has been developed to utilize colorimetric label as an indicator

Silver nanoparticles are well known for their antimicrobial properties and have been widely used in medical and industrial applications to prevent the growth of microorganisms. The effectiveness of silver nanoparticles (AgNPs) as an antimicrobial material is influenced by their shape and size; the smaller the size, the more active the AgNPs. To prevent aggregation, the nanoparticles can be maintained by stabilizing agents. This study aims to synthesize silver nanoparticles in situ using cellulose paper and to evaluate their antimicrobial activity. For reduction of Ag+ ions were used propane-1,2-diol. The reduction was carried out at 60, 80, and 100o C to accelerate the reaction. The formation of silver nanoparticles can be seen from the change in paper color from white to yellow or brown. This result is confirmed by the occurrence of the absorption peak in the UV-Vis spectrum between 300-500 nm. The TEM image shows the size distribution of silver nanoparticles affected by their reduction temperature. Antimicrobial tests provide a clear zone from the bottom of the paper to the edge. The reaction temperature at 60o C showed the best antimicrobial activity with AgNPs averaging at 6 nm. This method can be applied to antimicrobial paper preparation with controlled size and distribution.

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Studies on mechanical and barrier properties of Tapioca/PVA composites reinforced with pineapple leaf nanocellulose have been done to obtain an alternative new biodegradable label for freshness label of smart packaging for food. The aim of this research is to investigate changes of mechanical and barrier properties of Tapioca/PVA/Nanocellulose compared with Tapioca/PVA composite. Composition of Tapioca/PVA was 50:50 with nanocellulose concentration vary from 1, 3, 6 and 10% in composites. Tensile strength and elongation were used to evaluate the mechanical properties of the films. While for water barrier properties was investigated by vapor transmission rate. The microstructure of the films was evaluated by using FT-IR, and SEM. The results showed that increasing the concentration of nanocellulose decreasing the tensile strength and elongation of composites. The concentration of 1% nanocellulose increased the WVTR and in greater amount will reduce the value of WVTR. Addition of nanocellulose decreased the transparency of the composite films. For further application, it can be used as a label for freshness label of smart packaging with the addition of functional material.