Label Cerdas Indikator Warna dari Ekstrak Kubis Merah (Brassica oleracea).

Abstract

Smart packaging is an indicator, either it is placed internally or externally in the food packaging to provide information about the quality of the product packed. One of the most popular nowadays is in the form of film made from PVA (polyvinyl alcohol) with additional natural dyes as its indicator. The purpose of this research was to study and develop smart packaging made from PVA and red cabbage extract as the natural dyes and figure out the best formulation as well as to study the film coloring technic. First step was the red cabbage color extraction conducted in methods namely: 1) boiling, 2) crushing in a blender, and 3) solvent extraction using 98% ethanol; while the selected process was by boiling for 7 minutes resulting extract with pH of 6.21 and anthocyanin content of 25.02 mg per 100 gram red cabbage. Afterwards, film preparation with PVA powders formulations applied as following: 3 g (w/w), 3.5 g (w/w) and 4 g (w/w); while the best film resulted with thickness of 0.15 mm, tensile strength of 2.64 kgf/mm² and elongation of 210% shown by 3.5 g PVA powder film formulation. Film formulation technique by mixing method produced colorless film, whereas tinting method showed more uniform and stable colored film. Indicator film color measurement for room, cooler and freezer temperature showed L determination coefficient were 0.782, 0.418 and 0.066, respectively; a* value of 0.7975, 0.5880 and 0.7179, respectively; and b* value of 0.8393, 0.4534 and 0.3631, respectively. oHue linier equation revealed high determination coefficients of 0.8536, 0.6586 and 0.8061, respectively. Rising storage temperature lead to increase in ohue value, and the longer storage time the higher ohue value.