Comparison Of Carriers In Anthocyanin Smart Packaging From Water Hyacinth Flower For Soy Milk Freshness

Dairy products are highly susceptible to quality degradation caused by environmental conditions. The quality of soy milk is an important factor to consider before consumption. This study explores anthocyanin extract from water hyacinth flowers as a natural pH indicator due to its good sensitivity and eco-friendly potential. The flowers were chosen because their anthocyanin content has rarely been studied, and their use helps reduce waste while offering a safer alternative to synthetic dyes. The type of carrier material also influences the performance of the indicator label. This study compares the effectiveness of cellulose and starch as carriers in an anthocyanin-based smart packaging. The testing parameters included organoleptic tests, moisture absorption, FTIR characterization, and indicator label testing over 48 hours. The indicator label successfully detect pH changes in soy milk. At pH 9, both starch and cellulose carriers showed significant color changes, especially at 40°C, where spoilage accelerated enabling faster detection, indicating that starch had greater chromatic contras. In addition, FTIR results showed absorption bands at 1416 cm-1 (C=C group) and 1646 cm-1 (C=O group) for starch, demonstrating that the starch has more intense absorption bands compared to cellulose. RGB intensity confirmed that both carriers, starch and cellulose, are capable of detecting soy milk freshness through color changes in the indicator. However, measurements using the Euclidean Distance (ED) method revealed that starch-based material showed more consistent and significant RGB intensity change, especially at pH 3 and 9 with high temperatures. For example, starch show a much higher ED at pH 9 (85.6688) compared to cellulose (33.4957). This demonstrates the higher sensitivity of starch in detecting soy milk spoilage. Therefore, starch carrier is more effective than cellulose as a smart packaging indicator.