Smart Biopolymer Film from Water Hyacinth Cellulose and Red Cabbage Anthocyanin for Food Spoilage Detection

Food spoilage is one crucial problem and is very challenging to determine with accuracy. Food safety, food quality, shelf life and consumer health are factors linked to food spoilage and this research work explores the possibilities of developing a smart biopolymer film capable of detecting food spoilage. The anthocyanin extracted from red cabbage (Brassica oleracea var. capitata f. rubra) was incorporated into the cellulose matrix extracted from Water hyacinth (Eichhornia crassipes (Mart.) Solms), creating a smart pH sensitive biopolymer film. A 41% cellulose yield (8.2 g from 20 g) was obtained from WH, and 654.54 mg/L anthocyanin was incorporated to form a pH-sensitive biopolymer film. The Cellulose red cabbage anthocyanin (CRA) film showed distinct color transitions dark reddish pink (pH 2), purple (pH 5), grey-blue (pH 9) and improved mechanical properties with tensile strength rising to 22.25 ± 0.79 MPa and Young’s modulus to 1380.34 ± 223.86 MPa. Studies on cellulose extracted such as yield of cellulose, moisture and ash content and FT-IR, HPLC analysis to identify the various functional groups of cellulose were performed. The developed biopolymer film exposed to fresh milk (pH 6.7, 0.19% acidity) displayed a purple colour shade, whereas milk stored for 24 h (pH 5.25, 1.8% acidity) showed a pink-purple colour shade indicating spoilage in milk. The developed smart biopolymer film can detect spoilage of food with change in pH of food associated with spoilage.