Date of Award
Master of Science
Plant and Soil Science
Strawberries are a popular fruit with a pleasing color and flavor. However, its delicate tissue and high sugar content makes it highly perishable with visible mold. In this study, we have attempted to test feasibility of different edible coatings for extending shelf life of ‘Chandler’ strawberries subjected to simulated vibrations of local transportation. Six types of coatings were compared based on the quality of treated berries. Curcumin and limonene were used as natural antimicrobials and coatings were prepared from their liposomes and were over-coated with methyl cellulose. One set of each coating type were subjected to the simulated vibration of local transportation. The vibrated samples had lower shelf life than non-vibrated samples, indicating a robust coating which remains intact during road vibrations is required. Based on the number of berries with visible mold, limonene liposomes showed significantly lower fungal growth compared to the control on the 14th day of storage. Titratable acidity and total phenolic contents were also found to be higher in limonene-coated strawberries compared to other coatings. From the findings, further study of liposome coatings of limonene with different particle size and concentration of the lipid bilayer was necessary to characterize the liposome for an effective application in strawberries. To this regard, another study was done with the aim to develop and characterize alginate and limonene liposomes as edible coating materials and to determine their efficacy in shelf life extension and maintaining quality parameters of ‘Chandler’ strawberries. Alginate solution (1.5% w/v) and limonene liposomes prepared from 80% lecithin and 20% PDA were used as edible coating materials. Fungal decay percentage, total yeast and mold counts, headspace atmosphere analysis, total soluble solids, pH, titratable acidity, total anthocyanin content and total phenolics were analyzed to assess fruit quality during 14 days at 4ºC of storage. Days of storage were found to be significant in maintaining the quality of the strawberries. Among the coating types, strawberries coated limonene liposomes were found to be significantly effective in maintaining the lesser respiration rate, lower the change in pH (3.9), and had higher total anthyocyanin (43.849) content during storage. Thus, limonene liposomes were found to be useful for extending the shelf life and maintaining quality of strawberry fruits.
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