Quality changes and shelf-life determination of modifiedatmosphere packaged fresh-cut pumpkin slices

In this thesis, fresh-cut pumpkin (Cucurbita moschata L.) slices was packagedwith modified atmosphere (MAP), vacuum and stretch over wrap packaging afterdipping calcium citrate, calcium ascorbate and their mix solutions to determinethe quality chances and extend the shelf life. Fresh-cut pumpkin slices werepackaged with air (control), vacuum (V) and modified atmosphere (5% O2, 5%CO2 % 90N2) and stored at 4 °C. Microbial (total mesophilic bacteria, yeast andmold, coliform) parameters, chemical (pH, total solids, titratable acidity, totalphenolic content, ascorbic acid content and total carotenoids) parameters,package head space, and color changes of fresh-cut pumpkin samples weredetermined at days 0, 7, 14, 21, and 28.Results revealed modified packaging and vacuum application were suitablepackaging methods without any microbial growth during 28 days of storage.During storage, chemical parameters (pH, acidity and total soluble solids) offresh-cut pumpkin slices changed significantly after 21 days of storage. pH valuesof samples were decreased significantly while titratable acidy and total solublesolid values did not changed. In addition total carotenoids, ascorbic acid contentand total phenolic content decreased gradually. Package headspace analysisshowed that O2 concentration in MAP packages diminished after 7 days of storagewhile CO2 concentration increased during storage. No differences were observedin microbial quality of fresh-cut pumpkin slices without the effect of dippingsolution except the control samples. Control samples were spoiled before the 14day of storage while MAP samples were exceed the limits of total mesophilicbacteria and total coliform bacteria counts at 21 days, and vacuum packagedsamples after 28 days. Effect of dipping solutions showed that calcium citrate wasmost protective properties.