Prediction of Shelf Life ofGulabjamunMix Using Simulation and Mathematical Modeling - Based on Moisture Gain

Abstract

A mathematical model to predict the shelf life of gulabjamun mix based on moisture-induced spoilage by stickiness (caking) and nonenzymatic browning (NEB) was developed. The moisture adsorption isotherms of gulabjamun were determined at 10, 25 and 40C. The water vapor permeabilities of the packaging materials were also calculated. The critical moisture contents for stickiness and NEB to occur were determined and the moisture-limiting shelf life was predicted. Validation of the prediction model was done by accelerated shelf life testing at 38C and 90% RH. At 4.8% moisture content, the experimental shelf life of gulabjamun mix based on stickiness and NEB was observed respectively as 41 and 54 days in low-density polyethylene (LDPE) and 280 and >360 days in polyethylene terephthalate (PET)/Al foil/PET/LDPE pouches. The corresponding predicted values were 34 and 46 days in LDPE and 247 and 342 days in PET/Al foil/PET/LDPE, respectively. The simulation model was fairly accurate and reliable in predicting the shelf life of this product. Practical Applications Stickiness and nonenzymatic browning reactions, induced by moisture gain, affect the shelf life of gulabjamun mix. For dry powders like gulabjamun mix, having a regular shelf life of 6–12 months, accelerated shelf life testing (ASLT) is cumbersome and sometimes unfeasible. Simulation and mathematical modeling of shelf life is an alternative to long-term ASLT. In this study, a model for predicting the shelf life of gulabjamun mix was developed, incorporating the water vapor permeability of the packaging material, the adsorption of moisture from headspace of the package and the weight of moisture in the product. The shelf life prediction will be useful to monitor the product quality and stability against deteriorative reactions. The model could also be used for shelf life estimation of new products in flexible packaging materials.