Interested Members of the University Community are invited to attend the Final Oral Examination for the Degree of Doctor of Philosophy of Syndhiya Ranjan of the Department of Plant Agriculture

Date: Wednesday, 4 December 2019
Time: 10 am
Location: Room 202, Crop Science Building

Thesis Title: Development of novel hexanal encapsulated fiber (HEF) through electrospinning and its application to extend the shelf life of fruits.

Advisory Committee 
Dr. Jayasankar Subramanian (Advisor)
Dr. Gopinadhan Paliyath
Dr. Loong-tak Lim
Dr. Alan Sullivan

Examination Committee
Dr. Max Jones
Dr. Deepak Kumar (External Examiner)
Dr. Jayasankar Subramanian (Advisor)
Dr. Ashutosh Singh
Dr. Loong-tak Lim                                                    

ABSTRACT

Innovations in postharvest technology have gained more attention to increase the availability of nutrient rich food. One such novel method is the phospholipase D inhibition (PLD) technology which is a membrane preservation technique using hexanal. The application of hexanal in the form of spray and dip showed improvement in maintaining the post harvest fruit quality but its application in packaging is limited due to its rapid diffusion from the point of application. To overcome this issue, hexanal was encapsulated in a moisture-sensitive polymer fiber by the process of electrospinning. The release of hexanal from the fiber was activated by the moisture from the respiration of fruit which increases the relative humidity in the package headspace. Release profile of hexanal from the fiber was studied using gas chromatography (GC), morphological and interaction behavior was analyzed using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The prepared fiber was applied on peach and plums as a single treatment and in nectarines and pears as a combination treatment after dipping them in enhanced freshness formulation (EFF), which contains hexanal as the active ingredient. The storage stability of fiber was analyzed by using the fiber prepared freshly on the day of treatment or prepared 7 and 15 days prior to the treatment by storing in 0% RH. The decay percentage in nectarines, peaches, plums, and pears was reduced and in addition, the color in plums was also maintained. The shelf life increased by 4 days in peach, 5 days in nectarines and plums and 7 days in pears under ambient storage conditions irrespective of the age of fiber indicating the fiber quality does not diminish over time by storing it in the 0% RH. Application of this hexanal encapsulated fiber in the fruit packaging can enhance the shelf life during export or during local transportation where the cold storage facility is not well developed.