Optimizing quality losses and shelf-life in bakery products by edible coatings

Edible packaging is of increasing interest as a technological strategy for preserving quality, improving shelf-life as well as reducing the residual waste associated with food packaging. Alternative packaging systems with coatings and films that are viable have already been proven useful in fresh produce, fresh cuts; meat and milk products. However, in the past decade interest has been renewed in edible packaging application for bakery products to restrict moisture migration, texture changes, mould growth, incorporate functional compounds and reduce overall packaging impact. The objective of this thesis was to develop edible coatings to mitigate quality losses in bakery products. The coating and product as dynamic systems with different physico-mechanical characteristics were assessed individually by, (i) development and characterization of edible coating matrices for bakery application; (ii) evaluation of the drying of edible coating on bread to optimize temperature and time of drying; (iii) effect of coating during storage as influenced by type of coating and stage of application. Based on the obtained results, characterization of rheological, mechanical and thermal characteristics of edible coatings and films were found particularly useful to select suitable coating matrices. The use of rapid methods like near infrared spectroscopy enabled the monitoring and modelling of optimal temperature/time combinations to dry coatings. Also, a numerical model to understand the heat and mass transfer dynamics for the coated bread was designed. Furthermore, the study on storage indicated that the use of edible coatings can have a retaining effect on the moisture and textural quality of bread. The results evidenced in this doctoral project can contribute to the understanding of the role of edible coatings for bread. They could be further designed as potential alternatives to reduce the level of barriers used for packaging, for a more sustainable and eco-friendly production chain.