The Influence of Multilayer, “Sandwich” Package on the Freshness of Bread after 72 h Storage

Abstract

The goal of this research was to evaluate a polymeric system, including biopolymers, as a multi-component material coating on paperboard for bread. The main aim of the research was to create a humidity-controlling packaging material. This means that the packaging material should contain filler which will absorb water or water vapour from the bread. The ideal packaging should have high barrier qualities against water vapour, enabling the possible release of water from the product (to maintain proper humidity inside the packaging). The preliminary storage tests made of the bread confirmed that the freshness of a product kept in a climatic chamber in RH = 70% was the highest. To summarise, the obtained packaging should maintain the required humidity (in the case of bread, the optimal humidity is 70%) within the packaging to keep the bread fresh after more than 72 h of storage. A “sandwich” form of (multilayer) packaging was indicated as a solution to this problem. The main objective of this packaging was to obtain two paper layers and one starch layer to increase water absorption from the bread. It was also important to obtain a thin, external hydrophobic layer to decrease the water vapour transmission rate of the packaging (WVTR). A number of ‘’sandwich” packaging types were prepared, consisting of two sheets of paper with an external aquaseal coating and an internal starch coating (with a NaCl filler). The covered ‘’sandwich” papers were then used to create packaging that could be used for the bread storage tests. The study results confirmed that the bread stored for 72 h in the “sandwich” packaging was found to be fresher than the same product stored in commercial paper packaging.