Water is the most effective plasticizer in food matrices, decreasing glass transition temperature (Tg) and mechanical resistance anddetermining a softening effect with the increasing of its concentration. However an opposite effect (i.e. hardening, toughening) couldbe observed in some food and in specific moisture or aw range and this is referred to an anti-plasticization effect. Several are the possiblecauses for this phenomenon and various are the factors that have been recognized to affect its occurrence in a food matrix: mechanicaltesting method, mechanical parameter tested, type of food (composition and micro-macrostructure).In this paper, several studies on anti-plasticization effect of water are reviewed by focusing the attention on the interactions water–food matrix and in particular to those occurring in amorphous cell foods. The different chemical and physical factors that affect thisphenomenon are also discussed.The simultaneous occurrence of a plasticization and anti-plasticization effect of water, even if in different aw range, and the results ofstudies on amorphous food matrices may suggest an important effect of water–matrix interaction on the textural properties.[…]
Antiplasticization effect of water in amorphous foods. A review
PITTIA, Paola;SACCHETTI, Giampiero
2008-01-01
Abstract
Water is the most effective plasticizer in food matrices, decreasing glass transition temperature (Tg) and mechanical resistance anddetermining a softening effect with the increasing of its concentration. However an opposite effect (i.e. hardening, toughening) couldbe observed in some food and in specific moisture or aw range and this is referred to an anti-plasticization effect. Several are the possiblecauses for this phenomenon and various are the factors that have been recognized to affect its occurrence in a food matrix: mechanicaltesting method, mechanical parameter tested, type of food (composition and micro-macrostructure).In this paper, several studies on anti-plasticization effect of water are reviewed by focusing the attention on the interactions water–food matrix and in particular to those occurring in amorphous cell foods. The different chemical and physical factors that affect thisphenomenon are also discussed.The simultaneous occurrence of a plasticization and anti-plasticization effect of water, even if in different aw range, and the results ofstudies on amorphous food matrices may suggest an important effect of water–matrix interaction on the textural properties.[…]I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
