Bread Staling: A Calorimetric Approach 1
Alberto Schiraldi, Laura Piazza, Marco Andrea Riva
Abstract
Simple recipe breads with different water contents were allowed to stale in well-defined conditions. Bread crumb was investigated using differential scanning calorimetry, thermogravimetry analysis (TGA), and stress-strain determinations. Calorimetric investigations extended to subambient temperature allowed an exothermic signal to be recognized just about room temperature that appeared partially reversible on repeated heating-cooling cycles across the -10 to 35°C range. The corresponding thermal effect was maximum after aging 8-10 hr. According to the TGA investigations, the release of water on heating revealed two main binding states: water-i and water-2. The relevant fractions were bread-age dependent; water-i reached a minimum after aging 8-10 hr at room temperature, while the overall water content remained practically A number of works (Lindet 1902, Schoch and French 1947, Bechtel and Meisner 1954, Bechtel and Meisner 1959, Zobel and Senti 1959, Senti and Dimler 1960, Comford et al 1964, Herz 1965, Schoch 1965, Zobel 1973, Maga 1975, D'Appolonia and Morad 1981, Kulp and Ponte 1981, Pyler 1988, Stear 1990, Kulp 1991) have been devoted to the study of bread staling to explain the different processes that take place in the course of the shelf life and significantly modify the sensorial properties of the product. At present, no interpretation is available that encompasses the whole body of changes observed, although some tentative models have been proposed. Most of these recognize a key role of water and its mobility (Zeleznak and Hoseney 1987, Czuchajowska and Pomeranz 1989, He and Hoseney 1990, Piazza and Masi 1994). Great attention was paid to ingredients that interact with water, such as nonstarch compounds, proteins (gluten and nongluten), dextrins, sugars, emulsifiers, and hydrocolloids, etc., as well as endogenous and exogenous enzymes like amylases that can partially degrade the starch components to produce smaller polysaccharides (Whilloft 1973, Dragsdorf and Varriano-Marston 1980,
Extracted Claims
4 claims extracted from this paper into the knowledge graph
thermogravimetry analysis reveal two main binding states of water
“According to the TGA investigations, the release of water on heating revealed two main binding states: water-i and water-2. The relevant fractions were bread-age dependent; water-i reached a minimum a...”
differential scanning calorimetry detect exothermic signal
“Calorimetric investigations extended to subambient temperature allowed an exothermic signal to be recognized just about room temperature that appeared partially reversible on repeated heating-cooling ...”
thermogravimetry analysis reveal two main binding states of water
“According to the TGA investigations, the release of water on heating revealed two main binding states: water-i and water-2. The relevant fractions were bread-age dependent; water-i reached a minimum a...”