Effect of frozen storage duration on firming properties of breads baked from frozen doughs

Frozen bread doughs in three separate studies were prepared using a no-time dough formula. Two studies (I and III) used commercial flours supplemented with wheat gluten, and a third study (II) used flour from five hard red spring wheat varieties milled on a 55-cwt pilot Miag mill. Breads were baked from frozen doughs after one day and four, eight, 12, 16, and 20 weeks of frozen storage. The Instron Universal Testing Machine was used to measure crumb firmness of the breads 4 hr, one day, and four days after baking. Moisture contents of the breads in study III were determined. For all studies, bread crumb firmness increased with increased storage time after baking. Longer frozen dough storage yielded firmer bread. The length of storage time after baking did not significantly affect crumb moisture contents, which ranged from 45.18 to 48.29%. Crumb moisture contents were higher for breads baked from dough frozen for longer storage times and lower for breads baked from dough frozen for shorter durations. Some of the variation in increased firmness appeared to be associated with the decreased loaf volumes of breads baked from frozen doughs. Textural properties of bread crumb have become common criteria for evaluating bread quality and for assessing its tendency to lose freshness during storage. The firming of bread crumb accompanying staling has been recognized as one of the most important factors in reducing acceptability to the consumer. In response to the need for standard conditions, AACC method 74-09 was developed to evaluate the firmness of white an bread crumb using the Instron Universal Testing Machine (UTM). Although many researchers have examined staling and its associated changes, there are very few studies reporting staling or firmness of bread baked from frozen doughs. This article includes bread firmness measurements from three separate frozen dough storage studies. The relationship between bread firmness and bread moisture has been studied by a number of researchers. Rogers and coworkers found that moisture content was inversely proportional to the rate of bread firming. Slower bread firming rates were reported by He and Hoseney when crumb moisture contents were increased. Crumb moisture contents and firmness values of breads baked from frozen doughs have not been reported. The objectives of this study were to 1) investigate the effects of frozen storage duration and storage time after baking on firmness of breads baked from frozen doughs; 2) determine the effect of frozen storage duration on crumb moisture contents of breads baked from frozen doughs; and 3) examine the relationship between bread firmness and loaf volume of breads baked from frozen doughs.