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Changes During Accelerated Storage in Millet–Wheat Composite Flours for Bread

Singh, K. P., Mishra, H. N., Saha, S.
Food and bioprocess technology 2012 v.5 no.5 pp. 2003-2011
Echinochloa frumentacea, Panicum miliaceum subsp. miliaceum, breads, dough, gluten, millets, packaging materials, polyesters, polyethylene, response surface methodology, rheological properties, shelf life, starch, water content, wheat flour
Two millet–wheat composite flours, CF1 and CF2, were formulated based on the rheological and textural properties of dough using response surface methodology. The optimized contents of composite flour CF1 were 61.8% barnyard millet flour, 31.4% wheat flour, and 6.8% gluten, respectively. The optimized components of the composite flour CF2 were barnyard millet flour 9.1%, finger millet flour 10.1%, proso millet flour 10.2%, and wheat flour 70.6%. Millet–wheat composite flours were stored in three different packaging materials, namely, low-density polyethylene (LDPE), high-density polyethylene (HDPE), and metallized polyester (MP), at 90% RH and 40 °C temperature for 90 days. For the packaging of millet–wheat composite flour CF1, MP was found best among the tested packaging materials, where moisture gain in samples was minimum (55%) as compared with materials LDPE (124%) and HDPE (100%). Vitamin loss among the different packaging materials was not significantly different at the 5% level of significance. The shelf lives of the composite flours were estimated based on their critical moisture contents. After 90 days of storage of CF1, the highest retention of starch (91.85%) was recorded in MP packaging followed by HDPE (87.5%) and LDPE (84.8%). However, in CF2, the retention was not significant in all three packaging materials (P < 0.05). After 90 days of storage of CF1, the predicted shelf life of CF1 and CF2 in LDPE, HDPE, and MP packaging materials were 30, 38, and 61 days and 26, 34, and 54 days, respectively, which resemble closely with the experimentally determined (30, 40, and 65 days and 25, 35, and 55 days, respectively) values. The real shelf life will always be higher as compared with the accelerated one. This study may be useful for the safe storage of millet-based composite flours.