Antistaling effects of hydrocolloids and modified starch on bread during cold storage

Antistaling effects of some hydrocolloids (guar gum, xanthan, and sodium alginate; 0.3 g/100 g flour) and modified starches (acetylated, oxidized and hydroxypropylated corn starches; 10 g replacing flour) on bread during cold storage (4 °C for 10 d) were investigated. Loaf volume, moisture content, texture, and the degree of starch recrystallization of the bread crumb were examined. The minor addition of hydrocolloids increased the loaf volume of fresh bread and retarded textural changes of crumb induced by cold storage. The partial replacement (10%) of flour with modified starches induced antistaling effects similar to those obtained by hydrocolloid addition. In particular, acetylated or hydroxypropylated starches were more effective than oxidized starch. Crystallinity analysis of bread crumb using X-ray diffraction pattern revealed that the effects of hydrocolloids and modified starches on the starch recrystallization were not substantial. Amorphous rearrangements in starch were responsible for changes in crumb texture during storage, and the minor addition of hydrocolloids and the partial replacement of flour with modified starches retarded the rearrangement induced by the storage.