Studies On The Application Of ASK Gum In Frozen Dough

In this thesis, we found the best extracted conditions of Artemis sphaerocephala Krasch Gum (ASK gum) which was extracted from Artemis sphaerocephala Krasch seeds and studied the ASK gum effected the frozen dough on ferment rheology, dynamic rheology and texture of bread made from frozen dough.The optimum conditions of extraction for ASK gum were obtained by the orthogonality experiment: Temperature: 60℃, dip in time: 1 h, mixing time: 2 min and Ratio: 1:100. Under this condition the extraction of ASK gum was 14.35%(w/w). Compare with the ASK gum and locust bean gum for capability of holding water under room temperature and frozen storage. And found that ASK gum could hold about 27 times it self's weight water and it was twice of locust bean gum. In frozen storage the ASK gum could hold more water than locust bean gum. It showed that ASK gum had the better capability of holding water in frozen storage than frozen doug and it could reduce the damage from ice, and keep the amount of water in long time frozen storage.By using the six factors and two levels design experiment to select three important factors from six factors of the bread specific volume. The three important factors were analyzed by the experiment of response surface analysis. By ridge analysis, the optimal fermentation medium was determined: ASK gum addition: 0.95%(w/w), frozen storage temperature: -18.75℃, thawing time: 2h48mins. The bread specific volume was 6.89mL/g.We studied the effect of ASK gum on frozen dough by F3 Rheofermentometer and found that the capability of keeping gas of dough was increased and dough broken time was delayed with addition of ASK gum in the dough was increased. Extensometer test showed that toughness of frozen dough was increased by increasing the addition of ASK gum. Dynamic Rheometer results showed that in the same frozen storage time the dough with 1% ASK gum had the biggest G', and following one was the dough with 1% locust bean gum, and the smallest one was dough with nothing. The G''had the similar result, in the same frozen storage time the order was that dough with 1%ASK gum, dough with nothing and dough with 1%loucst bean gum. But the tanδhad the opposite order. The result of G', G''and tanδshowed that addition of ASK gum could get better effect on increasing elasticity and viscosity of frozen dough. Texture of bread test showed that gum could reduce the hardness and chewiness of bread comparing with without gum one. The results of texture of bread showed that gum could advance the sense and texture property.We studied the effect of ice on frozen dough in frozen storage by Scanning Electron Microscopy (SEM) and Differential scanning calorimetry (DSC).Scanning electron microscopy (SEM) showed that the gluten network of frozen dough with gums was better protected than the frozen dough without gum, and the frozen dough with 1% (w/w) ASK gum had the better result than the frozen dough with 1% (w/w) locust bean gum. The results of Differential scanning calorimetry (DSC) of frozen dough showed that: The enthalpy of frozen dough with 1% (w/w) ASK gum was smaller than frozen dough with 1% (w/w) locust bean gum. It indicated that ASK gum could have better effect on keeping the amount of freezable water.