| Cantonese barbecued pork bun was used as raw material, and the sensory evaluation system of barbecued pork bun was established. According to the needs of industrial production, the fermented condition, the process of the dough skin, and the steaming process were explored to the effect on the quality of barbecued pork bun. And the mechanism of steaming was studied, and the steaming dynamics and starch gelatinization rate model were studied, in order to provide theoretical basis and practical guidance for industrial production of barbecued pork bun.1. The sensory evaluation system for barbecued pork bun was established based on the theory of fuzzy mathematics, and the commercial barbecued pork buns were assessed by instrument and sensory evaluation system. The results showed that eight sensory indexes were selected, and the weight value was determined, and the centesimal sensory evaluation system could be established. The range values of instrumental indexes and the sensory scores of the superior barbecued pork bun were determined.2. In order to study the effect of fermentated conditions on the composite leavening property of the dough. The fermentated time of the dough, chemical leavening agent and the content of wet gluten were studied. Results showed that with the increased of fermentated time, the p H went down and TTA went up. The more uniform the rate of raising gas of leavening agent was, and the more lasting the time was, the better the quality of barbecued pork bun was. Flour was recommended for the better quality with low to medium wet gluten content(wet gluten content in 22~30%), the stability time in 1.30~1.90 min, maximum resistance in 492.50~700.00 BU, the area under the curve in 37.50~70.00 cm2, resistance-extensibility ratio(R/E) in 7.76~8.00, extensibility for 61.50~86.00 mm.3. In a certain steam condition, the optimization of the process of the dough skin of barbecued pork bun was investigated. The results showed that the p H was up then down, and TTA rose then reduced, and the specific volume went down with the the standing time of the dough increasing. For 1:2, 1:1.6, 1:1.3 of the filling-skin ratio, the heating rate was higher than that at 1:1, and the appearance on the top of barbecued pork bun was superior to 1:1. Orthogonal experiment results showed that the order of three factors: the standing time > the filling-skin ratio > the wet gluten content. The wet gluten content had no significant effect on the barbecued pork bun(P>0.05). When the standing time of the dough was 60 min, the quality of barbecued pork bun became bad. And the better options for filling-skin ratio were 1:2 and 1:1.6.4. The effect of the amount of steaming on selected Cantonese-style barbecued pork bun characteristics were investigated, and the dynamic model was established. Steaming was done at 100℃ for 5 min with steaming of 50, 75, 100, 150 and 200 m L. The results showed that according to heating rate, the ripening process of barbecued pork bun could be divided into three stages, which were the low rate, high rate and steady phase respectively. With the amount of steaming increasing, the internal and external pressure difference of the barbecued pork bun rose and decreased. And the higher the steaming was, the faster the pressure droped. During the steaming of barbecued pork bun, there was a significant correlation among the heating rate, internal and external pressure difference and steaming(R2≥0.96).The dynamic models of steamed and starch gelatinization rate showed that the rate of steaming and gelatinization of barbecued pork bun were rapid down and slow down with the steamed time increasing. There were no differences in sensory evaluation for the amount of steaming that was higher than 75 m L(P<0.05). |
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