Changes Of Texture, Microstructure And Proteolysis Of Sauced Duck Muscle During Processing

Duck meat belongs to high-protein, low-cholesterol food, contains about18%protein, about25%-30%fat content, rich in trace elements, B vitamins, vitamin Eand niacin. Use duck as the raw material for processing products mainly aretraditional duck roast duck, salted duck, sauced duck and so on. Because of theunique flavor, there are many consumers of sauced duck, its production process aresalting, baked grilled and sauced and other processes. After these processing, thecolor, texture, microstructure of meat have changed, at the same time, muscleproteins of raw duck have undergone significant changes. In this paper, the changesof color, texture, microstructure of duck meat and the changes of duck meat muscleproteins during the processing of sauced duck had been researched systematically,the main experimental results were listed as follows.1.The color difference meter was applied to measure color changes of duck meatduring the processing of sauced duck, the duck meat of different processing phaseswere used as sampling points, the results showed that a*value of raw duck meat was8.99, which increased to10.11after3h salting time. a*values of duck meatdecreased with the increasing salting time, and12h reached the lowest, the saltingprocessing has significant difference on a*values; While b*values decreased duringthe salting processing, b*value of raw duck is4.54, after12salting time, b*valuedecreased to1.09; L*values did not changed significantly during salting processing,L*value of raw duck is39.15, it was40.26after12salting time. a*values andb*values increased during the baked gilled processing, and a*value is7.46, b*valueis5.38while L*value decreased38.95after20min,after1h, a*value, b*value,L*value increased9.92,8.74,43.98,the baked gilled processing has significantdifference on duck meat color; During saucing processing, a*value decreased from9.92to6.88after20min, while a*value increased with the increasing saucing time,then a*value decreased after sterilizing; b*value increased significantly and L*valueincreased a little after20min saucing, then b*value decreased significantly with increasing saucing time, b*value and L*value continue to decrease after sterilizing.2. XT plus Texture Analyzer was applied to measure texture changes of duckmeat during the processing of sauced duck, significant changes were undergoneduring the processing of sauced duck. The hardness of duck meat increased during0-6h salting processing, while decreased after9h salting and the lowest hardnesswas reached at12h salting time; The spring decreased during the salting process, thespring of9h salting time is the lowest. The changes of chewiness values are notobvious during0-6h salting time,while chewiness values decreased after9h and12hsalting time; Cohesiveness values did not change obviously during saltingprocessing; The changes curve of Gumminess is similar to hardness changing curve,which increased during0-6h,then decreased during9h and12h salting time.The changes of hardness and cohesiveness of baked gilled, saucing andsterilizing processing is more significant than salting processing, while spring is less.In baked gilled phase, hardness increased, spring decreased, cohesiveness did notchange obviously; Hardness, chewiness, cohesiveness and gumminess values ofsaucing processing reached the highest, while the changes of hardness andcohesiveness were not significant; Compared with the saucing processing, hardness,spring, chewiness, cohesiveness and gumminess values of sterilizing processingdecreased.3. SDS-PAGE electrophoresis was applied to discuss muscle protein changes ofduck meat during the processing of sauced duck, SDS-PAGE results revealed thatα-actinin is stable while other myofibrillar proteins and sarcoplasmic proteins weredegraded during the salting processing of sauced duck; myofibrillar proteins bandswere disappeared, however, there are some new bands on the sarcoplasmic proteinsduring the saucing, juice absorbing, sterilizing process of sauced duck, because ofproteolysis, the content of product of proteolysis also varied, from the saltingprocessing to the end of saucing, Non-protein nitrogen decreased while increasedduring the sterilizing process; The weight of duck meat decreased during the wholeprocess, especially after0.5h saucing.4. Scanning electron microscopy and Transmission electron microscopy wasapplied to study changes of microstructure of duck meat during the processing of sauced duck. The result revealed that microstructure had changed significantly,Scanning electron microscopy showed that duck breast muscle fiber bundlescondensed after saucing and sterilizing, gaps was appeared between some musclefiber bundles, the diameter of muscle fiber became smaller, and there is closerbetween muscle fibers; Transmission electron microscopy results showed that duckmuscle fiber structure became vague, ever can not be identified after salting, bakedgilled, saucing process. A band, H band, M-lines, Z-lines of muscle fiber structurealmost disappeared, the extent of damage of some muscle fiber structure are moreobvious.5.The sauced duck was irradiated with ultraviolet for0.5h、1h、1.5h、8h, thenstored at4℃. Total bacteria number、pH under different ultraviolet irradiation time,peroxide value and acid value under8h ultraviolet irradiation were determined. Themicrobiological data results showed total bacteria number was reduced afterirradiation. the longer the irradiation time, the less the initial bacteria number; Totalbacteria number of sauced duck under0.5h and8h ultraviolet irradiation was lessthan the control group during the storage of1-2days, on the third day, total bacterianumber of sauced duck under1.5h ultraviolet irradiation was still less than the thecontrol group, while the total bacteria number of0.5h and8h ultraviolet irradiationwas significantly increased; with the increasing of storage time, the pH values ofsauced duck with different ultraviolet irradiation time during storage was decreased,the pH value of sauced duck with1.5h ultraviolet irradiation was higher than thecontrol group, while the8h ultraviolet irradiation’s pH values was remarkablydecreased on the fourth day; After8h ultraviolet irradiation, a bad flavor wasproduced, peroxide value and acid value were higher than control group, and wereincreased along with the increasing of storage time.