Abstract:
To examine the quality variations between Tibetan pork and Duroc×Landrace×Yorkshire (DLY) pork subjected to different thermal processing methods, this study analyzed changes in cooking loss rate, shear force, texture, and color under boiling, frying, and roasting conditions. Multivariate statistical analysis of volatile organic compounds (VOCs) was conducted using an electronic nose and gas chromatography-ion mobility spectrometry (GC-IMS). The findings indicated that, among the three thermal processing methods, the boiled pork exhibited the lowest cooking loss, shear force, and hardness. and the highest moisture content. The fried pork exhibited the highest hardness, shear force and chewiness due to the high heat transfer properties of the oil, which quickly formed a crust on the surface of the meat. Conversely, the roasted pork demonstrated the highest cooking loss and the lowest moisture content, indicating that using hot air as the heating medium tends to cause water loss, resulting in the highest cooking loss rate. Regarding different breeds, the protein content of Tibetan pork was approximately 1.07 times that of Duroc×Landrace×Yorkshire pork, whereas its intramuscular fat content was 0.73 times that of Duroc×Landrace×Yorkshire pork. The redness value (
a* value) of fried Tibetan pork, which was the highest at 14.53, was significantly greater than that of Duroc×Landrace×Yorkshire pork (
P<0.05), indicating that Tibetan pork had a deeper color. The electronic nose could effectively distinguish the aromas of Tibetan pork and Duroc×Landrace×Yorkshire pork under the three different heat processing methods. Gas chromatography-ion mobility spectrometry (GC-IMS) detected 58 volatile flavor compounds. 40 and 41 volatile compounds were detected in Tibetan and Duroc×Landrace×Yorkshire pork in boiling mode, 34 and 33 compounds were detected in Tibetan and Duroc×Landrace×Yorkshire pork in roasting mode, while 22 and 15 volatile compounds, mainly aldehydes, ketones and alcohols, were detected in Tibetan and Duroc×Landrace×Yorkshire pork in frying mode, respectively. The total content of sulfur-containing volatile compounds in Tibetan pork was significantly higher than that in Duroc×Landrace×Yorkshire pork during both boiling and roasting processes (
P<0.05).
α-Ionone and ethylene glycol dimethyl ether were the characteristic flavor compound in fried Tibetan pork, while 3-hydroxy-2-butanone and 4-methylthiazole were unique to roasted and boiled Tibetan pork, respectively. In sensory evaluation, fried Tibetan pork received the highest scores in terms of aroma, color, and overall acceptability. In conclusion, Tibetan pork exhibits outstanding performance in moisture content, hardness, color value, and heterocyclic volatile flavor compounds among the three different heat processing methods. The flavor differences between deep-fried Tibetan pork and Duroc×Landrace×Yorkshire pork are pronounced, with Tibetan pork showing relatively higher levels of flavor compounds, thus significantly enhancing flavor quality. These findings provide data support for fully utilizing the quality advantages of Tibetan pork.