Abstract: In order to investigate the effects of different reheating methods (microwave, steam, water bath, and open flame) on the quality of quick-frozen prepared pork rib soup with carrot and corn, heating characteristics, texture, soup color, taste substances, volatile components, and sensory quality were determined. The results demonstrated that microwave reheating was the most efficient, providing uniform heating. In terms of texture, microwave and water bath reheating had less effects on the hardness, stickiness, and meat firmness of pork ribs, while microwave and open-flame reheating maintained the hardness and stickiness of corn and carrot significantly better (P < 0.05). The steam reheated soup was golden and clear in color, whereas the open-flame reheat soup became thick and milky white due to oil emulsification. The steam reheated soup exhibited a good combination of umami amino acids and nucleotides, presenting the strongest umami taste with an equivalent umami concentration (EUC) of 178.4 g/100 g, followed by those reheated by microwave, open flame, and water bath (EUC of 109.9, 100.2, and 56.5 g/100 g, respectively). A total of 61 volatile components were identified across all samples. In total, 29, 33 and 32 volatile components were found in the microwave, steam and open-flame reheated samples, respectively, with aromatic substances being the major ones; 31 volatile components in the water bath reheated sample, alcohols being the major ones. There were significant differences in the contents of some volatile components (P < 0.05). Sensory evaluation showed that the microwave and steam reheated soups were more favored by consumers in terms of color and taste (P < 0.05), with the highest overall sensory score. In summary, steam and microwave reheating are ideal reheating methods for frozen pork rib soup with carrot and corn.

Key words: prepared food; pork rib soup with carrot and corn; quick-freeze; reheating methods; flavor; quality