BACKGROUND Oxidation is a major reason for nutritional and quality loss of dumplings during frozen storage. The addition of spice extracts in frozen dumplings may limit and inhibit oxidative impairments. In this study, the antioxidant effects of clove extract (CE) and rosemary extract (RE) and their influence on sensory and quality attributes of the meat‐based filler in frozen pork dumplings stored at −18 °C were investigated. RESULTS CE and RE significantly suppressed lipid and protein oxidation in terms of thiobarbituric acid‐reactive substances and protein carbonyls (P < 0.05) formation. During frozen storage up to 180 days, the dumpling samples with antioxidants had a significantly higher breaking strength and lower cooking loss (P < 0.05) compared with the control, and the effect of RE was stronger than that of CE. Sodium dodecylsulfate polyacrylamide gel electrophoresis showed that samples with antioxidants had reduced protein crosslinking, hence less aggregation. Differential scanning calorimetry analysis proved that the dumplings with antioxidants during storage had a higher thermal stability than those of the control. Based on dynamic rheological testing, the addition of RE to dumpling fillers was more effective in enhancing the gelling capacity of myofibrillar protein compared to the control. Sensory panel results confirmed significant positive effects of both spice extracts on oxidative stability (reduced rancidity) and palatability (texture and juiciness) of dumplings. CONCLUSION The addition of phenolic‐rich CE and RE in dumpling processing is an excellent approach for the inhibition of sensory and quality deterioration associated with oxidation during frozen storage. © 2019 Society of Chemical Industry

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The rheological properties and time effect of a quaternary ammonium salt gemini surfactant Cn‐s‐Cn•2Br solution were measured. The rheological properties were markedly different at various concentrations of the surfactant C12‐2‐C12•2Br solutions. When the alkyl chain of Cn‐2‐Cn•2Br solution is 14 or 16, the rheological properties of the solution exhibit fluid dilatancy very similar to C12‐2‐C12•2Br solutions. However, when the length of the spacer is four or six, C12‐s‐C12•2Br solutions exhibit Newtonian fluid behavior and are quite different from the C12‐2‐C12•2Br solution. A C12‐2‐C12•2Br solution at a high concentration shows negative thixotropy and time dependency.