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• A sandwiched electrochemical sensor was developed based on boronate affinity. • Boronate affinity and MIP endowed the sensor with dual-recognition ability to OVA. • The current changes of TH and Fc were combined as a dual-signal for OVA detection. • The sensor opened an avenue for glycoproteins selectively sensitive detection. Glycoproteins play extraordinary roles in biology and clinic. The specifically sensitive detection of glycoproteins by electrochemical methods is still a challenging task due to their poor electro-activity and sensitive nature to environment. In this work, ovalbumin (OVA), a model glycoprotein, was sensitively detected by a molecularly imprinted polymer (MIP) based electrochemical sensor, which was prepared by electropolymerizing 3-thiophene boric acid in the presence of OVA. Due to boronate affinity, the rebound OVA interacted with ferrocene boric acid (Fc-BA) to construct a sandwich structural sensing platform. Dual-recognition elements, imprinted effect and the boronate affinity, enabled the sensor to recognize OVA from other proteins. The rebinding of OVA caused the current changes of thionine and Fc-BA, which were combined as a dual-signal for OVA sensitive detection with a low limit of detection of 0.82 pg/mL (S/N = 3). The good performances of sensor indicated its potential applications in clinical diagnosis and other related fields. [ABSTRACT FROM AUTHOR]

• ST, LT and IS have specific myofiber type compositions that affect redox properties. • IS is prone to higher-level oxidation, especially protein oxidation. • Type Ⅰ myofiber positively correlated with T -Mb content and antioxidase activities. • Type Ⅰ myofiber has a positive relation with IMF and SFA and a negative one with MUFA. Yak infraspinatus (IS), longissimus thoracis (LT), and semitendinosus (ST) muscles were used to explore relationships between myofiber types and postmortem redox characteristics. IS mainly consisted of myofiber type Ⅰ (49.2%), LT has a vast majority of type IIa (72.7%), while ST possessed a similar percentage of type IIa (44.7%) and IIb (51.5%). Compared with LT and ST, IS exhibited higher initial H 2 O 2 , myoglobin (T-Mb), and metmyoglobin (MetMb) contents that provoked severe protein oxidation despite higher endogenous antioxidative capacity (e.g., glutathione antioxidative system). Three muscles showed specificities in myofiber type composition and redox characteristics, which were strongly correlated. Specifically, type Ⅰ myofiber positively correlated with H 2 O 2 , T-Mb, and multiple antioxidase activity/content while negatively correlated with lipid peroxidation, MetMb, and lactic dehydrogenase activity; also, they tended to employ more SFAs in more intermuscular fat assembly. Overall, muscle-specific myofiber type/redox attributes required differentiated processing to prevent meat oxidation and produce standardized products. [ABSTRACT FROM AUTHOR]

[Display omitted] • Age-related redox states during the postmortem period were investigated. • Muscles of older yak were prone to postmortem oxidation of lipid and protein. • Extending postmortem time elevated meat oxidation and reduced antioxidative capacity. • The formation of age-specific oxidative properties correlated to its antioxidant ones. • Older yak reserved more intramuscular fat with less polyunsaturated fatty acids. Effects of age on postmortem redox states were investigated in yak muscles. Extended postmortem time reduced the muscle antioxidant capacity and induced oxidation in lipids, myoglobin, and proteins. Compared with older yaks, muscles of younger ones could delay this oxidation process due to lower initial myoglobin content of 30.7%, lipid peroxidation of 42.4%, H 2 O 2 of 41.2%, and intramuscular fat of 65.6% (of 3.66 times higher PUFAs). They also possessed greater antioxidase content/activity, such as phospholipase A2 content of 30.7% and glutathione reductase activity of 50.6%. Muscles exhibited age-specific overall antioxidative characteristics during 72 h postmortem and gradually formed overall oxidative ones after 72 h postmortem with an initial similarity between 2- and 4-year (or 6- and 12-year) on canonical discriminant analyses. The formation of age-specific overall oxidative characteristics can be attributable to the antioxidative specificity of age on canonical correlation analyses. Age-specific redox characteristics required differentiated preference in meat processing and preservation. [ABSTRACT FROM AUTHOR]