Abstract Lipid oxidation is one of the important factors affecting the quality of α-instant rice. In this study, α- instant rice was detected with hydrogen peroxide value (POV), malondialdehyde value (MDA) and fatty acid value (FAV), colorimeter, electronic nose and HS-SPME GC/MS before and after storage. As well as, the effect of catalase treatment on the quality of α-instant rice during storage was investigated The results showed that the content of MDA in α-instant rice decreased by 41.4% in the late stage of the accelerated storage test (21 days), which was 4.3% lower than that of α-instant rice treated with BHT. At the same time, catalase had more advantages in maintaining the whiteness and aroma of α-instant rice, and inhibiting the aldehydes, ketones, hydrocarbons and various volatile odor substances produced by lipid oxidation of α-instant rice. Therefore, catalase, as a natural substitute for synthetic antioxidants, has great potential in the antioxidation of convenience foods.

Thiencynonate hydrochloride (N-methyL-9á-(3-azabicyclo[3,3,1]nonanyl)-2'-cyclopentyL-2'- hydroxyL-2'-thienylacetate, I·HCl), an new muscarinic receptor antagonist, was synthesized and its enantiomers were obtained form the optical pure of demethylation product II. A convenient resolution method of demethylation product II has been developed with N-p- toluenesulfonylglutamic acid as the resolution reagent. The structures of I and II were elucidated by X-ray analysis