| Dried fish is a popular aquatic product with a long history in China,and dried Lutjanus sanguinaus is one of the famous specialties in Zhanjiang.Dried Lutjanus sanguinaus is formed by low salt salting and sun drying.At the same time,Zhanjiang is high temperature,humid and rainy,which makes dried Lutjanus sanguinaus susceptible to mildew and fat oxidation during production and storage.The research shows that the hot air drying process is not affected by climate and region,and the drying speed is fast,the operation is simple,and it can be produced on a large scale.At the same time,Schisandra chinensis can not deteriorate for many years,with a variety of special flavor,high medicinal value.The results showed that the extract of Schisandra chinensis had obvious antibacterial and antioxidant activity.This study has established LC-MS/MS detection of five Schisandrae lignans content method,based on the four kinds of single factor experiment,using the method of central composite design-response surface method optimization ultrasonic extraction technology,tested the extract of DPPH and ABTS radical clearance and the total reducing power to determine antioxidant capacity,tested the mycelium growth rate method,oxford cup method and minimum bacteriostatic and bactericidal concentration method to detect extract antifungal capability.In this study,the drying process and formula conditions of hot air dried Lutjanus sanguinaus of Schisandra chinensis were optimized to obtain the best hot air dried Lutjanus sanguinaus of Schisandra chinensis,and the shelf life of hot air dried Lutjanus sanguinaus of Schisandra chinensis was predicted by constant temperature acceleration method.Conclusion :(1)The LC-MS/MS method was established for the simultaneous detection of five Schisandrae lignans by chromatographic and mass spectrometry.Methodological verification showed that the method had good linearity for the detection of five Schisandrae lignans,and the precision and accuracy were in line with the requirements of national standard.(2)In the single factor test,ethanol concentration was 40%,60% and 80%,ultrasound was performed for 10 minutes,extraction times were 1-3 times,and liquid-solid ratio was 5,10 and 15 m L/g.The optimal extraction conditions were as follows: extraction twice,liquid-solid ratio of 12 mg/m L,concentration of 70% ethanol,ultrasonic for 10 min.Through three parallel experiments,the extraction amount of lignans under this condition was(9.45± 0.11)mg/g.(3)SLE has obvious antioxidant effect.The IC50 of SLE against DPPH and ABTS free radicals were 11.37 and 59.58 ?g/m L,respectively.The antioxidant effect of SLE was about 1/3?1/2 of that of VC.SLE has a broad spectrum of antimicrobial effects against fungi.SLE inhibited the mycelial growth of Fusarium pachymenium,Fusarium putrifolium and Fusarium oxysporum by 91%,78% and 95%,respectively.The MIC of SLE against predominant aquatic fungi was 1.17-2.34mg/m L.The antibacterial effect of SLE on the eight fungi was in the order of strong to weak: Penicillium tangerine,Aspergillus niger,Fusarium oxysporum,Fusarium pachymenium,Aspergillus flavus,Penicillium extended,Trichoderma harzia and Fusarium solani.(4)50? is the best hot air drying temperature.As the temperature of hot air drying increased,the water drying rate of hot air drying Schisandra-flavored-red fish was accelerated,and the texture was firstly increased and then decreased.The contents of chloride,malondialdehyde,peroxide value,total number of bacteria and TVB-N all showed a downward trend,and reached the lowest value at 50?,while the content of lignans in Schisandra-flavored-red fish showed no significant change.Adding 10% salt+5%SLE of fish body weight is the best recipe for dried red fish salting.When the concentration of SLE was 5%,the sensory evaluation of dried red fish was significantly improved,and the total number of colonies,TVB-N content,peroxide value and malondialdehyde of low dried red fish all had the lowest values,indicating that 5% SLE had obvious antioxidant and antibacterial effects on dried red fish.(5)through the constant temperature accelerated method to predict drying red fish stem of shelf life,available,add fish weight 10% salt and 5% of SLE hot air dry red fish dry shelf life is significantly higher than the blank group,under the condition of 20?,the blank group of 26 to 32 days increased to 48?56 days,the experimental group under the condition of 4?,the blank group of 164?294 days added to the group of 390?576 days,the experimental group's shelf life is about the blank group 2 times,that SLE can significantly extend the shelf life of hot air drying dry red fish. |
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