Effects Of Storage And Processing Technic On Quality And Fluoroquinolones Residues In Beef

Beef production of China is the third largest in the world, quality and safety problems ofbeef products have drawn increasingly attention. Fluoroquinolones are broad-spectrumantibacterial drug developed in decades, and are widely used in animal husbandry, so theresidual problem of this class of drugs caused highly attention of researchers. Whether storageand processing have impact on fluoroquinolones residues in beef has been rarely reported atpresent. According to the market, this paper uses the spiked way to study the qualities andfluoroquinolones residues in beef by refrigerating and frozen storage and heating and fryingprocess processin, strives to find a suitable storage and processing conditions to degradefluoroquinolones residues and maintain good nutrition and quality of beef, and provide atheoretical basis for the preservation and processing of beef products. The main conclusionsare as below:1. The study by introduced of orthogonal design, different paramenters was optimizedsuch as the separation voltage, the concertration and pH of running buffer etc. A highperformance capillary electrophosis method has been developed for the determination of SARand DIF. Under optimum conditions, the running buffer consisted of35mmol/L sodium borate(pH8.8), separation voltage at25kV, separation temperature at22℃. Injection time was4s,injection pressure was0.5psi. Analyses were separated in an untreated fused-silica capillary(50μm×75mm), SAR and DIF could be well separated within5min. The calibration curve ofSAR and DIF were y=318.50x-232.95(R=0.9988) and y=517.24x-85.493(R=0.9975), theliner range of them were1-20μg/mL and0.5-20μg/mL respectively. The recoveries of FQswas between82.35%-92.89%, the relative standard deviation (RSD) were1.53%-9.79%. Theintra-precision and day–precision of the method were84.03-92.89%, the RSD were below15%.2. In the refrigerator (4±1℃) condition, the water content in the spiked beef had anupward trend. Changes of treatment protein content and ash content had no rules but wassignificant different with controls (P>0.05). The value of pH increased gradually. Ca, Feelement content decreased, Zn content increased. SAR and DIF have inhibition on the totalbacterial number and TBARS value. The effect of refrigerator storage condition on SAR andDIF content of beef was not significant. So the suitable storage of refrigerator condition ofbeef was12days, and the health indicators were in line with national requirements.3. In the frozen storage(-18±1℃) condition, the water content fluctuated. Ash contentincreased gradually, the protein content had no changes in the law. These thrree indexes oftwo groups were significantly different（P <0.05）. The pH value of spiked beef was falling gently with the extension of storage time. The TBARS value of treatment decreased rapidlyduring the early storage, and then tend to be gentle and lower than that of the blank group.The content of Fe, Zn increased gradually, and that of Ca reached the maximum in8-10weeks then has a fall trend. Effects of frozen storage conditions on SAR and DIF content ofbeef was not significant. So the suitable storage of frozen condition of beef was6weeks, andthe health indicators were in line with national requirements.4. The spiking beef after heating (60,80,100℃) and frying (140,160,180℃) process ofthree different temperature, protein content of spiking increased significantly, water contentdecreased in generally. Ash content changed without rules. The pH value and TBARS value ofspiking increased firstly and then decreased. The content of mineral elements, Ca, Fe, Zn inspiked beef was higher at80℃and180℃. Water distribution of beef roughly the same.Both heating and frying made the SAR and DIF residues lower in the beef tissue, and thedegradation rate of SAR was significantly higher than that of DIF. Comprehensive indexes inthe paper, by heating at80℃and frying at180℃, their products had the best quality.In summary: refrigerated, frozen storage had little impact on fluoroquinolone residues inbeef. Heating and frying process can reduce fluoroquinolone residues in beef. The storagetime which can meet the health indicators of beef was12days for refrigerator condition and6weeks for frozen condition. Heating at80℃and frying at180℃were the optimum processconditions with lowering the residues of fluoroquinolones and maintaining the nutrition andquality. Therefore, choosing appropriate processing conditions played an important role toreduce the residues of veterinary drugs, to improve quality, and to ensure the health ofconsumers.