| Aronia melanocarpa is mainly used for fruit juice production,and the fruit residue after fruit juice is usually discarded,which not only pollutes the environment,but also causes waste.The fruit residue is rich in polyphenols,which has many physiological functions such as antioxidant,anti-inflammatory,anti-aging and hypoglycemic.Based on the pomace of Aronia melanocarpa as raw material,study the polyphenols extraction,separation and purification technology,analyse the components of polyphenols,measured the polyphenols antioxidant capacity,and apply it to the preservation of cold fresh pork,get the results of the study are as follows:1.Study on the technology of enzymatic ultrasonic extraction of polyphenols from fruit residue of Aronia melanocarpa.On the basis of single factor,the optimum extraction conditions were optimized by response surface methodology as follows:enzyme addition amount was 3%,ultrasonic temperature was 47°C,enzymolysis time was 63 min,solid-liquid ratio was 1:53（g/m L）,and ethanol concentration was 75%.Under these conditions,the extraction amount of polyphenols from the pomace of Aronia melanocarpa reached（93.96±0.67）mg/g,which was close to the predicted value of 94.19 mg/g,providing a theoretical basis for the deep development of Aronia melanocarpa resources.2.Study on separation and purification technology of polyphenols from the fruit residue of Aronia melanocarpa.In the experiment,the adsorption and desorption effects of AB-8,D-101,HPD-600 and NKA-9 macroporous resins on the crude polyphenol extract from the fruit residue of Aronia melanocarpa were studied and compared,and NKA-9 was selected as the optimal experimental resin;Then,the purification process parameters of polyphenols from the fruit residue of Aronia melanocarpa were optimized.Taking the polyphenol content as the investigation index,the p H value of sampling solution was 3.0,the concentration of sample solution was 2.0 mg/m L,the loading flow rate was 2.0 m L/min,the ethanol concentration was 70%and the elution flow rate was1.0 m L/min.Under these conditions,the purity of polyphenols increased from（11.71±0.20）%to（62.61±0.78）%,which increased by 5.34 times;Through HPLC analysis,it was found that the polyphenols purified from Aronia melanocarpa pomace contained a variety of polyphenols such as chlorogenic acid,hyperoside,rutin,neochlorogenic acid,protocatechuic acid and ferulic acid.Among them,the content of chlorogenic acid reached 36.91 mg/g,the content of hyperoside reached 8.61 mg/g,and the least was quercetin,reached 0.79 mg/g.3.Study on the antioxidant capacity of polyphenols from the fruit residue of Aronia melanocarpa.When the concentration of polyphenols purified from Aronia melanocarpa pomace was 60μg/m L,the scavenging rates of DPPH·,OH·and ABTS+·were（95.06±0.45）%,（34.56±0.19）%and（99.34±0.02）%,respectively.Moreover,the free radical scavenging ability and Fe3+reduction ability were significantly higher than those of Vc control group,indicating that polyphenols from pomace of Aronia melanocarpa had good antioxidant capacity.4.Study on the fresh-keeping effect of polyphenols from the fruit residue of Aronia melanocarpa on cold fresh meat.The 0.5%polyphenols from fruit residue of Aronia melanocarpa and 1.5%gelatin were mixed for coating preservation of cold fresh meat.On the 12th day of storage,the total number of colonies of coated cold fresh meat was（5.41±0.06）lg CFU/g,the TVB-N value was（14.72±0.58）mg/100g,p H value was（6.23±0.04）,and juice loss rate was（6.86±0.12）%.Its water migration degree was low,which still met the standard of fresh meat,and the texture and sensory quality were also within the acceptable range;The blank meat sample was rotten and deteriorated on the9th day.This indicated that the combination of polyphenols from fruit residue of Aronia melanocarpa and gelatin had good preservation effect on cold fresh meat,and the storage period of cold fresh meat was prolonged by about 3 days. |
