Research On The Extraction Of Plant Polyphenols And Its Scavenging Effect On Nitrite

In recent years,food safety issues caused by endless,so the issue of food safety has become the focus of attention of consumers.In particular,the food can not be consumed in a timely manner,in order to extend the shelf life of food and we usually need to add food additives.Nitrite is a kind of food additive because of its antiseptic and color enhancing effect.However,the excessive amount of nitrite is easy to cause cancer in human body.Plant polyphenols,which are widely used in plants.Meanwhile,they are a kind of natural antioxidant,which is safer and more reliable than synthetic antioxidants.Plant polyphenols have a strong ability to hydrogen and nitrite in the acidic conditions of chemical reaction,thereby reducing the content of nitrite in food.The main contents of this experiment are as follows:1.Extraction and purification of polyphenols from Chinese yam and removal of nitrite(1)Extraction of Chinese yam polyphenolsThe tiegun for extraction of polyphenol from raw material.Based on single factor and orthogonal tests,the extraction temperature was 80?,the extraction time was 100 min,the ratio of material to liquid was 1:20,the ethanol volume fraction was 40%,and the maximum extraction rate was about 0.1834%.The experimental conditions were simple,and the pressure was not high,so it was safe and reliable.(2)Study on the purification of polyphenols and the scavenging effect of nitriteThe AB-8 resin was selected by static adsorption experiments,and it was used to purify the polyphenol extract of the yam,and the sodium nitrite was removed by the purified solution.On the basis of the single factor,the orthogonal experiment was used to optimize the conditions:the amount of the purified liquid was 15mL,the extraction temperature was 60?,the reaction time was 15min>the reaction pH was 2.20,and the maximum clearance rate was 78.65%.The content of polyphenol in the purified solution was 173.38 ?g/mL,which was 51.57%higher than that of the crude extract.At the same time,the crude extract and the purified liquid were used for the removal of nitrite in the salted fish sample.The average removal rate of the crude extract was between 60.30%and 63.60%,and the average removal rate of the purified liquid was 55.80%-57.30%.The removal rate of the yam purifying solution is slightly lower than that of the crude extract,which may be the loss of other active ingredients such as polysaccharide and vitamin C during the purification process,reducing removal effect.2.Extraction and determination of polyphenols from banana peel and removal of nitrite(1)Extraction and characterization of polyphenol from banana peelExtraction of effective components from banana peel with ethanol.The optimum extraction conditions were as follows:the ratio of material to liquid was 1:25,the volume fraction of ethanol was 80%,the extraction temperature was 70?,the reaction time was 100 min,and the maximum extraction rate was 0.5454%,whith was higher than yam.After purification by AB-8 resin,the purity of banana peel extract was increased by 42.29%,and the purification effect was good.Purification of liquid by high performance liquid chromatography quantitatively determine the polyphenols of banana peel polyphenols,whith contains gallic acid,protocatechuic acid,catechin,chlorogenic acid,caffeic acid,ferulic acid and rutin hydrate,the chlorogenic acid content is high.(2)Nitrite removalStudy on the optimum conditions for the removal of nitrite from banana peel polyphenol extract by orthogonal test,the extraction solution was 3mL,the reaction temperature was 70?,the reaction time was 5 min,the pH was 2.20,and the removal efficiency was 82.64%.