Studies On Preservation Of Fresh-Cut Apples

Fresh-cut fruits and vegetables are very popular by consumers,because of their convenient to eat.There are a series of physiological changes after cutting so that it shorten the shelf life,the sales at home and abroad have been greatly restricted.The selling vegetables in our country are made by hand at below 5℃,which is only store 3 days,therefore it limited the variety of fruits and vegetables and the scale of sales.In order to protect quality and extent the shelf life,the fresh apple had been taken as a test material.The effect of ascorbic acid,L-Cys,calcium ascorbic, sodium isoascorbate,citric acid and their combinations on browning controlling of fresh-cut apples was studied;Effect of the complex of ascorbic acid and calcium chloride are studied;The film results of three kinds of protein and three kinds of polysaccharide and the effect of protecting on fresh-cut apples are studied;The effect of five anti-corrosion agents on fresh-cut apples are studied;at the same time,the effect of the combination of inhibitors agents and coating agents and anti-corrosion are comprehensive studied,the studied results were as following:1.Polyphenol oxidase activity is different by PH,substrate concentration,the concentration of enzyme,inhibitor and other factors,the best test conditions are as follows:PBS(PH 6.8),adding 1.5mL 0.4%catechol,keep at 30℃for 5min,plus 1mL of the enzyme solution,mixing fast in the post-determination under the 416nm test the absorption of changes,calculate the activity of enzyme.2.Effects of 6.0%ascorbic acid,1.5%L-Cys,1.5%calcium ascorbic,0.6%sodium isoascorbate, 2%citric acid on browning inhibition of fresh-cut apples during storage period were best among the single browning inhibitors;the complex of ascorbic acid and calcium chloride(3:1) can inhibit browning of fresh-cut apple slices are more effective during storage period.3.The effect of combinations browning inhibitors was superior to the single browning inhibitors although it store at 14d by six kinds of index;The optimum combinations treatment was 6.0%ascorbic acid,0.5%L-Cys,0.5%Calcium chloride,0.4%sodium isoascorbate,l%citric acid.4.Soy protein 4/100g,whey protein 6/100g,CMC:0.5/100g,1.0/100g,soybean polysaccharide 2.0/100g have good film;Soy protein 4/100g is the best of them on protecting fresh-cut apples in one week.5.Added to liquid coating to optimize inhibitor combinations for the group:soy protein 4g/100g water,glycerin for 25%(w glycerol/w protein) for the film,and then adding 6.0% ascorbic acid,0.5%calcium chloride,0.5%L-cys,1.0%citric acid,0.4%sodium erythorbate,keep fresh in 15 days.6.Preservatives in a single 80mg/Kg natamycin,0.25g/Kg nisin,1.0g/Kg sodium benzoate, 0.2g/L sodium hypochlorite,40mL/L hydrogen peroxide are effective in anti-corrosion,the effect of descending order of preservatives Bactericidal:natamycin> hydrogen peroxide> sodium hypochlorite> sodium benzoate> nisin.7.The cooperation of browning and anti-corrosion are studied,the method of coating agents adding chemical inhibitors and anti-corrosion agents not only inhibit browning but also inhibit corrosion in the shelf of 20 days,the group:soy protein 4g/100g water,glycerin for 25%(w glycerol/w protein) for the film,and then adding 6.0%ascorbic acid,0.5%calcium chloride,0.5% L-cys,1.0%citric acid,0.4%sodium erythorbate,80mg/Kg natamycin.