Browning in fruits

L-ascorbic acid (AA) and its isomer D-erythorbic acid (EA) (also called D-isoascorbic acid) have been used as inhibitors of enzymatic browning in fruit and vegetable products for at least 50 years, (15-17). These compounds prevent quinone accumulation and subsequent pigment formation by reducing the 0-quinones generated from the phenolic substrates of PPO back to O-dihydroxyphenolic compounds (17-18). AA also can act as a PPO inhibitor (19-20). AA and EA are used interchangeably although there are indications that AA is more effective in some systems (21-22). 

Studies reviewed herein have demonstrated the potential ability of several new approaches to control enzymatic browning in fruit and vegetable products the use of novel AA derivatives, polyphosphates and (5-cyclodextrin as browning inhibitors the application of browning inhibitors to cut fruits and vegetables by pressure infiltration and the use of cvs. having a low tendency to brown. It is likely that one or more of these approaches will be useful as an alternative to sulfites to control browning in affected commodities. 

Edible film Controlled moisture transfer between food and the surrounding environment Controlled release of antimicrobial substances Controlled release of antioxidants Controlled release of nutrients, flavors, and drugs Reduction of oxygen partial pressure Controlled rate of respiration Temperature control Controlled enzymatic browning in fruits Reverse osmosis membranes... 

Walker, J.R.L. The control of enzymic browning in fruit juices by cinnamic acids, J. Food Technol., 11, 341, 1976. 

Stadtman, E. R. 1948. Nonenzymatic browning in fruit products. Advaruxs in Food... 

Earl R. Stadtman, Nonenzymatic Browning in Fruit Products. 325... 

Citric acid (pKi = 3.09 pK2 = 4.74 pKs = 5.41) is utilized in candy production, fruit juice, ice cream, marmalade and jelly manufacturing, in vegetable canning and in dairy products such as processed cheese and buttermilk (aroma improver). It is also used to suppress browning in fruits and vegetables and as a synergetic... 

Walker, JRL. The En2ymatic Control of Browning in Fruit Juices by Cinnamic Acids. Journal of Food Technology, 1976 11, 341-345. 

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