EFFECTS OF CATHODE RAY AND GAMMA RAY IRRADIATION ON SOME ORGANIC ACID‐CARBOHYDRATE SYSTEMS^a,b

Abstract

Use of ionizing radiation for the cold sterilization of heat sensitive foods has been the subject of intensive investigation in recent years. The thermal processing and storage of many products results in darkening or "browning" due to various types of nonenzymatic degradative reactions. In many instances, the Maillard reaction -the interaction of amino acids and reducing sugars-is involved, but in the case of some fruit products at least, organic acid-reducing reactions appear to take place. Since some of the products susceptible to this type of browning, such as juices, jellies and apple products have been studied in relation to radiation sterilization (2,11,12,13,14,15), it was deemed desirable to study the effects of irradiation upon the browning precursors and the browning of several organic acidreducing systems. Sugar solutions, sugar-acid solutions, pectin gels and apple sauce were selected because of the availability of previous data on the effects of thermal treatments upon the composition of these products (7,8,9,10,16).I t was the purpose of this investigation to determine the nature and severity of physical and chemical changes incurred by the above-mentioned organic acid carbohydrate systems under exposure to various dosages of cathode and gamma ray irradiation, to compare the effects with those of heat treatment, and to determine the efTect of pre-irradiation and post-irradiation heating on these systems. EXPERIMENTALPreparation of sugar and sugar acid solutions. One series of solutions containing 60% sucrose, 30% fructose, and 30% glucose was made up using distilled water. Another series of solutions containing 60% sucrose, 30% fructose and 30% glucose was made UP using a 1% malic acid solution as diluent. A third series of solutions containing 12% sucrose, 6% fructose and 6% glucose was made up using an O.S% malic acid solution as diluent. The fourth series consisted of solutions of 60% sucrose, 30% fructose and 30% glucose using an O.S% citric acid solution as diluent. All reagents used were of C.P., A.C.S. or reagent grade.Two ml. of each of the solutions mere filled into 10 ml. Kimble Neutraglass ampules ' for cathode ray irradiation, while 10 ml. portions were filled into 18 X 150 rnni. Pyrex test tubes for gamma ray irradiation. The ampules and tubes were sealed in an oxygen

γ-Radiation Influences Browning, Antioxidant Activity, and Malondialdehyde Level of Apple Juice

“…Major antioxidants in apple juice are phenolics (15,30), and phenolics, such as chlorogenic acid, are much more resistant to irradiation than is ascorbic acid (data not shown). During irradiation, reductants (33) and novel new antioxidants may be formed (34). The redox state of ions and compounds may also be changed by irradiation.…”

Polymer production from aqueous solutions of D‐glucose by high‐energy radiation

“…Reductones have been proposed as products to account for the absorption at 265 to 275 mu commonly observed with irradiated carbohydrate solutions (7, 31,32). The proposed mechanism involves hydrogen abstraction:…”