Storage Changes in the Phosphorus, Nitrogen, and Fatty Acid Constituents of the Lipid in Canned Florida Valencia Orange Juice

Abstract

The lipid component of orange juice has received considerable attention because of its possible influence on flavor changes which develop in the canned juice during storage. Several investigators (2,4,5, 7,8,9,10,11) have presented analytical data, both qualitative and quantitative, on this fraction. Huskins, Swift, and Veldhuis ( 4 ) analyzed the lipids from canned pasteurized orange juice stored for 2 years under normal climatic conditions at Winter Haven, Florida (annual mean temperature about 22°C.). They found that the phosphorus had decreased to one-tenth of its original value and the nitrogen to one-fifth, choline having entirely disappeared. Also, the amount of lipid which could be extracted from the stored juice had decreased. They concluded that the phosphatides had hydrolyzed and that the choline and ethanolamine, as well as part of the phosphorus, had been lost to the aqueous phase of the juice. These investigators also noted changes in the fatty acid constituents, which could have been the result of oxidation. I n this previous work, no attempt was made to establish whether these changes occurred rapidly o r slowly. The present analyses of the lipid from pasteurized, stored Valencia orange juice were carried out to study this question. Attention was given only to the changes in the phosphorus, nitrogen, and fatty acid constituents. EXPERIMENTAL Extraction of lipids. Fresh Valencia orange juice was obtained from a local cannery in 1950. I n the laboratory i t was mixed, pasteurized at 88"C., canned, and quickly cooled.About one-third of the cans were held at 0-5°C. for 2 days until the lipid could be extracted. The extraction was carried out by passing the juice through an Oliver Precoat filter and then extracting the lipid from the filter-aid with acetone as described by Huskins, Swift, and Veldhuis (4,5). The solvent was evaporated and the lipid taken up in petroleum ether. This step eliminated the water which the acetone also extracts from the damp filter-aid. The petroleum ether solution of the lipids was then stored under refrigeration (0-5°C.) until the analysis could be made.After storage periods of 6 and 13 months, portions of the stored juice were processed f o r lipids as outlined above.Prior to analysis, the petroleum ether solutions of the lipids were treated as follows: each solution, in a 3-necked flask equipped with a mechanical stirrer, condenser, and vacuum gauge, was warmed over a steam bath to evaporate most of the solvent at atmospheric pressure. Then the flask was immersed in cold water, the stirrer was started,The remaining two-thirds of the cans were stored in the laboratory loft.

Effects of storage conditions on the lipid composition of commercially prepared orange juice

“…High carbon number fatty acids, as found in orange juice, contribute very little to flavor; however, their importance is as precursors to many volatile off-flavor compounds. Fatty acid oxidative products, formed by autocatalytic and enzymic (lipoxidase) mechanisms, have been implicated in off-flavor development in aged orange juice (Huskins and Swift, 1953;Huskins et al, 1952). Many of these fatty acid oxidative products, e.g., alk-2,4-dienals, 2-octenal, and re-hexanal from linoleic acid, possess extremely malodorous and malflavorous properties.…”

Colorimetric determination of browning precursors in orange juice products

“…Orange and other citrus juice products are susceptible to various deterioration reactions during processing and storage, resulting in off-flavor development and browning. The chemical changes have been extensively investigated during the last three decades, and the main deterioration mechanisms considered to cause off-flavor buildup include degradation of essential oil and aroma compounds (Blair et al, 1952;Bielig et al, 1972;Askar et al, 1973a,b), 0021-8561/78/1426-0282S01.00/0 © 1978 American Chemical Society hydrolization and autoxidation of the lipid fraction (Huskins et al, 1952(Huskins et al, ,1953Nagy and Nordby, 1970), and browning processes, involving ascorbic acid degradation (Joslyn, 1957) and Maillard reactions (Wolfrom et al, 1974).…”