SUMMARY Reported for the first time are analyses of materials identified with and contributing to the cloud of orange juice. Hexane‐soluble materials provided up to one‐fourth of the cloud‐producing components. In contrast to the composition of structural components of the fruit, cloud components insoluble in alcohol, acetone, and hexane were shown to be rich in nitrogen (ca. 7%), pectins (ca. 80%), and phosphorus (ca. 1.5% as the pentoxide) and to be very low in cellulosic components (ca. 2–5%). This is evidence that cloud originates in the juice cells rather than from mechanical disintegration of structural tissue. No appreciable difference in cloud composition was observed between fruit varieties or between freeze‐damaged and normal fruit.

A new method has been developed for estimation of recoverable oil in citrus juices, based on quantitative combination in acid solution of d-limonene, the principal component of distilled citrus oils, with bromine. 2-Propanol is added to citrus juice, the mixture is distilled, and the distillate is acidified with HC1 and titrated with potassium bromate-bromide solution. End point is observed by disappearance of color from methyl orange indicator. The distillation requires about 3 min., and complete determination, less than 7 min. Recovery of added d-limonene was 100 ±1%, indicating a high degree of accuracy; replications seldom varied more than 0.001% oil, indicating excellent precision. Recoveries were consistently higher than by the Clevenger method.

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