Fruit and vegetable by-products as sources of oil

This chapter is a survey of the published research literature dealing with the feasibility of recovering edible oils from by-products of the food processing industry. Most of the by-products considered here have either not been exploited before, or have been done so locally on a limited scale. 

The locations where commodities are grown are identified and if available yield per acre, proportion of seed to kernel, etc. are given. The physical constants of the oil are given in addition to their fatty acid composition. By-products of the oil recovery process such as edible protein, carbohydrate and fiber, or presscakes suitable for cattle feed are discussed. 

Several things are necessary to ensure success and profitability with the processing of by-products for edible oil and other edible products. The by-product should be available in a highly localized area so that shipping and collecting costs are kept to a minimum. Ideally, the by-product should be stable so that it can be stored for a while without deterioration. The absence of lipolytic enzymes is desirable. For the continuous operation of an oil extraction plant, alternative and perhaps multiple sources of raw materials should be available to take up any slack in the availability of by-product. Many fruit crops are highly seasonal so for maximum 

Kamel et al. (eds.), Technological Advances in Improved and Alternative Sources of Lipids Chapman Hall 1994 

Utilization of a processing plant, it would be necessary to be able to process multiple varieties such as cherry, plum, peach, apple, etc. It is essential that the cost of by-product remain reasonable once a successful recovery operation has been established. Most of the data reported here are for oil samples prepared under laboratory conditions. The extracting solvent used for the oil recovery was usually n-hexane, which is acceptable for edible purposes. Chlorinated solvents are unacceptable for the recovery of edible oils because they may contain chlorinated components such as tetrachloroethane which is not removable by heat treatment and which if present would make the oil too toxic to be consumed. Often oils that are recovered from by-products have properties that make them desirable in cosmetics and in medical preparations. Such specialized application may command a premium price. 

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J. L. Weihrauch and B. B. Teter, Fruit and Vegetable By-product as Sources of Oil, in Technological Advances in Improved and Alternative Sources of Lipids, B. S. Kamel and Y. Kakuda, eds., Blackie Academic Professional, London, 1994, pp. 178-180. 

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