GB411822A - Improved method of conserving fruit juices and products produced thereby - Google Patents

Abstract

411,822. Preserving citrus fruit juices. CALIFORNIA FRUIT GROWERS EXCHANGE, 607, South Hill Street, Los Angeles, U.S.A. Dec. 12, 1932, No. 35183. Convention date, Dec. 12, 1931. [Class 49.] Concentrated or unconcentrated citrus fruit juices are preserved by heating rapidly, e.g. within not more than 2 minutes, to about 75-93‹ C. maintaining at this temperature for sufficient time, generally not exceeding 3 minutes, to render the enzymes inactive and then rapidly cooling to below 45‹ C. Examples are given of the temperatures and times of treatment employed for orange, lemon, mixed orange and lemon, and citrus fruit juices. The more acid juices require lower temperatures and shorter times of treatment, and acid may be added to the juice, e.g. to orange juice, to improve it in this respect. The juice may be supplied through a pipe 12 to a vessel 10 having an agitator 11 and connected through a pipe 13 to vacuum for deaerating the juice. The deaerated juice is fed by a pump 15 to a heater 16 where it is subjected to the heat treatment and from which it may pass to a vessel 25 where it is concentrated under vacuum at 35-45‹ C., a condenser 26 being provided. Alternatively the juice may pass from heater 16 to a cooler 23 where it is brought rapidly to low, e.g. freezing temperature by brine or other refrigerant, and the semi-frozen juice may be placed in containers and frozen hard for storage, the solids being thereby maintained in suspension during the freezing. The heater 16 consists of a tube 18 through which the juice is passed having a tube 19 centrally disposed therein and a conduit 20 surrounding it through both of which heating medium is passed. Spiral vanes may be placed in the juice space to give more uniform flow and more effective heat exchange. The cooler 23 is similarly constructed.