Patent GB-754821-A (GB)
Abstract: 754,821. Preserving vegetables, fruit and flowers. FROESCHEL, P., and GOLD, R. L. Oct. 19, 1951 [Oct. 19, 1950; May 7, 1951], Nos. 9569/50 and 10648/51. Class 49. In order to prevent wilting of plants, i.e. vegetables, fruit, and flowers, or to restore plants, if wilted, to freshness, the plants are wholly submerged in water and there subjected to a change or changes in pressure so as to cause water to enter the intercellular spaces of the plants, and then some of the water which has been caused to enter the intercellular spaces is removed therefrom. Examples are concerned with extending the shelf life of lettuces, spinach and Brussels sprouts. In treating flowers, colours may be dissolved in the water. One apparatus for the treatment, Figs. 2 and 3, comprises a drum 10 for the plants and water, a drum housing 17 having a hinged closure 24, a lid 35 for the drum on the underside of the closure', which lid can be moved relatively to the closure by manipulation of a spindle 29 to effect airtight sealing of the drum, a compressor or vacuum pump 70 in or on the housing for increasing or decreasing pressure within the drum, and means, e.g. an electric motor, for rotating the drum about a vertical axis 13; use of the apparatus involves placing the plants to a level 136 in a wire mesh container 134 in the drum 10, filling the drum with water from a pipe 53, placing the lid 35 and closure 24 in position and operating the spindle 29 to seal the lid 35 on the drum, increasing the pressure in the drum by forcing in air by a pipe 118B on operation of the pump 70, releasing the pressure in the drum by operation of the spindle 29 to lift a valve 32 over a hole 34 in the lid 35, repeating such alteration in pressure until sufficient water has entered the plants, turning the spindle 29 fully and lifting the lid 35 from the drum, and setting the drum in rotation to throw water off the plants until they are dried superficially. Another apparatus for the treatment, Figs. 9 and 11, comprises a drum 150 having a cover 153 hinged to an outer casing 154, a cross piece 157 linked to the cover 153, hinged at one end to the casing 154 and engageable at the other end by a screw 158 to the casing, a water jet pump 175 for evacuating the drum through a pipe 178, a vertical shaft 189 on which the drum is rotatable, an annulus of curved vanes 151 at the base of the drum, and a nozzle 182 for direction of a jet of water against these vanes ; use of the apparatus involves placing the plants in a wire mesh container 186 in the drum 150, filling the drum with water from a pipe 172, lowering the cover 153 and cross piece 157 and manipulating the screw 158 to press the cover on to the drum, evacuating the drum by operation of the pump 175, opening a relief valve 160 in the cover 153 by pulling a handle 161 and holding the handle until the vacuum in the drum is released to the extent desired, releasing the handle to allow re-evacuation of the drum, repeating the evacuation and release of vacuum treatments until sufficient water had entered the plants, lifting the cover of the drum, and directing water from the nozzle 182 against the vanes 151 to rotate the drum, throw water off the plants and dry them superficially. Specification 754,929 is referred to.