Submitted to: Patent Application
Publication Type: Patent Application
Publication Acceptance Date: 4/11/2006
Publication Date: 4/11/2006
Citation: Jackson, E.S., Haff, R.P. 2006. Method and apparatus for non-destructive detection of pits and seed fragments in fruit. U.S. Patent 7,024,942 B1.
Technical Abstract: A method and apparatus have been developed to detect pits in dried fruits, with emphasis on detection of pits in dried plums (prunes). The method is based on measuring the required force to compress the fruit to a particular thickness, which will differentiate pitted fruit from whole fruit with pits. Pitted fruit will consist only of meat, which will compress with less force than whole fruit. Compression and detection are achieved by passing the fruit between a roller and a force transducer, which produces a voltage proportional the amount of force applied to it. To force the pit into the transducer for a signal, the space between the roller and the force transducer must be smaller than the smallest dimension of the pit. Automatic compensation to allow for different sized fruits and pits to pass, while still providing compression for detection, is included using shock absorbers or springs. Signals from the force transducer are conditioned and fed to a comparator, which compares the signals to a threshold level (set empirically from training sets) and triggers a sorting mechanism. This method provides several benefits for the industry, including better product quality, reduction of repetitive motion injury involved with sampling, and increased food safety for consumers.