Search Results
Research is described on the development of an automated inspection system which uses digital images and artificial intelligence techniques. Procedures have been developed for evaluating size, shape, and color of apples, potatoes, and mushrooms. Current emphasis is being placed on developing algorithms for detection of surface defects. A major effort will also be expended toward the development of an overall “quality” score for automated inspection of fruit and vegetables. The automated results are compared with those obtained using conventional manual inspection methods. Apples, potatoes, and mushrooms are the primary crops being inspected although the algorithms and techniques are applicable to many different fruits and vegetables. Color and monochromatic image processing components in “MS-DOS” and “Macintosh” computers are being used in this study.
Abstract
Concentrations of patulin in blue mold lesions caused by Penicillium expansum Lk. ex Thom in pears and stone fruits were similar to those reported for apples. Of fruits tested, only the plum was a poor substrate for accumulation of the mycotoxin. The total patulin within disease lesions increased as the lesions enlarged. However, the concentration of patulin varied considerably, with the largest lesions usually yielding the lowest concentrations. Little or no patulin permeated healthy tissue surrounding the disease lesions unless fruits were overripe or had senescent breakdown.
Abstract
At any stage of the ripeness of ‘Bartlett’ pear fruits, subsequent ripening was inhibited if the fruits were warmed to 40°C. Both production of, and sensitivity to, ethylene (C2H4) were almost totally suppressed. Even at 30°C, C2H4 production was greatly reduced in both early- and late-season fruit. Unless treated with C2H4, early-season fruit failed to ripen at 30°C although late-season fruit ripened spontaneously, presumably because of high internal concentrations of the gas. In both cases ripening was characterized by a watery breakdown of the floral end of the fruit.
At 40° and 50°C, respiratory rates declined progressively unless the fruits were treated with C2H4, whereupon a stimulation occurred although ripening was unaffected.
Gas exchange was not limiting at temperatures as high as 50°C, even when the ends of the fruits were sealed with paraffin wax. Maximum modification of the internal atmosphere of any individual fruit resulted in 15.7% O2 and 7.2% CO2. Ripening of fruits held at 20°C in that atmosphere was delayed about 3 days, presumably via mild competitive CO2 inhibition of C2H4 action.
We conclude that failure of ‘Bartlett’ pears to ripen at 40°C results from lack of C2H4 production and loss of sensitivity to the gas. The mechanisms are unknown.
Abstract
Cut carnation flowers shipped from California by air occasionally arrive at eastern markets in a senescent condition with losses greater in the warm autumn months. CO2 and C2H4 production by the flowers has a pattern similar to that of climacteric-class fruits, with senescence correlated with a rise in release of the gases.
Cut carnation flowers show an enormous increase in respiratory heat with increasing temperature: 89 BTU/ton/hour at 0°C versus 14,718 at 50°C. In C2H4-free air, the flowers tolerate elevated temperatures but their vase life is reduced. Their sensitivity to C2H4 increases dramatically with increasing temperature, with the threshold concentration partially depending on prior stresses on the flowers.
Flowers in containers exposed to direct sunlight developed temperatures as high as 49.5°C. Air temperatures inside containers shipped via jet aircraft were as high as 35°C. The C2H4 concentrations in the containers may reach 10.5 ppm.
The remarkable resistance of cut carnation flowers to mechanical injury, combined with their low metabolic rates at low temperatures, makes refrigerated surface shipments feasible and perhaps economically desirable. Their resistance to injury seems related to their light weight, the damping action of the petals, and the lack of phenolase or readily oxidizable phenolic compounds in the petals.