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OF the 261,000 grape hectarage in California, 45 percent is raisins, 40 percent is wine and 15 per-cent is fresh. Systems have been developed for hauling the wine grapes to wineries in either open gondola tanks or in closed tanks that control contamination by wild yeasts where grapes are crushed in the field. A quality control system was developed for use in sampling and inspection for either handling system. Cores of bunches, berries or juice are withdrawn from top to bottom of gondolas or tanks. Samples are deposited on standard grading tables and graded for mold, yeast content, and soluble solids.

A microprocessor-based electronic weighing and re-cording system for use at processing tomato grading stations was developed and tested. The incoming sample, grade defect buckets, and peelability buckets are weighed on electronic scales. The color and soluble solids data are entered into switch registers. The central computer pro-cesses this information, computes the off grade category weights as a percentage of the incoming sample weight and prints it on the official certificate after determining whether the load passes or fails inspection.

A mechanism for filling tomato trailers was developed by utilizing critical analysis of the design features of fillers. The filling mechanism was field tested and results indicate the effects from a single initial drop height may not be as important as that from successive multiple im-pacts as fruits bounce down a long angle of repose of fruits already in the container. Results also showed that use of the new filler reduced from 12.9 to 7.3 the percent of tomatoes in the visible loculus category.

APROCEDURE for determining processing tomato color was developed by the University of Cali-fornia and the California State De-partment of food and Agriculture Tomato Inspection Service. The pro-cedure includes comminuting a repre-sentative sample in a blender, remov-ing air bubbles and determining the color in a color intensity measuring instrument as reported by O'Brien et al. (1974). This standard procedure used by the State of California tomato inspection service was considered to be time consuming, unsafe, and sub-ject to human error. This paper re-ports research on development of a procedure that retained the obtain-able accuracy yet reduced the human factor and the time required. The standard method consisted of obtaining 3.9 kg of tomatoes from the O'Brien subsampler as reported by O'Brien (1972). The washed and de-stemmed whole tomatoes (minus the damaged and grass green fruit) were then placed in a commercial blender as reported by Smith and Huggins (1972). To insure that these tomatoes would not bridge, some of the fruits were placed in the blender and al-lowed to blend for several seconds, thus providing a mulch in the bottom of the blender. The remaining toma-toes were then added to the blender and blended for one min. Eight hundred ml of the liquid in the blender was removed (400 ml for the actual deaeration and 400 ml for reserve). The 400 ml for deaeration were passed through a stainless steel screen, which removed the skins and seeds. The strained mascerate was placed in a 1000 ml Erlenmeyer flask under vacuum and was deaerated for 2 1/2 min. This strained mascerate consisted of approximately 50 percent air by volume, and after the 2 1/2 min under vacuum, the air was re-moved, leaving approximately 200 ml of juice. One hundred seventy-five ml of this juice was then measured visual-ly into a 15.24 cm diameter petri dish (directly from the 1000 ml Erlenmeyer flask). This sample was then placed in an Agtron E-5M color measuring instrument as reported by Marsh et al. (1969), and the reading was recorded.

THE development and testing of a bulk tomato handl-ing and weighing system is described. Compliance with design objectives was achieved for scales incor-porating a weigh hopper suspended from a direct weighing overhead electronic load cell. Tests confirmed the value of a passive, dashpot-free shock protection device. Accuracy was evaluated in accordance with stan-dards from the California State Department of Food and Agriculture, Division of Measurement Standards. A full season of commercial operation of a prototype system demonstrated its ruggedness and reliability while pro-viding information useful for its use by others.

LIGHT reflectance characteristics of tomatoes are used to evaluate the quality of fruit and provide a means of sorting for tomatoes. Reflectance studies have been undertaken to establish several criteria using combinations of light reflectances at different wavelengths, which will provide good separation of acceptable tomatoes for processing from unacceptable tomatoes, dirt clods, and stones. Reference levels for separation have been established at the 99.5 percent confidence level.

A first-generation system for automatically collecting and printing California processing tomato inspection data is discussed. It consists of a controller (micro-computer), a weigher, a ticket printer, and two panels for operator input. The 8080 software accommodates annual modifications to the grading procedure. During normal operation, the microcomputer (/^C) services the printer and panels. When inspection data is ready, however, the \xC is interrupted, the status of the interrupting channel is determined and an appropriate service is performed. Development systems, emulators, and high-level languages are essential in [xC design. Use of each is discussed.

A combined manual and automated tomato grading station has been developed and tested. Incoming samples are weighed electronically, graded by inspectors for defects. The grade defects are weighed electronically and the percent of offgrade is computed as a percent of the incoming sample weight. Samples for color and soluble solids are determined by vacuum blending and measured by a reflectance meter. The grade certificate is printed electronically.

A mathematical model is presented to predict dockage error at tomato grading stations that base grade defect percentages on volume rather than mass deter-mined samples. Reasonably good agreement was found between predicted dockage error and data from over 6,000 percentages recorded on official load certificates at a commercial grading station in California. The model shows that appreciable errors occur even when the average sample mass is at the target value of 45.36 kg (100 lbm). The monetary value of dockage errors at a typical grading station is shown by the model to exceed the cost of a computerized weighing, precentage calculation, and certificate printing system.

A complete weighing, grading and certificate printing system has been developed for fruit or vegetable grading stations. Electronics of the system is based on 8085 microprocessor in a central unit. Interfacing of man and machine functions are shown where each is assigned those operations best suited to their capabilities.

THE weighing of various defect categories that make up the official grade on which price for fruits and vegetables is determined has been automated at a pilot grading station. A compartmented conveyor scale is mounted in the center of a mechanical grading table. The weighing of the grade category in each compartment is controlled and calculated by a microprocessor that also controls other operations associated with oper-ating the scales and recording the data.

A system of continuous production of sweet potatoes in the tropics has been modelled using linear program-ming techniques. Two land management strategies have been defined and evaluated. Each was optimized under conditions of limited availability of machinery and labor individually and in combination. Land utilization and level of output was also studied. It has been shown that there is a cost tradeoff between a steady harvest, thus requiring no storage, and full utilization of labor, land, and machinery. Drops of at least 5 percent in output per input used indices are the minimum to be expected if a steady supply of sweet potatoes must be produced. Larger drops in productivity can be expected, depending on system design. These drops in productivity must be weighed against storage costs and other factors in each locality before a decision as to which land management strategy to adopt can be made.

REFLECTANCE studies were made to establish several criteria using a single reflectance, or com-bination of light reflectances at different wavelengths, which might separate good processing tomatoes from those having different kinds of mold, growth crack, sun-burn, sun scald, and possibly other substances. A single criterion was found that works very well.

HUMAN considerations were carefully evaluated in the design of a mechanical fruit and vegetable grading table. Body dimensions were used to determine machine dimensions and control locations in order to enhance worker comfort and productivity. Controls and shielding were used which promote worker safety.

LIGHT reflectance characteristics of tomatoes at vari-ous stages of maturity, dirt clods, mold and other tomato defects have been found to be sufficiently dif-ferent to identify them. By using combinations of light reflectances at different wavelengths, several criteria were found which will provide reasonable separation of good tomatoes from green tomatoes, dirt clods, and those having defects.