The engineering research will develop practical sensors and technologies for quality measurement and grading of fruits and vegetables before, at and after harvest. It also aims to generate new knowledge and understanding of the optical and mechanical properties of fruits and vegetables and their relationship with the physiological factors and quality attributes. A systems approach of integrating sensors development, properties characterization, and models/algorithms development will be applied to attain the following specific objectives: 1) develop cost effective sensors and sensing systems to measure and monitor the quality/maturity of individual apples in the orchard; 2) develop commercially viable technology to presort and grade apples in the orchard so as to decrease postharvest handling and storage costs for fruit growers; and 3) develop technology to accurately and rapidly assess, sort, and grade harvested tree fruits and vegetables for multiple internal quality attributes (firmness, flavor, ripeness) and defects.
The research is expected to develop new knowledge and insight on quality characterization of fruits and vegetables through nondestructive optical and mechanical means, new sensors enabling growers, packers, and researchers to measure and monitor quality/maturity of apples on the tree and after harvest, cost effective technology for presorting apples in the orchard, and new inspection technology for sorting, grading, and assigning value to fruits and vegetables based on desired quality traits to achieve improved product consistency.
The new knowledge and technologies developed from the research would enable growers and packers/processors to more efficiently manage harvest and postharvest operations, deliver better quality products to the market, and achieve production cost savings. Horticultural equipment manufacturers will also benefit via adoption of the new knowledge and technologies developed from the proposed research. U.S. consumers will benefit from the research as well because they can expect better, more consistent fresh fruits and vegetables.
Spectral scattering technique for quality assessment of fruit. Sorting and grading is a critical postharvest operation in ensuring fruit quality and adding value to the final products. Modern packinghouses can sort and grade fruit for color and size; some of them are now even capable of sorting fruit for soluble solids. However, it is still challenging to sort fruit for firmness, not to mention both firmness and soluble solids. A novel method/technique for assessing fruit firmness and soluble solids content was developed based on the measurement and mathematical characterization of light scattering in fruit in the visible and near-infrared region. The technology attracted attention from industry and researchers around the world, and other researchers are using it for assessing quality of other fruits and food products.
Hyperspectral imaging technology for quality inspection of fruits and vegetables. Fruits and vegetables should be free from both external and internal defect in order to enhance their marketability and quality grades. Automatic detection and sorting of defects, especially those internal, still presents technological challenges. A novel hyperspectral imaging system was developed for detection of pickling cucumbers/pickles for both external and internal quality characteristics including skin and flesh color, and defect (bruises and hollow hearts). The technology will be suitable for online inspection of pickling cucumbers or pickled products to ensure their quality and consistency.
Bioyield firmness tester. Fruit firmness is a key parameter in the grading standards for the shipping and marketing of apples, and it is routinely measured and monitored by the destructive testing method at various inspection points from orchard to packinghouse and to retailing. Horticulturists, fruit growers, storage operators, and fruit inspectors need a portable, low-cost testing device to measure and monitor the firmness of apples without degrading them. We developed a compact, portable device to measure the bioyield force of fruit as an indication of fruit firmness. The device does not degrade fruit and is suitable for use in orchards, laboratories, and packinghouses. The first version of the device has been used in horticultural lab, and researchers expressed great interest in the device for measuring and monitoring the firmness of apples.
Novel method for measuring the optical properties of horticultural and food products. Until now, no appropriate methods/techniques are available for measuring the optical properties of fruits and vegetables, which are needed for better understanding of light absorption and propagation in a food and for the development of effective optical techniques for quality assessment and grading. A novel method using hyperspectral imaging was developed for measuring the optical properties of horticultural and food products. Compared to other techniques currently available in the biomedical research, this technique is simpler, faster and more suitable for horticultural and food products. The method offers researchers a new means for measuring and understanding the optical properties of food and agricultural products, and instrumentation engineers can use the optical property data to assist in the design of sensing configurations for product quality assessment and grading.
Technique for fruit gloss measurement. Artificial wax is often applied to apples destined for the fresh market to improve fruit appearance/gloss and thus their appeal to the consumer. However, incidents of improper wax application have occurred recently, which made fruit less attractive on appearance and resulted in quality downgrading to the fruit shipped for international markets. In collaborating with researchers at Michigan State University, we developed an imaging device along with computer algorithm for objective measurement of the gloss of apples. The technology has enabled researchers to objectively assess the effect of different wax application procedures on fruit appearance (gloss) and establish proper waxing guidelines for Michigan fruit packers. The technology is also useful for measuring the gloss/appearance of other horticultural products.