Progress 07/01/01 to 06/30/04
Outputs
A field research trial during the 2003 asparagus harvest season evaluated a selective harvester for feasible use as a commercial machine. Initial results indicate the selective machine harvester did minimal field damage and harvested 55-60 percent of the weight harvested by a hand crew. The harvester generated as high as 77 percent useable number one spears based on fresh market standards. Results suggest that the machine has potential application as a commercial harvester. A financial evaluation of the harvester indicates the machine can harvest at approximately 70-80 percent of a hand crew and still generate an economic benefit to the grower. Recent research on selected electronic graders in the grading and sorting process of fresh asparagus packing firms demonstrated potential labor savings capabilities. For the first time in several decades Washington will adopt technology in the fresh packing sheds. Experiments were conducted to investigate the effects of heating
or enzyme treatments on the phenolic composition and antioxidant activity of asparagus juice. Several commercial pectolytic enzymes were used to produce asparagus juice. Eight commercial pectolytic enzymes were incubated with asparagus juice at 37 degrees C. Six of the eight enzyme preparations showed various abilities to hydrolyze rutin to quercetin. For most enzymes, although phenolic composition was changed, the total phenols were not apparently different from the control. Further research examined different methods of drying techniques for use in dehydrated soups. High quality dried asparagus can be made using Refractance Window (RW) methods.Hot water (HW) treatments to asparagus demonstrated beneficial quality attributes. Research focused on HW treatments followed by cold water, in depth modified atmosphere (MA) studies and treatment with an experimental growth regulator AVG to interfere with ethylene physiology of the spear. The combination of HW and AVG influenced asparagus MA
by lowering oxygen and increasing carbon dioxide in bags. Ethylene, a gaseous stress hormone, was decreased by HW treatment. The vitamin C and total antioxidant activity (TAA) experienced increases with MA-HW-AVG treatments. There is a demonstrated shelf life extension using these treatments, and they tend to have positive TAA effects. Michigan fresh asparagus spears were heated at various times and temperatures to find optimal treatment to improve visual quality and to prevent geotropism. Color, texture, phenolics, and antioxidant capacity were also measured. Heating at 47.5 degrees C for 1 minute was optimal to improve visual quality, but unexpectedly, heat treatment increased geotropism. Phenolics appear to show no significant change with heating. Antioxidant capacity is still being measured. Data analysis is still underway.
Impacts
The U. S. asparagus industry, if it is to survive the intensive offshore competition, must substitute technology for labor and shift the workforce to value-added employment. In a specialty crop industry such as asparagus, there are major barriers to developing innovative technologies to substitute for labor because there is a small market for such new technologies. It is imperative that public research universities do and/or foster the research to develop such technologies. At the farm level mechanized means of harvesting asparagus are being explored. This development would change the way asparagus is currently handled, allowing for development of value added products that make use of the whole spear. The outlook of the Washington asparagus industry would be altered because growers could compete with countries that have low wage rates. Significant progress has been made this past year with implementing technology in asparagus fresh packing sheds. Mechanical means to
handle asparagus will be implemented in several fresh sheds next season (2004) for the first time. The entire packing industry could move toward automation of the fresh handling process, based on a successful season by the packers with the new machines. Such technology adoption will benefit asparagus growers since the packer will have lower per unit costs, which can potentially be returned to the growers. In addition to the automation, improving and extending the shelf life of the fresh product will increase fresh handlers competitiveness in the national and international marketplace.
Publications
- Nindo, C.I., Sun, T., Wang, S.W., Tang, J., Powers, J.R. 2003. Evaluation of drying technologies for retention of physical quality and antioxidants in asparagus (Asparagus officinalis, L.). Lebensmittel-Wissenschaft und-Technologie, 36:507-516
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Progress 01/01/03 to 12/31/03
Outputs
A field research trial during the 2003 asparagus harvest season evaluated a selective harvester for feasible use as a commercial machine. Initial results indicate the selective machine harvester did minimal field damage and harvested 55-60 percent of the weight harvested by a hand crew. The harvester generated as high as 77 percent useable number one spears based on fresh market standards. Results suggest that the machine has potential application as a commercial harvester. A financial evaluation of the harvester indicates the machine can harvest at approximately 70-80 percent of a hand crew and still generate an economic benefit to the grower. Recent research on selected electronic graders in the grading and sorting process of fresh asparagus packing firms demonstrated potential labor savings capabilities. For the first time in several decades Washington will adopt technology in the fresh packing sheds. Experiments were conducted to investigate the effects of heating
or enzyme treatments on the phenolic composition and antioxidant activity of asparagus juice. Several commercial pectolytic enzymes were used to produce asparagus juice. Eight commercial pectolytic enzymes were incubated with asparagus juice at 37 degrees C. Six of the eight enzyme preparations showed various abilities to hydrolyze rutin to quercetin. For most enzymes, although phenolic composition was changed, the total phenols were not apparently different from the control. Further research examined different methods of drying techniques for use in dehydrated soups. High quality dried asparagus can be made using Refractance Window (RW) methods.Hot water (HW) treatments to asparagus demonstrated beneficial quality attributes. Research focused on HW treatments followed by cold water, in depth modified atmosphere (MA) studies and treatment with an experimental growth regulator AVG to interfere with ethylene physiology of the spear. The combination of HW and AVG influenced asparagus MA
by lowering oxygen and increasing carbon dioxide in bags. Ethylene, a gaseous stress hormone, was decreased by HW treatment. The vitamin C and total antioxidant activity (TAA) experienced increases with MA-HW-AVG treatments. There is a demonstrated shelf life extension using these treatments, and they tend to have positive TAA effects. Michigan fresh asparagus spears were heated at various times and temperatures to find optimal treatment to improve visual quality and to prevent geotropism. Color, texture, phenolics, and antioxidant capacity were also measured. Heating at 47.5 degrees C for 1 minute was optimal to improve visual quality, but unexpectedly, heat treatment increased geotropism. Phenolics appear to show no significant change with heating. Antioxidant capacity is still being measured. Data analysis is still underway.
Impacts
The U. S. asparagus industry, if it is to survive the intensive offshore competition, must substitute technology for labor and shift the workforce to value-added employment. In a specialty crop industry such as asparagus, there are major barriers to developing innovative technologies to substitute for labor because there is a small market for such new technologies. It is imperative that public research universities do and/or foster the research to develop such technologies. At the farm level mechanized means of harvesting asparagus are being explored. This development would change the way asparagus is currently handled, allowing for development of value added products that make use of the whole spear. The outlook of the Washington asparagus industry would be altered because growers could compete with countries that have low wage rates. Significant progress has been made this past year with implementing technology in asparagus fresh packing sheds. Mechanical means to
handle asparagus will be implemented in several fresh sheds next season (2004) for the first time. The entire packing industry could move toward automation of the fresh handling process, based on a successful season by the packers with the new machines. Such technology adoption will benefit asparagus growers since the packer will have lower per unit costs, which can potentially be returned to the growers. In addition to the automation, improving and extending the shelf life of the fresh product will increase fresh handlers competitiveness in the national and international marketplace.
Publications
- No publications reported this period
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Progress 01/01/02 to 12/31/02
Outputs
Field research was conducted during the 2002 harvest to identify the amount of waste that remains in the field, in addition to the growth characteristics of asparagus. Trials were done by using a 30 meter-plot over two rows to collect the waste that remains in the field after the harvest. Random plots were arranged throughout the field. The fields used for the evaluation were from seven farmer cooperators in the Columbia Basin. Based upon the field samples, roughly 50.4 kilograms per hectare per day is field waste. Assuming 137-centimeter row spacing and a 70-day harvest season, there is approximately 3,362 kilograms of field waste per hectare. The vast majority of the cullage is composed of the asparagus butt ends, while another component is the crooked/bent spears that are unusable for the processing or the fresh market. In fact, nearly 785 kilograms per hectare of these spears are culled and left in the field over a 70-day season. A nonselective harvester was
evaluated to determine the feasibility for use in the Washington asparagus industry. The nonselective harvester was run at a slower speed compared with trials that were run on the machine in 1995. Initial results suggest that the slower speed increases the efficiency of the machine. The total pay weight increased nearly 18%, while the culls decreased almost 17%. Making use of the cuts and tips market would be necessary to make the harvester a feasible alternative to manual cutting. At the fresh packing level the effects of reducing labor by using selected electronic graders in the grading and sorting process of fresh asparagus packing firms was evaluated. Four alternative electronic graders were considered using two throughput scenarios of 680 and 907 kilograms per hour with 25 people. To justify investing in a machine, investment costs must be recovered by the savings. In the first scenario, all four graders generate enough savings from labor reduction to cover the investment costs
of a new machine. Three out of the four graders have discounted payback periods of less than 2.5 years. In total, using the graders provided a range of $133,124 to $266,080 net present value (NPV) to the firm over 10 years. Under the second scenario, the returns were lower in comparison to the other scenario. However, three out of the four graders provided positive NPV, with a range of $66,248 to $107,974. In general, results indicate that electronic graders provide economic benefit to fresh sheds under both scenarios.
Impacts
Research advances have provided prospective solutions for the Washington/Oregon asparagus industry. Potential labor saving technology has been found for both the farmer and fresh packer with a selective harvester and machine grader/sorter, respectively. The grader/sorter can sort more accurately than by hand, improving the marketability of fresh product. Besides labor reduction there is progress in drying techniques that will provide an additional outlet for the current culled asparagus not being processed, which adds additional value to the spear. In addition, results suggest the shelf life of a fresh asparagus spear can be extended with new technology. Extending shelf life, while sustaining the color and quality enhances the shipping capabilities.
Publications
- Ball, T. and R. J. Folwell. 2002. Alternatives to Manual Sorting Using Selected Electronic Graders in Asparagus Fresh Packing: A Cost-Benefit Analysis. AE 02-7, Dept. of Agr. and Res. Econ., Wash. State U., Pullman.
- Ball, T. and R.J. Folwell. 2002 Establishment and Annual Production Costs for Washington Asparagus. EB 1779. 31 pgs.
- Tang, J., Yang, T. 2002. Dehydrated vegetables: principles and systems (70 pages). Handbook of Vegetable Preservation and Processing, (ed.) Hui, Y.H.. Marcel Dekker, Inc., New York.
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Progress 01/01/01 to 12/31/01
Outputs
Asparagus research determined that there is over 3.93 metric tons of waste per hectare that remains in the field. Growth trials were done over the second half of the harvesting season, which found that initial length, air temperature and spear distribution have an effect on the daily growth of the spears. In addition, data was collected to develop parameters in creation of a feasible mechanical harvester. Mechanical equipment for both harvesting and grading/sorting from New Zealand was evaluated on the efficiency, speed, and applicability to the Washington asparagus industry. Initial results indicate that packing sheds using the grader/sorter are 25% more efficient than the current methods used in Washington. The machines reduce labor and increase productivity. Preliminary experiments are being conducted to study the effects of different methods on drying asparagus for use in dehydrated soups. Tray drying, hot air fluidized bed or spouted bed drying, and microwave
spouted bed drying are various methods under evaluation. Using freeze-drying as a basis, the drying techniques are compared based on lightness, greenness, and yellowness. Testing of rehydration rates of the dried product is also being conducted. Studies have found that the antioxidant activity and phenolic content in the spear is located in the tip portion, at 6 fold and 3 fold greater amounts than the basal portion, respectively.
Impacts
Research advances have provided prospective solutions for the Washington/Oregon asparagus industry. Potential labor saving technology has been found for both the farmer and fresh packer with a selective harvester and machine grader/sorter, respectively. The grader/sorter can sort more accurately than by hand, improving the marketability of fresh product. Besides labor reduction there is progress in drying techniques that will provide an additional outlet for the current culled asparagus not being processed, which adds additional value to the spear. In addition, results suggest the shelf life of a fresh asparagus spear can be extended with new technology. Extending shelf life, while sustaining the color and quality enhances the shipping capabilities.
Publications
- No publications reported this period
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