James W. Rushing
Mature-green tomatoes stored up to 8 weeks at 11.5°C under 4% oxygen with no accumulation of carbon dioxide above ambient had reached turning stage of color by the end of the storage period. Control tomatoes stored at identical temperature without CA quickly turned red and were unmarketable after 4 weeks due to overripenessand high incidence of decay. Tomatoes held under CA for 8 weeks and then transferred to 20°C without CA ripened normally to full-red color within 10 days with less than 10% decay and no apparent mealiness or other symptoms of chilling injury. Weight loss from tomatoes stored under CA increased with storage time, but, after 8 weeks, the fruit still did not have noticeable shrivelling and visual appearance was excellent compared to tomatoes purchased from a local supermarket. Results of this research suggest that short-term CA storage is a feasible method of expanding the market window for tomatoes. This could be particularly useful for production regions such as South Carolina, where the harvest is practically completed within a 3-week window and low prices often prevail during the harvest period.
James W. Rushing
Mature-green fresh-market tomatoes (Lycopersicon esculentum Mill.) were held at 11 °C under controlled atmosphere (CA) at 4% O2 and 4% CO2 in a commercial intermodal shipping container equipped with a membrane-based nitrogen-generating CA system. After 4 weeks, tomatoes in CA had 11.9% decay compared to 46.4% decay in control samples held at the same temperature under normal atmosphere. During storage, color development in controls progressed from green to the light red stage in more than 50% of the fruit and only 4.5% remained green after 4 weeks. In contrast, CA stored samples had 25.7% of the fruit in green condition and only 3.9% had progressed to the light red stage. Following CA exposure tomatoes were held at 20 °C with or without 250 ppm C2H4 treatment to observe ripening. All samples ripened normally without symptoms of chilling injury. Results suggest that CA is a useful method for reducing decay and delaying ripening during international transport.
James W. Rushing
Broccoli (Brassica oleracea L. var. italica `Citation') florets were treated postharvest with either benzyladenine or trans-zeatin at either 10 or 50 ppm before packaging in perforated polyethylene bags and storage at 16C. The most pronounced effects were observed with benzyladenine at 50 ppm. Compared to controls, respiration rate was reduced 50% and ethylene production increased 40% throughout the first 4 days of storage. Total chlorophyll content had dropped 60% in controls, but was unchanged in cytokinin-treated florets, which had a 90% longer shelf life than controls. These effects depended on the amount of cytokinin applied and were of greater magnitude with benzyladenine than with zeatin.
James W. Rushing
The production, handling, processing and marketing of over-the-counter medicinal products manufactured from plants is virtually unregulated. This can include dietary supplements, functional foods and nutraceuticals, any of which may contain botanical constituents. Of particular concern is the possible presence of human pathogens in products offered at retail. A review of literature is presented. Options for sterilizing herbal medicinal products, including fumigation, irradiation and heat treatments, are presented. Experiences of the spice industry are discussed as they relate to the development of similar protocols for herbal medicines. Methods used to ensure microbiological safety must be evaluated for their effect on the medicinally active constituents in the plant material. Very little data of this nature are available. Avenues for future research are proposed.
James W. Rushing and Robert F. Testin
Antioxidants and certain variables in the processing protocol were evaluated for their influence on the respiration, ethylene production, color, and storage potential of shredded cabbage (Brassica oleracea L. var. capitata). Four commercially available antioxidants were compared to ascorbic acid and sodium metabisulfite. Compounds were applied either by dipping or by vacuum infusion after the cabbage was shredded. Weight changes occurring during each step of processing were measured. Shredded cabbage was packaged under vacuum in 1.75 mil polyethylene bags and stored at 4°C. In all studies, untreated controls had longer shelf life than any of the treated shredded cabbage based on subjective evaluation as well as objective color scores. Respiration and ethylene production were not influenced by treatment other than centrifugation immediately after shredding, which reduced the rate of both processes by about 50%. Any treatment resulting in weight gain, e.g. vacuum infusion or dipping in aqueous solutions, caused a decrease in shelf life.
James W. Rushing and Frederick J. Angulo
In response to epidemiological studies that linked outbreaks of salmonellosis to consumption of raw tomatoes in 1991 and 1993, a model HACCP was designed and implemented in a commercial tomato packinghouse in South Carolina in 1994. Testing of tomato fruit and packinghouse water samples by CDC and by a private laboratory for the presence of Salmonella confirmed that the HACCP was effective in controlling the risk of contamination in the packinghouse. Critical control points are identified and application of this model HACCP to other fresh fruit and vegetable handling systems is proposed.
James W. Rushing and Christopher S. Walsh
In 1998 the U.S. Food and Drug Administration (US-FDA) published formal guidelines for the microbial safety of fresh produce. The guidelines identify and suggest the use of good agricultural practices (GAP) and good manufacturing practices (GMP) for producers and handlers. To extend this important information to international producers and suppliers, an agreement was made to create a GAP and GMP training program through the Joint Institute for Food Safety and Applied Nutrition (JIFSAN). JIFSAN combined resources of US-FDA, the University of Maryland, and other universities to reach audiences outside the U.S. with food safety information. The program is based on the train-the-trainer concept. Its success depends on the ability of the newly trained program participants to reach key audiences in the target country. We present an overview of the development of a training manual and its content, the selection of a teaching team and target countries, and the methods for implementation of the training. Examples of activities in various countries are summarized. Results of a program review conducted in 2004, following nine program deliveries, are also discussed. Future needs are identified and current programming plans are provided.
James W. Rushing and Donald J. Huber
Enzymically active cell wall isolated from mature-green and ripening tomato (Lycopersicon esculentum Mill cv. `Rutgers') fruit was employed to investigate the mobility of the enzyme polygalacturonase (PG, EC 126.96.36.199). Cell walls from mature-green `Rutgers' fruit or from the ripening mutant rin, which alone exhibits little or no release of pectin, were unaffected by the addition of enzymically active cell wall from ripening `Rutgers' fruit, indicating that PG is either not transferred at all or is not transferred to sites of pectin hydrolysis. The quantity of pectin released by the addition of soluble PG to enzymically active wall depended on the quantity of enzyme added. Similar data were obtained using purified PG2. Pectin solubilization from all wall isolates exhibiting enzymically mediated pectin release diminished with time; however, transfer to fresh buffer initiated a resumption of autolytic activity, indicating that an inhibitor is released during the course of pectin hydrolysis.
James W. Rushing and Gerald D. Christenbury
Through an agency called Volunteers for Overseas Cooperative Assistance (VOCA), funded primarily by the U.S. Agency for International Development (USAID), professionals from many disciplines are recruited to assist less-developed countries (LDCs) with establishing new industries and/or improving management practices in existing businesses. We were recruited to evaluate the causes of postharvest losses of horticultural products in Russia. These losses historically have been high due to the limited availability of mechanical refrigeration and poor postharvest management practices. This paper reports on the success of an extension demonstration project in Russia where traditional storage and handling systems for carrots were compared to systems using improvements in grading and prestorage sanitation. An evaluation of storage facilities and recommendations for improvements are discussed.