GAP Harvesting & Post-Harvest Handling 3 — Questions and Answers
Question 1: When testing irrigation or wash water used during harvest, which pathogen indicator is most commonly monitored under U.S. GAP guidelines?
- Generic E. coli (Correct answer)
- Salmonella spp.
- Listeria monocytogenes
- Staphylococcus aureus
Correct answer: Generic E. coli
Generic E. coli is used as an indicator organism for fecal contamination in agricultural water testing under FSMA and GAP guidelines.
Question 2: A packing shed is located adjacent to animal housing. Under GAP, which measure is most critical to implement?
- Physical barriers and buffer zones to prevent animal intrusion and runoff contamination (Correct answer)
- Painting the shed walls to repel insects and birds
- Installing bright lighting to deter animals at night
- Requiring all workers to wear full protective suits
Correct answer: Physical barriers and buffer zones to prevent animal intrusion and runoff contamination
Physical separation via barriers and buffers prevents animal feces and runoff from contaminating the packing environment.
Question 3: Which method of produce washing is most effective at reducing microbial load on the surface of fresh vegetables?
- Chlorinated water wash with maintained free chlorine of 1–3 ppm (Correct answer)
- Plain tap water rinse for 30 seconds
- Warm water wash at 140°F (60°C)
- Dry brushing to remove surface debris
Correct answer: Chlorinated water wash with maintained free chlorine of 1–3 ppm
Chlorinated wash water maintained at proper concentration effectively reduces surface microbial populations compared to plain water alone.
Question 4: During harvest, a supervisor discovers that a portable toilet in the field has not been serviced in two weeks and is overflowing. The GAP-compliant response is to:
- Halt harvesting near the unit, restrict the area, and arrange immediate servicing (Correct answer)
- Allow harvesting to continue while workers use the next nearest facility
- Have workers use the field edge away from the unit until it is full
- Drain the unit into the nearest irrigation ditch to remove the hazard
Correct answer: Halt harvesting near the unit, restrict the area, and arrange immediate servicing
GAP requires sanitary facilities to be properly maintained; an overflowing unit is a contamination hazard requiring immediate halting of adjacent operations.
Question 5: What is the recommended minimum frequency for cleaning and sanitizing food-contact surfaces in a produce packing operation under GAP?
- Before each use and periodically throughout the day as needed (Correct answer)
- Once per week regardless of usage
- Monthly with deep cleaning quarterly
- Only when visible soil is present
Correct answer: Before each use and periodically throughout the day as needed
GAP requires food-contact surfaces to be cleaned before use and as frequently as necessary during operations to prevent pathogen buildup.
Question 6: Wax coatings are applied to some fresh produce after harvest primarily to:
- Reduce moisture loss and improve appearance during marketing (Correct answer)
- Kill surface bacteria and mold spores
- Extend storage life by providing oxygen to the flesh
- Replace natural protective coatings removed by washing
Correct answer: Reduce moisture loss and improve appearance during marketing
Post-harvest wax application reduces transpiration water loss and enhances appearance, though it may also replace some natural wax removed during washing.
Question 7: A GAP audit finds that harvest workers are eating in the field among the crop rows. This practice is a concern primarily because:
- Food and drink consumption in the field can introduce pathogens via hands and personal items to the crop (Correct answer)
- It reduces worker productivity during harvest hours
- Workers may drop food packaging that attracts pests
- It violates OSHA break-time regulations
Correct answer: Food and drink consumption in the field can introduce pathogens via hands and personal items to the crop
Eating in the field can transfer pathogens from workers' hands and personal items directly to harvested produce.
GAP Harvesting & Post-Harvest Handling 3
When testing irrigation or wash water used during harvest, which pathogen indicator is most commonly monitored under U.S.
GAP guidelines?