• Quality is the composite of product characteristics that impart value to the  consumers.
  • Low quality- produce not meeting consumer expectations
  • Acceptable quality- produce satisfying consumer expectations
  • High quality- produce exceeding consumer expectations
• Product salability depends on quality developed during production and enhanced postharvest.
• Consumers usually buy with their eyes (appearance quality) but repeat sales are determined by unseen internal quality attributes.
• However, vegetables are often perceived to be unsafe due to the general knowledge of heavy pesticide use during production and poor hygiene and use of toxic preservatives (e.g. formaldehyde) after harvest. Exacerbating factor is  the widely publicized food poisoning cases associated with consumption of fresh  vegetables.

Quality components

• Appearance (visual) quality – for fruit-vegetables, it may include right maturity or color, right size and shape, glossy, and free of defects such as shriveling, spots or rots; for leafy vegetables, fresh-looking, well-formed or well-shaped, right size, right maturity, right color, turgid or not wilted, free of defects such as rots, physical damage, yellowing or wilting.

Figure 1 Examples of quality grading and color charts

•  Texture (feel) – firmness; tenderness, crunchiness, solidity or compactness
• Flavor (eating quality) – aroma, taste, sourness, spiciness
• Nutritional quality- vitamins, minerals, lipids, protein, carbohydrate, phytonutrients (antioxidants and flavonoids) and dietary fibers
• Food safety – pesticide residues (most important safety issue among consumers), microbial contamination (number one food safety concern among health authorities and scientists), natural toxicants (e.g. oxalates and nitrates),  natural contaminants (e.g. mycotoxins, bacterial toxins and heavy metals
  (e.g. lead, cadmium and mercury), and environmental pollutants
• Credence attributes– additional dimension of quality that has evolved in  international markets and depends on the method of production, regardless of  whether the method of production has a visible or analyzable impact on the produce.

Quality loss

• The nature of quality loss depends on the type of produce:
  Tomato, chili – overripening, shriveling, rots
  Eggplant – shriveling, rots
  Beans, bitter gourd, cucumber – shriveling, yellowing, rots
  Leaf mustard, kale and other leafy type – wilting, yellowing, rots
  Cabbage, head – bacterial soft rot, wilting of outer leaves
  Cauliflower – browning, bacterial soft rot, desiccation
  Broccoli – yellowing, bacterial soft rot, desiccation

Food safety

• Assurance that food will not cause harm to the consumer when it is prepared and/or eaten according to its intended use.
• Assuring food safety is for consumer protection, a universal mandate.

Food safety assurance

• Measures taken during production and postharvest (handling, storage and distribution) to ensure that product consumption does not represent a risk to human health.
• Expands market access and market confidence.
• Hazard is a biological, chemical or physical agent in food with the potential to cause an adverse health effect.
• Risk is the probability of a hazard occurring.
• Produce is vulnerable to hazards at every step of the chain.
• Biological hazards include pathogenic organisms (e.g. Eschirichia coli and Salmonella) and spoilage organisms, insect pests, animals etc.
• Sometimes, pathogenic microbial load may be insufficient to cause product decay but may be enough to cause human illness.
• Produce that appears to be perfect could be microbiologically contaminated and thus could represent a risk to consumer health.

Figure 2 shows the sources of microbial contamination of vegetables

Role of growers and handlers

• Personnel associated with growing and harvesting should apply Good

Agricultural Practices (GAPs) and protect harvested produce from

contamination.

• Personnel associated with growing and harvesting should apply good hygienic practices (GHP) in the field and in all handling operations, and protect harvested produce from contamination.

• Personnel should ensure proper sanitation of harvesting equipment and tools, packhouse facility, equipment and surroundings, containers, and transport systems. Sanitation is about attention to details.
• Proper records must be kept in order to facilitate traceability.
• Keep records on seed quality; pesticide application; water quality (irrigation and wash in packhouse); soil analysis; pest control program; postharvest treatment; cleaning and maintenance program (establishment, machinery, tools, etc.); and workers’ training.

Ways to minimize Postharvest diseases

1. Hygiene and sanitation
   • Wash produce with water
   • Clean/disinfect cutting tools, containers, postharvest equipment.
   • Change wash water as often as necessary.
2. Culling out of infected produce
3. Hot water treatment, where appropriate
4. Application of organic pesticides
5. Curing ( root crops)
6. Temperature/ RH management – Remove all free moisture before packing.
7. Handling with TLC.