Early season apples intended for direct marketing begin to lose quality immediately after harvest. Likewise apples from CA storage lose quality as soon as the gas seal is broken. In both cases, without sufficient control of produce respiration, the quality of product reaching the consumer may be inadequate to provide satisfaction. This can have an immediate and long-term adverse reaction on the sales of UK fruit.
Much can be done to ensure higher quality product in the market place through an awareness of the benefits of temperature control after harvest (early apples) or after grading (storage cultivars). Following best practice will help to ensure that all the efforts to achieve high quality through application of good husbandry and storage practice are not wasted after fruit leaves the packhouse.
Where cool temperatures cannot be maintained and the period between packing and consumption exceeds 10 days, the use of modified atmosphere (MA) packaging provides useful improvements in product quality. However, it is important that growers discuss the use of MA packaging with their marketing agents and their customers (retailers and wholesalers) to ensure their acceptance in the market place.
It is particularly important that supply of product in retail MA packs is acceptable to retailers that are accustomed to selling the bulk of their product ‘free-flow’. In this regard it may be that the bulk packs (18kg cardboard cases lined with a suitable polymeric film) that preserve quality to the retail shelf are the most appropriate application of MA technology for UK retailers. It is also important for producers to be able to achieve higher prices for their higher quality product in order to meet the additional costs of packaging.
Although the quality benefits of MA packaging are proven for a number of cultivars these are achieved generally at ambient temperatures and over periods in excess of 2 weeks. Where prompt distribution of product occurs at cool temperatures the use of MA techniques may not be justified. Consequently, at the present time the use of MA packaging is not included in best practice.
Early season apples
- Keep fruit shaded after picking and during transport from the orchard.
- Ensure fast removal of field heat by loading fruit into store that has been pre-cooled to 0oC. Load no more than 10% of the total capacity of the store e.g. a maximum of 10 tonnes of fruit into a 100 tonne store.
- After pre-cooling grade and pack quickly, return packed fruit to a pre-cooled holding store.
- Short journeys in non-insulated transport should be made during the hours of darkness.
- Insulated or refrigerated transport should be used for long or daytime journeys.
- All transfers on and off vehicles should be done rapidly.
- Encourage the use of cool displays at the retail level
Storage varieties
- Terminate storage while there is sufficient quality to allow for packing and distribution.
- Keep packed fruit cool, ideally 3.5oC but at below 10oC at least.
- Use chilled distribution where possible.
- Encourage cool display in retail outlets.
- Avoid ‘back-storage’.
Growers can use Table 28 below to convince marketers and distributors of the need for prompt delivery of their product to the retail shelf and of the importance of maintaining cool temperatures during distribution. These results apply to Cox apples removed from CA storage where the intention is to achieve 6 kg firmness on the retail shelf.
Table 28. Effect of temperature on firmness decline in Cox apples
| Days to reach 6 kg fruit firmness (projected) | ||||
| Firmness ex-store (kg) | 1.5oC | 3.5oC | 10oC | 18oC |
| 6.6 | 30 | 20 | 12 | 9 |
| 6.4 | 20 | 13 | 8 | 6 |
| 6.2 | 10 | 7 | 4 | 3 |