In this review of breeding soft fruit for processing, I shall be concerned primarily with fruit produced specifically for processing outlets. I hardly need to point out that a high proportion of all soft fruit is eventually processed in some way or other, no matter whether it is bought at a farmer's market, a pick-your-own farm or a roadside stall. Hence the processing qualities of fruit are basic requirements which all breeders must consider, and, of course, it is the breeders, working co-operatively with food technicians and processors, who will ultimately determine the qualities of future cultivars and of the processed products that come from them.
Both breeders and processors are being influenced increasingly by consumers, who have become very knowledgeable about quality. Consumers are becoming more selective and more demanding for fruits with specific characteristics. In general, they are seeking food which is more nutritionally wholesome, has a high dietary value and is entirely of natural origin. The improvements that they require of fruit and fruit products are a higher vitamin content, a higher sugar to acid ratio and a better natural colour and flavour with little or no need for colour additives. A good illustration is the considerable trend towards increased consumption of pure fruit juices, which are being preferred to carbonated and other 'drinks', because of their better taste and nutrient value.
In the past, processors have not always taken sufficient account of some of these characteristics, largely because there was little or no economic advantage in doing so. Similarly, breeders, faced with the need to select for a large number of qualities, horticultural characteristics and resistances to diseases, have been accused of neglecting quality, especially flavour and nutritional value. An example from black currant breeding shows how vital it is that breeders continue to seek a balance in these selection criteria: eighty percent of the British black currant crop is used for processing, but the main factor limiting market development is not processing quality but yield variability, caused by frost damage or poor fruit set. Yield fluctuation leads to price fluctuation, and this causes uncertainty and reluctance by growers to invest in and maintain a competitive industry: hence breeding for yield stability is the best way of supporting the processing industries, provided of course that juice quality is maintained.
In this talk I shall limit myself to discussion of the particular fruit qualities that are required for processing. One of the first decisions a fruit breeder has to make is whether cultivars should be multi-purpose, or specialised to meet particular market outlets.