Both the appearance and the quality of fruit are partly determined by their position on the tree. This is especially true of apples and pears from older orchards consisting of big trees with complex canopies. Fruit on the inside of such canopies may receive less than 5% of the light that fruit on the outside receive, and average peel temperatures of outside fruit can be as much as 10°C higher than peel temperatures of inside fruit. Several research projects conducted by the Departments of Horticultural Science and Food Science at Stellenbosch University have investigated the link between canopy position, fruit appearance, fruit quality, eating experience and consumer preference. Their conclusion? What you see is not always what you get.
The ins and outs of colour
A study by Hamadziripi and co-workers compared Starking, Golden Delicious and Granny Smith apples sampled during two consecutive seasons from the outer and inner canopy. Starking apples from the outer canopy had higher concentrations of red pigments – anthocyanins – and yellow pigments – carotenoids – than Starking apples from the inner canopy. Outercanopy Starking apples looked redder and consumers preferred their appearance over the less-red option.
Both the Golden Delicious and the Granny Smith apples sampled from the outer canopy in this trial had visible red blush and higher anthocyanin concentrations. Chlorophyll levels were lower in outer- than inner-canopy fruit. Consumers preferred the appearance of the inner-canopy apples in both cases.
Golden Delicious apples from the outer canopy were yellower than those from the inner canopy, but consumers found red blush on the outer-canopy fruit off-putting. And pink cheeks on a Granny were simply unacceptable.
Other studies by Cronje, Manning and colleagues looked at blushed pears. Consumers prefer pears with a bright red or pink blush against a light and bright background colour. They are averse to strong red colouration when this results in an overall dull appearance.
Forelle pears sampled from the outer canopy had a red blush on the sun-exposed side, whereas those from the inner canopy had almost no red pigmentation. Bon Rouge pears sampled from the outer canopy were redder, darker, and duller than those sampled from the inner canopy. A panel of consumers gave outer-canopy Forelles a few extra marks for appearance but made no distinction when it came to the Bon Rouge pears.
Consumers find it difficult to assess the ripeness and internal quality of pears based on external appearance.
The proof is not in the eating
Hamadziripi and co-workers wanted to see how consumers responded to the taste of inner- and outer-canopy apples without the influence of visual cues. Consumers were given peeled apple segments of each cultivar and not told which were inner- and which outer-canopy fruit. They preferred the eating quality of outer-canopy apples in all cases.
Outer-canopy fruit generally has higher sugar levels and higher dry-matter content than inner-canopy fruit. The trial also found that the outer-canopy fruit had higher levels of ascorbic acid, phenolic compounds and antioxidants, all of which are viewed as health-promoting in humans. Consumers reported that the outer canopy Starking and Golden Delicious apples had a stronger apple flavour.
So, if outer-canopy fruit taste better, and possibly are better for human health, why would consumers not prefer them every time? It has to do with expectations.
Experiments have shown that people associate redness with sweetness, and greenness with sourness. Consumers expect red apple cultivars, such as Starking, to be sweet, and they use fruit colour as a helpful guide to internal quality. On the other hand, they expect Grannies to be sour, and therefore green. The average person might prefer any apple to be sweeter, but the consumer who seeks out a Granny is probably in search of a different eating experience.
Golden Delicious is a yellow apple and local consumers are used to seeing it without any blush. Blushed Goldens are rejected and never have the opportunity to demonstrate their better eating qualities.
The study by Cronje and colleagues on Forelle pears found that outer-canopy Forelle were more likely to be mealy than inner-canopy Forelle. Consumers therefore preferred the eating quality of inner-canopy fruit. Inner- and outer-canopy Bon Rouge pears were very similar in quality and consumers made no distinction between them.
On the whole, consumers find it difficult to assess the ripeness and internal quality of pears based on external appearance, especially in blushed pears. This may be one reason why consumers showed stronger appearance-based preferences for apples than for pears in these studies.
Work on consumer preferences highlights the difficulties facing growers who need to produce fruit that both look great and taste great. Perhaps renewed worldwide interest in human health presents an opportunity to start educating consumers about the benefits of eating more sun-ripened – even if less conventionally beautiful – fruit.
References
Cronje, A. 2014. Effect of canopy position on fruit quality and consumer preference for the appearance and taste of pears. Doctoral dissertation. Stellenbosch University.
Hamadziripi, E.T., Theron, K.I., Muller, M. and Steyn, W.J. 2014. Apple compositional and peel color differences resulting from canopy microclimate affect consumer preference for eating quality and appearance. HortScience, 49(3):384–392.
Manning N. 2009. Physical, sensory and consumer analysis of pear genotypes among South African consumers and preference of appearance among European consumers. Doctoral dissertation. Stellenbosch University.