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We hypothesized that the microclimate at different positions in the tree canopy may affect the appearance, eating quality, and consumer preference for apple fruit. Hence, the aim of this study was to evaluate the internal and external quality of inner and outer canopy apples in relation to consumer preference for the eating quality and appearance of these fruit. We determined peel color, flesh firmness, percentage starch breakdown, soluble solids concentration (TSS), titratable acidity (TA), and dry matter concentration (DMC) for inner and outer canopy ‘Starking’, ‘Golden Delicious’, and ‘Granny Smith’ from the Ceres region in South Africa in the 2009–10 and 2010–11 seasons. We also determined reducing sugars, total phenolics, and total antioxidant capacity in the 2009–10 season. A trained panel assessed the sensory characteristics of fruit while consumers were asked to indicate their liking for the eating quality and appearance of fruit. Outer canopy fruit of all three cultivars had higher antioxidant capacity, TSS, DMC, lower TA, and were generally sweeter than inner canopy fruit. Consumers could discern eating quality differences and generally preferred the eating quality of outer canopy fruit. The appearance of outer canopy fruit was not preferred in the ‘‘green’’ cultivars, probably as a result of the unfamiliarity of consumers with such fruit. Consumers did, however, prefer the redder outer canopy to the less red inner canopy ‘Starking’ fruit. The redness of ‘Starking’ fruit in this study can therefore be seen as a true signal of eating quality, i.e., the redder the fruit, the better the eating quality, and this would probably apply to other fully red and bicolored apple cultivars. Hence, the classification of red cultivars into different quality classes based on the extent of red color development seems justified from an eating quality perspective. In contrast, blushed outer canopy ‘Granny Smith’ and ‘Golden Delicious’ are culled for aesthetic reasons. It might be possible to develop a niche local market for these blushed fruit based on their better eating quality. Our data were generated in older orchards with trees planted at low density and with large canopies. Planer, two-dimensional canopies are likely to reduce the differences between inner and outer canopy fruit. Differences in macroclimate or in fruit maturity between seasons may also have an overbearing effect on fruit quality parameters compared with canopy microclimatic conditions. Fruit are exposed to different microclimatic conditions determined by their position in the tree canopy. The two main factors that vary highly in the canopy are light and temperature. Inner canopy fruit experience lower light and temperature conditions compared with outer canopy fruit. In a ‘Granny Smith’ orchard with a canopy width of 2.5 m, inner canopy fruit received only 2% (33 mmol·m·s) of full sun photosynthetic photon flux on average over the season compared with 54% (962 mmol·m·s) in the outer canopy (Fouché et al., 2010). Peel temperatures of outer canopy fruit on the northern side of the rows were found to exceed air temperatures by 5 C on average, whereas fruit from the inner canopy did not differ from the ambient temperature. Apple fruit appearance and eating quality can vary considerably between trees in an orchard and within the tree (Johnson and Ridout, 2000), and this may relate to exposure to different microclimatic environments. Fruit quality is of paramount importance because it forms the basis of consumer satisfaction in fresh produce (Jaeger et al., 2002). The first assessment of fruit by the consumer is of a visual nature. Pigment composition determines the appearance of the fruit, which from an aesthetic and from a quality-signaling perspective has an important function in consumer acceptability (Steyn, 2012). Hence, peel color is an important quality attribute in determining consumer acceptance of apples (Telias et al., 2011). The red color in apple peel is for many apple cultivars one of the most important factors in consumer acceptance (Saure, 1990). The intensity of red blush on the apple peel is an important consideration for the consumer in purchasing fruit and is also used as grading standards in retail outlets and when fruit is packed (Iglesias et al., 2008). Fruit may be downgraded as a result of insufficient red color development. However, in some cases, red pigmentation is an undesirable feature; for instance, any trace of blush in ‘Granny Smith’ apples results in the downgrading of the fruit (Hirst et al., 1990). Consumers use peel color to identify apple cultivars as well as their eating quality preferences; for example, consumers were found to associate red-colored apples with sweet sensory descriptors and green apples with grassy, acidic, or sour sensory descriptors (Daillant-Spinnler et al., 1996). Upon tasting, internal quality characteristics such as flavor, sweetness, sourness, and texture attributes are also determinants of consumer preference in apples (Jaeger et al., 1998). Consumer acceptability based on how the product tastes shows that soluble solids concentration is a useful tool to determine the minimum acceptable eating quality and is a satisfactory indicator of eating quality in many fruits including peaches, nectarine, and apples (Crisosto et al., 2003; Harker et al., 2002). Apple taste is more accurately reflected by the concentration of soluble solids and acids and the balance between these two quality parameters (Jackson, 2003). DMC is also an important holistic measurement because it is an indicator of physiological and metabolic processes that contribute to the final composition of the fruit (Harker et al., 2009). Apples with higher DMC have been found to have higher consumer preference (Palmer et al., 2010). Apart from gustatory reasons, consumers indicate that they eat apples because they are healthy and promote long life (Jaeger and MacFie, 2001). Apples are a rich source of phenolic compounds (Boyer and Liu, 2004). Phenolic compounds are an important dietary component as a result of their anticancer and chemopreventive properties (Kang et al., 2004; Santos-Buelga and Scalbert, 2000). Phenolics as a group constitute the largest fraction of the total antioxidant capacity of apple fruit (Lee et al., 2003). Total phenolics correlated strongly with total antioxidant 384 HORTSCIENCE VOL. 49(3) MARCH 2014 activity in the flesh (r = 0.91) and peel (r = 0.98) of seven apple cultivars (Drogoudi et al., 2008). Antioxidants play an important role in preventing free radicals from causing oxidative damage, which is linked to many diseases in humans (Dragsted et al., 1993; Lila, 2004). Apples contain relatively low levels of ascorbic acid compared with other fruits (Leong and Shui, 2002). However, consumers associate ascorbic acid with health benefits (Jaeger and MacFie, 2001) and in that regard, it is an important component of any fruit. This study was conducted over the 2009– 10 and 2010–11 seasons to investigate the chemical, textural, sensory, and consumer preference differences that may exist between inner and outer canopy fruit of ‘Starking’, ‘Golden Delicious’, and ‘Granny Smith’ apples and how such differences, if present, would affect consumer preference for apple eating quality and appearance. Of particular interest were the chemical components that affect the appearance, eating quality, and nutritional value—or perceptions thereof—of the fruit. These findings would indicate whether differentiation between inner and outer canopy fruit could increase consumer satisfaction. Results would also indicate the potential to develop a niche local market for blushed ‘Granny Smith’ and ‘Golden Delicious’ apples. Materials and Methods Plant material and experimental design. Three commercial apple cultivars were used for this study, viz. ‘Granny Smith’, which is dark green at harvest maturity, ‘Golden Delicious’, which is yellow–green at harvest maturity, and ‘Starking’, which vary from red-striped to green depending on canopy position. Fruit were sourced from Vastrap Farm in the Witzenberg Valley, Ceres (lat. 33 23# S, long. 19 19# E), Western Cape, South Africa. In the 2009–10 season, ‘Golden Delicious’ and ‘Starking’ were harvested on 1 Mar. 2010 and ‘Granny Smith’ on 8 Apr. 2010. In the 2010–11 season, ‘Golden Delicious’, ‘Starking’, and ‘Granny Smith’ were harvested on 28 Feb., 22 Mar., and 5 Apr. 2011, respectively. These harvesting dates immediately preceded the commercial harvesting of the respective orchards in the 2009–10 and 2010–11 seasons. The ‘Granny Smith’ and the ‘Golden Delicious’ orchards were planted on seedling rootstock in a north–south row orientation at a spacing of 6.71 m · 3.35 m in 1974 and 1960, respectively. ‘Starking’ on seedling rootstock was planted in 1974 at a spacing of 5 m · 3 m and similar row orientation as mentioned. These older open vase orchards were selected so as to maximize the contrast between inner and outer canopy fruit. For ‘Granny Smith’ and ‘Golden Delicious’, only fruit with red blush, mainly found at the top outer positions of the tree canopy, were harvested as the outer canopy fruit. The study was laid out to a complete randomized design with 10 replications for each canopy position. Fruit harvested from three consecutive trees represented a replicate and 15 inside and outside fruit were harvested for each replicate. Maturity analysis was carried out immediately after harvest as assessment of the percentage of starch breakdown. One fruit from each replicate (i.e., 10 fruit per canopy position) was randomly selected and assessed to ensure that the inner and outer canopy fruit were of comparable maturity. Fruit were stored at –0.5 C before physical measurements, chemical analysis, sensory analysis, and consumer preference studies, all conducted within 1 month after harvest. Of the 14 fruit remaining per replicate, four were allocated for the consumer panel, five were allo

Apple Compositional and Peel Color Differences Resulting from Canopy Microclimate Affect Consumer Preference for Eating Quality and Appearance