Consumer reference (of red-fleshed apples) an quantification of quality related traits, particularly skin and flesh colour, in apple breeding families

[摘要] ENGLISH ABSTRACT: In order to develop a novel pink- or red-fleshed apple for the fresh consumer market,the red-fleshed genotype, 'KAZ 91' (Malus niedzwetzkyana Dieck.), was crossed with'Meran' (M. domestica Borkh) at the Agricultural Research Council (ARC) apple breeding programme in South Africa. The objective of this study was to evaluate and quantify colour variability in the flesh and peel of this progeny (Family 1), to assess quality traits (i.e., acidity and total soluble solids) and phenolic levels in fruit peel and flesh, and to investigate consumer preference for the taste and appearance of redfleshedapples. All data, except for consumer preference, were also collected on twowhite-fleshed M. domestica Borkh families, i.e., 'Reinette Burchardt' x 'Treco RedGala' (Family 2) and 'Meran' x 'Treco Red Gala' (Family 3). Fruit of Family 1 seedlings were on average darker red with greater blush coverageand higher anthocyanin and phenolic levels compared to fruits of Family 2 and 3. Theproportion of bearing trees with red-fleshed fruits in Family 1 increased from 25% in2007 to 35% in 2008. The intensity and distribution of red pigmentation in the fleshvaried considerably between seedlings and even between individual apples from thesame tree. A high intraclass correlation coefficient was found for red-flesh coveragewithin Family 1, indicating a high level of genetic determination that can be used inbreeding. When only red-fleshed seedlings were considered, an intermediaterepeatability coefficient (0.54) for red-flesh coverage indicates that the extent of redflesh coverage varies to some extent between seasons. The effect of environmentalfactors on red flesh colour needs to be assessed and breeders need to take care toselect for genotypes with stable flesh colour intensity and coverage. Small intraclasscorrelations were found between families for other traits. No correlation was found foranthocyanin and total phenolics in both peel and flesh or between anthocyanin levelsin the peel and flesh of Family 1 fruit. This suggests that red-fleshed fruit will notnecessarily be high in antioxidants – since phenolics is by far the greatest contributorto fruit antioxidant capacity. The lack of a correlation between peel and fleshanthocyanin levels also suggest that fruit with dark red flesh will not necessarily havea dark red skin colour. Family 1 fruit were more prone to flesh browning and weremore acidic compared to fruit of Families 2 and 3. With regard to consumer preference for flesh colour, 74% of South Africanconsumers preferred white flesh while 64% preferred an attractive 'floral patterncreated by the combination of a red cortex and white core. Consumers indicated amuch lower liking for other distribution patterns and lower intensities of red fleshcolour. Consumers preferred the taste of apples that were crisp, crunchy and high inapple flavour irrespective of flesh colour. Red-fleshed fruit were generally acidic orhad poor texture, and some were also astringent. However, despite a general dislike inacidic fruit, consumers showed a preference for acidic fruit if that fruit also had highred-flesh coverage.

[发布机构] Stellenbosch University