The base colour of fruit as an indicator of optimum harvest date for two apple cultivars (Malus domestica Borkh.)
The CIE L* a* b* colour system is used to evaluate food colours. Its advantage is that the base skin colour in apples can be measured on the same fruit before and on the optimum harvest date. The aim of the research conducted between 2002 and 2006 was to evaluate a quick and non-destructive method of determining the optimum harvest date of apples intended for long storage based on the changes observed in the base skin colour. Another important research aspect was to compare this method with other methods or indicators used to determine the harvest date. The colour measurement was conducted on two apple cultivars, Šampion and Royal Gala, with the aim of, amongst other factors, establishing a standard for each that could be used in practice in fruit production. From amongst the evaluated colour indicators L*, a*, b*, Hueab angle and chroma, changes in the base colour were best illustrated by the a* coordinate value and Hueab angle value. Based on the evaluation of the quality of fruits after storage, it can be stated that the fruits had the best quality when the a* coordinate during harvest ranged between -7 and -8 for ‘Šampion' and between -3 and -5 for ‘Royal Gala’. The Hueab angle assumed a value between 100 and 101 for ‘Šampion' and between 96 and 99 for ‘Royal Gala’ during the optimum harvest date. Therefore, the a* coordinate and the Hueab angle can be used to indicate harvest maturity.
Carreño, J., Martinez, A., Almela, L., Fernandez-López, J.A., 1995. Proposal of an index for the objective evaluation of colour of red table grapes. Food Res. Intl. 28(4): 373-377.
Brookfield, P., Murphy, P., Harker, R., Macrae, E., 1997. Starch degradation and starch pattern indices; interpretation and relationship to maturity. Postharv. Biol. Technol. 11:23-30.
Corey, K.A., Schlimme, D.V., 1988. Relationship of rind gloss and groups of colour to flesh quality of watermelon fruits during maturation. Sci. Hort. 34: 211-218.
Delwiche, M.J., Baumgartner, R.A., 1983. Ground color measurements of peach. J. Am. Soc. Hort. Sci. 108(6): 1012-1016.
Delwiche, M.J., Baumgartner, R.A., 1985. Ground color as a peach maturity index. J. Amer. Soc. Hort. Sci. 110(6): 53-57.
Ferer, A., Remon, S., Negueruela, A.I., 2005. Changes during ripening of the very late season Spanish peach cultivar Calanda Feasibility of using CIELab coordinates as maturity indices. Sci. Hort. 105: 435-446.
Francis, F.J., 1980. The quality evaluation of horticultural crops. HortSci. 15: 58-59.
Gonçalves, B., Silva, A.P., Moutinho-Pereira, J., Bacelar, E., Rosa, E.M., Meyer, A.S., 2007. Effect of ripeness and postharvest storage on the evolution of colour and anthocyannis in cherries (Prunus avium L.). FoodChem. 103: 976-984.
Goupy, P., Amiot, M.J., Richard-Forget, F., Duprat, F., Aubert, S., Nicolas, J., 1995. Enzymatic browning of model solutions and apple phenolic substrates by apple polyphenoloxidase. J. Food Sci. 60(3): 497-501.
Hoehn, E., Gasser, F., Guggenbuhl, B., Kunsch, U., 2003. Efficacy of instrumental measurements for determination of minimum requirements of firmness, soluble solids and acidity of several apple varieties in comparison to consumer expectations. Postharv. Biol. Technol. 27: 27-37.
Kader, A.A., 1999. Fruit maturity, ripening, and quality relationships. Acta Hort. 485: 203-208.
Kang, S.P., East, A.R., Trujillo, F.J., 2008. Colour vision system evaluation of bicolour fruit: A case study with ‘B74’ mango. Postharv. Biol. Technol. 49: 77-85.
Kays, S.J., 1991. Postharvest physiology of perishable plant products. Van Nostrand Reinhold, New York.
Konopacka, D., Płocharski, W., Zwterz, J., 2003. Perception of apple quality in relation to texture attributes. Acta Hort. 604: 443-448.
Lin, S., Walsh, C.S., 2008. Studies of "tree factor" and its role in the maturation and ripening of ‘Gala’ and ‘Fuji’ apples. Postharv. Biol. Technol. 48: 99-106.
Luchsinger, L.E., Walsh, C.S., 1998. Development of an objective and non-destructive harvest maturity index for peaches and nectarines. Acta Hort. 465: 679-688.
Łysiak, G.P., Kurlus, R., 2000. Rootstock effect on optimum harvest date and storability of two apple cultivars. Proc. Int. Conf. Fruit Production and Fruit Breeding, 12-13 September, Tartu, Estonia: 72-75.
Łysiak, G., 2011. The determination of harvest index of Šampion apples intended for long storage. Acta Sci. Pol. - Hortorum Cultus 10(3): 273-282.
Mclellan, M.R., Lind, L.R., Kime, R.W., 1995. Hue angle determinations and statistical analysis for multiquadrant Hunter L, a, b data. J. Food Quality 18: 235-240.
Meredith, F.I., Robertson, J.A., Horvat, R.J., 1989. Changes in ethylene rate and ground color in peaches (cv. Redhavesn and Marqueen) and nectarines (cv. Fantasia) during maturation and ripening. J. Agric. FoodChem. 37(5): 1210-1214.
Peirs, A., Schenk, A., Nicolai, B.M., 2005. Effect of natural variability among apples on the accuracy of VIS-NIR calibration models for optimal harvest date predictions. Postharv. Biol. Technol. 35: 1-13.
PN-90-A-75101/04, 1990. Przetwory owocowe i warzywne. Przygotowanie próbek i metody badań fizykochemicznych. Oznaczanie kwasowości ogólnej. [Fruit and vegetable products. Preparations of samples and methods of investigating chemical and physical properties. Marking general acidness] (in Polish).