Journal of Fruit and Ornamental Plant Research Vol. 20(2) 2012: 51-61 DOI: 10.2478/v10290-012-0015-7 THE COMPARISON OF SENSORY QUALITY AND PROCESSING POTENTIAL OF ‘TOPAZ’ APPLES GROWN IN ORGANIC ORCHARDS AND ORCHARDS MANAGED IN INTEGRATED PRODUCTION SYSTEM Dorota Konopacka 1, Urszula Kaczmarek1, Aneta Matulska1, Anna Wawrzyńczak1, Dorota Kruczyńska2 and Krzysztof P. Rutkowski1 1Department of Fruit Storage and Processing 2 Department of Pomology, Genetic Resources and Nursery Research Institute of Horticulture 96-100 Skierniewice, Konstytucji 3 Maja 1/3, POLAND e-mail: [email protected] (Received Novembr 22, 2012/Accepted December 14, 2012) ABSTRACT The aim of the study was to compare the sensory quality of scab resistant ‘Topaz’ apples grown in certified organic orchards (ECO) with those grown in orchards man- aged within integrated method (IP), and to determine their potential processing suit- ability. Fruits were harvested in five certificated IP and ECO orchards at the optimum ripeness stage and stored for two months in normal atmosphere at 1 ºC. Apple quality was assessed one day after cold storage and after 7 days of storage at the temperature 18 ºC to simulate shelf life. The results of taste and flavour sensory assessment did not explicitly demonstrate the effect of the orchard management system on the overall eating quality. Although the fruits from the organic orchards were perceived as less sweet and sourer, the management system did not influence the overall eating quality. There was no effect of the growing technology on quality traits connected with aroma and overall texture assessment. Regarding appearance evaluation, fruits from organic orchards were characterized by a higher variation in shape and size, and more fre- quently than in the case of IP apples had blemishes, scars and rust, which negatively affected their attractiveness. Analysis of the chemical composition of fruits indicates that apples from organic orchards are characterized on average by higher titratable acidity and higher soluble solids content than apples from IP orchards, which could favour their potential application as the additive regulating acidity and shaping the desirable sensory traits of processed organic products. Key words: organic production, fruit quality, sensory attractiveness, chemical composition, processing usefulness D. Konopacka et al. INTRODUCTION natural substances (WE, 2007). These limitations cause that pests and dis- eases protection became the most dif- The increasing interest of con- ficult element of organic apple produc- sumers in food safety and healthiness tion (Bryk, 2006). One of the possibili- favours the development of organic ties to handle these restrictions, and to fruit growing. In Poland, the organic produce organic apple fruit of high food production and consumption is quality, is to use cultivars resistant to still not very popular, but the amount apple scab (Venturia inaequalis). of organic food consumers is grow- Amongst available scab resistant apple ing. Although a dynamic increase of cultivars `Topaz` is one the most often organic farms, accompanied by an recommended for organic orchards increasing number of organic proc- (Czynczyk et al., 2008; Kruczyńska essing plants, may be observed and Rutkowski, 2006; Pitera, 2006). (Zmarlicki, 2009), their amounts are Despite of occasional reports that some still lower than in other countries in scab races overcome the resistance of which development of organic pro- ‘Topaz’ (Vavra and Bocek, 2010, Bryk duction is much more advanced, as and Kruczynska, 2011), this cultivar is in Switzerland, Austria or Denmark. considered as highly promising for One of the most serious barriers for orchards managed within organic sys- organic production in Poland is the tem. ‘Topaz’ fruit has more advantages elevated price of organic food that in – this cultivar loses its firmness and its the case of fruits (i.e. apples or characteristic sour taste slower than strawberries) is twice higher than for fruit of other scab-resistant cultivars, regular (or managed in integrated even during long storage (Konopacka production system) products. Fur- et al., 2006). Therefore, it has high thermore, limited access to informa- trade potential being highly attractive tion on the rules of organic farming, not only as fresh fruit for direct con- as well as poor accessibility of the sumption but also as raw material for organic food products, had been in- home-made preserves or commercial dicated as barriers for further devel- processing. opment of organic food consumption The aim of the study was to com- (Zmarlicki, 2009; Weibel et al., pare the sensory quality and process- 2012). Besides, there is worse ap- ing potential of scab resistant ‘To- pearance of organic fruits than those paz’ apples produced in certified grown conventionally, resulting from organic orchards (ECO) with those pest or pathogen damage that affect produced in orchards using inte- their visual attractiveness (Adamczyk grated methods (IP). et al., 2006; Cmelik et al., 2007). The technology of organic fruit produc- MATERIALANDMETHODS tion excludes any means of crop protection using chemically-synthesized The experiment was conducted in products. The only ones allowed are 2010 season at the Research Institute 52 J. Fruit Ornam. Plant Res. vol. 20(2) 2012: 51-61 The comparison of sensory quality and processing… of Horticulture in Skierniewice (IO). one day after cold storage and after 7 Apple fruits of ‘Topaz’ cultivar were days of storage at the temperature collected in five certified organic 18 ºC to simulate shelf life. The orchards (ECO) and in five certified quality characteristics analyses covered orchards in which integrated soluble solids and titratable acidity technology (IP) was used. All (taken as a measure of processing orchards were located in the central usefulness and indicators of sugar/acid region of Poland. The ECO and IP balance), physical characteristic of orchards were matched in pairs (A-E) apple texture (firmness and juiciness) according to geographical proximity and the sensory assessment including and/or climate-soil similarity. In all external as well as internal (eating) cases, fruits were collected from the quality attributes. For each orchard, trees grafted on M.26 rootstock, and the checking date 15 apples were grown in the mid-intensity (1250- tested (altogether – 150 apples for 1500 trees/ha). Fruits were picked at each technology: 5 orchards x the harvest maturity recommended 1 picking date x 2 checking dates x for fruit destined for storage (internal 15 apples = 150 apples). From each procedures of IO Fruit Storage sample 10 fruits were subjected to Department). Nevertheless in some instrumental measurements and then commercial IP orchards (B, D and E), sensory assessment while 5 fruits the harvesting date was intentionally were presented as sample for delayed due to weak (unsatisfied) blush appearance evaluation. The colour. The postponing time was instrumental analyses consisted of controlled by regular checking of the following measurements: firmness ethylene concentration in the seed (N) by penetrometer method with the cavity, not to exceed the values Magness-Taylor probe of 11.1 mm characteristic for pre-climacteric diameter (Instron texture press 4303), stage. Immediately after harvest juiciness index (%) according to fruits were transported to storage Konopacka and Płocharski (2001); facilities of IO. Fruit taken for acidity with potentiometric method by storage were matched in size, shape titration to pH 8.1 and calculation to and colour and had no visible marks malic acid content (%), and soluble of mechanical or microbial damage. solids contents of freshly squeezed Before storage, each batch of apples fruit juice by refractometric method was subjected to routine analyses (%). For sensory assessment of stored that allow characterization of fruit apples, the scaling-profiling method maturity. Among others ethylene was used. The data were collected concentration in seed cavities, starch through the computerized data index, skin blush percentage, collecting system “ANALSENT NT” firmness, soluble solids and titratable (Caret, Systemy Cyfrowe, Polska) acidity were determined. Fruits were developed at the Polish Academy of stored for two months at 1 ºC. The Sciences, Warsaw, Poland. 27 quality of stored apples was assessed qualitative traits connected with J. Fruit Ornam. Plant Res. vol. 20(2) 2012: 51-61 53 D. Konopacka et al. appearance, aroma, taste and texture of RESULTSANDDISCUSSION tested fruits that can influence potential buyers’ perception were evaluated. In Objective quality characteristics the current paper only the attributes In Table 1 quality characteristics that significantly impact the quality of of fruit after picking are given. compared apple batches are to be Considering blush percentage it may discussed while others such as be noticed that fruit grown in organic astringency, or odd-taste that were not orchards (ECO) reached its noticed in this experiment, were omitted. harvesting maturity earlier than those Each attribute was rated on a continuous produced by integrated method (IP). linear scale with anchor points at each However, at the same time fruit end, marked as 0 and 100 points. In the produced in organic orchard (ECO) case of sensory assessment 0 denotes were characterised by higher lack/low intensity or inappropriate firmness and also by significantly harmonization of evaluated higher titratable acidity. Similar characteristic, and 100, high