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Pomologia Croatica : Glasilo Hrvatskog agronomskog društva, Vol. 14 No. 1, 2008.

Original scientific paper

Influence of apple variety on dry product quality

Nadica Dobričević ; Agronomski fakultet Sveučilišta u Zagrebu, Zagreb, Hrvatska
Sandra Voća ; Agronomski fakultet Sveučilišta u Zagrebu, Zagreb, Hrvatska
Stjepan Pliestić ; Agronomski fakultet Sveučilišta u Zagrebu, Zagreb, Hrvatska
D. Magdić

Full text: croatian pdf 403 Kb

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Abstract

Apple varieties Gloster, Jonagold, Idared, Melrose and Mutsu from the production region of North-western Croatia were picked at technological maturity and cool stored at an average temperature of 2.0 oC and relative humidity of 98 % until consumable maturity.
Apple fruits intended for drying were cleaned and cut into 1x1x1 cm cubes. Analyzed varieties had 63.37-75.46 % of flesh, 9.11-12.85 % of skin, the core accounted for 10.82-20.34 % and the unusable part for 0.25-0.87 %. Prepared cubes were soaked in sugar syrup of 64oBx density for 24 hours. Cube drying was carried out in five replications in a RETSCH TG 1 laboratory dryer, at air temperature from 50 oC to 60 oC. Drying air velocity was 2.0–3.5 m/s, drying time was 140 minutes. Average drying sample size was 250 grams.
Fresh cubes contained 85.11-86.89 % of water, cubes soaked in sugar syrup 63.96-72.03 %, and dry cubes 15.65-17.92 %.
Average drying rate curves modelled by linear regression gave the following equations:
Gloster y = 0.0028x2 – 0.7420x + 67.025, with r = - 0.9988; R2 = 0.9978 where: y – water content (%); x – drying time (min)
Jonagold y = 0.0044x2 – 0.9620x + 67.96 uz r = - 0.9864; R2 = 0.9731
Idared y = 0.0042x2 – 0.8850x + 60.501 uz r = - 0.9840; R2 = 0.9684
Melrose y = 0.0030x2 – 0.7864x + 69.707 uz r = - 0.9983; R2 = 0.9967
Mutsu y = 0.0031x2 – 0.7348x + 61.090 uz r = - 0.9855; R2 = 0.9714
Jonagold and Idared varieties released water faster during the drying procedure.
The rehydration index of dry cubes of the studied varieties was 2.29-2.68. Sensory evaluation ratings of the dry product quality were satisfactory for the taste, smell and consistency of cubes of all varieties. Sensory evaluation rating for the colour of Gloster apple cubes was not satisfactory.

Keywords

apple; convection; osmosis; drying

Hrčak ID:

28143

URI

https://hrcak.srce.hr/28143

Publication date:

23.10.2008.

Article data in other languages: croatian

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