Determination of drying characteristics and some quality parameters of vacuum dried diced apples differently pretreated


Thesis Type: Postgraduate

Institution Of The Thesis: Bursa Uludağ University, FEN BİLİMLERİ ENSTİTÜSÜ, Turkey

Approval Date: 2020

Thesis Language: Turkish

Student: Melisa Yağcıları

Supervisor: ÖMER UTKU ÇOPUR

Abstract:

In this study, apple samples prepared by dipping in a spicy pure water and sucrose solutions in an oven (at 75 ° C at atmospheric pressure 9 min) and vacuum impregnation (at 75 ° C/ 600 mbar 9 min) were dried under vacuum (75 ° Cwith 100, 200 and 300 mbar). It was aimed to obtain a healthy snack product. The drying kinetics, physicochemical properties and bioactive components of apple cubes produced for this purpose were investigated. L *, a * and b * values of the dried apple cubes were found between 50.64 - 65.28, 0.93 - 9.85 and 26 - 62.41 respectively. Total phenolic content (TPC) and total antioxidant capacity (TAC) values of the dried samples increased compared to fresh apples. While TPC amounts of dried apple cubes varied between 124.70-174.5 mg GAE / 100 g dry matter (dm); TAC amounts were changed among 5.17 - 5.69, 9.5 - 18.77 and 9.23 - 65.17 μmol trolox /g dmfor DPPH, FRAP and CUPRAC assaysrespectively. When the drying kinetics of the samples were examined, the shortest drying time was obtained from the sample VI-SA-100 (vacuum impregnation pretreatment dipped in a spicy sucrose solution at 75°C/ 600 mbar and dried in vacuum at 75°C/ 100 mbar) with 240 min. According to the applied mathematical modeling R2, RMSE and χ2 values were ranged between 0.8265- 0.9993, 0.004422 - 0.095429 and 0.000345 - 0.121394 respecitvely while Page, Modified Page and Wang and Singh were found as the best models fitted to the drying method.