Μεταβολές της σύστασης των σακχάρων κατά την ωσμωτική αφυδάτωση ολόκληρων φρούτων ακτινιδίου (Master thesis)

Αναγνώστου, Νικόλαος


Osmotic drying is a process of partial removal of water and simultaneous uptake of solids. This is causing changes in texture and composition of foods and the same time is affecting the quality of the end product. In the present work osmotic drying was applied in whole, small size, kiwi fruits employing two different sugars as osmotic agents i.e. glucose syrup and sucrose. The temperatures at which osmotic drying was carried out were 30 and 35oC for glucose syrup whereas for sucrose were 25 and 35oC. The processing times were 2, 4 and 6 hours. In the present study the effect of osmotic drying on the sugar up take by whole fruits as well as by sections of the fruit i.e. outer pericarp, inner pericarp and core were determined using High Performance Liquid Chromatography (HPLC). For sugar determination a refractive index detector was employed. The linear range of determination for glucose, fructose, sucrose and maltose was found to be 0.5 -50 mg.ml-1. The relative standard deviation (% RSD) was for all sugars examined lower than 1.5% (12 replicates). The lower limit of detection (LOD) and the lower limit of quantification (LOQ) for glucose were 0.62 mg.ml-1 and 1.88 mg ml-1, for fructose 0.81 mg ml-1 and 2.46 mg ml-1, for sucrose 0.46 mg.ml-1 and 1.40 mg.ml-1 and for maltose 0.56 mg.ml-1 and 1.70 mg.ml-1 respectively. The optimum period of time for osmotic drying was found to be 4 h. Besides, the results showed that both osmotic agents caused similar weight loss from the dried fruits. The conditions for higher sugar uptake in kiwi fruits were found to be with the use of sucrose as osmotic agent at 25oC.
Alternative title / Subtitle: Changes in sugar composition during osmotic drying of whole kiwi fruits
Institution and School/Department of submitter: Σχολή Γεωπόνων και Τεχνολογίας Τροφίμων και Διατροφής-Τμήμα Ζωικής παραγωγής
Subject classification: Σάκχαρα
Όσμωση
Ακτινίδια
Sugars
Osmosis
Kiwis
Keywords: Φρούτα;Σάκχαρα;Ωσμωτική αφυδάτωση;Προβλήματα;Μελέτη;Ανιχνευτές
Description: Μεταπτυχιακή εργασία –Σχολή Γεωπόνων και Τεχνολογίας Τροφίμων και Διατροφής-Τμήμα Ζωικής παραγωγής
URI: http://195.251.240.227/jspui/handle/123456789/12448
Appears in Collections:Πτυχιακές Εργασίες

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