Effect of osmotic dehydration in fructose, sucrose and fructooligosaccharide solutions on the content of saccharides in plums and apples and their energy value

M Uczciwek,R Klewicki

doi:10.2137/145960608787235559

Abstract

Plums (Najbolia and Stanley) and apples (Idared) were subjected to osmotic dehydration in 50% solutions of fructose, sucrose and fructooligosaccharides (FOS) at 22, 40 and 60 °C for 24 hours. The content of fructooligosaccharides, sucrose and monosaccharides in dried material was determined. Plums osmosed in fructose contained from 22.3% w/w to 29.6%w/w of this saccharide depending on the process temperature. The content of sucrose in plums and apples varied from 18.6% w/w to 30.4% w/w after using sucrose as osmotic agent. Material processed at 40 °C was characterised by the highest content of FOS: 22.624.7% w/w in plums (nystose as osmotic agent) and 13.7% w/w in apples (FOS preparation as osmotic agent). The partial replacement of sucrose and monosaccharides by fructooligosaccharides reduced the energy value of carbohydrates in dried material by 1237% depending on the process conditions.;

Highlights

Osmotic dehydration is a preservation technique that is often used as a pre-treatment to improve the quality of conventional dried products (Monnerat et al 2006)
The aim of our study was to determine the amount of fructooligosaccharides and other carbohydrates occurring in dried apples and plums after osmotic dewatering at different temperatures using fructose, sucrose and FOS as osmotic agents
Taking into consideration the content of saccharides in the initial material, the greatest differences between the apples and the plums occurred in the case of sucrose – from 1.3%w/w in the apples to nearly 9.5%w/w in the plums of Stanley variety (Table 1)

Summary

Introduction

Osmotic dehydration is a preservation technique that is often used as a pre-treatment to improve the quality of conventional dried products (Monnerat et al 2006). This kind of dewatering (with hypertonic aqueous solutions) has been proposed as a method to obtain partially dehydrated fruits and vegetables, which can be included in foods such as ice-cream, desserts, yogurt, dairy, cereals, confectionery and bakery products One of the most popular osmotic agents for fruits is sucrose because of it’s low cost, but other agents such as glucose or concentrated fruit juices, are used (Mandala et al.2005, Rastogi et al 2002). In order to reduce the energy value of dried products fructooligosaccharides can be used as an osmotic agent

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