Influence of osmotic dehydration on texture, respiration and microbial stability of apple slices (Var. Granny Smith)

• Published in: Journal of food engineering 2009-03, Vol.91 (1), p.1-9
• Main Authors: Castelló, M.L., Igual, M., Fito, P.J., Chiralt, A.
• Format: Article
• Language: English
• Subjects: Apple; apples; Biological and medical sciences; brix; Calcium; carbon dioxide; cell respiration; drying; food contamination; Food engineering; Food industries; food microbiology; fresh-cut foods; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; General aspects; Malus; microbial activity; microbial contamination; Microbiology; Osmodehydration; osmotic treatment; oxygen; Respiration; Texture; Vacuum impregnation; vacuum processing
• ISSN: 0260-8774; 1873-5770
• DOI: 10.1016/j.jfoodeng.2008.07.025

In order to analyse the feasibility of obtaining minimally processed apple samples, the effect of osmotic dehydration, at atmospheric pressure (OD) and by applying a vacuum pulse (PVOD), on mechanical properties, respiration rates and microbial stability of apple slices was analysed throughout storage at 10 °C. Treatments were carried out until reaching 20 and 30 °Brix in the samples. They caused a decrease in the values of the force dependent mechanical parameters, especially when applying vacuum pulse, whereas a small increase was observed when 1% calcium was applied. Nevertheless, these parameters were better preserved during storage when sample concentration was 20 °Brix and vacuum was applied. Osmotic treatments reduced oxygen consumption and, only when samples had 30 °Brix did CO 2 generation increase. During storage, treated samples showed lower respiration rates than the control ones, which remain practically constant during storage when they had 20 °Brix. A greater microbial stability was obtained in dehydrated samples, especially in PVOD treated ones.