Influence of potassium metabisulphite pre-treatment, osmotic dip and packaging materials on dehydration and some chemical properties of apple rings

Investigations were carried out to optimize potassium metabisulphite (KMS) pre-treatment and osmotic dip for dehydration of apple rings. The apple cv. ‘White Dotted Red’ fruits were divided into two lots. One lot was dipped in sugar (sucrose) syrup of 0, 40, 50 and 60° Brix for 8 hr. The other lot was first pretreated with 1.5% KMS for 45 minutes before sugar syrup dip. The apple rings were packed in low density either polyethylene or laminated almunium pouches and stored under ambient conditions (temperature 18±2°C, pH 65±5%) for 180 days. The moisture content and acidity also showed significant increase during storage whileas reducing sugars showed non-significant increase. The samples packed in laminated almunium pouches were found more acceptable after storage.