Vitamin C content during processing and storage of pineapple

Purpose This paper aims to determine the effects of processing pineapple fruits into different products and storage of the processed products on the ascorbic acid content. Design/methodology/approach Pineapples (variety “Queen Victoria”) were processed into juice, jam and sorbet. Vitamin C was analysed by the 2‐6 dichloroindophenol titrimetric method and tests were performed during preparation and storage of the products. The pineapple juice was stored for nine days at 8°C, whilst the jam and sorbet were kept for two months at 22‐25°C and −18°C respectively. Findings Fresh peeled pineapple fruit contains an average ascorbic acid content of 24.8 mg/100 g of fruit. During the juice making process, peeling led to the highest percentage loss of vitamin C (41.8 per cent) followed by exhausting (23.7 per cent). Processing of pineapples into jam was revealed to be most destructive towards ascorbic acid (a loss of 46.8 per cent) as compared to juice making (38.5 per cent) and sorbet preparation (15.5 per cent). Storage of the three processed products in the specific conditions led to a significant decrease (p<0.05) in vitamin C content, and the highest rate of degradation was in pineapple juice (0.6 mg loss per day). Originality/value This paper deals with the retention of vitamin C potency in pineapple products, which is important both to consumers concerned with maintaining good health, and to pineapple processors, who are interested in quality assurance, nutrient labelling and product storage.