Influence of Pre-drying treatments on Quality and Safety of Sun-dried Tomatoes. Part Ⅱ. Effects of Storage on Nutritional and Sensory Quality of Sun-dried Tomatoes Pretreated with Sulfur, Sodium Metbisulfite, or Salt

摘要

Pre-drying treatments have been found to improve the quality of stored sun-dried tomatoes. Based on previous investigation (Part Ⅰ), 5 specific pretreatments were chosen for effects on nutritional value, sensory quality, and safety before and after 3 mo of storage (25℃ and 30% to 34% relative humidity). These pretreatments included (1) direct gas sulfuring with 2.3 kg (5 lb) SO_2; (2) with 3.6 kg (8 lb) SO_2; (3) dipping in 10% salt for 5 min; (4) 8% sodium metabisulfite for 5 min; and (5) 8% sodium metabisulfite and 10% salt for 5 min. The use of SO_2 improved color, rehydration ratio, and minimized the loss of ascorbic acid and lycopene. Sodium metabisulfite dipped tomatoes had better rehydration ratio and color than gas sulfured sun-dried tomatoes. Untrained consumers ranked gas sulfured tomatoes higher than sun-dried tomatoes produced by dipping in either sodium metabisulfite alone or sodium metabisulfite plus salt.