Optimization of Drying Conditions and Effect of Storage on Some Quality Attributes of Tomato Powder

Abstract

Tomato (Solanum lycopersicon L) fruit is rich in nutrient and antioxidant properties. Drying accelerates some reactions that adversely affect the product quality especially nutritional value. Optimization of the drying process for Eva tomato was conducted to obtain a powder with high nutritional value and functional properties. The physical, chemical and microbiological properties of fresh Eva tomato fruit were determined. Central composite design of response surface methodology was used to obtain 13 combinations of drying temperature (60-70 ° C) and drying time (12-18 h). Tomato powder samples from the experimental runs were analyzed for chemical, functional and antioxidant properties using standard laboratory procedures. Tomato powder dried at optimum drying conditions were stored in low density polyethylene (LDPE) and laminated aluminum foil (LAF)] for three months at room temperature (28±2 °C) and analyzed for selected properties. Optimum tomato powder was obtained at 66.32 °C for 16 h and characterized by moisture (9.91%), lycopene (45.67 mg/100 g), vitamin C (15.23 mg/100 g), and redness (53.46) among other properties. Generally, an increase in the drying temperature and drying time caused a decrease in moisture content, β-carotene, pH, and bulk density while ash, total soluble solid, total titratable acidity, ascorbic acid, lycopene, non-enzymatic browning, total phenol, antioxidant activity, scavenging activity, bulk density, water absorption capacity and solubility content increased. Optimized powder stored in LAF had better properties.

Keywords: Tomato, drying, optimization, food quality.