Tomato powder processing involving different pretreatments: its effect on quality of the product packaged in polyethylene terephthalate pouches

Abstract

The method of drying fresh tomato (Lycopersicon esculentum mill) to prevent quick spoilage, could affect the quality of the product, and influence consumer acceptability. This study is focused on determining the effect of different pretreatments on the quality of tomato powders packaged in polyethylene terephthalate pouches, and stored for 16 weeks at room temperature (25±2 ºC). A total of six tomato powder samples, which include the blanched ascorbic acid pretreated (BAAP), unblanched ascorbic acid pretreated (UAAP), blanched lime juice pretreated (BLJP), unblanched lime juice pretreated (ULJP), sundried without pretreatment (SDTP), and the control (without pretreatment; dehydrator used for drying), was prepared. The total viable counts (TVC) of the stored tomato powders were within the range of 4.40-7.31 log10CFU/g. Although the TVC of the samples increased within the first few weeks, the values reduced as the storage period increased. The SDTP tomato powder maintained a higher TVC compared with other stored samples. There was a reduction in pH, moisture, ash, titratable acidity, and vitamin C content of the powdered tomatoes. The lycopene content of tomato powders was within the range of 102.13±1.53-132.70±1.46 mg/100g, while the fruit tomato was 18.96±1.27 mg/100g. There were significant differences (p<0.05) in the functional properties of the tomato powders, with few exceptions. Different pretreatments increased the water absorption capacity and bulk density of the samples, but reduced their emulsion stability. The BLJP and BAAP tomato powders had a very high sensory rating, whereas the SDTP sample was the least. Based on the overall results, blanched ascorbic acid pretreatment is recommended for the production of good quality tomato powder. Article history: Received 14 October 2024; Revised 02 December 2024; Accepted 04 March 2025; Available online 25 June 2025