Effect of Irradiation and Storage on the Physico-chemical Properties of Tomato (Solanum lycopersicon L.) Powder under Solar and Freeze-Dried Conditions in Ghana

Abstract

A study was conducted to assess the effect of irradiation and storage on the physico-chemical properties of tomato (Solanum lycopersicon L.) powder under solar dried and freeze-dried conditions in Ghana.  Forty kilogrammes (40 kg) of tomato fruits were obtained for the study. The fruits were solar and freeze dried and tomato powder obtained from them. These were exposed to gamma radiation from 1-3 kGy, with 0 kGy as control. The parameters investigated in the study for the two-month period include; moisture content, total soluble solids, total titratable acidity, pH and colour.  The pH of the samples ranged from 4.02 to 6.18, moisture content from 12.55% to 23.47%, total titratable acidity from 0.11% to 0.99%, total soluble solids from 4.80% to 5.06%, L*(colour) from 32.71 to 36.97, a* (colour) from 6.69 to 22.02 and b*(colour) from 14.38 to 22.91. Gamma radiation did not affect moisture content of the samples, total soluble solids, total titratable acidity and pH (p>0.05). Gamma irradiation affected the colour of the samples significantly (p<0.05).

Key words: irradiation, storage, moisture content, pH, total soluble solids, solar dried, freeze dried, Akoma, month.