EFFECT OF IRRADIATION ON THE SHELF LIFE AND NUTRITIONAL QUALITY OF TOMATO (Solanum lycopersicon L.) POWDER

ABSTRACT Tomato (Solanum lycopersicon L.) is a major horticultural crop with an estimated global production of over 153 million metric tons. It is the most important fruit vegetable and the second most widely cultivated crop in the world after potato, with a total production of about 141 million tons. In 2009, the average total yield in Ghana was 7.5 Mt ha-1 compared to the achievable yield of 15.0 Mt ha-1. The tomato industry in Ghana for the past decade has been bedevilled by a myriad of problems of which post-harvest losses range between 30% and 70% in the major seasons of production, hence a study was conducted into the preservation of S. lycopersicon L. through drying and packaging to reduce post-harvest losses. Two drying methods comprising of solar and freeze drying were employed for three varieties of tomato which are cultivated locally. The methods were compared to determine the more efficient for the three varieties used in the study and the impact of drying and radiation on some physico-chemical properties, microbial load as well as shelf-life of the samples. Evaluation of the packaging material for the dried samples was also carried out. The samples were exposed to gamma irradiation at 0 kGy, 1 kGy, 2 kGy and 3 kGy. The parameters determined included moisture content, pH, titratable acidity; total soluble solids total carotenoids, lycopene, lutein and beta carotene. Microbial analysis carried out included total aerobic mesophilic bacteria count, total coliform count and moulds and yeasts using standard methods. Data were analyzed using ANOVA. Storage had significant effect (p