Studies of some simple techniques for extending shelf-life of tomato (Lycopersicon esculentuin Mill) fruits

Thumbnail Image
Journal Title
Journal ISSN
Volume Title
A study was undertaken, at the Horticulture Department, University of Science and Technology, Kumasi, to develop simple techniques that will significantly improve the shelf-life of tomato (Lycopersicon esculentum cv. “Power) commonly grown in Ghana. Treatments of the experiments were to study the effects of benomyl (a broad- spectrum fungicide) and hot water as pre-package treatments, perforated and unperf orated low density polyethylene (LDPE) bags as packaging materials and storage in an evaporative cooler (Cooler), in the laboratory (Room) and under Shed (with ambient condition) on tomato fruits. Eight hundred and ten (810) freshly harvested, healthy tomato fruits, at the mature-green and breaker stages of ripening, were randomly divided into three groups and each group treated with (dipped in) either benomyl(0.8g a.i./l), hot water(55°C ± 2°C) or tap water (as control) . Each group was then further divided into three and each subgroup was packaged in each of the storage materials before they were stored under the three storage environments. The percentage weight loss, colour, firmness, total soluble solids, pH and percentage rot of the tomato fruits were monitored. The time (in days) taken for 50 of fruits to rot was taken as the shelf-life. The experiment was repeated twice. The Cooler achieved and maintained a low mean temperature of 25.2°C, about 3°C lower than both Room and Shed, and mean relative humidity of 83.7, about 10% higher than in either the Room or under the Shed. The mean daily percentage weight loss in fruits stored in the Cooler (0.10%) was more than twice lower than those in either Room or under shed which had 0.24 and 0.256 respectively. The conditions in the Cooler helped in maintaining the firmness of the fruits more than fruits stored in Room and or under Shed. The mean shelf-life for the fruits in the Cooler (14 days) was, however, the same as in the Room, though incidence of rot in the Cooler was higher. Mean shelf-life of benomyl-treated fruits (14 days) was longer than both the control and the hot water-treated fruits. The hot water-treated fruits had the shortest mean shelf- life (12 days) and were significantly different from the benomyl-treated fruits but not the control (13 days). Fruits without any packaging material had the longest mean shelf-life of 15 days but were not significantly different from those in perforated polybags which scored 14 days. Fruits in unperforated polybags were worst with 11 days and were significantly different from both the unpackaged fruits and those in perforated polybags. Pretreating tomato fruits with benomyl (0.8g a.i/l aqueous suspension), packaging them in perforated low density polyethylene bags before storing them under normal room conditions or just washing (cleaning) the fruits, allowing them to dry before storing them in an evaporative cooler (without any pre-package treatment and polybags) were the two most effective techniques that prolonged the storage life of tomato fruits.
A thesis submitted to the Board of Postgraduate Studies, Kwame Nkrumah University of Science and Technology, Kumasi, in partial fulfilment of the requirement for the award of the Degree of Master of Science in Post-Harvest Physiology, 1998