Effectiveness of three different storage structures and curing process for the storage of sweet potato (Ipomoea batatas) in Ghana

Three different storage structures and two curing processes for the storage of sweet potato (Ipomoea batatas) were studied at the CSIR-Food Research Institute, Accra. Sweet potato roots initially cured under warm(30-35 °C) and very humid (90-95% relative humidity) conditions for 7 and 14 days were stored in local (traditional), pit, and clamp storage structures for 84 days. After 0-84 days of storage, the roots were sampled and physically assessed into wholesome, sprouted, fungalinfected, and insect and rodent-damaged. The decrease in percentage wholesome roots corresponded to an increase in percentage fungal-infected roots from 0 to 84 days of storage in all the three different storage structures. Clamp storage structure recorded the highest percentage wholesome roots (20.0%) compared to pit (16.3%) and local (0%) after 84 days of storage when roots were cured for 7 days. However, for 14 days cured roots stored for 84 days, local storage structure recorded the highest percentage wholesome roots (20%), pit (0%), and clamp (10%). Higher percentages of fungal-infected sweet potato roots were recorded from roots cured for14 days. Percentage sprouted roots was higher in clamp, followed by pit and local storage structures. Sprouting was delayed for sweet potato roots that were cured for 14 days in all the storage structures. Percentage damage of sweet potato roots by insect and rodent was lower inall the three storage structures compared to the fungalinfected sweet potato roots

The microbiota of dried traditional vegetables produced in the Sudan Savannah and Guinea Savannah agro-ecological zones of Ghana

Abstract: Traditional vegetables are an important article of diet of the ethnic groups from the northern parts of Ghana. Such vegetables are preserved by sundrying and consumed throughout the year. These are mostly leafy vegetables and include Hibiscus sabdariffa (sorrel), Bomtax costatum (kapok), Ceratotheca sesamoides, Adansonia digitata, and Hibiscus esculentus (okro), respectively called by the local names shure or sobolo, daala, yaudo, kuuka, and okro (common name). The dominant microbiota of ten common dried traditional vegetables were investigated by enumerating total bacteria, yeasts and moulds, lactic acid bacteria, Bacillus species and coliform bacteria. Isolates were characterized by colony and cell morphology, and by biochemical tests. The water activities of all the dried vegetables were between 0.513 and 0.539. Shuri and bisap had low pH values, between 2.6 and 2.71, whilst the other vegetables had relatively higher pH values ranging from 5.21 to 6.39. Moulds and Bacillus spp. dominated the biota of all the dried vegetables although lactic acid bacteria and coliforms were also isolated in most of these products. Bacterial counts of the dried vegetables were between 10 3 and 10 7 CFU/g. Aspergillus spp, Rhizopus spp, Eurotium spp, Penicillium spp and Aureobasidium spp. were the major genera of moulds identified in the dried vegetables. The dominant Bacillus species in all samples was Bacillus subtilis except in the okro pods and leaves where Bacillus cereus was dominant. The dominant lactic acid bacteria were Lactobacillus plantarum and pediococci. Escherichia coli was not detected in any of the dried vegetables, however, Enterobacter aerogenes was detected in most of the samples. Because of the high microbial levels in the dried vegetables, it is recommended that handling procedures be improved by primarily sanitizing the fresh vegetables prior to drying in solar dryers