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

Application of a value chain approach to understanding white kenkey production, vending and consumption practices in three districts of Ghana

Traditional processing and street vending of foods is a vital activity in the informal sector of the Ghanaian economy and offers livelihood for a large number of traditional food processors. Kenkey is a fermented maize ‘dumpling’ produced by traditional food processors in Ghana. Ga and Fante kenkey have received research attention and there is a lot of scientific information on kenkey production. White kenkey produced from dehulled maize grains is a less known kind of kenkey. A survey was held in three districts of Ghana to study production, vending and consumption of white kenkey and to identify major bottlenecks related to production, which can be addressed in studies to re-package kenkey for a wider market. Questionnaires were designed for producers, vendors and consumers of white kenkey to collate information on Socio-cultural data, processing technologies, frequency of production and consumption, product shelf life, reasons for consumption and quality attributes important to consumers using proportional sampling. The survey was conducted in white kenkey production zones and trade centers. Results showed that production of white kenkey is done on small-scale levels by middle-aged women in households with 10-50 kg of dehulled maize processed into white kenkey, 1-3 times weekly. A third (28%) of the women processed up to 50-100 kg of maize per week. Although 62% of vendors sell 50-100 balls of white kenkey daily, 15% of them sell more than 170 balls. Majority of consumers (45.9%) liked white kenkey because of its convenience (ready-to-eat). Texture and taste were quality attributes desired by kenkey consumers. Producers did not have written records of process controls and product throughputs. Inspite of their cottage nature, production of white kenkey is a profitable employment for producers and vendors and is popular among consumers. Product improvement, process and product characteristics could offer scale-up criteria for development of white kenkey production using standardized procedures for steeping times, steeping temperature and fermentation times.Keywords: maize, white kenkey, value chain, traditional, product development, re-engineerin

Comparison of the microbial composition of African fermented foods using amplicon sequencing

Fermented foods play a major role in the diet of people in Africa, where a wide variety of raw materials are fermented. Understanding the microbial populations of these products would help in the design of specific starter cultures to produce standardized and safer foods. In this study, the bacterial diversity of African fermented foods produced from several raw materials (cereals, milk, cassava, honey, palm sap, and locust beans) under different conditions (household, small commercial producers or laboratory) in 8 African countries was analysed by 16S rRNA gene amplicon sequencing during the Workshop “Analysis of the Microbiomes of Naturally Fermented Foods Training Course”. Results show that lactobacilli were less abundant in fermentations performed under laboratory conditions compared to artisanal or commercial fermentations. Excluding the samples produced under laboratory conditions, lactobacilli is one of the dominant groups in all the remaining samples. Genera within the order Lactobacillales dominated dairy, cereal and cassava fermentations. Genera within the order Lactobacillales, and genera Zymomonas and Bacillus were predominant in alcoholic beverages, whereas Bacillus and Lactobacillus were the dominant genera in the locust bean sample. The genus Zymomonas was reported for the first time in dairy, cereal, cassava and locust bean fermentations