Probiotic potential of spontaneously fermented cereal based foods – A review

The realization that food has a role beyond provision of energy and body forming substances has shifted scientific investigations with growing interest in the research and development of functional foods. A lot of attention is being focused on probiotics due to the enormous support showing health benefits. Probiotics are associated with fermented foods and it is therefore of importance that spontaneously fermented foods, that are so common in Africa, be assessed for their probiotic attributes. These foods are within the economic means of the people and are widely accepted in populations where they are produced. The foods have relatively long shelf-lives under ambient temperatures (without spoiling), are widely accepted especially by the vulnerable groups such as children, expectant/breastfeeding mothers, the aged and are commonly served to the sick and recovering persons. These foods would therefore render an invaluable health benefit to communities when consumed and would impart an invaluable economic benefit to society. Probiotics are associatedwith lactic acid bacteria that are commonly found in fermented foods. This paper reviews studies that have been carried out to enumerate, isolate, characterize and identify the microorganisms involved in the spontaneous fermentations of cereal based products and their assessments for  potential probiotic attributes

Microbiological quality and safety of raw and pasteurized milk marketed in and around Nairobi Region

The microbiological quality of raw and pasteurized milk marketed in Nairobi and its environs was determined. Milk samples were collected randomly at milk selling points from three market areas: rural (Kiambu/Ngong), urban (East/West of Tom Mboya street) and slum (Kibera/Mathare). Samples were analysed for titratable acidity, total viable count (TVC), Staphylococcus aureus, coliforms and Enterobacteriaceae. Titratable acidity was determined using titration method, while TVC, S. aureus and Enterobacteriaceae were determined by the spread plate methods and coliforms were determined by most probable number. Data collected were subjected to analysis of variance using Genstat statistical package. The mean acidity was 0.20% lactic acid (LA), while mean counts for TVC, S. aureus, coliforms and Enterobacteriaceae were 6.05, 3.46, 2.30, and 3.93 log10cfu/ml, respectively. The  ercentage of milk samples with acidity values greater than 0.18% LA, the upper limit set by Kenya Bureau of Standards (KEBS), was 52.8 %. Total viable count (TVC) greater than 106 cfu/ml, was detected in 95.2% and 21.4% of raw and pasteurized milk, respectively. Coliform counts greater than 4.70 and 1.0 log10cfu/ml for raw and pasteurized milk were detected in 77.8% and 4.8%, respectively of raw and pasteurized milk samples collected. Enterobacteriaceae and S. aureus were detected with mean counts ranging from 6.08-6.86 and 5.82-6.32 log10/ml, respectively. Highest mean acidity and counts were recorded from slum areas of Nairobi and there were significant differences between raw and pasteurized milk (P<0.05). The poor bacterial quality coupled with high acidity of raw milk, indicates poor hygienic practices and lack of temperature control during marketing. The incidence of high acidity and bacterial counts in pasteurized milk could indicate post process contamination and/or inappropriate storage of the milk. Most vendors of pasteurized milk were observed selling directly from the distributor crates without refrigerated storage. The rapid deterioration of raw and pasteurized milk marketed in Nairobi, at the time of this study, may be largely due to poor hygienic standards and non-adherence to temperature controls during handling, distribution and marketing. This requires urgent attention by the appropriate authorities, because the poor microbiological quality of raw milk and pasteurized milk may expose consumers to health risks associated with the consumption of contaminated milk.Key words: Marketed milk, quality, acidity, total viable count, coliforms, enterobacteriaceae, Staphylococcus aureu

Isolation and identification of the genera Acetobacter and Gluconobacter in coconut toddy (mnazi)

This study investigated the occurrence and identified the dominant spoilage genera of acetic acid bacteria in coconut wine (mnazi), by plating the dilution series previously pre-enriched in a basalmedium onto GYP agar, followed by physiological and biochemical tests. Both Acetobacter and Gluconobacter strains were Gram variable, oxidase negative and catalase positive. All Acetobacterstrains over-oxidized ethanol to acetic acid and finally to CO2 and H2O, while Gluconobacter were unable to oxidize acetic acid to CO2 and H2O. Acetobacter and Gluconobacter alike showed positivegrowth at 25, 30 and 40°C and also at pH 7.0 and 4.5, while there was no growth at 45°C, pH 2.5 and 8.5. Acetobacter strains oxidized both lactate and acetate while Gluconobacter oxidized lactate only. Bothgenera were unable to liquefy gelatin. Acetobacter showed negative growth at 15°C and also in peptone medium, while Gluconobacter showed positive growth both in peptone medium and at 15°C. Bothgenera were able to ferment arabinose, xylose, ribose, glucose, galactose, mannose and melibiose and unable to ferment amylagdine, cellibiose, esculine, lactose, maltose, mannitol, melezitose, Nagluconate, raffinose, rhamnose and salicine. The Acetobacter and Gluconobacter strains isolated in this study were found to be responsible for the spoilage of mnazi

TRADITIONAL TAPPING AND DISTILLATION METHODS OF COCONUT WINE (Mnazi) AS PRACTISED IN THE COASTAL REGION OF KENYA

The coconut palm (cocos nucifera) which is currently grown in nearly 90 countries that spread along the tropical belt is a versatile plant. In Kenya the most important palm tree is the coconut palm. Other palms found in Kenya include the borassus palm (Borassus aethiopum), the doum palm (Hyphae coriacea) and the wild date palm (phoenix reclinata). Tapping of coconut sap and utilization of this sap in various ways are a widespread practice in the Coastal region of Kenya. The study aimed at availing information on coconut wine tapping and distillation in Kenya. The findings could be used for further research, technological improvement and creation of awareness to those not acquainted with the technology despite having interest. The survey was conducted in Kilifi, Malindi and Kwale districts. Information was obtained on identification of the right spathe, tapping procees, sap collection, wine storage and distillation. Ripe spathe was identified as that which was sword like in shape, swollen at the base but not at the tip. The tapping procees involved: tying of the ripe spathe; cutting and removal of the spathe tip; sheath peeling-at a position 4 to 6 cm from the cut end; tying of the exposed spikelets with leaflets followed by trimming 2 to 3 mm of the leaflets tied section from the cut end to allow continuous oozing of the sap. The oozing sap was collected in containers made of plastic or gourd materials. Trimming was done two to three times a day, while wine collection was done twice a day. The first sap to ooze out was discarded daily for a period of three to six days. Wine meant for distillation was matured for one to seven days. The distillation equipment comprised of an assembly of pots with different sizes with a metallic container serving as a condenser. The number of times the cooling water was replaced depended on the capacity of the distillation equipment. This study is part of the project on study, improvement and industrial application of coconut alcoholic beverage (mnazi). Key Words: Coconut wine, Sap, Mnazi, tapping, distillation, spathe, spikelets, sheathe. MÉTHODES TraditionNELLES DE MISE EN VALEUR ET DE distillation DU VIN DE NOIX DE coco (mnazi) TELLES QUE pratiQUÉES DANS LA rÉgion COTIÈRE DU Kenya . Résumé Le cocotier (cocos nucifera ) est une plante à usages multiples ; il pousse actuellement dans près de 90 pays qui s'étendent le long de la ceinture tropicale. Au Kenya, le palmier le plus important est le cocotier. D'autres palmiers trouvés au Kenya sont notamment le palmier borassus (Borassus aethiopum) , le palmier doum (Hyphae coriacea) et le dattier sauvage (phoenix reclinata ). La mise en valeur de la sève de la noix de coco et l'utilisation de cette sève de plusieurs manières sont des pratiques bien connues dans la région côtière du Kenya. La présente étude avait pour but de publier des informations sur l'extraction et la distillation du vin de coco au Kenya. Les résultats pourraient être utilisés dans des recherches plus approfondies, pour améliorer la technologie et faire prendre conscience aux personnes qui ne connaissent pas encore bien cette technologie alors qu'elles s'y intéressent. Cette étude s'est déroulée dans les districts de Kilifi, Malindi et Kwale. Les informations ont été collectées sur base de l'identification de la bonne spathe, du processus de mise en valeur, de la collecte de la sève, de la conservation et de la distillation du vin. La spathe mûre a été identifiée comme étant celle qui était comme une épée de par la forme, gonflée à la base mais pas à l'extrémité. Le processus de mise en valeur impliquait qu'il fallait nouer la spathe mûre; couper et enlever le bout de la spathe; éplucher la gaine –à une position de 4 à 6 cm du bout coupé; attacher les épillets exposés avec des folioles. Il fallait ensuite émonder légèrement 2 à 3 mm de la section ligotée avec des folioles à partir du bout coupé afin de permettre un écoulement continu de la sève. La sève en écoulement a été collectée dans des récipients faits de matière plastique ou de calebasse. L'émondage se faisait deux ou trois fois par jour, tandis que la collecte de vin se faisait deux fois par jour. La première sève recueillie était jetée chaque jour pendant une période de trois à six jours. Le vin destiné à la distillation était gardé pendant un à sept jours pour qu'il arrive à maturité. L'équipement de distillation était composé d'un assemblage de pots de différentes dimensions avec un récipient métallique qui servait de condenseur. Le nombre de fois que l'eau de refroidissement était remplacée dépendait de la capacité de l'équipement de distillation. Cette étude s'inscrit dans le cadre du projet portant sur l'étude, l'amélioration et l'application industrielle de la boisson alcoolisée fabriquée à partir de la noix de coco (mnazi). Mots-clés: Vin de noix de coco, sève, Mnazi, mise en valeur, distillation, spathe, épillets, gaine foliaire. AJFAND Vol.4(1) 200

Educational Level and Major Constraints Faced by Farmers and Tappers in Production and Marketing of Coconut-based Products

Kenya like other tropical countries has a coastal belt that is suitable for the growth and production of coconut and oil palms. More than 80% of the small-scale farmers in the coastal region derive their livelihood directly or indirectly from the coconut tree. This study, which was conducted between June 2002 and April 2003, sought information on the educational level and the major constraints faced by coconut tree farmers and tappers. Both stratified and area-sampling methods were employed using two questionnaires; one for the tappers and the other one for the farmers. A total of 9,155 coconut tree farmers and 2,812 mnazi tappers from six geographical districts in the Kenyan coastal province were interviewed. On average, 32.5% of the 9,155 farmers interviewed were found to be illiterate, while 42.0 % had primary school level of education. Only 11.2% had secondary school education while only 2.1% had college or university certificate. Out of the tapers interviewed, 40.3 % were found to be illiterate while 53.1% had primary school certificate. Only a few had secondary school education (4.5%) and less than 0.4% had tertiary level of education. The major constraints faced by the farmers in all the six districts were: lack of market (28.6%), low/fluctuation of prices (20.3%), pests and diseases (12.4%), poor transport/infrastructure (9.4%) and lack of credit/loans (7.7%). The major constraints faced by the tappers in all the five districts were: lack of market or poor marketing (31.1%), police and/or provincial administration harassment (20.8%), low/fluctuation of prices (15.7%), poor storage/preservation facilities (8.7%) and risk of falling due to snake-bites/strong winds/slippery trees (5.7%). The study identified all the major constraints that attributed to the amorphous marketing structures and lack of processing industries. The findings when well utilized could act as major catalysts in the process of revitalizing the coconut industry in the coastal region of Kenya.Keywords:coconut; tapper; farmer; constraints; educational levelJAGST Vol 5 (1), 200

Partial characterisation and identification of lactic acid bacteria involved in production of ikii: a traditional fermented maize porridge by the Kamba in Kenya

Ikii is a fermented maize grits porridge prepared by the Kamba community in Kenya and is a favourite amongst children, breastfeeding mothers and the aged. It is a food commonly served to the sick and recovering persons and can store for as long as a week under ambient temperatures (25 – 30 oC) without spoiling. The pH during the fermentation process of ikii showed a decreasing trend from an initial average value of 6.4 to an average value of 3.9 at 36 hours and through to 72 hours, indicating production of acid. The population and diversity of lactic acid bacteria involved in production of ikii was studied. Lactic acid bacteria (LAB) were found to be the dominant microorganisms that bring about fermentation process leading to production of ikii. After 36 hours of the fermentation period, LABs and yeasts were found to exhibit a synergistic relationship that boosted the population growth of each other. From 40 samples of ikii suspension, 185 lactic acid bacteria strains were isolated, characterised and identified by use of morphological features, biochemical and phenotypical tests as well as sugar fermentation profiles of the API 50 CHL kit. The genus Lactobacillus (62%) formed the dominant microbiota and the rest of the isolated strains belonged to the genus Pediococcus (38%). Of the isolated strains, L. fermentum formed the dominant species (43%); other species were L. plantarum (10%), L. confusus (8%) and L. rhamnosus (1%). Keywords: Traditional fermented maize porridge; Lactic acid bacteria; Ikii; Kamba. Journal of Tropical Microbiology and Biochemistry Vol. 4 (1) 2008: pp. 3-1