Z. Farah

Composition and characteristics of camel milk

Present distribution and milk production. Main components (proteins, casein fractions, size distribution of casein, whey protein fractions, lipids, fatty acids, phospholipids, physical state and properties of fat globules, lactose, minerals and vitamines). Enzymic coagulation. Effects of heat on milk. Antibacterial activity

Preparation and consumer acceptability tests of fermented camel milk in Kenya

There are estimated to be 600000 camels ( Camelus dromedarius ) in Kenya (Wandera, 1985). Almost 80% of these are kept by pastoral tribes living in arid areas in eastern and north-eastern parts of the country. In these regions, camels are important dairy animals. A camel in north-east Kenya can be expected to yield about 4 kg milk daily as compared with 0·5–1·5 kg for a cow in the same area. Most of the camel milk is consumed in the form of fermented milk. The milk is allowed to ferment naturally at ambient temperature and without prior heat treatment until it turns sour. The resulting fermented camel milk is known as Susa. Due to the spontaneous nature of the fermentation, this traditional method results in a product with varying taste and flavour and is often of poor hygienic quality, in addition, because of the limited scale of production, the product can be sold only in the immediate vicinity of the herd. For production of fermented milk under controlled conditions, thermophilic or mesophilic lactic acid cultures are normally used. In warm countries, mesophilic lactic cultured milk offers some advantages, as it can be incubated at ambient temperature (20–30 °C) and the fermentation stops at 1–1·2% lactic acid, eliminating the need for cooling to stop further souring as occurs in the case of yoghurt (Kurwijila, 1980).

Use of gibberellic acid to prolong dormancy and reduce losses during traditional storage of yams

The annual vegetative cycle of the yam (Dioscorea spp) necessitates a long period of storage. Losses during this period are high and are mainly due to germination. Trials on the effectiveness of gibberellic acid (GA3) for controlling storage losses were carried out on the two main species of yam (D cayenensis rotundata and D alata) grown in the Ivory Coast. Methods of application at the apex adapted to the rural environment were tested. Treatment with GA3 prolonged the dormancy period and thus reduced losses. This substance was effective at low concentration with a long soaking duration (75 mg litre−1 for 2 h) and during a soaking of short duration with a higher concentration (0·5 h at 150 mg litre−1). Because of its stability at ambient temperature, the solution was still active 3 days after being prepared and after reuse of the same dip six times.

Diarrhoea, vomiting and the role of milk consumption: perceived and identified risk in Bamako (Mali)

Objectives  To evaluate the public health impact of milk contamination in Bamako, Mali.

Iso-electric focusing of camel milk proteins

(Received 18 November 1997; accepted 27 June 1998) The procedure for phenotyping of most genetic variants in cow milk was optimised for iso-electric focusing (IEF) of camel milk proteins and milk from individual camels of different breeds was screened. The caseins obtained from IEF bands were also investigated by Nterminal sequencing. Camel milk casein was separated at different pH and the proteins in the whey obtained were then separated by IEF. Above pH 4.3 casein bands were observed in the whey. According to the pattern of protein bands in IEF, the 103 camels screened had one of the three main groups of milk designated aa, ab and, bb. A small number of camels differed from bb milk type by an extra band and this group was designated as bb l . The high frequency of particular milk type in some breeds suggests that their production characteristics could be related to the phenotypes.

Effect of storage system and sprout removal on post-harvest yam ( Dioscorea spp.) fresh weight losses

SUMMARY Two aspects of yam storage practice were tested from 1994 to 1995 in central Co# te d’Ivoire. The first experiment compared the storage environment in pits or sheds with that of the traditional yam open barn method. The pits allowed the daily range of variation in temperature to be reduced while maintaining a high relative humidity (RH), whereas the temperature and RH in the sheds were similar to those of the yam barns. Dierences in temperature and RH between the storage systems had little eect on the fresh weight losses of the tubers. The more eective protection against solar radiation and rain aorded by the sheds and pits reduced fresh weight losses in D. cayenensis rotundata by 12% over 6‐5 months in comparison with the barns. The second experiment tested the regular removal of the sprouts. Sprout removal reduced fresh weight losses equally over 5 and 6 months’ storage. The reduction in fresh weight loss was 12% for cv. Gnan (D. cayenensis rotundata) during 6 months’ storage. Monthly sprout removal gave an equal benefit in pits, in sheds and on yam barns. The monthly cutting of sprouts at the base should be encouraged in places where this is not already done. The total loss is mainly determined by the growth of the sprouts and the reduction in weight after onset of sprouting, which are highly dependent on species and cultivar. Be’ te’ be’ te’ yams had better keeping qualities than all the other cultivars tested.

Risk factors for symptoms of gastrointestinal illness in rural town Isiolo, Kenya.

This study assesses risk factors for food‐borne gastrointestinal illness indicated by diarrhoea and/or vomiting using 14‐day recalls among children and young adults. The study was set in Isiolo, a rural town of Kenya, inhabited mainly by pastoralists of different ethnic groups. The preparation methods of milk at the household level were also investigated. The study was cross‐sectional and involved 900 participants from randomly selected households. They were interviewed using a structured questionnaire. An unmatched nested case‐control study was constructed by randomly selecting three controls for each case. Potential risk factors for gastrointestinal illness were analysed using both univariate and multivariate logistic regression models with random effect on ethnic groups. The study results showed that consumption of mutton, carrots, Irish potatoes, raw camel milk, boiled camel milk and fermented camel milk were important risk factors for diarrhoea and/or vomiting, whereas the consumption of boiled goat milk, boiled cow milk, spinach, washing of hands with soap and the presence of proper drainage system had protective effects (odds ratio < 1). We conclude that in this setting, primarily vegetables and the camel milk market chain pose the greatest risks for symptoms of food‐borne gastrointestinal illness.