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International Journal of Food Microbiology 63 (2001) 189–197www.elsevier.nl / locate / ijfoodmicro

The microbiology of South African traditional fermented milks

a , b a*Elisabeth M. Beukes , Bernie H. Bester , Johannes F. MostertaARC-Animal Nutrition and Animal Products Institute, Private Bag X2, Irene 0062, South Africa

bDepartment of Food Science, University of Pretoria, Pretoria 0002, South Africa

Received 22 May 2000; received in revised form 26 July 2000; accepted 3 August 2000

Abstract

A total of 15 samples of traditional fermented milk were collected from individual households in South Africa andNamibia. Lactic acid bacteria dominated the microflora of these samples, especially the genera Leuconostoc, Lactococcusand Lactobacillus. Other groups identified included pyogenic streptococci and enterococci. The dominant lactococci specieswas Lactococcus lactis subsp. lactis. Eighty-three percent of the leuconostoc isolates were identified as Leuconostocmesenteroides subsp. dextranicum. Other species identified included Leuconostoc citreum, Leuconostoc lactis, Lactobacillusdelbrueckii subsp. lactis and Lactobacillus plantarum. 2001 Elsevier Science B.V. All rights reserved.

Keywords: Traditional fermented milk; Lactic acid bacteria; Maas; Amasi

1. Introduction tural History Museum, personal communication).The art of making these products was handed down

Many people throughout Africa enjoy soured milk from one generation to the next. The Xhosa and Zuluproducts. In these products, the lactic acid bacteria people used mainly calabashes to make ‘amasi’perform an essential role in preserving a highly while the South-Sotho preferred clay pots to makenutritious food product. Fermented milk products are their ‘mafi’. Fox (1939) stated that clay pots gave aalso of great significance for their therapeutic value, better flavour to the fermented milk than calabashes.for alleviating lactose intolerance, social value and as A calabash needed to be seeded with a microbiala means of generating income. The peoples of South inoculum before it could be use for the production ofAfrica used to ferment their milk in milk-sacks, fermented milk. According to a description of Bryantcalabashes, clay pots, stone jars and baskets (Fox, (1967), a calabash filled with fresh milk was covered1939; Quinn, 1959; Bryant, 1967; Fehr, 1968; and placed outside the hut. After coagulation theBohme, 1976; Moifatswane, 1995 — National Cul- whey was drained through a hole in the bottom of

the calabash. The hole was initially stoppered with apiece of stalk. The calabash was now ‘ripened’ and*Corresponding author. Tel.: 1 27-12-672-9041; fax: 1 27-12-filled with fresh milk again. Fermentation took place665-1563.

E-mail address: [email protected] (E.M. Beukes). within 2 to 3 h whereafter the curd was poured out as

0168-1605/01/$ – see front matter 2001 Elsevier Science B.V. All rights reserved.PI I : S0168-1605( 00 )00417-7

190 E.M. Beukes et al. / International Journal of Food Microbiology 63 (2001) 189 –197

snow-white lumps. The specific container used, as Basingstoke, Hampshire, UK), incubated at 30618Cwell as the environmental conditions, contributed to for 7262 h for enumeration of total aerobic platethe gradual selection of specific micro-organisms that count. The total colony count was determined aswere responsible for the rich, full flavours that described in the International Dairy Federationcannot easily be imitated by modern dairy starter (1991) reference method (IDF 100 B: 1991). (ii)cultures. Although traditional fermented products MRS agar (De Man et al., 1960) (Oxoid CM 361),still enjoy loyal following in rural communities in incubated anaerobically for 4862 h at 42618C forSouth Africa (Hughson, 1995), the traditional con- enumeration of thermophilic lactobacilli and strep-tainers are increasingly being replaced with commer- tococci. MRS agar plates were also incubated an-cially available ones, especially plastic containers aerobically for 4862 h at 35618C for enumeration(Coetzee et al., 1996). of mesophilic lactobacilli and leuconostocs. (iii)

There is no scientific information available on M17 agar (Terzaghi and Sandine, 1975) (Oxoid CMtraditional fermented milk in South Africa. Modern 785), incubated aerobically for 4862 h at 30618Csocio-economic changes mean that some traditional for the enumeration of lactococci. (iv) Rogosa agartechnologies for the production of fermented foods (Rogosa et al., 1951) (E. Merck, D-61 Darmstadt),will eventually be lost together with the associated incubated anaerobically for 4862 h at 35618C formicro-organisms. It is therefore imperative that enumeration of lactobacilli. (v) Violet red bile agartraditional, indigenous products as well as the pre- (Oxoid CM 107 with added MUG supplement BROservation and exploitation of the associated fermenta- 71 E), incubated aerobically for 2462 h at 37618Ctive micro-organisms be investigated. The objectives for enumeration of coliforms and Escherichia coli.of this study were to collect indigenous fermented The supplement containing 4-methylumbelliferyl-B-milk samples in different rural areas, to determine D-glucuronide (MUG) allowed the separate enumera-the predominant microbial groups and to identify the tion of Escherichia coli which contain glucuronidaselactic acid bacteria in the fermented milks. activity. Plates were examined under long wave UV

light (366 nm) for the presence of fluorescingcolonies. (vi) Milk agar (Harrigan and McCance,

2. Materials and methods 1976) was used for detection of proteolytic bacteria.The plates were incubated for 24–48 h at 258C. (vii)

2.1. Collection of samples Citrate fermenting organisms were detected on themodified medium of Nickels and Leesment (Vog-

Fifteen samples of indigenous fermented milk ensen et al., 1987), incubated for 48 h at 258C.were obtained from individual households in rural Anaerobic jars (Biolab and Oxoid) with gasareas in northern South Africa and Namibia. These generating kits (Oxoid BR 38B) were used forsamples were collected from July 1995 to September anaerobic incubation. Ten isolates were obtained1996. Seven samples were in clay pots, six in randomly from the countable plates of Rogosa agar,calabashes and two in plastic containers. On receipt M17 agar, MRS agar (incubated at 428C for thermo-the pH of the samples was measured and the philic bacteria and at 358C for mesophilic bacteria).microbiological analyses performed within 24 h. The Isolates were cultivated in MRS broth (Oxoidclay pots and calabashes were covered with tinfoil CM359) at 258C. Purity was checked by streaking onand stored under refrigeration at 4 to 78C. MRS agar. Isolates were preserved by a modification

of the method described by Joubert and Britz (1987)2.2. Isolation of micro-organisms and cultures were stored at 2 208C.

Ten millilitres of each sample was pipetted asepti- 2.3. Identification of the lactic acid bacteria tocally into 90 ml of quarter strength Ringer’s solution genus level

21and mixed thoroughly. Serial dilutions (10 to2810 ) were made and 1 ml portions of the appro- Gram-positive, catalase-negative isolates were as-

priate dilutions were pour-plated on the following signed to a genus on the basis of key characteristicsmedia. (i) Plate count agar (Oxoid M325) (Oxoid, and tests indicated in Table 1. Microscopic appear-

E.M. Beukes et al. / International Journal of Food Microbiology 63 (2001) 189 –197 191

Table 1Differential characteristics of lactic acid bacteria (Harrigan and McCance, 1976; Garvie, 1984; Hammes et al., 1992; Holzapfel and

aSchillinger, 1992; Teuber et al., 1992; Weiss, 1992; Axelsson, 1993)

Characteristic Leuconostocs Streptococci Enterococci Pediococci Lactobacilli

b c dPyogenes Viridans Lactic Strepto Thermo Beta

Cell form Spherical but Spherical or ovoid Spherical Spherical Rods /Coccobacilli

often lenticular to ovoid

Cellular Pairs and Chains and pairs Mainly in Pairs, tetrads, clusters, Chain formation common

arrangement chains pairs, single cells are rare,

short chains no chains

Growth

at 108C 1 2 2 1 1 6 ND ND ND

at 458C 2 2 1 2 1 6 6 1 6

at 158C 1 1 2 6

NH from arginine 2 1 2 6 1 6 2 6 63

Gas from glucose 1 2 2 2 2 2 2 2 1

Growth in

6.5% NaCl 6 2 2 2 1 6 6 6 6

Reaction in Comparatively inactive. No No ARC ARC Comparatively Various reactions depending

litmus milk Few strains capable of reduction reduction inactive. Rarely on the species

producing acid. Very of litmus of litmus produce

few strains capable of before before sufficient

clotting the milk. No clotting clotting acid to

strains giving reduction of milk of milk cause clotting

a1 , positive; 2 , negative; 6, response varies between species; ARC, acid, reduction, clot; ND, no data.

b Streptobacterium.c Thermobacterium.d Betabacterium.

ances of 24 h old cultures were judged using Gram- 2.4. Identification of the lactic acid bacteria to thestained preparations (Gerhardt et al., 1981). Growth species levelat 10, 15 and 458C in MRS broth was evaluatedvisually after 72 h incubation. Tests for presence of Arginine tetrazolium agar (Turner et al., 1963;catalase, production of ammonia from arginine and Harrigan and McCance, 1976) was used to differen-production of CO from Gibson’s medium were tiate between Lactococcus lactis subsp. lactis and2

carried out as described by Harrigan and McCance Lactococcus lactis subsp. cremoris. The scheme(1976). The salt tolerance test was done using MRS outlined by Villani et al. (1997) was used for thebroth, containing 6.5% (m/v) NaCl with incubation presumptive identification of the leuconostoc species.for 4 days at 378C. All isolates were also tested for The method of Garvie (1984) was used to divide thetheir action on chalk litmus milk (Oxoid CM45 with leuconostoc isolates into dextran-producing and non-added calcium carbonate) (Harrigan and McCance, dextran-producing isolates. Subsequent tests done on1976). Kanamycin aesculin azide agar (Oxoid these two groups differed: dextran-producing isolatesCM591) was used for the presumptive identification were tested for fermentation of arabinose, maltose,of enterococci. Nickels and Leesment medium as raffinose, galactose and for growth at 378C; non-modified by Vogensen et al. (1987) was used to dextran-producing isolates were tested for fermen-differentiate between citrate fermenters and non-cit- tation of sucrose, fructose, galactose and trehalose.rate fermenters. The insoluble calcium citrate is Growth at 158C and growth in MRS broth containinghydrolyzed by the citrate fermenters, which form a 6.5% (m/v) NaCl were also tested. The basalclear zone around the colony. medium described by Garvie (1984) was used for all


the carbohydrate fermentation tests. The individual 1995b). Staphylococcus aureus was detected usingsugars were prepared as 2% (m/v) solutions, filter- the reference method of the IDF (International Dairysterilised using a 0.45 mm porosity filter (Millipore, Federation, 1990).Bedford, MA, USA) and 0.5 ml of the sterile filtratewas added to 5 ml of basal medium. Growth studiesat 15 and 378C were done in MRS broth.

3. ResultsTen representative isolates were selected for

identification to species level using the API 50 CH3.1. pH of the samples

´galleries and API 50 CHL medium (bioMerieux sa).Bacterial cells were inoculated into tubules of the

The pH of 11 of the samples ranged from 4.0 toAPI galleries according to the manufacturer’s in-

5.4 with an average of 4.6.structions. The galleries were incubated at 308C andreactions were observed after 24 and 48 h. The

´ 3.2. Enumeration of micro-organismsAPILAB PLUS database (bioMerieux sa) was usedto interpret the results.

Table 2 summarises the microbial counts obtainedfrom traditional fermented milk samples. Mean2.5. Detection of pathogenscounts on MRS agar (358C) and M17 agar were

8 8 21All samples were tested for the presence of 7.7 3 10 and 7.05 3 10 cfu ml , respectively, andSalmonella, Staphylococcus aureus and Listeria were higher than the mean total plate count (5.5 3

8 21monocytogenes. The IDF reference method (Interna- 10 cfu ml ), indicating the predominance of lactictional Dairy Federation, 1995a) was used for pre- acid bacteria. These counts also exceeded countssumptive detection of Salmonella species with the obtained on Rogosa agar. The mean thermophilic

8use of Brilliant Green agar, Bismuth Sulphite agar count (428C/48 h) on MRS agar (3.86 3 10 cfu21and XLD (Xylose Lysine Desoxycholate) medium as ml ) was less than the mean mesophilic count

8 21selective solid media. Listeria selective medium (358C/48 h) (7.7 3 10 cfu ml ) for calabash and(Oxford formulation CM856) as well as PALCAM clay pot samples. The presence of proteolytic organ-Listeria selective agar (Oxoid CM877) were used for isms in high numbers (mean value for 12 samples:

8 21isolation and identification of presumptive Listeria 1.89 3 10 cfu ml ) contributed substantially to themonocytogenes (International Dairy Federation, total bacterial population of the samples tested. The

Table 2Microbiological profile of samples from indigenous fermented milk in South Africa

21Medium Ranges of counts Mean counts (cfu ml )21(cfu ml ) for all Clay pots Calabashes

samples (n 5 13) (n 5 7) (n 5 6)5 9 8 8Total plate count 8.6310 –1.56310 9.43310 1.58310

agar (n 5 12) (n 5 6)5 9 8 6MRS agar (428C) 4.7310 –1.27310 7.65310 7.63106 9 9 8MRS agar (358C) 6.5310 –2.03310 1.28310 2.63106 9 9 8M17 agar 1.4310 –1.87310 1.2310 2.13105 8 8 8Rogosa agar 3.2310 –5.1310 2.47310 1.53310

7 6 4Violet red bile agar ,1–1.51310 3.05310 5.8310(n 5 12) (n 5 6)

4 8 8 7Milk agar 3310 –9310 3.62310 1.67310(n 5 12) (n 5 5)

8 8 8Nickels and Leesment ,1–8.4310 1.47310 1.12310medium (n 5 11) (n 5 4)


6 7highest coliform counts (3.2 3 10 and 1.5 3 10 cfu distribution of the 366 bacteria identified from21ml ) were obtained from two clay pot samples. An traditional fermented milk in South Africa.

important finding was the presence of Escherichiacoli in three clay pot samples with counts varying 3.4. Identification of the lactic acid bacteria to

3 3 3 21between 4 3 10 , 7 3 10 and 19 3 10 ml . species level

All the lactococci isolates (a total of 103 isolates)3.3. Identification of lactic acid bacteria to genus belonged to Lactococcus lactis subsp. lactis. Eighty-level six isolates from a total of 104 Leuconostoc isolates

produced dextran from sucrose. With the exceptionThe greater part of the total number of isolates of two isolates, all of these isolates fermented

was Gram-positive and catalase-negative. A total of maltose and galactose but not arabinose and raffin-366 isolates isolated from seven clay pots and two ose, and grew at 378C. According to the scheme ofcalabashes could be identified and were divided into Villani et al. (1997), Leuconostoc mesenteroidesfive genera: Lactococcus, Leuconostoc, Lactobacil- subsp. dextranicum and Leuconostoc carnosum arelus, Enterococcus and Streptococcus. Some the only two species that form dextran from sucroseheterofermentative lactobacilli grew as coccobacilli and do not form acid from arabinose. Since mostand were not easy to distinguish from leuconostocs. strains of Leuconostoc carnosum did not grow atTwenty-nine isolates were assigned to the Leuconos- 378C (Dellaglio et al., 1995) the above-mentionedtoc /Betabacterium group, which means that they isolates were presumptively identified as Leuconos-may either belong to the genus Leuconostoc or toc mesenteroides subsp. dextranicum. Eighteen ofLactobacillus. Eighty-four of the isolates were un- the Leuconostoc isolates were non-dextran-producingmistakably rod-shaped and could easily be identified isolates. All of these formed acid from sucrose,as Streptobacterium (57 isolates) or Betabacterium fructose, galactose and trehalose and were able to(27 isolates) (Harrigan and McCance, 1976). The grow at 158C and in the presence of 6.5% NaCl.ability to produce gas from Gibson’s milk (Garvie, According to the identification scheme these isolates1984) was an important characteristic for distin- could either be Leuconostoc paramesenteroides orguishing the leuconostocs. One hundred and thirty Leuconostoc mesenteroides subsp. mesenteroides.isolates belonged to the genus Leuconostoc, 103 From the 10 isolates identified with the API 50isolates to Lactococcus, 13 isolates to Streptococcus CH identification system, three belonged to theand seven isolates to Enterococcus. Members of the species Lactobacillus plantarum, two belonged togenus Lactococcus dominated in two clay pot sam- Leuconostoc citreum, two belonged to Leuconostocples, while Leuconostoc species prevailed in the lactis, one belonged to Lactobacillus delbrueckiicalabash samples. Fig. 1 illustrates the percentage subsp. lactis, and one belonged to Leuconostoc

Fig. 1. Identity of 336 bacteria isolated from indigenous traditional South African fermented milks.


dextranicum. One of the isolates could not be traditional foods are usually primitive, compared toidentified. modern ways of food preparation (Dirar, 1997).

Major risk enhancing factors are the use of contami-nated raw materials, lack of pasteurisation, use of

3.5. Detection of pathogenspoorly controlled natural fermentations and inade-quate storage and maturation conditions (Nout,

Staphylococcus aureus was isolated from fer-1994).

mented milk produced in a plastic container, clay potThe fact that no Lactococcus lactis subsp. lactis

and a calabash gourd. Salmonella species and Lis-biovar. diacetylactis and Lactococcus lactis subsp.

teria monocytogenes were not detected in any of thecremoris could be identified in this study was

samples.disappointing from both an ecological and practicalpoint of view. All the Lactococcus isolates belongedto Lactococcus lactis subsp. lactis. According to

4. Discussion other reports, Lactococcus lactis subsp. lactis wasmore frequently isolated than Lactococcus lactis

The lactic acid bacteria predominated the micro- subsp. cremoris from raw milk samples (Moreno and5bial population and numbers between 4.7 3 10 and Busani, 1990), raw milk cheeses (Centeno et al.,

92.03 3 10 were recorded with mean values of ca. 1996), Raib (Morocco) (Hamama, 1992) and Dahi8 2110 cfu ml on MRS, M17 and Rogosa agars. The and buttermilk samples from India (Padmanabha-

counts compared favourably with findings of similar Reddy et al., 1994). According to Holler and Steelestudies on fermented milks by other workers. Ac- (1995), Lactococcus lactis subsp. cremoris wascording to Stadhouders (1975) the numbers of isolated only rarely from natural sources. According

9lactococci may easily reach 10 viable units per to Crow et al. (1993) and Weerkamp et al. (1996),gram of sour milk. lactococci isolated from natural sources were usually

The dominance of mesophilic bacteria may be identified as Lactococcus lactis subsp. lactis, where-explained by the fact that 12 of the 15 samples were as the phenotype Lactococcus lactis subsp. cremoris,collected in the cooler months of May, July and which is common in industrial mixed-strain starterAugust and the ambient temperatures at which the cultures, was isolated only rarely. The natural habitatnatural fermentation of the tested samples took place of Lactococcus lactis subsp. cremoris remains uncer-probably favoured proliferation of mesophilic bac- tain (Salama et al., 1995). From 21 isolates identifiedteria. The higher counts on MRS agar (incubated at form Amazi, a fermented milk in Zimbabwe,358C) and M17 agar compared to counts on Rogosa Mutukumira (1996) found that five isolates belongedagar may be explained by the fact that MRS and to Lactococcus lactis subsp. lactis and four toM17 agars are elective while Rogosa agar is selec- Lactococcus lactis subsp. lactis biovar. diacetylactis.tive (Reuter, 1985). The fact that no Lactococcus lactis subsp. lactis

The coliforms along with the yeasts formed the biovar. diacetylactis could be detected in this studyminority groups. The high coliform count in some of may be explained by the fact that only phenotypicalthe samples was alarming when considering the tests were used for identification. LeuconostocSouth African health regulation that states that ‘‘no mesenteroides subsp. cremoris was also not encoun-person shall sell for consumption raw milk that has tered in this study. This may be explained by the factbecome sour which contains more than 50 coliform that the characteristic of citrate metabolism is en-

21bacteria ml of the product’’ (South Africa, 1997). coded on plasmid DNA, which may be lost in someAccording to Hamama (1992), Moroccan traditional strains (Cogan, 1985). Studies on 182 representativefermented dairy products like Lben and Jben showed strains of lactic acid bacteria associated with rawhigh counts of indicator micro-organisms (e.g., milk in Brazil showed Leuconostoc mesenteroidescoliforms, enterococci) and pathogens such as Sal- subsp. cremoris as a minor group, representing onlymonella spp., Yersinia enterocolitica, Listeria mono- 1.1% of the total population (Antunes and Decytogenes and enterotoxigenic Staphylococcus au- Oliveira, 1986, cited by Holzapfel and Schillinger,reus. The methods of production of the various 1992).


In the present study, three isolates were assigned of inhibitory components of the smoke used in theto the species Lactobacillus plantarum. Of the treatment of the gourds. Hosono et al. (1989) found

7 21identified 21 isolates from naturally fermented milk an appreciable number of yeasts (1.1 3 10 ml ) inin Zimbabwe (Mutukumira, 1996), three were iden- samples of Dadih, an Indonesian fermented milk,tified as Lactobacillus plantarum. From a total of which is made by pouring buffalo milk into fresh100 isolates from fermented milk in Northern Tan- bamboo tubes and capping them with banana leaves.zania, Isono et al. (1994) identified four as Lac-tobacillus plantarum. From cultured milk inCameroon, Jiwoua and Milliere (1990) identified 47 5. Conclusionout of 426 isolates as Lactobacillus plantarum.According to Daeschel et al. (1987) (cited by In this study on traditional fermented milk inOlasupo et al., 1997), Lactobacillus plantarum is South Africa it was established that the method ofknown to be commonly associated with plants. Thus, preparing cultured milk in traditional containers suchin studies on the occurrence of lactic acid bacteria, as calabashes and clay pots has diminished and isLactobacillus plantarum constituted the highest nowadays probably only practised in the most remotenumber of Lactobacillus species isolated from fer- rural areas of the country. Modern containers that aremented plant materials (Olukoya et al., 1993; readily available are replacing the calabashes andOlasupo et al., 1997). clay pots of which the fabrication and preparation is

Leuconostoc lactis was one of the main species a dying art. The availability of milk is also determin-recovered from Jben, a traditional soft cheese from ing the production of fermented milk products. TheMorocco (Hamama, 1992). Only two strains were microbiological composition of the lactic acid bac-identified as Leuconostoc lactis in our study. From teria found in the samples of traditional fermentedthe total of 72 leuconostoc isolates obtained from a milk products coincided with that of commercial

´raw cows’ milk cheese in Spain (Arzua cheese), 31 mesophilic starter cultures with regard to the domi-were identified as Leuconostoc mesenteroides, 18 as nance of lactococci and leuconostocs. However, theLeuconostoc dextranicum, 22 as Leuconostoc industrially important species of Lactococcus lactisparamesenteroides and one as Leuconostoc lactis subsp. cremoris, Leuconostoc mesenteroides subsp.(Centeno et al., 1996). The isolation of Leuconostoc cremoris and Lactococcus lactis subsp. diacetylactiscitreum from dairy products has not been reported were not encountered in the natural products. Tradi-frequently by researchers. It was, however, isolated tional fermented milk has successfully been up-from Afuega’l Pita cheese (Cuesta et al., 1996). Two graded in South Africa since the 1980s to large-scaleof the 10 isolates in our study, which were character- industrial production in the form of ‘Maas’ andised by the API 50 CH system, were Leuconostoc ‘Inkomasi’ (Keller and Jordaan, 1990). Commercialcitreum. mesophilic cultures containing Lactococcus lactis

In a parallel study on the same traditional fer- subsp. lactis, Lactococcus lactis subsp. cremoris andmented milk samples, it was found that the yeast Leuconostoc mesenteroides subsp. cremoris are

6 21counts (mean value: 4.1 3 10 cfu ml ) were being used in the production of these products. Innoticeably lower than the counts for lactic acid addition to the production of safer foods, industriali-bacteria (Loretan, 1999). Other researchers inves- sation has further advantages such as standardisedtigating fermented milk products reported varying products (Reilly and Westby, 1997), reduced pro-amounts of yeasts and moulds present in those cessing times, increase in the production of tradition-products. The presence of yeasts may be influenced al dairy products as well as better distribution andby the age of the product as well as the containers marketing (Hamama, 1992).and processing methods used. In the production of According to Hughson (1995), traditional fer-Iria ri Matii in Kenya, glowing splints of wood are mented milk has been commercialised in Southused to scratch the inside of the gourd. This process Africa with an estimated production of 60 000is repeated until the inside is smooth and even. The kilolitres in 1995. She also stated that there was alow counts of yeasts reported by Kimonye and scarcity of new product development for fermentedRobinson (1991) may be explained by the presence dairy products targeted at the black consumer mar-


Fehr, W., 1968. Ludwig Alberti’s Account of the Tribal Life andket. Ideas for new products may come as a develop-Customs of the Xhosa in 1807. A.A. Balkema, Cape Town, 22ment from existing ones or from re-discovering oldpp.

ones (Marshall, 1986). The knowledge behind the Fox, F.W., 1939. Some Bantu recipes from the Eastern Capeproduction of traditional products has dwindled and Province. Bantu Studies XIII (1), 65–74.

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future developments, but also gives insight into the 16. Academic Press, London, pp. 147–178.importance of this highly appreciated product for Gerhardt, P., Murray, R.G.E., Costilow, R.N., Nester, E.W., Wood,their consumers. W.A., Krieg, N.R., Phillips, G.B., 1981. Manual of Methods

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