This review article summarizes research on tempeh, a fermented soybean food. Tempeh is high in protein, fiber, vitamins, and minerals. It is fermented using Rhizopus mould, which improves digestibility and nutrient availability. Fermentation also produces compounds that inhibit pathogens and cancer growth while promoting heart, bone and digestive health. Tempeh is widely consumed as a low-cost, nutritious meat substitute and its production can be improved through modern sanitary methods and controlled microbial cultures. Overall, tempeh provides various health benefits and is a staple food for many populations.

1. World Journal of Dairy & Food Sciences 4 (1): 22-27, 2009
ISSN 1817-308X
© IDOSI Publications, 2009
A Low Cost Nutritious Food “Tempeh”- A Review
1
P. Dinesh Babu, 2R. Bhakyaraj and 2R. Vidhyalakshmi
1
Department of Biotechnology, Anna University, Tiruchirapalli - 620 024, Tamilnadu, India
2
Indian Institute of Crop Processing Technology, Thanjavur - 613 005, Tamilnadu, India
Abstract: A variety of indigenous fermented foods exist today; however, tempeh has been one of the most
widely accepted mold-modified fermented products. Tempeh is a popular fermented food in Indonesia which
is rich in nutrients and active substances. Recently, the consumption of Tempeh has been increasing rapidly,
not only in Indonesia but also in the United States and Europe. Although Tempeh is not likely to be exported,
the product is consumed and produced in many countries. This paper reviews the significance of soybean
fermentation in tempeh on the vitamins, amino acids, Nutritional quality, functional and physico-chemical
properties.
Key words: Soy protein % Meat replacer % Fermentation % Functional Properties
INTRODUCTION or nutritive value [8]. Heseltine et al. [9] isolated
many fungi from different lots of tempeh made in
Tempeh is a fermented product made from soybeans Indonesia and found that only Rhizophus could make
that have been soaked and cooked to soften them [1]. Like tempeh in pure culture fermentation. They also found that
sour dough bread, tempeh requires a starter substance, the 40 strains of Rhizophus studied, 25 of them are
which is added to the cooked beans. This mixture is left R.oligosporus others are R.stolonifier,
for 24 hours and the result is a firm textured product with R.arrhizus.R.oryzae, R.formosaensis and.This finding was
a somewhat nutty flavor and a texture similar to a chewy also confirmed by Saono et al [10], who isolated 118
mushroom. Because Tempeh is firm and it can be formed cultures from 81 tempeh samples collected from markets in
into a patty, it is used as a substitute for animal products various parts of Indonesia.
in what in the West is typically called as "mock" burgers Mulyowidarso et al [11] also reported variable
or sandwiches [2]. This soya product is especially popular growth of bacteria during fermentation of soybeans into
in Indonesia and is considered a national specialty. It has tempeh with R.oligosporus. Liem et al. [12] first reported
the necessary characteristics of a dietary staple in that is that Klebsiella pneumonia was responsible for the
high in protein and fiber and is rich in other nutrients. It production of vitamin B12 in commercial tempeh.Yeasts
also has the advantage of containing Vitamin B-12, which are frequently detected in tempeh, but their role is still
is a by-product of the fermentation process [3]. In this unknown [13]. Rhizopus moulds produce natural, heat-
paper the research work carried out on tempeh stable antibiotic agents against some disease-causing
fermentation and tempeh based products is reviewed. organisms. Indonesians who eat tempeh as a regular part
of their diet recognize it as a medicine for dysentery and
Role of Microorganisms in Tempeh Production: The type rarely fall victim to the intestinal diseases to which they
of microorganisms involved in tempeh production has are constantly exposed [14]. All these workers agree on
been reported by many workers [4, 5]. Tempeh is the the fact that Soybean fermentation in tempeh is mainly
result of mixed culture fermentation by a diverse group of Rhizophus oligosporus dependent.
microorganisms including moulds, yeasts, lactic acid
bacteria and different gram-negative bacteria [6]. Process of Tempeh: The process involved in Tempeh
Rhizopus oligosporus is the dominant tempeh production differs from each and everyone reported their
fungus [7] although some other moulds, such as R. oryzae process based on various factors. The overall production
and Mucor spp, may also contribute to the flavour, texture method is followed by flowchart representation [15, 5].
Corresponding Author: R.Vidhyalakshmi, Scientist Indian Institute of Crop Processing Technology, Thanjavur-613 005 (TN), India
22

2. World J. Dairy & Food Sci., 4 (1): 22-27, 2009
In addition to oxygen, the mould grows better in
high humidity levels (75-78%). However, no liquid water
should be in contact with the beans [17]. The ideal
temperature for Rhizopus growth is 37°C, so the trays of
beans are best kept at this temperature. During the phase
of active mould growth, however, the temperature of the
beans will naturally rise above the ambient temperature.
Temperatures of up to 49°C were measured, where further
mould growth was inhibited by this high temperature. It
was found that keeping the temperature below 415°C and
above 25 °C was sufficient for satisfactory mould growth,
although at 25 degrees Celsius, fermentation takes 5 days,
which is 5 times as long as the time it takes to ferment at
37°C [5].
Stages of Fermentation: Steinkraus et al [6] reported that
the initial few hours after inoculation, germination of
Production Processes of Soybean Tempeh spores takes place. Slow mould growth takes place for
Principles of Tempeh Production: Although the principle several hours after the germination phase. Later, rapid
step in making tempeh is the fermentation of soybeans by mould growth and temperature increase continues for 4 to
Rhizopus mould, many factors affect the success in 5 hours. As mould growth declines, the beans should be
production and the quality of the product. In the method
bound into a solid mass by the mycelium. After mould
employed by Steinkraus et al [16] raw, dried soybeans are
growth declines, sporulation and ammonia production due
hydrated by soaking in cold water overnight or for a
to protein breakdown appears.
shorter period of time if warm water is used. Lactic acid or
Beuchat [18] reported that the pH level on the beans
acetic acid is added to the water to lower the pH of the
also changes as mould growth occurs. From an initial pH
solution and soybeans to 5 or below. This step is
of 5.0, the pH level reaches 6.0 to 6.7 during the peak of
performed to discourage growth of undesired
mould growth and continues to increase to 7.6 as time
microorganisms.
passes. It was found that the tempeh is most palatable
The Rhizopus mould is largely unaffected by the
when the pH is between 6.3 and 6.5. This is the same time
acidic environment. It was found that mould growth rate
that the mould overgrows the soybean cotyledons. In
remained stable as long as the pH is at or above 3.5 and
short, two characteristic events from mould growth need
was slightly slower when the beans were more acidic.
to take place for the fermented soybeans to become
After hydration, the skins on each bean are removed to
encourage better growth of the mould. This step can be tempeh. Firstly, the individual beans will be bound into a
done by rubbing the beans together with hands or by solid cake by the mould mycelium. Secondly, the
other mechanical means. The skinned beans are then soybeans become partially digested by the mould
partially cooked by boiling them in the acidic soaking enzymes.
water at 100 °C for 90 minutes.
When the beans have cooled to 37-38 °C, the ideal Anti-microbial Effects of R. Oligosporus: R. oligosporus
temperature to begin the inoculation and the beans have can inhibit the growth and aflatoxin B1 accumulation of
been dried, the Rhizopus starter culture is mixed to the Aspergillus flavus and A. parasiticus [19]. R. oligosporus
beans. Sufficient amounts of the culture, or inoculums, has been reported to produce 4 to 5 anti-bacterial
needs to be present. In the 1960 study by Steinkraus et al, compounds during soybean tempeh fermentation [20-22].
the inoculums were added at 1 gram per kg of cooked The fungus also produces phenolic compounds that
soybeans. The inoculated beans are then placed on inhibit the growth of pathogenic bacteria such as
covered trays, in a layer no thicker than 2 inches, so that Helicobacter pylori [23-27].
sufficient oxygen is available on the bean surfaces for An antibacterial protein has been purified from
mould growth. Small holes in the trays are also beneficial R. oligosporus, with activities against Bacillus spp.
in ensuring sufficient oxygen supply. (especially against Bacillus subtilis), Staphylococcus
23

3. World J. Dairy & Food Sci., 4 (1): 22-27, 2009
aureus and Streptococcus cremoris [28]. R. oligosporus Health Benefits of Tempeh: Soy's key health benefits are
can also produce certain compounds that interfere with related to its excellent protein content, its high levels of
the adhesion of E. coli to small intestinal brush-border essential fatty acids, numerous vitamins and minerals, its
membranes [29]. isoflavones and its fibre. Recent reports suggest that
tempeh contains a wealth of nutrients that are tied to an
Preservation of Tempeh: Freshly made, raw Tempeh impressive array of health benefits, including decreased
remains edible for a few days at room temperature. The risk of heart disease and strokes, osteoporosis, cancer
tempeh is neither acidic nor does it contain large amounts and digestive disorders, losing excess weight in addition
of alcohol. Tempeh does, however, possess stronger to easing some of the symptoms of menopause.
resistance to lipid oxidation than unfermented soybeans,
due to its antioxidant contents [17]. Traditionally, fresh Soy Protein and Cardiovascular Disease: Krumhar and
Kim Carleton [32] reported that Considerable evidence
tempeh is preserved by sun-drying, but modern methods
supports a role for soy protein in reducing the risk of
are faster and reduce the risk of contamination. In the
cardiovascular disease, the number one killer of adults.
study by Steinkraus et al [16] the tempeh were preserved
Soy products are free of the saturated fat implicated in
by quick freezing (-15 °C) and lyophilisation, or by drying
many health problems and particularly heart related
in a circulating hot air oven at 69°C. Deep fat frying is
problems. Soy products appear to lower total blood
another possible preservation method for tempeh. cholesterol and LDL levels at about the same rate as
Biotechnology improved the inoculum, which makes decreasing fat in the diet. The U.S.A. Food and Drug
a Tempe variant possible that may be protected by an Administration states that: "25 grams of soy protein a day
international patent [30].Modern processing methods as part of a diet low in saturated fat and cholesterol may
mainly entail improving equipment needed, maintaining a reduce the risk of heart disease".
sanitary and hygienic environment, creating an inoculum
by selected microorganisms and modernizing the methods Soy Protein and Bone Health: Messina and Messina [33]
of packaging [31]. reported isoflavones in soybean increase the bone mineral
content of postmenopausal women, decreasing the
Nutritional Information: The nutritional and functional possibility of osteoporosis. Good bone health throughout
characteristics of fermented soybean have been examined life helps prevent osteoporosis, a major cause of disability
and reported. in later years. Research suggests that consuming soy
protein may help protect bones from becoming weak and
Tempeh is: brittle, especially for post-menopausal women whose risk
of osteoporosis is increased.
C An excellent source of protein, contains all the
essential amino acids; same quality protein as meat or
poultry.
C Excellent source of calcium.
C Low in saturated fat
C High in essential fatty acids & B vitamins
C Cholesterol free.
C High in soluble dietary fiber.
C Fermentation neutralizes the phytate acid present in
the soybeans; therefore tempeh does not restrict the
body’s absorption of minerals.
C Easy to digest because the fermentation process
breaks down the complex proteins found in
soybeans, making tempeh more easily digested than
non-fermented soy foods or whole soybeans.
C High in isoflavones.
C A good source of folic acid.
C Low in sodium.
24

4. World J. Dairy & Food Sci., 4 (1): 22-27, 2009
Table 1:
Raw materials Organisms References
Legumes
Soybeans (Glycine max) R.oligosporus Nout et al [40], Varzakas [41]
Black gram (Phaseolus mungo) R.oligosporus Jha and Verma [42]
Cereals
Barley (Hordeum vulgare) R.oligosporus Nout and Rombouts[2],Hachmeister and Fung[15],Berg et al., [43]
Wheat (Triticum vulgare) R.oligosporus Hesseltine and Wang [44] Nout and Rombouts[2], Hachmeister and Fung[15]
Sprouted Broken rice R.oligosporus Dinesh [45]
Mixture of legumes with nonlegumes
Sesame and soybean R.oligosporus Shurtleff and Aoyagi [14]
Maize and soybean R.oligosporus Nout and Kiers [5]
Press cake (by-products)
Soybean residue from soy milk preparation or okara R.oligosporus Ko Swan and Hesseltine[46], Matsuo [47]
Groundnut presscake (Arachis hypogaea) R.oligosporus Gandjar [48]
Soy Protein and Cancer: Badger et al [34] reported that Some substrates can only be processed to obtain high
soy protein may have a role in reducing the risk of certain quality tempeh by combining them with soybeans
cancers, particularly breast, colon and prostate cancer. [21, 39, 14].
Weight Loss: Yee Kaye [35] reports that fat levels are CONCLUSION
known to lead to increased risk of several diseases,
including heart disease, stroke, bone fractures, breast Tempeh provides the staple food for a large
cancer and other cancers. Research studies have population in Indonesia and Malaysia. Soybeans are the
documented two key properties of soy protein that primary ingredient in many processed foods, including
help with weight loss independent of its low-calorie and dairy product substitutes. It is commonly consumed by
low-carbohydrate content. The studies show that poor masses of many countries and it forms a major
consumption of soy protein contributes to weight loss by source of proteins and calories. Now it is also made in
decreasing the amount of fat your body stores while modern, sanitary plants, using stainless steel equipment
increasing lean muscle mass. and sometimes, pure cultures of mould. Fermentation of
soybean improves digestibility by reduction of anti-
A Healthy Transition Through Menopause: D Lee Alekel nutritional factors: tannin and phytase in addition to
et al [36] reported that soy products appear to decrease production of acids which inhibit the production of
the symptoms of menopause, especially hot flashes. pathogenic bacteria and this is particularly important in
the manufacture of food designated for special targeted
A Health-Promoting Meat Replacer: Adisak Akesowan groups such as infants and old aged ones. Tempeh is a
[37] reported that the soy products are excellent vegetable low cost nutritious food and can consume by all socio-
sources of protein. Many current health recommendations economic groups.
suggest limiting animal protein, so substituting tempeh
for chicken, beef, or pork makes sense. Most of the REFERENCES
non-vegetarians started to consume soy protein Tempeh
instead of meat. 1. Astuti, M., A. Meliala, F.S. Dalais and
M.L. Wahlqvist, 2000. Tempe, a nutritious and
Mild for Kidney: Pedraza Chaverrí [38] reported that the healthy foodfrom Indonesia. Asia Pacific Journal of
people with reduced kidney function--such as those with Clinical Nutrition, 9: 322-325.
diabetes who have nephropathy--can benefit by replacing 2. Nout, M.J.R. and F.M. Rombouts, 1990. Recent
animal protein with soy. developments in Tempe research. Journal of Applied
Bacteriology, 69: 609-633.
Tempeh Based Products: Traditionally, tempeh was 3. Irene, T., H. Liem, Keith H. Steinkraus and Ted C.
made from soybean. Yellow-seeded soybeans are Cronk, 1977. Production of Vitamin B-12 in Tempeh, a
usually preferred as raw material [7], but many different Fermented Soybean Food. Applied and
substrates can be used to produce tempeh (Table 1). Environmental Microbiology, pp: 773-776.
25

5. World J. Dairy & Food Sci., 4 (1): 22-27, 2009
4. KO Swan, D. and C.W. Hesseltine, 1979. Tempe and 18. Beuchat, L.R., 2001. Traditional fermented foods.
related foods. Economic Microbiology, 4: 115-140. In Food Microbiology. Edited by L.R.B. Michael
5. Nout, M.J.R. and J.L. Kiers, 2005. Tempe P. Doyle, Thomas J. Montville. ASM press, American
fermentation, innovation and functionality: update Society for Microbiology. Washington, DC. pp:
into the third millennium. Journal of Applied 701-719.
Microbiology, 98: 789-805. 19. Nout, M.J.R., 1989. Effect of Rhizopus and
6. Steinkraus, K.H., R.E. Cullen, C.S. Pederson, Neurospora spp. on growth of Aspergillus flavus and
L.F. Nellis and B.K. Gavitt, 1983. Indonesian A. parasiticus and accumulation of aflatoxin B1 in
tempeh and related fermentations. In Handbook of groundnut. Mycological Research, 93: 518-523.
indigenous fermented foods. Edited by.KH. 20. Anon, M.C., 1969. Tempeh: protein-rich food may
Steinkraus, R.E. Cullen, C.S. Pederson, L.F. Nellis & increase disease resistance. Agricultural Research
B.K. Gavitt. New York,Marcel Dekker. pp: 1-94. (Washington) 17, 5.
7. Sharma, R. and A.K. Sarbhoy, 1984. Tempeh-a 21. Wang, H.L., D.I. Ruttle and C.W. Hesseltine, 1969.
fermented food from soybean. Current Science, Antibacterial compound from a soybean Product
53: 325-326. fermented by Rhizopus oligosporus. Proceedings of
8. Wiesel, I., H.J. Rehm and B. Bisping, 1997. the Society for Experimental Biology and Medicine,
Improvement of tempe fermentations by application 131: 579-583.
of mixed cultures consisting of Rhizopus sp. and 22. Nowak, J. and K.H. Steinkraus, 1988. Effect of tempeh
bacterial strains. Applied Microbiology and fermentation of peas on their Potential flatulence
Biotechnology, 47: 218-225. productivity as measured by gas production and
9. Hesseltine, C.W., M. Smith, B. Bradle and K.S. Djien, growth of Clostridium perfringens. Nutrition Reports
International, 38: 1163-1171.
1963. Investigations of tempeh, an Indonesian food.
23. McCue, P., A. Horii and K. Shetty, 2003. Solid-state
Developments in Industrial Microbiology, 4: 275-287.
bioconversion of phenolic antioxidants fromDefatted
10. Saono, S., H. Karsono and D. Suseno, 1976. Ann
soybean powders by Rhizopus oligosporus: Role of
bogor. VI: 83-95.
carbohydrate-cleavingenzymes. Journal of Food
11. Mulyowidarso, R.K., G.H. Fleet and K.A. Buckle,
Biochemistry, 27: 501-514.
1990. Association of bacteria with the fungal
24. Correia, R.T.P., P. McCue, M.M.A. Magalhaes, G.R.
fermentation of soy bean Tempe. J. Appl. Bacteriol.,
Macedo and K. Shetty, 2004a. Production of
68: 43-47.
phenolic antioxidants by the solid-state
12. Liem, I.T.H., K.H. Steinkraus and T.C. Cronk, 1977.
bioconversion of pineapple waste mixed with
Production of vitamin B-12 in tempeh fermented
soy flour using Rhizopus oligosporus. Process
soybean food. Applied and Environmental
Biochemistry, 39: 2167-2172.
Microbiology, 34: 773-776.
25. Correia, R.T.P., P. McCue, D.A. Vattem,
13. Samson, R.A., J.A.V. Kooij and E.D. Boer, M.M.A. Magalhaes, G.R. Macedo and K. Shetty,
1987. Microbiological quality of commercial tempeh 2004b. Amylase and Helicobacter pylori inhibition
in the Netherlands. Journal of Food Protection, by phenolic extracts of pineapple wastes
50: 92-94. bioprocessed by Rhizopus oligosporus. Journal of
14. Shurtleff, W. and A. Aoyagi, 2001. The Book of Food Biochemistry, 28: 419-434.
Tempeh, 2nd edition. Pgs 48-50, 103-113. 26. McCue, P., Y.T. Lin, R.G. Labbe and K. Shetty, 2004.
15. Hachmeister, K.A. and D.Y.C. Fung, 1993. Tempeh: a Sprouting and solid-state bioprocessing by Rhizopus
mold-modified indigenous fermented food made from oligosporus increase the in vitro antibacterial activity
soybeans and/or cereal-grains. Critical Reviews in of aqueous soybean extracts against Helicobacter
Microbiology, 19: 137-188. pylori. Food Biotechnology, 18: 229-249.
16. Steinkraus, K.H., B.H. Yap, J.P. Van Buren, M.I. 27. Vattem, D.A., Y.T. Lin, R.G. Labbe and K. Shetty,
Provvidenti and D.B. Hand, 1960 Studies on tempeh 2004. Antimicrobial activity against select food-borne
an Indonesian fermented soybean food. Food Res., pathogens by phenolic antioxidants enriched in
25: 777. cranberry pomace by Solid-state bioprocessing using
17. Farnsworth, Edward R. Handbook of Fermented the food grade fungus Rhizopus oligosporus. Process
Functional Foods. CRC Press, 2008. Biochemistry, 39: 1939-1946.
26

6. World J. Dairy & Food Sci., 4 (1): 22-27, 2009
28. Kobayasi, S.Y., N. Okazaki and T. Koseki, 1992. 38. Pedraza-Chaverrí, J., D. Barrera, R. Hernandez-Pando,
Purification and characterization of an antibiotic O.N. Medina-Campos, C. Cruz, F. Murguía, C. Juárez-
substance produced from Rhizopus oligosporus IFO Nicolás, R. Correa-Rotter, N. Torres and AR. Tovar,
8631. Bioscience, Biotechnology and Biochemistry, 2004. Soy protein diet ameliorates renal nitrotyrosine
56: 94-98. formation and chronic nephropathy induced by
29. Kiers, J.L., M.J.R. Nout, F.M. Rombouts, puromycin aminonucleoside-Life Sciences, pp:
M.J.A. Nabuurs and J. van der Meulen, 2002. 987-99.
Inhibition of adhesion of enterotoxigenic Escherichia 39. Mugula, J.K., 1992. Evaluation of the nutritive value
coli K88 by soya bean Tempe. Letters in Applied of maize-soybean Tempe as a potential Weaning food
Microbiology, 35: 311-315. in Tanzania. International Journal of Food Sciences
30. Adnan, M. and Sudarmadji, 1997. Contribution of and Nutrition, 43: 113-119.
tempeh for the economy and health of Indonesian. 40. Nout, M.J.R., M.A.D. Dreu, A.M. Zuurbier and
Proceedings International Tempe Symposium, July T.M.G. Bonants van Laarhoven, 1987c. Ecology of
13-15, Bali, Indonesia. controlled soybean acidification for Tempe
31. Kuswanto, Kapti Rahayu, 2004. Industrialization of manufactures. Food Microbiology, 4: 165-172.
Tempe Fermentation, in Steinkraus, K.H. (Ed). 41. Varzakas, T., 1998. Rhizopus oligosporus mycelial
Industrialization of Indigenous Fermented Foods; penetration and enzyme diffusion in soya bean
2nd ed. pp: 587-635, Marcel Dekker, Inc., New York. Tempe. Process Biochemistry, 33: 741-747.
32. Krumhar and Kim Carleton. 2005. Method for 42. Jha, K. and J. Verma, 1980. Removal of flatulence
treatment of inflammation and pain in mammals. principles from legumes by mold fermentation. Indian
United States Patent, 424/601. Journal of Experimental Biology, 18: 658-9.
33. Messina M. and V. Messina, 2000. Soy foods, 43. Berg, S., J. Olsson, M. Swan berg,, J. Schnauzer and
soybean isoflavones and bone health: a brief A. Eriksson, 2001. Method for theproduction of
overview. J. Renal. Nutr., 10: 63-68. fermented cereal food products and products thereof.
34. Thomas M. Badger, J.J. Martin Ronis, C.M. Rosalia In World IntellectualProperty Organization. Sweden:
Simmen and Frank A.Simmen, Vattem. 2005. Soy Olligon AB.
Protein Isolate and Protection against Cancer. 44. Hesseltine, C.W. and H.L. Wang, 1980. the
Journal of the American College of Nutrition, importance of traditional fermented foods. Bioscience,
24(2): 146S-149S. 30: 402-404.
35. Yee K. Kaye, Azhar Mat Easa and Noryati Ismail. 45. Dinesh Babu, P., 2009. Designing a low cost
2001. Reducing weight loss of retorted soy Protein nutritious antioxidant food using Rhizophus
tofu by using glucose- and microwave-pre-heating oligosporous. Thesis submitted for the award of
treatment.International Journal of Food Science & Bachelor of Technology in Biotechnology to
Technology, 36(4): 387-392. Bharathidasan University.
36. D Lee Alekel, Alison St Germain, Charles T Peterson, 46. KO Swan, D. and C.W. Hesseltine, 1979. Tempe and
Kathy B Hanson, Jeanne W Stewart andToshiya related foods. Economic Microbiology, 4: 115-140.
Toda. 2000. Isoflavones-rich soy protein isolate 47. Matsuo, M., 1990. Suitability of 'okara tempe' as
attenuates bone loss in the lumbar spine of foodstuff. Nippon Nogeikagaku Kaishi, 64: 1235-1236.
perimenopausal women. American Journal of Clinical 48. Gandjar, I., 1981. Soybean fermentation in Indonesia.
Nutrition, 72(3): 844-852. In The 6th international fermentation Symposium,
37. Adisak Akesowan, 2007. Effect of a Konjac Flour / Edited by M.a.R. Young, C. W. London, UK:
Soy Protein Isolate Mixture on Reduced-fat, Added Pergamon Press. pp: 531-534.
Water Chiffon Cakes. AU J.T. 11(1): 23-27.
27