toxoflavin (Figure 9.18). Since 1951, at least 1000 people are known to
have died as a result of this intoxication and in 1988 the Indonesian
Government prohibited the production of tempeh bongkrek.
Two factors are thought to give rise to this problem. Reduction or
omission of an initial soaking of the presscake may fail to give a lactic
fermentation sufficient to reduce the pH below 6, a level at which the
bacterium cannot grow. Also, the fungal inoculum may be too small
since it has been shown thatB. cocovenenanscannot grow ifRhizopus
oligosporushas more than a tenfold numerical superiority (estimated by
plate counts).
Ontjom is a tempeh-like product produced in Indonesia from peanut
presscake which normally has a fruity/mincemeat character. It can be
produced using the tempeh mould butNeurospora intermediais also often
used. This mould has stronga-galactosidase activity which can further
contribute to the reduction of flatulence-inducing oligosaccharides.
9.12.2 Soy Sauce and Rice Wine
Though they are markedly different in character, rice wine and soy sauce
share sufficient common features in their production to warrant discuss-
ing them together. Both are representatives of products which involve
mould activity in a two-stage fermentation process. The mould starter
used is often known askoji, a Japanese term derived from the Chinese
character for mouldy grains. In thekojistage, aerobic conditions allow
moulds to grow on the substrate producing a range of hydrolytic
Figure 9.18 Toxoflavin and bongkrekic acid
Chapter 9 365