49
4.4.2.9 Mycology of Sufu
The fungal family involved in sufu formation is Mucoraceae. The most common
genera involved in Sufu formation are Actinomucor, Mucor and Rhizopus. Some of
the mycelial fungal species involved in furu production across China and neighbouring countries like Vietnam are Mucor racemosus, Mucor circinelloides, Mucor
hiemalis, Actinomucor repens, Rhizopus microsporus var. microsporus and
Actinomucor taiwanensis (Han et al. 2004). The mould used in pehtze formation is
crucial and must possess certain characteristics to be an effective producer. Firstly,
these moulds should have an efficient enzymatic system having high lipolytic and
proteolytic activities as the raw substrate provided for pehtze formation is rich in
lipid and protein and poor in carbohydrates. Secondly, the density of mycelial mat
should be such that it should act as a protective layer for the final product of sufu.
Another characteristic which these moulds should possess is the soothing colour of
the mycelium in order to impart attractive colour to the product. Excess growth of
these moulds during fermentation might result in off-odour, accumulation of mycotoxins and bacterial contamination which can adversely affect the quality of product.
The temperature that can be used for the growth of the above-mentioned mould
responsible for sufu formation is 20–30 °C. According to the studies carried out by
Han et al. in 2003, it was found that the optimum relative humidity required for
pehtze formation was about 95–97%. The activity of β-glucosidase purified from
Actinomucor elegans is affected by the change in incubation temperature of the
mould (Yin et al. 2005). Actinomucor elegans and Actinomucor taiwanensis were
found to be the best-suited moulds for pehtze development commercially in Beijing
and Taiwan, respectively. Other popular starter cultures for furu development are
Mucor sufu and Mucor wutongqiao (Han et al. 2004). Since these moulds grow well
at 20–30 °C, it becomes really difficult to produce furu in hot summer. For the ease
of furu production round the year, researchers screened several mutants produced
using traditional mutagens and found they were capable of isolating Mucor sp. M 263
and Mucor sp. H 4 surviving at 30–40 °C (Deng et al. 1996; Hu and Zhao 1998).
4.4.2.10 Manufacturing Process
Earlier, sufu was prepared in every household of China and Japan using the process
of natural fermentation. This is still in practice in some parts of China such as
Jiangsu and Zhejiang (Wang and Du 1998). Nowadays, furu is being produced at a
large scale in industries following the same principle as that of traditional method.
The basic steps involved in furu formation have been shown schematically in
Fig. 4.2.
4 Fungi in Food Bioprocessing
4.4.2.9 Mycology of Sufu
The fungal family involved in sufu formation is Mucoraceae. The most common
genera involved in Sufu formation are Actinomucor, Mucor and Rhizopus. Some of
the mycelial fungal species involved in furu production across China and neighbouring countries like Vietnam are Mucor racemosus, Mucor circinelloides, Mucor
hiemalis, Actinomucor repens, Rhizopus microsporus var. microsporus and
Actinomucor taiwanensis (Han et al. 2004). The mould used in pehtze formation is
crucial and must possess certain characteristics to be an effective producer. Firstly,
these moulds should have an efficient enzymatic system having high lipolytic and
proteolytic activities as the raw substrate provided for pehtze formation is rich in
lipid and protein and poor in carbohydrates. Secondly, the density of mycelial mat
should be such that it should act as a protective layer for the final product of sufu.
Another characteristic which these moulds should possess is the soothing colour of
the mycelium in order to impart attractive colour to the product. Excess growth of
these moulds during fermentation might result in off-odour, accumulation of mycotoxins and bacterial contamination which can adversely affect the quality of product.
The temperature that can be used for the growth of the above-mentioned mould
responsible for sufu formation is 20–30 °C. According to the studies carried out by
Han et al. in 2003, it was found that the optimum relative humidity required for
pehtze formation was about 95–97%. The activity of β-glucosidase purified from
Actinomucor elegans is affected by the change in incubation temperature of the
mould (Yin et al. 2005). Actinomucor elegans and Actinomucor taiwanensis were
found to be the best-suited moulds for pehtze development commercially in Beijing
and Taiwan, respectively. Other popular starter cultures for furu development are
Mucor sufu and Mucor wutongqiao (Han et al. 2004). Since these moulds grow well
at 20–30 °C, it becomes really difficult to produce furu in hot summer. For the ease
of furu production round the year, researchers screened several mutants produced
using traditional mutagens and found they were capable of isolating Mucor sp. M 263
and Mucor sp. H 4 surviving at 30–40 °C (Deng et al. 1996; Hu and Zhao 1998).
4.4.2.10 Manufacturing Process
Earlier, sufu was prepared in every household of China and Japan using the process
of natural fermentation. This is still in practice in some parts of China such as
Jiangsu and Zhejiang (Wang and Du 1998). Nowadays, furu is being produced at a
large scale in industries following the same principle as that of traditional method.
The basic steps involved in furu formation have been shown schematically in
Fig. 4.2.
4 Fungi in Food Bioprocessing