Creative Fermentation Technology for the Future

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Creative Fermentation Technology for the Future

Cherl-Ho Lee

Graduate School of Biotechnology, Korea University

Seoul, 136-701 Korea

Introduction

Fermentation technology is one of the oldest food technology applications

that has been developed and utilized for survival. The origin of Asiatic

fermentation technology evolved as early as the littoral foragers period of the

Primitive Pottery Age (8,000-3,000 B.C.), which led the Neolithic culture of

agriculture in the Northeast Asia. The importance of Primitive Pottery Age for

the dietary culture of the region was discussed during the 11th IUFoST World

Congress in Seoul (Lee, 2001a). Fermentation technology has developed

indigenously all around the world by using natural products from the respective

region to produce required food materials, from which the characteristic taste

and aroma of each cultural society have been made. Steinkraus(1993) classified

fermentation technology of the world which is responsible for man’s survival

into six groups: alcoholic, lactic acid, leavened breads, meat substitutes, meat

flavored sauces/pastes and protein/flavoring agents fermentation.

The meat eating habit of Western culture needed food preservation technology

in order to keep their perishable meat and milk edible for longer period. Meat

sausage, cheese and acid fermented milk making were important food preservation

technology methods until the time when refrigerators were available in homes. On

the other hand, people who ate cereals as staple food in the East wanted to have

meaty flavored and salty condiments, which make the bland taste cereal foods

more palatable. This demand led Asian people to develop soybean sauce and fish

sauce fermentation technology.

Consumer perception of food has changed through history. Until the 20th

century, the food situation of the world was always problematic. Food shortage

could occur any time even in the affluent societies. Therefore, man mostly lived

for food, and we may call this earlier period the “survival food age.†In

the 20th century access to food no longer was a problem in most of the affluent

societies, but time was short for work and leisure. People wanted to save time

cooking and obtaining food. Consequently convenience food became the major item

in the food market. Now, we all notice that the 21st century is the

“functional food era.†Health oriented food and nutraceuticals are major

concerns of today’s consumer.

Fermentation technology has adapted itself to social demands. During the

survival food age, fermentation was used mainly for food preservation and

condiments production. In the convenience food age, it was used for flavor

production and other ingredients for industrial mass production of food. The

21st century is called the era of tailor made goods satisfying personal demands,

and together with the health benefit demands, fermentation technology finds new

challenges in the market. Many of the traditional fermented foods are receiving

new attention for their health promoting or disease preventing/curing effects.

Scientific evidences for their physiological functions are accumulating and the

technologies enhancing the beneficial effects are developing rapidly by using

modern biotechnological and genetic engineering techniques. Some of the recent

developments and future prospects are discussed below.

Lactic acid fermentation for probiotics

Yogurt and sour milk products are well known in Western society as probiotic

food. Similar products made with rather inexpensive raw materials are found in

many indigenous fermented foods around the world. Korean Kimchi is one of the

examples. It is made from vegetables lightly salted (ca. 3%) and fermented by

lactic acid bacteria, mainly Leuconostoc mesenteroides. The lactic acid bacteria

grown in kimchi could survive in gastric acid and bile juice reaching to the

large intestine (Lee 1997). More important is that kimchi contains various

functional components either originated from the ingredients or formed during

fermentation as shown in Table 1. The same beneficial effects can be expected

from African cereal gruels like ogi and uji, Nigerian gari, and Asian vegetable

foods like dhamuoi in Vietnam, dakguadong in Thailand and burong mustala in the

Philippines and acid fermented seafoods mixed with cereals (Lee 1994). In

addition to the probiotic effect, these vegetable products have excellent

prebiotic function.

Combining Western milk fermentation technology and Eastern cereal processing

skills led to the creation of fusion foods like soybean yogurt and rice yogurt.

Risogurt is an example of lactic acid fermented vegetable drink studied in Korea

made from the mixture of rice and soybean protein (Mok,1994). Many of the

vegetable yogurt products are found in markets of USA and Japan.

The antimicrobial activity of some lactic acid bacteria against Helicobacter

pylori, which is known to cause stomach cancer, is well applied to acid

fermented milk beverages and highly accepted by the consumer in Korea (Park et.

al. 2001). Anti-diarrhea effect of lactic acid bacteria like Lactobacillus

acidophilus is enhanced by protein coating (Chung et al. 2001). The freeze dried

bacterial cells coated with protein are added to food for preventing diarrhea

and other health benefits, and this market is increasing rapidly.

Soybean fermentation for cancer and degenerative disease prevention

The physiological function and health benefit of soybean is widely

recognized today. The blood cholesterol level reduction activity of soybean

protein and its hydrolysate and the pseudoestrogenic effect of soybean

isoflavones are experimentally proved. In addition to flavor formation, soybean

fermentation increases the digestibility and the nutritional value, and also

produces health benefit functional compounds (Lee 2001b).

Soybean fermentation for soybean sauce and paste, Korean chongkukjang and

Japanese natto production involve the process of enzymatic hydrolysis of protein

to make peptides and amino acids. Some peptides in soybean sauce and paste are

known to have ACE inhibition, antithrombotic and anti-cancer effects(Shin et.

al. 1995, Shon et. al. 1996, Kim 1995). Fermentation with molds, Aspergillus and

Rhizopus, converts glycoside form of isoflavones, daidzin and genistin, to

aglycones, which have higher potency of estrogenic effect. Production of mucous

polysaccharides and enzyme kinase during bacterial (Bacillus) fermentation of

soybean is related to the fibrinolytic and immune modulating activity of

chongkukjang and natto (Lee et.al. 1991, Sumi et.al. 1987). By enforcing these

components through molecular breeding of the microorganisms involved and novel

fermentation skills and improved downstream processes, numerous health oriented

food products are produced and also under trial in East Asia and will be

launched to the world market in near future.

The advantage of mixed culture fermentation

Industrial yogurt production in the West and soybean sauce production in the

East were achieved by purely isolated starter culture techniques. However, many

of the traditional fermentation starters in the East are naturally fermented

mixed culture system. The consumer in their taste and aroma often prefers the

traditional fermented products made by the naturally fermented starter culture.

The deep and bountiful aroma of Korean rice wine, chongju, and the sharp, strong

flavor of Korean soybean sauce, kanjang, are more preferred by Korean people

than those of industrial counter parts. The anti-cancer activity of doenjang

made from Korean traditional mixed culture starter meju was reported to be

higher than that of the industrial product made from koji. The physiological

characteristics of microbial strains isolated from traditional fermentation

starters and their interactions for growth and biosynthesis of functional

compounds are under investigation. More studies on the interaction of different

species of microorganism in a fermentation system are needed. Computer aided

analysis of microbial interaction will make this sort of study possible and

manageable.

Safety issue of fermented products

Since fermentation makes raw food materials edible without cooking, the

risks of hazardous microbial contamination always exist in fermented food

especially naturally fermented traditional foods. The uneven distribution of

salt in lactic acid fermented fish products and contamination of Aspergillus

flavus in traditional starter cultures for rice wine and soybean sauce may

result in severe food poisoning incidences (Lee 1989, Lee and Lee 2002).

On the other hand, most of the traditional fermentation methods have their

own inbuilt safeguard mechanisms. The food infectious and poisoning

microorganisms contaminated on the vegetables and other raw materials of kimchi

are killed within one week of fermentation period mainly due to the acid

formation and bacteriocin production (Lee 1997). Also, large amounts of nitrate

and secondary amines in vegetable products are reduced by fermentation (Lee

1986). The importance of fermentation technology for the improvement of hygienic

situation of needed region, where cold-chain system is not well established, was

discussed at the FAO/WHO Workshop on the Assessment of Fermentation as a

Household Technology for Improving Food Safety held in December 11-15, 1995,

Pretoria, Republic of South Africa (WHO 1996).

Conclusion

Fermentation technology has confronted new challenge in the era of

functional food with its efficient biosynthesis potential. Research for useful

strains from traditional fermented foods continues worldwide and relevant

information is accumulating. Exchange of knowledge and skills of fermentation

technology of the West and the East will accelerate the technology innovation

and new product development. Considering the importance of fermentation

technology in the era of functional food, the public sectors and international

bodies should pay attention to the relevant R & D efforts of academic institutions

and industrial research groups. The R & D support of national and international

funding organizations should include the following research priorities.

1. Nationwide search for useful microbial strains from indigenous

fermented products and characterization of their physiological properties.

2. Establishment of a global network on fermentation technology and

microbial strains and starter culture information.

3. Studies on the mixed culture fermentation and the interaction of

microorganisms in fermentation system.

4. Evaluation of physiological function and health benefit mechanism of

the metabolites obtained during fermentation process.

5. Evaluation of safety of fermented products, the microorganisms involved

and the metabolites.

6. Evaluation and dissemination of fermentation technology for the

improvement of hygienic condition of developing countries.

We expect an active discussion on this subject through the IUFoST Internet

discussion and during the 12th World Congress of Food Science and Technology in

Chicago 2003.

References

1. Chung M.J., Cho, Y.C., Hong, U.P. and Kim. D. (2001) Improvement of

stability in protein-coated LAB(PROLAC) and dual coated LAB(DUOLAC) using soy

protein and polysaccharides, Presented at the First Asian Conference on Lactic

Acid Bacteria for Industrial Application and New Technology, October 27-28,

Suwon, Korea

2. Kim, S.E. (1995) Tumor suppressive peptides derived from traditional

Korean soy sauce, MS Thesis, Seoul National University, Suwon, Korea

3. Lee, B.Y., Kim, D.M. and Kim, K.H. (1991) Physico-chemical properties of

viscous substance extracted from Chongkook-jang, Korean J. Food Sci. Technol.,

23(5) 599-604

4. Lee, C.H. (1986) Kimchi; Korean fermented vegetable foods, Korean J.

Dietary Culture, 1(4), 395-402

5. Lee, C.H. (1989) Fish fermentation technology, Korean J. Applied

Microbiology and Bioengineering, 17(6), 645-654

6. Lee, C.H. (1994) Importance of lactic acid bacteria in non-dairy food

fermentation, in Lactic Acid Fermentation of Non-dairy Food and Beverages, ed.

C.H. Lee, J. Adler-Nissen and G. Barwald, HarnLimWon, Seoul, p.132-150,

7. Lee, C.H. (1997) Lactic acid fermented foods and their benefits in Asia,

Food Control, 8(5/6), 259-269

8. Lee, C.H. (2001a) The importance of Primitive Pottery Age (8,000-3,000

B.C.) of northeast Asia in the history of food fermentation, Presented to the

11th World Congress of Food Science and Technology, April 22-27, 2001, Seoul,

Korea

9. Lee, C.H. (2001b) Fermentation Technology in Korea, Korea University

Press, Seoul, p. 70-91

10. Lee, C.H. and Lee, S.S. (2002) Cereal fermentation by fungi, in Applied

Mycology and Biotechnology Vol. 2, Agriculture and Food Production, ed. p.

151-170

11. Mok, C.K. (1994) Lactic acid fermentation of rice and its quality

improvement strategy, in Lactic Acid Fermentation of Non-dairy Food and

Beverages, ed. C.H. Lee, J. Adler-Nissen and G. Barwald, HarnLimWon, Seoul,

p.132-150,

12. Oh, Y.J., Hwang, I.J. and Leitzmann, C. (1994) Nutritional and

physiological evaluation of kimchi. p.226 In: The Science of Kimchi. Korean

Society of Food Science and Technology, Seoul.

13. Park, M.J., Kim, J.S., Yim, J.Y., Jung, H.C., Song, I.S., Yu, E., Lee,

J.J., Huh, C.S., and Baek, Y.J. (2001) The suppressive effect of a feremented

milk containing Lactobaculli on Helicobacter pylori in human gastric mucosa,

Korea J. Gastroenterology, 38(4), 233-240

14. Shin, Z.I., Ahn, C.W., Nam, H.S., Lee, H.J., Lee, H.J., Moon, T.H.

(1995) Fractionation of angiotensin converting enzyme(ACE) inhibitory peptides

from soybean paste, Korean J. Food Sci. Technol., 27(2) 230-234

15. Shon, D.H., Lee, K.E., Ahn, C.W., Nam, H.S., Lee, H.J. and Shin, J.K.

(1996) Screening of antithrombotic peptides from soybean paste by the microplate

method, Korean J. Food Sci. Technol., 28(4) 684-688

16. Steinkraus K.H. (1993) Comparision of fermented foods of the East and

West, in Fish Fermentation Technology, ed. C.H. Lee, K.H. Steinkraus and P.J.A.

Reilly, United Nations University Press, Tokyo, p. 1-12

17. WHO, (1996) Fermentation: Assessment and research, WHO/FNU/FOS/96.1

Table 1. Biologically-active compounds in kimchi (Oh et.al. 1994)

Chemical Compounds

Occurrence

Possible Effect

Benzylisothiocyanate, indol compound, thiocyanate, flavonoid

chinese cabbage, allium vegetable, red pepper

antibiotic, anticcarcinogenic, immune stimulant

Sistosterol

chinese cabbage

reducing the cholesterol level

Diallylsulfide, diallyltrisulfide, diallylmethylsulfide

allium vegetable

anticarcinogenic, antioxidant, fibrinolytic

Gingerrol, gingerin

ginger

antibiotic, fibrinolytic

Capsaicin

red pepper

laxative, secretion of neuropeptides

Lactic acid bacteria

kimchi

antagonistic

Bacteriocine

kimchi

antibiotic

L-(+)-lactic acid

kimchi

modulation of T-cell function

Acethylcholine

kimchi

laxation

Dextran

kimchi

laxation

γ-Aminobutyric acid

kimchi

laxation

Acetate

kimchi

antibiotic

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About the author: Cherl-Ho Lee has been teaching Food Engineering and Food

Preservation at Korea University since 1979. He received his Ph.D. at the Royal

Veterinary and Agricultural University of Denmark and post doctorate training at

MIT, U.S.A., under the supervision of Prof. Chokyun Rha and Prof.

Sinskey. He was project coordinator of Fish Fermentation Technology Network of

United Nations University, and project director of Industrialization of Lactic

Acid Fermentation Technology of Cereals and Its Dissemination to the Developing

Countries for UNIDO. He was appointed as the Secretary General of the 11th

IUFoST World Congress of Food Science and Technology which was held in Seoul

2001, and for this occasion he published a book on Fermentation Technology in

Korea. Professor Lee has been a member of National Food Hygiene Advisory

Committee of Korea since 1988, and received the National Merit-Medal

(Seokryujang) for his achievements in national health promotion and activities

including writing a book “Food Hygiene Incidences White Paper.†He published

over 200 research papers and 10 books in food science and technology.