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Comparison of γ-glutamyl hydrolase (conjugase; EC 3. 4. 22. 12) and amylase treatment procedures in the microbiological assay for food folates

Published online by Cambridge University Press:  09 March 2007

Jens C. Pedersen
Jens C. Pedersen
Affiliation:
National Food Agency, Central Laboratory Division A: Food Chemistry and Microbiology, Mørkhøøj Bygade 19, DK-2860 Søborg, Denmark
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Abstract

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1. It has been suggested that deconjugation of food folates with pig kidney, compared with chicken pancreas, may increase measureable folate by approximately 50% (Phillips & Wright, 1983). Therefore deconjugation with conjugases from these two enzyme sources was optimized and compared. Folate was measured microbiologically with Lactobacillus casei (ATCC 7469) as the test organism at pH 5·6.

2. Treatment for 6 h with 200 mg pig kidney/200 mg sample was compared with the conventional assay employing overnight incubation with 20 mg chicken pancreas/5 g sample. Comparison of the deconjugation systems showed chicken pancreas to be superior for peas (Pisum sativum) and beans (Phaseolus vulgaris), while there was no difference for potatoes.

3. γ-Glutamyl hydrolase (conjugase; EC 3. 4.22. 12) treatment for 2 and 20 h with pig kidney and chicken pancreas was optimized for raw potatoes and green frozen peas. Treatments with pig kidney were conducted at pH 4·6, which is optimal, and at pH 5·2. There was no significant difference between 2 and 20 h treatments at pH 5·2. Treatments with chicken pancreas were conducted at pH 6·1. Treatment for 2 h was preferred as it resulted in significantly higher measureable folate activity in peas and potatoes, and because overnight treatment can be influenced by microbial production of folate.

4. With optimal treatment conditions the source of enzymes did not significantly influence measureable folate activity. Chicken pancreas is the traditional source of conjugase in Scandinavia and was preferred for deconjugation.

5. Chicken pancreas, 20 and 60 mg, was used for deconjugation of sixteen different food samples, each containing approximately 200 ng folate. Chicken pancreas at 60 mg/sample gave significantly higher results. Further addition of enzyme did not increase the folate values.

6. A combined amylase treatment using heat-resistant α-amylase (EC 3.2.1.1) during extraction to ensure the gelatinization of the sample, and glucan 1,4-α-glucosidase (amyloglucosidase; EC 3.2.1.3), along with the incubation with chicken pancreas to complete the digestion, was shown to give a small but significant increase in folate values of starch-containing samples.

7. Folate results using the recommended procedure are given for raw potatoes, wheat bran, rolled oats, wheat flour and dark rye bread.

8. Chicken pancreas was shown to contain equally high amounts of amylases as did the α-amylase and amyloglucosidase sources. This finding may explain the relatively small benefit of a specific amylase addition.

Type
Other Studies Relevant to Human Nutrition
Information
British Journal of Nutrition , Volume 59 , Issue 2 , March 1988 , pp. 261 - 271
Copyright
Copyright © The Nutrition Society 1988

References

Anon. (1985). Food Chemical News 43–44.Google Scholar
Bailey, L. B., Cerda, J. J., Bloch, B. S., Busby, M. J., Vargas, L., Chandler, C. J. & Halsted, C. H. (1984). Journal of Nutrition 114, 1770–1776.CrossRefGoogle Scholar
Bates, C. J., Black, A. E., Phillips, D. R., Wright, A. J. A. & Southgate, D. A. T. (1982). Human Nutrition: Applied Nutrition 36A, 422–429.Google Scholar
Bates, C. J., Fleming, M., Paul, A. A., Black, A. E. & Mandal, A. R. (1980). Age and Ageing 9, 241–248.CrossRefGoogle Scholar
Bell, J. G. (1974). Laboratory Practice 23, 235–242.Google Scholar
Bender, A. E. & Nik-Daud, N. I. (1983). In Thermal Processing and Quality of Foods, pp. 880–884 [Zeuthen, P., Cheftel, J. C., Eriksson, C., Jul, M., Leninger, H., Linko, P., Varela, G. and Vos, G., editors]. London and New York: Elsevier.Google Scholar
Bird, O. D. & McGlohon, V. M. (1972). In Analytical Microbiology, vol. 2, pp. 409–437 [Kavanagh, F., editor]. London: Academic Press.CrossRefGoogle Scholar
Cerná, J. & Kás, J. (1983). Die Nahrung 27, 957–964.CrossRefGoogle Scholar
Chen, M. F., Hill, J. W. & McIntyre, P. A. (1983). Journal of Nutrition 113, 2192–2196.CrossRefGoogle Scholar
Chen, T.-S. & Cooper, R. G. (1979). Journal of Food Science 44, 713–716.CrossRefGoogle Scholar
Herbert, V. (1987). American Journal of Clinical Nutrition 45, 661–670.CrossRefGoogle Scholar
Hoppner, K., Lampi, B. & Perrin, D. E. (1972). Canadian Institute of Food Science and Technology Journal 5, 60–66.CrossRefGoogle Scholar
Jägerstad, M., Lindstrand, K. & Westesson, A.-K. (1975). Scandinavian Journal of Social Medicine 10, 78–83.Google Scholar
Jägerstad, M. & Westesson, A.-K. (1979). Scandinavian Journal of Gastroenterology 14, Suppl. 52, 196–202.Google Scholar
Jakobsen, K., Jensen, M., Lund-Rasmussen, J. & Christensen, A. (1985). Microbiological Determination of Folacin in Foods, A Methodological Investigation. Laboratorienotat NT 005/85. Søborg: National Food Agency (In Danish).Google Scholar
Käferstein, H. & Jaenicke, L. (1972). Hoppe-Seylers Zeitschrift für Physiologische Chemie 353, 1153–1158.CrossRefGoogle Scholar
Kirsch, A. J. & Chen, T.-S. (1984). Journal of Food Science 49, 94–98.CrossRefGoogle Scholar
Krumdieck, C. L., Tamura, T. & Eto, I. (1983). Vitamins and Hormones 40, 45–104.CrossRefGoogle Scholar
Leichter, J., Landymore, A. F. & Krumdieck, C. L. (1979). American Journal of Clinical Nutrition 32, 92–95.CrossRefGoogle Scholar
Malin, J. D. (1976). Proceedings of the Nutrition Society 35, 143A–144A.Google Scholar
National Research Council (1980). Recommended Dietary Allowances, 9th ed. Washington, DC: National Academy of Sciences.Google Scholar
Nordic Committee on Food Analysis (1985). Folate, Biologically Active, in Milk and Milk Products. Microbiological Determination with Lactobacillus casei, no. 111. Uppsala, Sweden: Nordic Committee on Food Analysis.Google Scholar
Phillips, D. R. & Wright, A. J. A. (1982). British Journal of Nutrition 47, 183–189.CrossRefGoogle Scholar
Phillips, D. R. & Wright, A. J. A. (1983). British Journal of Nutrition 49, 181–186.CrossRefGoogle Scholar
Phillips, D. R., Wright, A. J. A. & Southgate, D. A. T. (1982). Lancet ii, 605.CrossRefGoogle Scholar
Rogozinski, H., Ankers, C., Lennon, D., Wild, J., Schorah, C., Sheppard, S. & Smithells, R. W. (1983). Human Nutrition: Applied Nutrition 37A, 357–364.Google Scholar
Rosenberg, I. H. (1976). Clinical Haematology 5, 589–618.CrossRefGoogle Scholar
Rosenberg, I. H., Bowman, B. B., Cooper, B. A., Halsted, C. H. & Lindenbaum, J. (1982). American Journal of Clinical Nutrition 36, 1060–1066.CrossRefGoogle Scholar
Tamura, T., Shane, B., Baer, M. T., King, J. E., Margen, S. & Stokstad, E. L. R. (1978). American Journal of Clinical Nutrition 31, 1984–1987.CrossRefGoogle Scholar
Tamura, T., Shin, Y. S., Williams, M. A. & Stokstad, E. L. R. (1972). Analytical Biochemistry 49, 517–521.CrossRefGoogle Scholar
Tamura, T. & Stokstad, E. L. R. (1973). British Journal of Haematology 25, 513–532.CrossRefGoogle Scholar
Wagner, P. A., Bailey, L. B., Krista, M. L., Jernigan, J. A., Robinson, J. D. & Cerda, J. J. (1981). Nutrition Research 1, 565–569.CrossRefGoogle Scholar
World Health Organization (1972). Nutritional Anemias. Report of a WHO Group of Experts. Technical Report Series no. 503. Geneva: WHO.Google Scholar