Return to the Search page
Search FAQs 
Search Tips 
FAQ Tips 
Ask Med Ed 
Reports 
 
Administration 

Answers from the Research Department

 /csr/questiondisplay.asp
E-Mail this question ||  Print this for a Customer ||  Resubmit to Med Ed
Jump To:  Answer || Reference || Keywords


Times Referenced:
0
Question:
#2639		 How does the soy content in Soy Extract compare or measure up to a block or packet of tofu?
Answer: It is important to remember that Soy Extract is an extract from soybeans and tofu is a whole soyfood. A comparison of the soy content in Soy Extract and a serving of tofu may not be meaningful. As an example, oranges contain vitamin C. If one obtained vitamin C extracted from oranges, the only comparisons that could be made would be on the vitamin C content of both. One could not compare the amount of orange in an orange with the amount of orange in a vitamin C tablet. One could only compare the vitamin C (a key compound in oranges) content of both. Similarly, saponins and isoflavones are key compounds that are found in soy (tofu). One can compare the key compounds in Soy Extract with those found in tofu. Soy Extract contains 100 mg of soy extract standardized to contain 15% isoflavones calculated as their glycoside forms, genistin and daidzin. A 12 oz. commercial box of tofu is equivalent to 360 grams of tofu. The scientific literature lists varying quantities of isoflavones in tofu, for example 0.5 mg/g total isoflavones,1 1-3 mg/g total isoflavone concentration,2 and 73-98 mcg/g daidzein per gram wet weight (tofu without the moisture removed) and 187-216 mcg/genistein per gram wet weight.3 Soy Extract provides 13-17 mg of isoflavones per capsule. To estimate a comparison, 6 oz (1/2 block) of tofu would yield 180 mg of isoflavones if the concentration were 1 mg/gm. Soy Extract is designed to provide high levels of phytoestrogens (eg, genistein and daidzein), compounds that are abundant in tofu and play a supporting role in women's health. Because tofu products often do not list the content of isoflavones and are not standardized to these important compounds, a direct comparison is difficult. However, Soy Extract contains approximately 13 to 17 mg of genistein per capsule. Estimating the amount of genistein in tofu based on the above study as 190 mcg per gram, 6 oz (1/2 block) of tofu would yield approximately 34 mg of genistein. There are other factors to consider also when comparing Soy Extract to tofu. All commercially prepared tofu is not equal. There may be variances in the quantity of protein, carbohydrates, fat, amino acids, isoflavones, saponins, and phytic acid, etc. Furthermore, the metabolism of the isoflavones will be affected by processing and cooking methods.
Back to Top
References: 1. Setchell KDR. Phytoestrogens: the biochemistry, physiology, and implications for human health of soy isoflavones. Am J Clin Nutr. 1998; 68(suppl): 1333-1346.2. Song T, Barua K, Buseman G, Murphy PA. Soy isoflavone analysis: quality control and a new internal standard. Am J Clin Nutr. 1998;68(suppl):1474-1479.3. Dwyer JT, Goldin BR, Saul N, Gaultieri L, Barakat S, Adlercreutz H. Tofu and soy drinks contain phytoestrogens. J Am Diet Assoc. 1994;94:739-743. Abstract.
Back to Top
Keywords: Soy Extract, Tofu, Standardization, Comparison
Back to Top
Question Date:
 9/12/2001
Released Date:
 9/12/2001
Author: Randy Vande Hei
Sales Division: ENZY
 
Search Tips  ||  FAQs  ||  Administration  ||  Intranet Home  ||  Contact the Webmaster
 
©2001 Enzymatic Therapy Corporate Intranet