Inositol Phosphate Content of Selected Dry Beans, Peas, and Lentils, Raw and Cooked

JOURNAL OF FOOD COMPOSITION AND ANALYSIS ARTICLE NO.

9, 2–12 (1996)

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Inositol Phosphate Content of Selected Dry Beans, Peas, and Lentils, Raw and Cooked1 EUGENE R. MORRIS2

AND

A. DAVID HILL

Metabolism and Nutrient Interactions Laboratory, Beltsville Human Nutrition Research Center, U. S. Department of Agriculture, Beltsville, Maryland 20705, U.S.A. Received August 18, 1995, and in revised form November 10, 1995 Fourteen varieties of dry legumes available in local supermarkets were analyzed for inositol phosphate profile in the raw state and after cooking. Inositol tris-, tetrakis-, pentakis-, and hexakisphosphate (IP3 –IP6) were determined by a HPLC procedure. The concentration of inositol phosphates in raw dry legumes did not differ significantly among three different brands. Phytic acid (IP6) concentration (per kg dry basis) ranged from 6.0 mmol in chickpeas to 14.2 mmol in black beans. Phytic acid was the predominate inositol phosphate of the total inositol phosphates determined in raw dry legumes, ranging from 77% in chickpeas and pigeon peas to 88% in black beans. The remainder of the inositol phosphates in raw, dry legumes were IP4 and IP5 , except lentils contained, in addition, a detectable amount of IP3 . The cooked legumes all contained detectable amounts of IP3 , increased amounts of both IP4 and IP5 , but lower amounts of IP6 in comparison to the raw dry legume (differences between uncooked and cooked were statistically significant, P õ 0.05). The concentration of IP6 in the cooked legumes averaged 83%, ranging from 68% in red kidney beans to 86% in chickpeas, of the concentrations in the raw dry legumes. Phytic acid remained the predominate inositol phosphate in cooked legumes, averaging 68% of the total and ranging from 60% in pigeon peas to 78% in yellow split peas. Quick soak vs overnight soak of beans before cooking resulted in no difference in inositol phosphate concentration or profile of cooked beans. Although the total inositol phosphates did not differ significantly between raw and cooked dry legumes (P ú 0.1), the IP6 and IP5 / IP6 represented a smaller percentage of the total in the cooked legumes, suggesting that cooking decreases the potential adverse impact of inositol phosphates on mineral utilization when legumes are included in the diet. q 1996 Academic Press, Inc.

Beans and other legumes can provide protein, complex carbohydrate, and dietary fiber in human diets (Slavin, 1991; Young, 1991; USDA, 1992). Adults in the United States are estimated to consume from 15 to 35 g of legumes daily (USDA, 1995). In some areas of the world where the predominant diet pattern is vegetarian, or animal meat is available in only small amounts, legumes may be a major type of food in human diets (Borade et al., 1984; El Tinay et al., 1989; Khokhar and Khokhar, 1995; Wyatt and Triana-Tejas, 1994). Although legumes are purported to provide health benefits in such reviews as those by Geil and Anderson (1994) and Messina (1995), legumes also contain antinutrients, enzyme inhibitors, tannins, hemagglutinins, and phytic acid. Enzyme inhibitors, specifically some protease and amylase inhibitors must be either inactivated or eliminated from the legume before ingestion. This is generally accomplished by heating or physical separation of legume components as described 1 Presented in part at Experimental Biology ‘95, Atlanta, GA, April 9–13, 1995. Morris, E. R., and Hill, A. D. (1995). Inositol phosphate profile of cooked beans, peas and lentils. FASEB J. 9, A451. 2 To whom correspondence or reprint requests should be addressed. Fax: (301) 504-9456.

0889-1575/96 $18.00

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Copyright q 1996 by Academic Press, Inc. All rights of reproduction in any form reserved.

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by Bishnoi and Khetarpaul (1993), Borowska and Kozlowska (1986), Deshpande et al. (1982), Kantha et al. (1986), and Vidal-Valverde et al. (1994). Tannin or polyphenol content is generally greater in pigmented legumes and hemagglutinating activity is altered by heating (Tan et al., 1983). Phytic acid (inositol hexakisphosphate, IP6), the subject of this communication, is considered an antinutrient by virtue of its potential adverse action on the utilization of dietary cations (Morris, 1986). Lolas and Markakis (1975) reported that phytic acid P represented from 55 to 80% of the total P in several varieties of beans analyzed. The PHYTATE3 content of bean flour is increased by dehulling the bean (Deshpande et al., 1982), but cooking or heat treatment results in decreased amounts of PHYTATE (Pawar et al., 1986; Sievwright and Shipe, 1986; Tabekhia and Luh, 1980). Cooking or heat treatment also reduces PHYTATE content of peas, lentils, and other legumes (Beal and Mehta, 1985; Bishnoi et al., 1994; Kumar et al., 1978; Manan et al., 1987). Germination and fermentation reduced PHYTATE concentrations of legumes considerably (Beal and Mehta, 1985; Borade et al., 1984; Pawar et al., 1986; Reddy and Salunkhe, 1980; Tabekhia and Luh, 1980; Vidal-Valverde et al., 1994). PHYTATE methodology used in these studies was based on the property of inositol phosphates to complex with ferric ion (Latta and Eskin, 1980; Makower, 1970; Wheeler and Ferrel, 1971) or the step-gradient anion exchange procedure (AOAC, 1990; Ellis and Morris, 1983), neither of which differentiates between IP6 and inositol phosphates of a lesser degree of phosphorylation. Consequently, the IP6 concentration may be overestimated if hydrolysis products of IP6 are present (Lehrfeld and Morris, 1992). Ferrel (1978) separated inositol phosphates of beans by an anion-exchange procedure and found IP4 and IP5 as well as IP6 in dry beans, especially after autolysis or germination. Only 44% of the total inositol phosphates in canned red kidney beans was determined to be IP6 (Phillippy et al., 1988). Gustafsson and Sandberg (1995) used an HPLC procedure to monitor reduction of IP6 in brown beans by treatment with exogenous phytase. We used a HPLC procedure to show that breakfast cereals may contain substantially lower amounts of IP6 than if the different inositol phosphates had not been quantitated (Morris and Hill, 1995). The objectives of the work reported in this communication were (a) determine the inositol phosphate profile in raw dry legumes by the HPLC procedure and (b) study the effect of cooking by usual household procedures on the inositol phosphate profile of cooked dry legumes. The legumes selected were available as dry seeds at local supermarkets and were not intended to be a survey of all available in the area. For the most part, the raw, dry seeds contained predominately IP6 . The IP6 concentration was reduced in the cooked legumes, but relatively small changes in total inositol phosphate content resulted from cooking. The potential impact of the inositol phosphates in cooked legumes is discussed. MATERIALS AND METHODS

Packages of three brands (Goya, Jack Rabbit, and Townhouse)4 of dry baby lima beans, black beans, blackeye peas (cowpeas), great northern beans, green and yellow 3 Abbreviations and terms: IP3 , IP4 , IP5 , IP6 , respectively, inositol tris, tetrakis, pentakis and hexakisphosphate; PHYTATE, phytic acid determined by methods which will not differentiate between IP6 and, if present, other inositol phosphates. 4 Data reported for commercial brand names are factual information only and are limited to the samples analyzed. No warranty or guarantee is made or implied that other samples of these products will have the same or similar composition.

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split peas, lentils, navy beans, pinto beans, and red kidney beans and one brand (Goya) of chickpeas (garbanzo beans), pigeon peas, red chili beans, and Roman beans were purchased at local supermarkets. Approximately 100 g of the raw dry legumes from each package were ground in a micro Wiley mill5 to pass a 20-mesh screen. This material was used for moisture determination and analysis of the inositol phosphates in the raw dry legume. Two cups of the dry legumes were weighed and cooked according to package directions. All legumes except green and yellow split peas and lentils were soaked overnight (18 h) at ambient room temperature in the requisite amount of deionized water. The green and yellow split peas and lentils were soaked for 30 min before cooking. A separate amount of the Goya brand beans, blackeye peas, and chickpeas was subjected to a quick soak procedure (boiling water was added, boiled for an additional 5 min, and then allowed to stand for 2 h) to compare two methods of soaking. After soaking, the water was heated to boiling and simmered for 1.5 h to complete cooking. The cooked legumes were each transferred (liquid and cooked legume) to plastic containers, frozen, and lyophilized. The lyophilized, cooked legumes readily disintegrated to a powder for mixing and sampling for analysis. Triplicate aliquots of each ground, raw dry, and lyophilized, cooked legume were analyzed for inositol phosphate content. Inositol phosphate analysis. The inositol phosphate (IP3 –IP6) methodology was the HPLC procedure of Lehrfeld (1989) as described by Morris and Hill (1995). Aliquots, 0.4–0.6 g, of the ground, raw, dry, and pulverized cooked legumes were extracted with 6 ml of 0.5 M HCl at ambient temperature overnight. The extract was filtered through No. 41 filter paper and an accurately measured amount of the filtrate was diluted and passed onto small SAX (Analytichem International, Harbor City, CA) ion exchange columns. The columns were washed with 5 ml of deionized water and eluted with 2 ml of 2 M HCl, which was collected in 30-ml glass scintillation vials. The HCl was removed to dryness by means of a vacuum-rotary evaporator (Jouan Corp., Winchester, VA) and the dried residue was dissolved in 1 ml of mobile phase used for the HPLC procedure. Separation and quantitation was achieved with a Waters (Millipore Corp., Milford, CT) HPLC instrument using a Hamilton (Hamilton Co., Reno, NV) PRP-1 reversed phase column and a Waters 410 differential refractometer. The mobile phase was 50% methanol, 0.015 M formic acid adjusted to pH 4.3 with H2SO4 and 0.1% tetrabutylammonium hydroxide. Sodium phytate (inositol hexakisphosphoric acid, dodecasodium salt) was purchased from Sigma Chemical Co. (St. Louis, MO) and tetrabutylammonium hydroxide (40 wt% solution in water) from Aldrich Chemical Co. (Milwaukee, WI). Water of hydration must be determined for each lot of sodium phytate. Readers may consult Lehrfeld (1994) for additional details of the HPLC procedure. A reference material is not available which is certified for inositol phosphate content; however, wheat flour standard reference material No. 1567 ( National Institute of Standards and Technology, Gaithersburg, MD) was included with each analytical run as a quality assurance material. This is a homogeneous reference material certified for trace element concentrations. The inositol phosphate values (mmol per g) for five independent analytical runs were IP3 0.015 { 0.01, IP4 0.25 { 0.02, IP5 0.81 { 0.05, 5 Mention of a specific equipment or materials manufacturer or trade name is descriptive only and does not constitute endorsement by the U.S. Department of Agriculture at the exclusion of other suitable equipment or material.

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and IP6 1.86 { 0.06. The inositol phosphate concentrations are lower than found for the legume materials and the relative standard deviation (RSD) is quite large for IP3 ; however, the RSD for the other inositol phosphates was õ10%. Statistical analyses. Data were tested by one-way-ANOVA by InStat software program (GraphPad, San Diego, CA). RESULTS AND DISCUSSION

Table 1 summarizes the inositol phosphate values for raw and cooked dry legumes. The ANOVA analysis of inositol phosphate values for the nine legumes purchased in all three brands revealed no significant brand effect for values of IP5 or IP6 in raw (P Å 0.453 and ú0.8) and cooked (P Å 0.290 and 0.078) dry legumes. The nine legumes of Goya brand tended to have lower IP4 values in raw (P õ 0.001 for brand effect) than did the Jack Rabbit or Townhouse brands and, overall, represented less than 2% of the total inositol phosphates in raw, dry legumes. However, no brand effect (P Å 0.476) was found for IP4 in the cooked items. Thus, the data are presented as means for the brands purchased. The overall mean RSD (includes replicates across brands) for the inositol phosphate values in raw dry legumes were; IP3 28%, IP4 10%, IP5 4%, and IP6 2%. The respective RSDs for cooked dry legumes were 8, 4, 2, and 2%. Inositol phosphate concentrations §0.1 mmol/kg are reported to 2 or 3 significant figures (Stewart, 1995). Values £0.005 mmol per kg or when one or more brands contained no detectable inositol phosphate are reported as none detected (nd). Raw, dry lentils contained 0.3 mmol/kg of IP3 , IP3 values of all other raw, dry legumes were either less than 0.005 mmol/kg or none was found in one or more brands. The highest IP4 concentration in raw, dry legumes was 0.26 mmol/kg in blackeye peas and accounted, on the average, for only slightly more than 1% of the total inositol phosphates in raw, dry legumes. The mean IP5 concentration in raw, dry legumes was 1.9 mmol/kg, ranging from 1.36 in green split peas to 2.52 in blackeye peas, accounting for an average of 16% of total inositol phosphates determined. The most abundant inositol phosphate in raw, dry legumes was IP6 , accounting for an average of 83%, ranging from 77% in chickpeas to 88% in black beans, of the total inositol phosphates determined in the raw dry legumes. The IP6 concentration tended to be higher in raw dry beans, blackeye peas, and pigeon peas than in lentils, green and yellow split peas, and chickpeas and ranged between 14.2 mmol/kg in black beans and 6 mmol/kg in chickpeas. Varietal and agronomic factors, alone and in combination, will often result in a wide variation in PHYTATE content of mature legume seeds and cereal grains (Dintzis et al., 1992; Griffiths and Thomas, 1981; Michael et al., 1980; Mason et al., 1993). Thus, our values for IP6 may not necessarily be less than literature values for PHYTATE determined by procedures which do not differentiate between the different inositol phosphates. Deshpande et al. (1982) reported 17.6 to 43.3 mmol/kg in 10 varieties of beans and Lolas and Markakis (1975) found 8.3 to about 24.2 mmol/kg in several bean varieties and cultivars over a period of 3 years. Makower (1970) reported a range of 16.5 to 20.9 mmol/kg of PHYTATE in mature pinto beans. Blackeye peas and red kidney beans contained 17.4 and 17.7 mmol/kg, respectively, of PHYTATE (Tabekhia and Luh, 1980). Chickpeas and lentils grown in Sudan contained 13–17 and 4–6 mmol/kg, respectively, of PHYTATE (El Tinay et al., 1989). Garfield peas grown in Washington state (U.S.) contained 12 mmol/kg of PHYTATE (Beal and Mehta, 1985). Bishnoi et al. (1994) reported vegetable peas in India to contain 9.5 to 9.9 mmol/kg of PHYTATE and field peas contained 11.5

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MORRIS AND HILL TABLE 1 INOSITOL PHOSPHATE CONTENTS OF RAW AND COOKED DRY BEANS, PEAS, AND LENTILS1

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to 11.8 mmol/kg. Raw Pakistani lentils contained 9.4 mmol/kg of PHYTATE (Manan et al., 1987) and brown and white Bengal grams contained 18.5 and 12.1 mmol/kg (Khan et al., 1988). Mature black beans contained 19.3 mmol/kg of PHYTATE before storage (Sievwright and Shipe, 1986). Few literature references are available in which the inositol phosphates in raw, dry legumes are differentiated. Ferrel (1978) determined that 66% of the inositol phosphates in unautolyzed California small white beans was IP6 , 15% was IP4 , with smaller amounts of the others, including the mono- and di-phosphate esters. Gustafsson and Sandberg (1995) determined 1.01 and 12.6 mmol/kg, respectively, of IP5 and IP6 , IP6 accounting for 92% of the total, but detected no IP3 or IP4 in raw brown beans. All cooked, dry legumes contained measurable concentrations of IP3 , ranging from 0.05 mmol/kg in yellow split peas to 0.44 mmol/kg in lentils (Table 1). Concentrations of both IP4 and IP5 were greater in cooked than in the raw, dry legumes. Concentrations of IP4 ranged from 0.45 to 1.08 mmol/kg, respectively, in cooked, green split peas and baby lima beans and IP5 concentrations ranged from 1.5 to 3.6 mmol/kg, respectively, in cooked, yellow split peas and black beans. The mean concentrations in cooked legumes were about 6 times greater for IP4 and 1.5 times greater for IP5 than in the raw, dry legumes. The mean percentage of total inositol phosphates accounted for by IP4 and IP5 in cooked, dry legumes was 7 and 25%, respectively, significantly greater (P õ 0.0001) than in raw, dry legumes. Cooked, red chili beans contained the maximum concentration of IP6 , about 10.1 mmol/kg, and green split peas, the minimal concentration, 4.9 mmol/kg, of the cooked, dry legumes. IP6 concentrations of cooked legumes averaged about 77% of the concentrations found in the raw, dry legumes. The greatest percentage decrease was in red kidney beans (68% of the raw) and the smallest percentage change in chickpeas and Roman beans (86% of the raw). Statistical analysis by one-way ANOVA indicated a significant effect of cooking on inositol phosphate concentrations, P õ 0.0001 for both IP4 and IP5 and P õ 0.006 for IP6 . Green and yellow split peas, chickpeas and lentils do not require a prolonged presoak before cooking. However, the beans, blackeye peas and pigeon peas require a presoak to shorten the time needed for application of heat during the cooking process. We attempted to emulate the cooking process suggested for home preparation on the packages. Two different soaking procedures are suggested on the packages, an overnight soak at ambient temperature and a quick soak in which the soak water is brought to boiling then heat application is discontinued for 1 h. After either the overnight or quick soak, heat is applied until liquid is boiling then simmered to complete the cooking. If phytase is responsible for the decrease in IP6 during soaking, the activity should be at least partially inactivated with the quick soak procedure. Table 2 presents results of inositol phosphate analyses of cooked Goya brand beans soaked by either the overnight or quick soak procedures. Mean concentrations of IP3 , IP4 , and IP5 tend to be greater, and IP6 less in the quick soak cooked beans than in the overnight soak cooked beans. The differences were small, however, and ANOVA indicated statistically insignificant difference between the two methods of soaking (P values: IP3 , 0.099; IP4 , 0.339; IP5 , 0.602; IP6 , 0.594). A detailed comparison of our findings with the published literature is not in the scope of this report, but a few comparisons follow. Beal and Mehta (1985) observed that 25% of P diffused from peas incubated in water for 6.5 h at 607C, but the decrease could not be accounted for by an increase in inorganic P in the soak water and they speculated that hydrolysis products of phytic acid may have diffused from the peas. We did not separate liquid from solids after cooking, but IP6 concentrations in cooked

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MORRIS AND HILL TABLE 2 OVERNIGHT SOAK VS QUICK SOAK DID NOT INFLUENCE INOSITOL PHOSPHATE PROFILE OF COOKED BEANS1

green and yellow split peas (Table 1) were about 20% less than in the raw, dry seeds. Bishnoi et al. (1994) found an 8% decrease of PHYTATE in peas by ordinary cooking and 12% by pressure cooking. Boiling of white and brown Bengal grams as practiced in Pakistan resulted in 25% loss of PHYTATE (Khan et al., 1988). We found about 15% less in cooked chickpeas and lentils (Table 1). Manan et al. (1987) reported about an 80% reduction in PHYTATE P in cooked peas and lentils, but excess water was discarded after both soaking and cooking. Vidal-Valverde et al. (1994) also separated excess water from cooked lentils and reported a 40% reduction in PHYTATE. We froze in toto the liquid and solids after cooking. Thus, any soluble inositol phosphates that would have been discarded with excess water was determined and we believe emulates what would be consumed in households in the United States. Commercially canned red kidney beans contained about 60% of the total inositol phosphates as IP6 (Phillippy et al., 1988) compared with 68% as IP6 in the cooked red kidney beans in our study. Tabekhia and Luh (1980) found little effect of cooking at 1007C on the PHYTATE content of beans, but processing at 115.57C in cans did

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result in a reduction of PHYTATE. Canned beans may be subjected to higher heat than obtained by the domestic cooking procedure we used. Wyatt and Triana-Tejas (1994) reported about 10 mmol/kg of PHYTATE in refried (pinto) beans prepared according to traditional recipes. We determined 12.6 mmol/kg of IP in pinto beans (Table 1) of which 65% was IP6 . The storage conditions are not known for the legumes we purchased. Changes in levels of the lesser phosphorylated inositol phosphates in the raw, dry legumes may be reflective of storage conditions. Overall decreases in PHYTATE during storage have been reported (Herna´ndez-Unzo´n and Ortega-Delgado, 1989; Sievwright and Shipe, 1986), but differentiation of the inositol phosphates may be instructive about the processes occurring during storage. If temperature and humidity are suitable to initiate germination processes in the stored seeds, increased amounts of IP3 and IP4 will likely be found (Gustafsson and Sandberg, 1995), even though a decrease in PHYTATE levels occur (Kumar et al., 1978; Pawar et al., 1986). However, Crans et al. (1995), using 31P NMR, concluded that IP6 may be synthesized post germination. One interference which may occur in the HPLC analysis for inositol phosphates as we conduct it is that ATP (adenosine triphosphate) coelutes with IP3 (Morris and Hill, unpublished observation). Raw, dry lentils contained slightly greater amount of IP3 than of IP4 (Table 1) and could have been due to ATP, but seems unlikely because of the following. Immature seeds might contain ATP, but these were mature seeds with less than 10% moisture. Furthermore, the initial extraction is by 0.5 M HCl followed by elution from SAX column by 2 M HCl, during which procedures ATP probably would undergo hydrolysis and not be present for the HPLC separation. The mean total inositol phosphates (not shown in Table 1) in the raw dry legumes was 12.6 mmol/kg and in the cooked was 11.9 mmol/kg (not significantly different, P Å 0.503). If the inositol phosphates had not been differentiated, phytic acid/dietary mineral molar ratios would predict no beneficial effect of cooking on mineral bioavailability from the legumes. For example; the phytic acid/Zn molar ratios calculated using IP6 values are Ç12 and 18, respectively, for cooked blackeye peas and great northern beans, but would be Ç17 and 31, respectively, if the inositol phosphates had not been differentiated (Zn values based on actual analysis; A. D. Hill, unpublished). Likewise, (phytic acid 1 Ca)/Zn values will differ considerably, Ç0.3 and 0.8 mol/ kg based on actual analysis compared with Ç0.4 and 1.3 mol/kg based on total inositol phosphates as PHYTATE. Human studies suggest that dietary Zn utilization may be impaired if dietary phytic acid/Zn molar ratio is greater than 12–15 (Morris and Ellis, 1989) or the (phytic acid 1 Ca)/Zn value is greater than 0.5 mol/kg (Davies et al., 1985). Of course, these values are not established with certainty and these legumes are not normally consumed alone so that other components of a meal will contribute additional Zn and other minerals which will alter the phytic acid to mineral ratios. Nevertheless, when hydrolysis products of IP6 are present, the best estimation of dietary mineral bioavailability can be made only if the inositol phosphates are quantified separately. The degree of inhibitory action of the inositol phosphates on mineral utilization is directly proportional to the degree of phosphorylation, i.e., IP4 õ IP5 õ IP6 , in animal, human, and cell culture models (Brune et al., 1992; Han et al., 1994; Sandstro¨m and Sandberg, 1992). Harland and Morris (1995) reviewed to mid-1994 some of the literature on antineoplastic activity of phytic acid administered through drinking water in several rodent models of carcinogenesis. Whether IP6 per se or a hydrolysis product is responsible for the antineoplastic action is not known, nor is the mechanism understood. Graf and

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Eaton (1993) suggest that IP6 serves as a dietary antioxidant by complexing Fe/3 ion in a manner which prevents it from catalyzing hydroxyl radical formation. Hawkins et al. (1993) demonstrated that a specific configuration (equatorial-axial-equatorial) of the phosphate groups at positions 1,2,3 of IP6 is apparently responsible for the antioxidant activity. Only IP3 , IP4 , and IP5 structural isomers having the same configuration at positions 1,2,3 were efficient antioxidants in vitro. The reader should note that we did not determine the spatial configuration of the IP6 hydrolysis products in the raw and cooked legumes. Gradient ion chromatography in conjunction with nuclear magnetic resonance can be used to isolate and identify structural and conformational isomers of inositol phosphates (Phillippy and Bland, 1988). Future investigations may show that even the detail we provide here may be rudimentary as far as the ultimate knowledge needed of inositol phosphate composition of foods. REFERENCES Association of Official Analytical Chemists (1990). Phytate in foods, anion-exchange method, No. 986.11. In Official Methods of Analysis, 15th ed., pp. 800–801. Association of Official Analytical Chemists, Arlington, VA. BEAL, L., AND MEHTA, T. (1985). Zinc and phytate distribution in peas. Influence of heat treatment, germination, pH, substrate, and phosphorus on pea phytate and phytase. J. Food Sci. 50, 96–100. BISHNOI, S., AND KHETARPAUL, N. (1993). Effect of domestic processing and cooking methods on in-vitro starch digestibility of different pea cultivars (Pisum sativum). Food Chem. 47, 177–182. BISHNOI, S., KHETARPAUL, N., AND YADAV, R. K. (1994). Effect of domestic processing and cooking methods on phytic acid and polyphenol contents of pea cultivars (Pisum sativum). Plant Foods Hum. Nutr. 45, 381–388. BORADE, V. P., KADAM, S. S., AND SALUNKHE, D. K. (1984). Changes in phytate phosphorus and minerals during germination and cooking of horse gram and moth bean. Qual. Plant. Plant Foods Hum. Nutr. 34, 151–157. BOROWSKA, J., AND KOZLOWSKA, H. (1986). Isolates from faba bean and soybean with lowered content of phytic acid and activity of the trypsin inhibitors. Die Nahrung 30, 11–18. BRUNE, M., ROSSANDER-HULTE´N, L., HALLBERG, L., GLEERUP, A., AND SANDBERG, A.-S. (1992). Iron absorption from bread in humans: Inhibiting effects of cereal fiber, phytate and inositol phosphates with different numbers of phosphate groups. J. Nutr. 122, 442–449. CRANS, D. C., MIKUSˇ, M., AND FRIEHAUF, R. B. (1995). Phytate metabolism in bean seedlings during postgerminative growth. J. Plant Physiol. 145, 101–107. DAVIES, N. T., CARSWELL, A. J. P., AND MILLS, C. F. (1985). The effect of variation in dietary calcium intake on the phytate-zinc interaction in rats. In Trace Elements in Man and Animals—TEMA 5 (C. F. Mills, I. Bremner, and J. K. Chesters, Eds.), pp. 456–457. Commonwealth Agricultural Bureaux, Farnham Royal, United Kingdom. DESHPANDE, S. S., SATHE, S. K., SALUNKHE, D. K., AND CORNFORTH, D. P. (1982). Effects of dehulling on phytic acid, polyphenols, and enzyme inhibitors of dry beans (Phaseolus vulgaris L.). J. Food Sci. 47, 1846–1850. DINTZIS, F. R., LEHRFELD, J., NELSEN, T. C., AND FINNEY, P. L. (1992). Phytate content of soft wheat brans as related to kernel size, cultivar, location, and milling and flour quality parameters. Cereal Chem. 69, 577–581. ELLIS, R., AND MORRIS, E. R. (1983). Improved ion-exchange method for assaying phytate. Cereal Chem. 60, 121–124. EL TINAY, A. H., MAHGOUB, S. O., MOHAMED, B. E., AND HAMAD, M. A. (1989). Proximate composition and mineral and phytate contents of legumes grown in Sudan. J. Food Comp. Anal. 2, 69–78. FERREL, R. E. (1978). Distribution of bean and wheat inositol phosphate esters during autolysis and germination. J. Food Sci. 43, 563–565. GEIL, P. B., AND ANDERSON, J. W. (1994). Nutrition and health implications of dry beans: A review. J. Am. Coll. Nutr. 13, 549–558.

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GRAF, E., AND EATON, J. W. (1993). Suppression of colonic cancer by dietary phytic acid. Nutr. Cancer 19, 11–19. GRIFFITHS, D. W., AND THOMAS, T. A. (1981). Phytate and total phosphorus content of field beans (Vicia faba L.). J. Sci. Food Agric. 32, 187–192. GUSTAFSSON, E-L., AND SANDBERG, A-S. (1995). Phytate reduction in brown beans (Phaseolus vulgaris L.). J. Food Sci. 60, 149–152. HAN, O., FAILLA, M. L., HILL, A. D., MORRIS, E. R., AND SMITH, J. C., JR. (1994). Inositol phosphates inhibit uptake and transport of iron and zinc by a human intestinal cell line. J. Nutr. 124, 580–587. HARLAND, B. F., AND MORRIS, E. R. (1995). Phytate: A good or a bad food component. Nutr. Res. 15, 733–754. HAWKINS, P. T., POYNER, D. R., JACKSON, T. R., LETCHER, A. J., LANDER, D. A., AND IRVINE, R. F. (1993). Inhibition of iron-catalysed hydroxyl radical formation by inositol polyphosphates: A possible physiological function for myo-inositol hexakisphosphate. Biochem. J. 294, 929–934. HAYTOWITZ, D. B., AND MATTHEWS, R. H. (1986). Composition of Foods: Legumes and Legume Products. Agriculture Handbook Number 8-16. United States Department of Agriculture, Washington D.C. HERNA´NDEZ-UNZO´N, H. Y., AND ORTEGA-DELGADO, M. L. (1989). Phytic acid in stored common bean seed (Phaseolus vulgaris L.). Plant Foods Hum. Nutr. 39, 209–221. KANTHA, S. S., HETTIARACHCHY, N. S., AND ERDMAN, J. W., JR. (1986). Nutrient, antinutrient contents, and solubility profiles of nitrogen, phytic acid, and selected minerals in winged bean flour. Cereal Chem. 63, 9–13. KHAN, N., ZAMAN, R., AND ELAHI, M. (1988). Effect of processing on the phytic acid content of Bengal grams (Cicer arietinum) products. J. Agric. Food Chem. 36, 1274–1276. KHOKHAR, P., AND KHOKHAR, S. (1995). The composition of Indian foods- mineral composition and intakes of Indian vegetarian populations. J. Sci. Food Agric. 67, 267–276. KUMAR, K. G., VENKATARAMAN, L. V., JAYA, T. V., AND KRISHNAMURTHY, K. S. (1978). Cooking characteristics of some germinated legumes: Changes in phytins, Ca//, Mg// and pectins. J. Food Sci. 43, 85– 88. LATTA, M., AND ESKIN, M. (1980). A simple and rapid colorimetric method for phytate determination. J. Agric. Food Chem. 28, 1313–1315. LEHRFELD, J. (1989). High-performance liquid chromatography analysis of phytic acid on a pH-stable macroporous polymer column. Cereal Chem. 66, 510–515. LEHRFELD, J. (1994). HPLC separation and quantitation of phytic acid and some inositol phosphates in foods: problems and solutions. J. Agric Food Chem. 42, 2726–2731. LEHRFELD, J., AND MORRIS, E. R. (1992). Overestimation of phytic acid in foods by the AOAC anionexchange method. J. Agric. Food Chem. 40, 2208–2210. LOLAS, G. M., AND MARKAKIS, P. (1975). Phytic acid and other phosphorus compounds of beans (Phaseolus vulgaris L.). J. Agric. Food Chem. 23, 13–15. MAKOWER, R. U. (1970). Extraction and determination of phytic acid in beans (Phaseolus vulgaris). Cereal Chem. 47, 288–295. MANAN, F., HUSSAIN, T., ALLI, I., AND IQBAL, P. (1987). Effect of cooking on phytic acid content and nutritive value of Pakastani peas and lentils. Food Chem. 23, 81–87. MASON, A. C., WEAVER, C. M., KIMMEL, S., AND BROWN, R. K. (1993). Effect of soybean phytate content on calcium bioavailability in mature and immature rats. J. Agric. Food Chem. 41, 246–249. MESSINA, M. (1995). Modern applications for an ancient bean: soybeans and the prevention and treatment of chronic disease. J. Nutr. 125, 567S–569S. MICHAEL, B., ZINK, F., AND LANTZSCH, H. J. (1980). Effect of phosphate application on phytin-phosphorus and other phosphate fractions in developing wheat grains. Z. Pflanzenenernaehr. Bodenkd. 143, 369– 376. MORRIS, E. R. (1986). Phytate and dietary mineral bioavailability. In Phytic Acid; Chemistry and Applications (E. Graf, Ed.), pp. 57–76. Pilatus Press, Minneapolis, MN. MORRIS, E. R., AND ELLIS, R. (1989). Usefulness of the dietary phytic acid/zinc molar ratio as an index of zinc bioavailability to rats and humans. Biol. Trace Elem. Res. 19, 107–117. MORRIS, E. R., AND HILL, A. D. (1995). Inositol phosphate, calcium, magnesium, and zinc contents of selected breakfast cereals. J. Food Comp. Anal. 8, 3–11.

6u04$$0472

02-19-96 19:47:54

jfcaal

AP: JFCA

12

MORRIS AND HILL

PAWAR, V. D., SAWATE, A. R., AND INGLE, U. M. (1986). Changes in phytate phosphorus and minerals during germination and cooking of moth bean (Phaseolus aconitifolius Jacq) seeds. J. Food Sci. Tech. Mysore 23, 36–39. PHILLIPPY, B. Q., AND BLAND, J. M. (1988). Gradient ion chromatography of inositol phosphates. Anal. Biochem. 175, 162–166. PHILLIPPY, B. Q., JOHNSTON, M. R., TAO, S-H., AND FOX, M. R. S. (1988). Inositol phosphates in processed foods. J. Food Sci. 53, 496–499. REDDY, N. R., AND SALUNKHE, D. K. (1980). Effects of fermentation on phytate phosphorus and mineral content in black gram, rice, and black gram and rice blends. J. Food Sci. 45, 1708–1712. SANDSTRO¨M, B., AND SANDBERG, A.-S. (1992). Inhibitory effects of isolated inositol phosphates on zinc absorption in humans. J. Trace Elem. Electrolytes Health Dis. 6, 99–103. SIEVWRIGHT, C. A., AND SHIPE, W. F. (1986). Effect of storage conditions and chemical treatments on firmness, in vitro protein digestibility, condensed tannins, phytic acid and divalent cations of cooked black beans (Phaseolus vulgaris). J. Food Sci. 51, 982–987. SLAVIN, J. (1991). Nutritional benefits of soy protein and soy fiber. J. Am. Diet. Assoc. 91, 816–819. STEWART, K. K (1995). Are they different? II. Significant digits. J. Food Comp. Anal. 8, 1–2. TABEKHIA, M. M., AND LUH, B. S. (1980). Effect of germination, cooking, and canning on phosphorus and phytate retention in dry beans. J. Food Sci. 45, 406–408. TAN, N.-H., RAHIM, Z. H. A., KHOR, H.-T., AND WONG, K.-C. (1983). Winged bean (Psophocarpus tetragonolobus) tannin level, phytate content, and hemagglutinating activity. J. Agric. Food Chem. 31, 916–917. U.S. Department of Agriculture, Human Nutrition Information Service (1992). The food guide pyramid. Home and Garden Bulletin No. 252. U.S. Department of Agriculture, Agricultural Research Service. (1995). Food and nutrient intake by individuals in the United States, 1 day, 1989-91. Continuing Survey of Food Intakes by Individuals, 1989–91, Nationwide Food Survey Report No. 91-2, in press. VIDAL-VALVERDE, C., FRIAS, J., ESTRELLA, I., GOROSPE, M. J., RUIZ, R., AND BACON, J. (1994). Effect of processing on some antinutritional factors of lentils. J. Agric. Food Chem. 42, 2291–2295. WHEELER, E. L., AND FERREL, R. E. (1971). A method for phytic acid determination in wheat and wheat fractions. Cereal Chem. 48, 312–320. WYATT, C. J., AND TRIANA-TEJAS, A. (1994). Soluble and insoluble Fe, Zn, Ca, and phytates in foods commonly consumed in northern Mexico. J. Agric. Food Chem. 42, 2204–2209. YOUNG, V. R. (1991). Soy protein in relation to human protein and amino acid nutrition. J. Am. Diet. Assoc. 91, 828–835.

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