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LETTERS 934 A new Dear term Various EDITOR in nutrition terms have to define components not digested by by the been proposed in recent that part of food plants, of the plant cell wall, that human human enzymes or gastrointestinal abtract (1-3). Most of these suggestions, which have been previously discussed by Spiller and Amen (1) and which are illustrated in Figure 1, include the term “fiber,” an expression that is not quite correct. Fiber is used in many other fields, such as anatomy (muscle and nerve fiber), optics, and textiles. Also, in dealing with the effects of the plant cell wall, we include both fibrous and nonfibrous components. There is undoubtedly a need for a term to represent the sum of substances designated as C in Figure 1, and perhaps another to encompass these substances plus associated plant cell wall factors, C + D. The sum of the components listed in C can then be substituted in nutritional studies and food composition tables for crude fiber, which is acknowledged to be both an imprecise term and an inaccurate analytical procedure (46). We propose a new word, plantix, derived from two Latin words: planta and matrix (plant and with plant matrix). We are obviously recognized first and step that in the our suggestion adaptation of this Gayle Department Syntex Gene A. Spiller, Fasseit-Cornelius, of Nutritional Research, Palo Science Alto, California A B FIBER COMPLEX (Trowell 121) C D PURIFIED PLANT FIBER (PPF( (Spiller & Amen (1)) DIETARY FIBER (Trowell (21) ASSOCIATED PLANT CELL FACTORS (APF) WALL - cellulose - waxes, cutins - hemicelluloses - proteins - mucilages cell wall-bound (undigestible) - pectins - minerals gums cell wall-bound (undigestible) - - other cell wall-bound undigestible substances - lignin DIGESTIBLE I. Suggested classification of COMPONENTS Proteins, fats and other lipids, carbohydrates, vitamins, minerals and water that are digested such, or hydrysed by human digestive enzymes and then absorbed (the sum of all of them; or a single entity. Analyses to be given whenever possible) FIG. will be the nomencla- ture. NONPURIFIED PLANT FIBER (NPPF) (Spiller and Amen 11)) NONNUTRITIVE FIBER (Kritchevsky (3)) DIETARY dealing materials, the undigested com-. pounds form a matrix in the digestive system of humans (up to the ileocecal valve), and the action of colonic bacteria on this matrix is responsible for many physiological effects. Plantix would be used to describe the sum of substances given under C in Figure 1 (C + D could be called complantix from complex plant ix). Such adjectives as “purified,” “nonnutritive,” and “dietary” could further particularize the basic “plantix.” Differences in value between crude fiber and plantix (Trowell’s dietary fiber and Spiller and Amen’s purified plant fiber) are shown in Table 1 as an illustration of the need for an explicit term. We hope that the need for a definitive nomenclature in this field will be universally plant fibers. Ph.D. B.A. Downloaded from ajcn.nutrition.org at PENNSYLVANIA STATE UNIV PATERNO LIBRARY on May 11, 2016 sorbed fibers THE Sir: years mostly are for plant TO LETTERS TABLE TO THE EDITOR I Approximate plantix content of some common foodstuffs Neutral detergent fiberNDF Food Plantix (total) P2 (proposed) NDF+P’ g/lOO Fruits Crude fiber CF’ = g dry mailer and vegetables 12 14 9 Lettuce 17 Squash (whole (peeled) (peeled) 4 5 IS 17 5 19 4 12 7 3 29 19 28 21 16 12 18 9 8 6 12 3 1 6 7 kernel) Whole barley 27 Traces 27 Whole corn 13 Traces 13 3 31 14 60 Traces Traces Traces Traces Traces 31 14 60 45 24 13 3 14 11 13 Whole oats Whole wheat Corn bran Wheat bran Rice bran 45 24 ‘NDF = Cellulose + hemicelluloses + lignin according to Van Soest’s methods analyzed by Robertson and Steh (4) for fruits and vegetables, and Van Soest (5) for grains. Cellulose, hemicelluloses, and lignins can be also analyzed by the Southgate method (4). 2 Pectin = Total pectic substances (soluble + insoluble pectins) expressed as calcium pectate. Data from Kertesz (6). Pectin is extremely low in grains, usually about 1%. Plantix (proposed term) = NDF + pectin; for foods with negligible amounts of gums and mucilages. In other cases, gums, and mucilages should be included in the sum. Crude fiber analyses by Robertson and Steh (4) for fruits and vegetables and Van Soest (5) for grains. George M. Briggs, Ph.D. 2. H. C. Ischaemic heart disease and dietary J. Clin. Nutr. 25: 926, 1972. 3. KRITCHEVSKY, D., AND J. A. STORY. Binding of bile salts in vitro by nonnutritive fiber. J. Nutr. 104: 458, 1974. 4. SPILLER, G. A., AND R. J. AMEN. Dietary fiber in human nutrition. CRC Crit. Rev. Food Sci. Nutr. 7: 39, 1975. 5. VAN SOEST, P. J. Proceedings: Cornell Nutrition TROWELL, fiber. Department University Berkeley, of Nutritional of California California Science References 1. SPILLER, G. A., nutrition: need Nutr. 28: 675, Fortification Dear We R. J. AND AMEN. for better 1975. nomenclature. of salt with Plant fibers Am. in J. Clin. Am. Conference 6. KERTESZ, New York for Feed Z. I. The Interscience Manufacturers, Pectic 1973. Substances. Publishers, 1951, New pp. York: 281. iron Sir: were greatly interested in the paper by B. S. Narasinga Rao and C. Vijayasarathy in the American Journal of Clinical Nutrition 28: 1395, 1975 on the experimental fortification of salt with various iron compounds. Stott (1) and others (2-4) carried out a long-term study of this subject in Mauritius and the Seychelles in the early 1960’s. Their results showed that an iron fortification pro- gram carried out in the field is a great deal more complicated to mount than originally thought. The predominant anemia in Mauritius is iron deficient and mostly due to blood loss from hookworm infestation, so it was decided to fortify the locally made sea salt with soluble iron pyrophosphate. Prior to this, the import of salt was prohibited and when the Downloaded from ajcn.nutrition.org at PENNSYLVANIA STATE UNIV PATERNO LIBRARY on May 11, 2016 Apples(peeled) Cabbage Carrots Oranges Potatoes Grains 935