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L Prosky

Publications and source records attributed to L Prosky.

At least 19 recordsLinked to original sources
PubMed2001

Inulin and oligofructose as dietary fiber: a review of the evidence.

This critical review article examines the composition and source of inulin and oligofructose, the physiological effects of their consumption, and how these materials relate to the concept of dietary fiber. Inulin and oligofructose are fructans extracted on a commercial basis from the chicory root. Inulin has been defined as a polydisperse carbohydrate material consisting mainly, if not exclusively, of beta (2-1) fructosyl-fructose links ranging from 2 to 60 units long. Native chicory inulin has an average degree of polymerization (DP) of 10 to 20, whereas oligofructose contains chains of DP 2 to 10, with an average DP of 4. While a universally accepted definition for dietary fiber does not exist, it is generally agreed that this term includes saccharides (+ lignin) that are not hydrolyzed or absorbed in the upper part of the gastrointestinal tract. These materials reach the colon, where they may be totally fermented, partially fermented, or remain unfermented. In addition, fibers contribute to fecal bulking. Inulin and oligofructose are not digested in the upper part of the gastrointestinal tract or are they absorbed and metabolized in the glycolytic pathway, or directly stored as glycogen like 'sugars' or starches. None of the molecules of fructose and glucose that form inulin and oligofructose appear in the portal blood. These materials are quantitatively fermented by the microflora of the colon; further, it has been demonstrated that this fermentation leads to the selective stimulation of the growth of the bifidobacteria population. After reviewing their chemistry, origin, and physiological effects, it is the opinion of the authors that inulin and oligofructose are dietary fiber. They share the basic common characteristics of dietary fibers, that is, saccharides of plant origin, resistance to digestion and absorption in the small intestine, and fermentation in the colon to produce short-chain fatty acids that are absorbed and metabolized in various parts of the body. Moreover, this fermentation induces a bulking effect.

Animals↗
PubMed2000

When is dietary fiber considered a functional food?

Before answering the question of when dietary fiber can be considered a functional food we must first decide what can be called a dietary fiber. The generally accepted definition of dietary fiber is that of Trowell that dietary fiber consists of the remnants of edible plant cells polysaccharides, lignin, and associated substances resistant to (hydrolysis) digestion by the alimentary enzymes of humans. In Japan the food tables list the dietary fiber content of animal as well as plant tissues, while many countries accept saccharides of less than DP-10 as dietary fiber (inulin, oligofructose, Fibersol-2, polydextrose, fructooligosaccharides, galactooligosaccharides etc.). These shorter chain oligosaccharides do not precipitate as dietary fiber in the standard Association of Official Analytical Chemists (AOAC) method, which is accepted by the US Food & Drug Administration, the US Department of Agriculture and the Food & Agriculture Organization of the World Health Organization for nutrition labeling purposes. In the United Kingdom the term dietary fiber has been replaced in nutrition labeling by nonstarch polysaccharides. Therefore the American Association of Cereal Chemists (AACC) commissioned an ad hoc committee of scientists to evaluate continuing validity of the currently used definition, and if appropriate, to modify and update that definition. Obtaining scientific input from the community of analysts, health professionals, and dietary fiber researchers was considered a high priority. To this end three meetings were held in the space of six months to assure input from all persons knowledgeable in the field with the answer expected sometime before 2000. Dietary fiber can be considered a functional food when it imparts a special function to that food aside from the normal expected function and similarly when the dietary fiber is used as an additive to foods. For example, dietary fiber contributes to colonic health, bifidobacterial or lactobacillus stimulation in the gut, coronary artery health, cholesterol reduction, glucose metabolism, insulin response, blood lipids, cancer etc. The author discusses in detail the functional food properties of dietary fiber.

Dietary Fiber↗
PubMed1999

Methods to determine food inulin and oligofructose.

The fructans, inulin and oligofructose, were known to possess many of the physiologic properties of dietary fiber (DF) but were not listed as DF on the labels of foods that contained them because they did not precipitate in 78% ethanol as prescribed in the AOAC International methods for DF. In the latter part of 1995, the Food and Drug Administration (FDA) agreed to consider fructans as DF if an AOAC-accepted analytical method could be successfully developed for fructans. Six blind duplicate pairs of foods, containing from 4 to 40% of inulin or oligofructose, were sent to nine collaborators in five countries for assay. These foods included a low fat spread, cheese spread, chocolate, wine gum, dry ice mix powder and biscuits. In the proposed method, the samples were treated with amyloglucosidase and inulinase, and the sugars released were determined by ion-exchange chromatography. The concentration of the fructan was calculated by the difference in sugars present in the two enzymic treatments and the initial sample. The repeatability standard deviations (RSDr) for the inulin and oligofructose ranged from 2.9 to 5.8% and the reproducibility standard deviations (RSDR) for these fructans ranged from 4.7 to 11.1%. The method was accepted by the AOAC as an official first action.

Chromatography, Ion Exchange↗
PubMed1982

Perspective of Food and Drug Administration on Dietary sodium.

The sodium and potassium content of typical American diets of infants, toddlers, and adults was determined, both for total content and for content at the commodity group level, by chemical analysis of representative diets from 1977 through 1980. In recent years the scientific community has reached a consensus that high sodium intake is positively associated with hypertension. Various professional groups urge the American public to reduce their sodium intake. Several monitoring initiatives of the Food and Drug Administration relative to sodium in the national food supply are discussed.

Adolescent↗
PubMed1981

Estimation of dietary iodine intake of Americans in recent years.

The iodine content of diets of typical American infants, toddlers, and adults in recent years was found to be far in excess of the amount necessary for adequate nutrition. Dairy products were the major contributor. Other large contributors were grain and cereal products, sugars and adjuncts, and meat, fish, and poultry in adult diets and grain and cereal products and meat, fish, and poultry in infant and toddler diets. A statistical evaluation of the data and a discussion of possible sources of iodine are presented.

Adolescent↗
PubMed1980

Calcium, phosphorus, iron, iodine, and zinc in the "total diet".

Advances in food technology have changed the nutrient composition of foods, raising questions as to whether mineral intakes in the U.S. are now adequate or excessive. When the FDA assayed "market basket" samples collected at the retail level in twenty urban areas of the U.S. during 1974 and 1975, the following minerals and the daily intake as percentages of the U.S. RDAs were found: (a) For adults (based on a 2,800 kcal intake)--calcium, 114; phosphorus, 171; iron, 98; iodine, 428; and zinc, 89; (b) for six-month-old infants--calcium, 163; phosphorus, 173; iron, 47; iodine, 878; and zinc, 112; and (c) for two-year-olds--calcium, 114; phosphorus, 130; iron, 112; iodine, 526; and zinc, 106.

Adolescent↗