Potential Source Of Dietary Fiber Research Articles

Water sorption isotherms for lemon peel at different temperatures and isosteric heats

Lemon peel constitutes a potential source of dietary fiber to formulate new and healthier products, as well as a source of essential oils. The relationship between moisture content and water activity provides useful information for lemon peel processing, especially for drying and storage. Water sorption isotherms of lemon peel were obtained using a standardized conductivity hygrometer at four different temperatures (20, 30, 40 and 50 °C) and wide ranges of moisture content (5.381–0.002 kg water/kg dry solid) and water activity (0.984–0.106). One theoretical (GAB) and four empirical equations (Oswin, Henderson, Halsey and Ratti) were used for modelling sorption isotherms. After evaluating the models according to several criteria, the GAB model appeared as the best option. Isosteric heats of sorption were assessed from experimental sorption isotherm data using different methods.

Spent residue from cumin – a potential source of dietary fiber

Cumin has total dietary fiber content (TDF) of 59.0%, insoluble dietary fiber (IDF) of 48.5%, and soluble dietary fiber (SDF) of 10.5%, while the spent residue from cumin (after oil and oleoresin extraction) was found to contain 62.1% TDF, 51.7% IDF and 10.4% SDF. The spent residue also contained 7.7% starch and 5% bound fat. Particle size analysis showed a direct effect on the hydration properties of the fiber. The spent residue exhibited 3.3 g/g water holding capacity, 4.0 g/g water retention capacity and 4.47 ml/g swelling capacity. Scanning electron microscopy revealed spherical starch granules embedded within cell wall material, which upon differential sedimentation gave differently sized starch granules (5.8 μm). Upon defatting the spent residue showed typically a ‘honey comb’ structure, almost devoid of starch granules. Thus, the spent residue from cumin, not having much commercial value at present, can be a rich source of useful dietary fiber and can find food applications. It can be an effective way of utilizing industrial waste from the point of view of environmental pollution from the residues of spice processing industries.

Chemical and Microbiological Characterization of Portuguese Varieties of Pears

The sun-dried pears of the local variety known as S. Bartolomeu , found in the centre of Portugal, are relatively small fruits, characterized by an intense reddish brown colour, that loose their pronounced astringency with drying. However, and since their production has been declining over the past decades, there has been an increasing interest in drying also for other varieties of pears, also with small dimensions, as an alternative to produce the dried pears. The aim of this work is the evaluation of the nutritional properties of fresh and dried pears of the local varieties known as Amendoa, Amorim, Carapinheira Branca and S. Bartolomeu , all original from of the centre of Portugal. The results enable us to conclude that the fresh pear pulp of all varieties has a low content of protein and a high level of total sugars, as is generally true for fruit. However, their values of dietary fiber ranged between 12 and 15% (dry mass) constituting these pears a potential source of dietary fibre. In addition, it is also possible to conclude that, apparently, the solar stove-drying process has no effect on the nutritional characteristics of the pears, except on total sugars and acidity. The range of water activity values and microbial charge of the different pears also allow inferring that the dried fruits obtained from the four varieties studied are potentially safe from a microbiological point of view. The resemblance in the characteristics of the fruits, together with the similarity of behaviour towards drying, suggests that the fruits of the varieties Carapinheira Branca, Amendoa and Amorim can be viewed as a good alternative to those of the variety S. Bartolomeu for the production of dried pears.

Potato Peel Dietary Fiber Composition: Effects of Peeling and Extrusion Cooking Processes

Potato peels are a potential source of dietary fiber. The abrasion peeling method used by chip manufacturers results in more starch and less dietary fiber than the steam peeling procedure used for production of dehydrated potatoes. The objective of this study was to identify differences in dietary fiber composition between these types of peels and the effects of extrusion on fiber. Peels were extruded in a twin screw extruder at barrel temperatures of 110 or 150 °C and feed moistures of 30% or 35%. Extrusion cooking reduced starch content and increased total dietary fiber in steam peels. Total dietary fiber in abrasion peels was not affected by extrusion. Extrusion increased soluble nonstarch polysaccharides in both types of peels. More glucose was recovered from insoluble fiber of extruded steam peels than from abrasion peels, suggesting that resistant starch may have been formed. Lignin increased in extruded steam peels but decreased in extruded abrasion peels. Keywords: Dietary fiber; starch; peeling; potato; extrusion

Inulin as the soluble fiber in liquid enteral nutrition

Dietary fibers are a necessary part of human nutrition. Inulin is a fermentable fiber that improves bacterial ecology in the large bowel and is also a relevant substrate for short-chain fatty acid (SCFA) production. The aim of the present study was to evaluate the clinical effect of inulin, added as dietary fiber into the fiber-free enteral nutrition (Nutrison Standard). Inulin (30–35 g/d) was administered for 1 wk to a group of patients requiring the nutritional support of a liquid enteral diet. A significant increase in flatulence, an indication of rapid bacterial fermentation, was apparent during its infusion in comparison with a fiber-free enteral diet. Moreover, an increment in ability to dehydrate the cecal stream (stool consistency) was apparent in nearly half of patients. No changes in SCFA concentration in stool and indican output in urine were apparent after 1 wk of inulin administration. Intestinal permeability ( 51Cr-EDTA absorption test) was not influenced by either enteral nutrition or inulin and enteral nutrition administration. Because of good tolerance inulin seems to be a potential source of dietary fiber in clinical enteral nutrition.

Glycoalkaloid Content and in vitro Glycoalkaloid Solubility of Extruded Potato Peels

Potato peelings from French fry production are a potential source of dietary fiber, but the presence of naturally occurring glycoalkaloids could limit their use as a food additive. Potato peels were twin-screw extruded at 110 or 150 o C and 30 or 35% feed moisture to potentially reduce levels of glycoalkaloids. Individual glycoalkaloids were measured by HPLC. Neither α-chaconine nor α-solanine decreased on a dry weight basis from nonextruded peels (3.9 and 8.0 mg/10g, respectively). Extrusion did not change α-chaconine/α-solanine ratios. Only 3-5% of total glycoalkaloids were solubilized during in vitro digestion

Cocoa hull: A potential source of dietary fibre

AbstractCocoa hull dietary fibre (DF) was evaluated by an enzymic‐gravimetric method. Insoluble dietary fibre (IDF) and soluble dietary fibre (SDF) were subjected to acid hydrolysis and the resultant neutral sugars, uronic acids, and Klason lignin were quantified. Cocoa hull exhibited a high content of total dietary fibre (TDF), 504 g kg−1 on a dry weight (DW) basis, IDF being the main fraction found. Glucose was the major sugar constituent of the IDF fraction whereas the uronic acids were equally distributed in the IDF and SDF fractions. The chemical composition reveals that pectic polysaccharides and cellulose contributed in similar amounts to TDF (107 g kg−1 and 92 g kg−1 DW, respectively). Non‐starch polysaccharides accounted for 222 g kg−1 DW, while the content of Klason lignin was lower (161 g kg−1 DW). The main pectic substances in the insoluble fibre were low methoxyl pectins whilst those of the soluble fibre were high methoxyl pectins. Cocoa hull appears to be a good source of DF that might be used to supplement other sources of fibre or food products.

Enzymatic Starch Hydrolysis of Extruded Potato Peels

AbstractPotato peels discarded by potato processors are a potential source of dietary fiber and starch. This starch may be hydrolyzed for fermentation to value‐added products. Dried steam peels were extruded at 135°C and 22% feed moisture and digested with α‐amylase and/or amyloglucosidase. Two barrel temperatures and feed moistures were also studied. Glucose was measured colorimetrically at O,1,2,4,8 and 24h of incubation. All peels treated with either no enzymes or α‐amylase alone produced minimal glucose. Nonextruded peels digested with both enzymes produced more glucose than did those treated with amyloglucosidase alone. Complete digestion of starch occurred in extruded peels digested with amyloglucosidase, but not when α‐amylase was used.

Dietary fiber from mango byproducts: Characterization and hypoglycemic effects determined by in vitro methods

Mango (Mangifera indica L.) byproducts, which represent 35-60% of the processed fruit, are a potential source of dietary fiber. After ethanolic purification, we found that peels and fibrous waste pulp had a high dietary fiber content (74% of the dry matter) with a soluble/insoluble ratio close to 1 and a 15-20% uronic acid content. The fiber water-soluble fraction showed shear-thinning behavior. In vitro studies indicate that these fibers decreased total starch digestibility and slowed the final rate of amylolysis of mashed potatoes as the starch source. Glucose diffusion was also retarded in the presence of mango fiber. These results suggest that mango byproducts are a good source of dietary fiber which could be of potential benefit in controlling plasma glucose. (Resume d'auteur)

食物繊維原料としてのカンキツ果実の搾汁かす

食物繊維原料としてのカンキツ果実の搾汁かす

Peanut Hull Flour as a Potential Source of Dietary Fiber

ABSTRACTPeanut hull flour (PHF) was prepared from two types of peanuts and subsequently analyzed and evaluated as a dietary fiber source. The yield of PHF from the sheller‐run hulls ranged from 15–33%. The PHF averaged 47.3% crude fiber. The neutral detergent fiber content was 78.1% and consisted of 25.5% lignin, 18.0% hemicellulose, and 34.6% cellulose. Fourteen elements were determined in the ash: P, Ca, Mg, and K were present in the highest concentrations. Holding capacities were 3.1g water/g flour and 1.7g oil/g flour. Cation exchange capacity was 1.0 meq/g flour; emulsifying capacity, 26.6 ml oil/g flour. Gross energy content was 4.57 Kcal/g, but about 0.52 Kcal/g would be available in the monogastric digestive system. Toasting caused a slight darkening of the flour and the flours had a slight peanut flavor. Thus, PHF seems to have potential for use as dietary fiber.