Chemical and Physical Properties, Safety and Application of Partially Hydrolized Guar Gum as Dietary Fiber

Abstract

The ideal water-soluble dietary character for the fiber-enrichment of foods must be very low in viscosity, tasteless, odorless, and should produce clean solutions in beverages. partially hydrolyzed guar gum ( PHGG ) produced from guar gumwood by enzymatic procedure has the same chemical structure with integral guar mumble but less than one-tenth the original molecular length of guar gum, which make available to be used as film erstwhile, foam stabilizer and swelling agentive role. The viscosity of PHGG is about 10 mPa·s in 5 % aqueous solution, whereas 1 % solution of guar glue shows range from 2,000 to 3,000 mPa·s. In addition, PHGG is greatly stable against depleted ph, heat, acidic and digestive enzyme. For these reasons, PHGG seems to be one of the most beneficial dietary fiber materials. It besides showed that interesting physiological functions still in full exert the nutritional officiate of a dietary fiber. PHGG has, therefore, been used chiefly for a nutritional purpose and became amply integrated food material without altering the rheology, taste, texture and tinge of final examination products. PHGG named as Benefiber® in USA has self-affirmation on GRAS condition of standard grade PHGG. PHGG named as Sunfiber® is nowadays being used in respective beverages, food products and medicative foods as a safe, natural and functional dietary roughage in all over the world. Keywords:

Cyamoposis tetragonolobus, partially hydrolyzed guar gum (PGHH), dietary fiber

Introduction

dietary fibers are considered as crucial alimentary component for human health, and particularly, water-soluble dietary fibers have received much attention due to its diverse physiologic function. The dietary fibers can be defined as a wide variety show of substances that belong to the class of carbohydrate and that resist to be digested by the endogenous secretions of the human digestive tract, which would include gums, pectin, lignin, cellulose and hemicellulose. It besides includes repellent starch as a minor component remaining after the hydrolysis of starch by the addition of starch metabolizing enzymes in the assay procedure of the AOAC ( Association of Official Agriculture Chemists ) method acting. Basically, dietary fibers are natural polysaccharides and the origin of that is natural component .

Guar Gum as Dietary Fiber

Guar glue, one of the most promise dietary fibers, is a gel-forming galactomannan obtained by grinding the endosperm assign of Cyamoposis tetragonolobus L., a leguminous plant grown for centuries chiefly in India and Pakistan to produce the seed for human and animal food [ 1 ]. It was reported that guar gingiva was foremost used for food products in the U. S. in 1949 [ 2 ]. Since 1953, the seeds of the guar plant have been processed into guar gingiva, and wide used in modern food industry as thickening and emulsion stabilizer for both food and industrial purposes in all over the world with increasing amounts. Guar mumble is structurally comprises long, straight chains of α-D-mannopyranosyl units linked together by β-D- ( 1-4 ) -glycosidic linkage. The hexose linked along this chain is α-D-galactopyranose and these side groups appear on both side of the mannose chain at about every other mannose link in the main chain [ 3 ] ( Fig. A ). consequently, the proportion of mannose to galactose in galactomannan of guar gumwood has been known approximately 2:1 [ 4, 5 ]. Although a single molecular weight can not be given due to difficulty for determination, it is estimated to be in the crop of 200,000 to 300,000 daltons [ 6 ]. Galactomannan is presents in assorted natural sources such as coffee beans, soy beans, alfalfa seeds, pineapple, sugar beets, and locust beans [ 7 ]. There are surely benefits when guar gumwood are included in human diets. however, guar gingiva is highly syrupy which results in the liquid products with high viscosity when it is added to enteric formulas at a physiologically effective concentration, thereby its utilization may be restricted for dietary fiber supplement in actual food products, particularly for liquid products. high viscosity of guar glue besides decreases the protein efficacy [ 8 ] and lipid use [ 9 ] by interfering with the digestion and assimilation of food [ 10 ] when it dissolved into body of water, results in a slower gastric emptying [ 11 ] .Open in a separate window

Guar Gum and Emzymatic Hydrolysis

partially hydrolyzed guar glue ( PHGG ) is a natural body of water soluble dietary roughage. The guar plant, Cyamoposis tetragonolobus L. has been grown in India and Pakistan since ancient times and used for both human foods and animal tip stuffs. In 1950s, the seeds of the guar plant have been processed into guar mumble in always increasing amounts to meet the demand of the modern food industry. however, the viscosity of guar gum limits its applications in assorted foods particularly melted products. PHGG is produced by controlled overtone enzymatic hydrolysis of guar glue seeds. As the metabolic, nutritional and analytic properties of the low-viscosity PHGG represent to those of guar gum, this product is used chiefly for a nutritional purpose, i.e. for the fiber-enrichment of processed foods. Its safety was confirmed by subchronic feed cogitation and mutagenecity test. Its specific chemical and physical properties could make it possible to improve the choice of food token world-widely .

Chemical Structure of PHGG

To solve the problems of guar gingiva as mentioned in above, PHGG was produced by controlled enzymatic hydrolysis using β-endo-mannanase, followed by sterilization and spray dry, and last produced as shown in manufacturing scheme [ 12 ] ( Fig. ( B ) ). The product was named as Sunfiber®, and of which repeating unit of structure is depicted in Fig. ( A ). Endo-β-D-mannanase can hydrolyze galactomannan and thereby PHGG by selectively cutting the main mannan backbone-chain [ 13, 14 ], leaving the pendent galactosyl groups integral. The resulting product obtained through by the promote processes, separating, purifying, drying and powderize, would have the same natural character with smaller galactomannan molecules in human diets. The molecular size of PHGG, was one-tenth the original length of guar gum, ranged from 1,000 to 100,000 daltons, and average molecular weight unit was 20,000 daltons when it was analyzed by gel filtration HPLC.

Physical Properties of PHGG

Guar gum formed a gluey colloidal solution when hydrated in coldness water, while PHGG showed clear solution with lower viscosity than non-hydrolyzed guar gum. The viscosity of 1 % aqueous solution of commercial food-grade guar gum ranged from 2,000 to 3,000 mPa·s, whereas that of a 5 % solution of PHGG was less than 10 mPa·s, ideal viscosity for increase the dietary fiber contentedness in beverages [ 15 ], which indicated that the β1→4 mannosidic linkages available for the enzyme attack strongly contribute to maintaining viscosity of guar gum [ 16, 17 ]. low viscosity of PHGG provides a distinct advantage for the use of fiber in enteric feed products that need to be administered through feeding tubes as the method acting of feeding access dictated by the clinical set. PHGG is white might, soluble in water, colorless and guileless in body of water solution, and about tasteless. When exposed to high temperature over long periods of time, the chemical structure of PHGG undergo no variety and its viscosity was decreased systematically with increasing the temperature, which make it easy to application in manufacturing procedure with high temperature. PHGG is stable and soluble at diverse ph levels normally found in foods deoxyadenosine monophosphate well as insubordinate to hotness, acidic, salt, gamey pressure and digestive enzyme [ 18, 19 ]. It appeared to have little or no interaction between PHGG and other common food ingredients. PHGG does not destabilize emulsions, change the viscosity of protein solution, affect to flavor and color of the products, or campaign soluble materials to precipitate. In addition, PHGG prolongs the self-life of high starch foods such as boodle by decreasing the turbidity of dextrin when it added to dextrin solution at moo temperatures. The dietary fiber content of PHGG was identical high gear, more than 75 %, when measured by the AOAC method. The characteristics and properties of PHGG are summarized in Table .

Table 1

Physical propertyStructure typeGalactomannanMolecular weight (average)20,000 daltonspH value6.7–7.0Viscosity (5% solution)≤10 mPa·sAppearanceWhite powderSolubility in waterHighAppearance on waterColorless, TansparentSweetness≤10*BacteriologicalTotal plate count≤3,000/gColi formsNegativeViscosity stabilityHeat≤130°CAcidpH 3.0–7.0Salt (NaCl)≤10%Digestive enzymeResistance to amylase, pectinase, esterase, etc.CompositionDietary fiber≥75%Moisture≤7%Ash≤2%Protein≤1.0%Heavy metal≤20 ppmOpen in a separate window

Safety Aspects of Guar Gum and PHGG

The base hit data on guar glue may be largely available to establish the guard of its partially hydrolyzed analogue, PHGG. The safety of guar gingiva has been assessed by JECFA ( Joint Expert Committee on Food Additives ) in 1975 [ 20 ] and by the EEC ’ sulfur SCF ( european Economic Community, Scientific Committee on Foods ) in 1978 [ 21 ]. In USA, guar gum has been considered GRAS ( by and large Recognized As Safe ) since 1974 in numerous food applications [ 22 ]. Guar glue did not elicit measurable mutagenic responses in the host-mediated assay using Salmonella [ 23 ], and was not carcinogenic in either species or sexual activity [ 24 ]. When glycosidic linkage in mannose main chain of guar mumble is partially bankrupt and thereby shorten in molecular size, the question, however, can be arisen whether this merchandise plays an peer action in homo nutrition as the natural form or not. consequently, it should be confirmed that the human body handles partially hydrolyzed guar gingiva, in the like manner as intact guar gingiva, and thereby partially hydrolyzed guar gum is safe because structural change might influence of its fortune when ingested. Studies indicated that PHGG had not only lower molecular weight and lower viscosity than guar gum but besides lapp physiological effect as the larger molecular weight soluble character in vivo tests [ 25, 26 ]. There is a report that the procedure of partial hydrolysis by enzyme breaks the guar gum down in the lapp manner as the human intestinal tract in which guar chewing gum is metabolized by the colonic irrigation microflora as is entire guar gum tree, with the products of metabolism being the same, since in both cases metamorphosis is based on the agitation of mannose and galactose [ 27 ]. therefore, the overtone hydrolysis is merely a predigestion step occurring in the convention digestion of the guar gum by the body. Because the structural change in guar gum tree is merely shortening the mannose chain, geomorphologic relationships between the mannan chain and the galactosyl side group in PHGG remains the same with unhydrolyzed guar gum tree. There is no tell to assume that size or viscosity would have any influence on the guard of the hydrolyze galactomannan molecules. The Life Sciences Research Organization of the Federation of American Societies for Experimental Biology commissioned a gore of 6 experts to assess the function of PHGG in consumer foods in 1993 [ 28 ], and the FDA accepted for filling a GRAS avowal prayer of PHGG in May 1995 [ 29 ]. A history of condom manipulation has been established in Japan where the intersection is used as a dietary roughage in versatile foods since 1987. perniciousness of PHGG was tested with male and female Sprague-Dawley rats at drug levels of 0, 0.5 and 2.5 g/kg soundbox weight/day for 28 days [ 26 ]. The results demonstrated that PHGG was well tolerated, and food pulmonary tuberculosis and consistency weight gain were not influenced by the treatment. urinalysis, hematologic examination and blood chemical analysis did not reveal any abnormalities that could be attributed to the treatment arsenic good as no deaths and no changes were observed in the general condition of the rats. In another test, the dietary levels up to 10 % PHGG were tolerated without any signs of perniciousness in a subchronic ( 13-week ) feeding survey in rats [ 30 ]. The mutagenecity of PHGG was examined in a microbial reverse mutant assay with Salmonella typhimurium TA100 and TA98 strains, in which concentrations of up to 5 mg/plate did not have any impression on inverse mutant rates. From all these evidences, a low-viscous galactomannan ( PHGG ) can be, consequently, considered as safe. administration of PHGG for 4 weeks to adult men at the drug of 36 g/day has resulted in no side effects [ 31 ], and a daily inhalation of 20–40 g/day PHGG has well tolerated and showed no side effects [ 32 ]. For the desire consumption value, 20–30 g/day of dietary fiber has been recommended based on 2,000–2,500 kcal/day for an average in Japan. On the base of all of experiment data and published scientific testify, PHGG is considered as safe and allow to use as a ingredient of enteric nutrition products and liquid oral addendum products for function of providing dietary fiber .

Applications of Guar Gum and PHGG

In addition to the usage of guar glue in food reviewed in book written by Whistler and Hymowits [ 33 ], use for pharmaceutical planning was besides suggested, in which a assortment of guar gingiva, a bovine gelatin hydrolysate, sodium glycinate, and an allow measure of flavoring agents was blended and heated to yield product which could be administered orally for the discussion of digestive tract disorders [ 34 ]. Because partially hydrolyzed guar glue ( PHGG ) is soluble in body of water, very depleted in viscosity, and about loose of color and taste, which correspond to those of guar chewing gum, it can well be used with sufficient amounts to give dietary roughage effect in food, and thereby it has wide been used in Japan as a new fiber resources since 1987 for a nutritional determination. These specific chemical and physical properties could make it possible to improve the quality of food detail. For example, addition of PHGG can improve in march of cereals by increasing hang ability, provide body and mellowly relish in most beverages, stabilize the colloid system of dry and liquid meal replacements, laid-back acerbity and firm texture in yogurt, stabilize the foam system of shakes, improve pause of particulate in soups and dressings and give good eat qualities in broil goods [ 12 ]. besides, PHGG has been widely used in food formulation such as beverages and breads [ 35 ], food binder [ 36 ], paper coating [ 37 ], and petroleum industry [ 38 ]. On the footing of those characteristics, the PHGG, partially hydrolyzed guar gum, is now being used in many different ways in a versatile fields of beverage and food as bulge agent ( i.e. in Yogurt beverages, carbonated beverages, frosting cream and starch syrup ), option of wheat flour ( i.e. in cookies ), food stabilizer ( i.e. in whisk skim ), source of dietary fiber ( i.e. in bavarian desserts and custard pudding ), substitute of sugar ( i.e. in whisk cream and steamed boodle ), accessory for readiness of powder from fluid sugars, coating materials ( i.e. in meringue cake with high-fat nuts and dried pisces with luster ), and inhibitor of starch dispersion from the surface of boiled rice without any change in smack and texture of final intersection .

Recommended Daily Intake of Dietary Fiber

The most thorough late analysis of fiber intake in the United States was conducted by FASEB ( Federation of American Societies for Experimental Biology ) [ 39 ] as share of their “ Physiological Effects and Health Consequences of Dietary Fiber ” monograph prepared for FDA. FASEB summarized a total of consumption studies and calculated ranges of roughage intake, whose data showed a daily per caput consumption of 11.1–23.3 g/day or 5.8–11.8 g/1,000 kcal [ 40 ]. The estimate total dietary fiber intake varies between about 10–25 g/day in most develop countries. A WHO study group has recommended a casual consumption of about 37 g sum dietary fiber. The FASEB expert panel has recommended a daily inhalation of 20–35 g/day total dietary character from foods for the goodly, pornographic population of the USA [ 37 ]. The minimal value was based on the effects of dietary fiber on intestinal function, while the maximum measure was chosen with an eye towards the possibly deleterious effects of bombastic amounts of dietary fiber on mineral poise. This recommendation calculates out to be 10 to 13 g dietary fiber/1,000 kcal. The American Diabetes Association has recommended a roughage consumption of 40–50 g/day [ 41 ]. This degree is significantly higher than the level recommended by FASEB. When Fredstrom et alabama. analyzed the soluble, insoluble, and total dietary fiber subject of a number of presently marketed enteric products, the fiber content of these products varied widely, ranging from 5–20 g/1,000 kcal [ 42 ]. The insoluble character, soluble fiber, and total dietary fiber in one merchandise were 5.4 g/1,000 kcal, 4.6 g/1,000 kcal, and 9.9 g/1,000 kcal, respectively ; approximately 45 % of the total dietary fiber in those products were soluble fiber. The craved inhalation value of 20–30 g/day of dietary fiber has been recommended in Japan based on 2,000–2,500 kcal/day.

Conclusions

The ideal water-soluble dietary fiber for the fiber-enrichment of foods must be very low in viscosity, tasteless, odorless, and should produce clear solutions in beverages. partially hydrolyzed guar gum ( PHGG ) produced from guar gum tree by enzymatic process has lapp chemical structure with integral guar gum but one-tenth the original molecular distance of guar gum, which make available to be used as film early, foam stabilizer and swelling agentive role. The viscosity of PHGG is about 10 mPa·s in 5 % aqueous solution, whereas 1 % solution of guar gum shows range from 2,000 to 3,000 mPa·s. In addition, PHGG is greatly static against broken ph, heat, acid and digestive enzyme. PHGG seems to be one of the most beneficial dietary roughage materials. It showed that interesting physiological functions placid in full exert the nutritional function of a dietary fiber. PHGG has, consequently, been used primarily for a nutritional purpose and became fully integrated food material without altering the rheology, smack texture and color of final products. PHGG named as Benefiber® in USA has self-affirmation on GRAS condition of standard degree PHGG [ 29 ]. PHGG named as Sunfiber® is now being used in assorted beverages, food products and medicative foods as a safe, natural and functional dietary character in all over the earth ( Fig. ) .Open in a separate window