gamma-cyclodextrin and maltodextrin

The gastrointestinal tolerance of gamma-cyclodextrin (gamma-CD) was examined in 24 healthy human volunteers. In a double-blind, placebo-controlled, randomized cross-over study, single acute doses of 8 g maltodextrin (placebo) or 8 g gamma-CD (test) were consumed as a mid-morning snack after addition to 100 g yogurt. Gastrointestinal symptoms as well as frequency and consistency of stools were recorded before and after lunch at between 3-4 and 7-8 h after intake respectively. The perception of the symptoms was rated on a subjective scale ranging from 1 ('more than normal') to 3 ('exceptionally more than normal'). Following consumption of maltodextrin, five subjects reported a total of 12 symptoms of which seven, two and three were rated as having grade 1, 2 and 3, respectively. Following consumption of gamma-CD, five subjects reported six symptoms all of which were graded as 1. Two subjects reported flatulence, which is a frequent consequence of the consumption of malabsorbed carbohydrates, after placebo and test treatment. The incidence of individual and combined side-effects as well as the number and consistency of faeces passed was not significantly different between placebo and test treatment. It is concluded that single doses of 8 g gamma-CD and maltodextrin are tolerated equally well. This is in keeping with a good digestibility of gamma-CD by salivary and pancreatic amylase.

Topics: Adolescent; Adult; Cross-Over Studies; Cyclodextrins; Double-Blind Method; Female; Food Additives; gamma-Cyclodextrins; Gastrointestinal Diseases; Humans; Male; Polysaccharides

The crystal structure of a Thermoactinomyces vulgaris cyclo/maltodextrin-binding protein (TvuCMBP) complexed with gamma-cyclodextrin has been determined. Like Escherichia coli maltodextrin-binding protein (EcoMBP) and other bacterial sugar-binding proteins, TvuCMBP consists of two domains, an N- and a C-domain, both of which are composed of a central beta-sheet surrounded by alpha-helices; the domains are joined by a hinge region containing three segments. gamma-Cyclodextrin is located at a cleft formed by the two domains. A common functional conformational change has been reported in this protein family, which involves switching from an open form to a sugar-transporter bindable form, designated a closed form. The TvuCMBP-gamma-cyclodextrin complex structurally resembles the closed form of EcoMBP, indicating that TvuCMBP complexed with gamma-cyclodextrin adopts the closed form. The fluorescence measurements also showed that the affinities of TvuCMBP for cyclodextrins were almost equal to those for maltooligosaccharides. Despite having similar folds, the sugar-binding site of the N-domain part of TvuCMBP and other bacterial sugar-binding proteins are strikingly different. In TvuCMBP, the side-chain of Leu59 protrudes from the N-domain part into the sugar-binding cleft and orients toward the central cavity of gamma-cyclodextrin, thus Leu59 appears to play the key role in binding. The cleft of the sugar-binding site of TvuCMBP is also wider than that of EcoMBP. These findings suggest that the sugar-binding site of the N-domain part and the wide cleft are critical in determining the specificity of TvuCMBP for gamma-cyclodextrin.

Topics: Bacterial Proteins; Binding Sites; Carrier Proteins; Fluorescence; gamma-Cyclodextrins; Micromonosporaceae; Polysaccharides; Protein Structure, Tertiary

Powdery encapsulation of shiitake flavors, extracted from dried shiitake, was investigated by spray drying. Flavor retention increased with an increase in drying air temperature and solid content, and decreased with an increase in dextrose equivalents of maltodextrin. A heat-treatment of the extract liquid made the lenthionine concentration increase, but did not influence the concentrations of the other flavors. The formation of lenthionine with heat-treatment could be described by the consecutive unimolecular-type first order reaction. Lenthionine content in a spray-dried powder prepared with the heated extracted liquid significantly increased. alpha-Cyclodextrin was the most suitable encapsulant of alpha-, beta-, and gamma-cyclodextrins to prepare the spray-dried powder, including lenthionine. The flavor retentions were markedly increased by using of alpha-cyclodextrin and maltodextrin in combination as an encapsulant.

Topics: alpha-Cyclodextrins; beta-Cyclodextrins; Capsules; Cyclodextrins; Food Technology; gamma-Cyclodextrins; Hot Temperature; Polysaccharides; Powders; Shiitake Mushrooms; Taste; Temperature; Thiepins

The influence of substrate or product level on the initial velocity of cyclodextrin (CD) production by cyclodextringlycosyltransferase from a Brazilian isolate of Bacillus firmus was studied. Our results indicate that the product gamma-CD is a stronger inhibitor to the reaction than beta-CD. Small saccharides could also inhibit CD production, although to a lesser extent than the products, and maltose was the strongest inhibitor among small saccharides. Increasing substrate concentration resulted in greater reduction on enzyme activity for the formation of beta-CD than for gamma-CD. We modeled the kinetics of CD production with a set of four reversible reactions including the cyclization/coupling reaction that forms/opens CDs, and three disproportionation reactions. Our model on the initial velocity data explained well the substrate inhibition phenomenon. Kinetic parameters were determined by fitting the initial velocity data into our model.

Topics: Bacillus; Cyclodextrins; gamma-Cyclodextrins; Glucosyltransferases; Hydrogen-Ion Concentration; Kinetics; Polysaccharides; Software; Substrate Specificity

The production of cyclodextrins (CDs) by cyclodextrin-glycosyl-transferase (CGTase) from Bacillus firmus was studied, with respect to the effect of the source of starch upon CD yield and on the selectivity for producing gamma-CD. Cyclodextrin production tests were run for 24 h at 50 degrees C, pH 8.0, and 1 mg/L of CGTase, and substrates were maltodextrin or the starches of rice, potato, cassava, and corn hydrolyzed up to D.E. 10. Cornstarch was the best substrate for producing gamma-CD. Later, glycyrrhizin (2.5% [w/v]), which forms a stable complex with gamma-CD, was added to the cornstarch reaction medium and increased the yield of gamma-CD to about four times that produced with only maltodextrin, but the total yield of CDs remained practically unchanged. Therefore, the results showed that the studied CGTase is capable of giving relatively high yield of gamma-CD in the presence of glycyrrhizin as complexant and cornstarch as substrate.

Topics: Bacillus; Cyclodextrins; gamma-Cyclodextrins; Glucosyltransferases; Kinetics; Manihot; Oryza; Polysaccharides; Solanum tuberosum; Starch; Substrate Specificity; Zea mays

The taste and flavor of spray-dried powdered products are the most important quality factors. In the present study, molecular encapsulation in cyclodextrin was applied to prevent the loss of a hydrophobic flavor compound (l-menthol) during the drying of a droplet. beta-Cyclodextrin appeared to be a better encapsulant for menthol than alpha- and gamma-cyclodextrin. The retention of menthol increased with increasing concentration of both cyclodextrin and maltodextrin. A simple mathematical model is proposed for estimating the flavor retention. The theoretical results by this model estimated well the final retention of menthol encapsulated in a blend of beta-cyclodextrin and maltodextrin.

Topics: alpha-Cyclodextrins; beta-Cyclodextrins; Cyclodextrins; Drug Compounding; Freeze Drying; gamma-Cyclodextrins; Menthol; Models, Chemical; Polysaccharides; Taste