Production and Physicochemical Properties of Hydrogenated Glucose Syrups

An obvious and as yet little explored alternative to glucose syrups, for use in foods, is a series of hydrogenated derivatives of the commercial glucose syrups. Sorbitol is already widely used in the food industry and like maltitol offers certain metabolic advantages in foods for diabetics. It is relatively easy to produce a series of partially or totally hydrogenated glucose syrups based on this form of modification. This paper presents details of the production of some hydrogenated glucose syrups and a selection of their physicochemical properties.     

GAS-LIQUID CHROMATOGRAPHY OF WORT AND BEER CARBOHYDRATES I. THE CHARACTERIZATION OF WORT,BEER, AND BREWING SYRUP CARBOHYDRATES

Gas-liquid chromatography has been applied to the separation of the trimethylsilyl derivatives of wort, beer and corn syrup carbohydrates. The major carbohydrates identified in worts, beers, and corn syrups include fructose, glucose, sucrose, maltose, isomaltose, maltotriose and maltotetraose.     

Some Human Physiological Responses to the Consumption of Glucose Syrups and Related Carbohydrates

Although the chemical composition of glucose syrups determines their physiological response, such effects may be difficult to establish using conventional methods. Experimental design, and especially carbohydrate loading, are important factors in any attempt to distinguish physiological response in relation to chemical structure. This paper presents details of changes in blood chemistry after ingestion of different carbohydrates at different loadings by human subjects over short time periods. Similarly, psychophysical aspects of glucose syrups and related carbohydrates are investigated in relation to chemical structure.     

Mineral Complexing Properties of Food Carbohydrates

The complexing of minerals by both low and high molecular weight carbohydrates is now well established and can be demonstrated by, for example, depression of conductivity, alteration of specific rotation, redox potential or techniques such as ligand exchange chroma-tography. It is likely that mineral complexes will exist in food systems and, in mixtures of sugars such as glucose syrups, a variety of complexes will be present. Recent interest in the hydrogenated carbohydrates shows that these too complex minerals, sometimes better than their unhydrogenated counterparts. The complexing of Cu²⁺ by hydrogenated glucose syrups, for example, increases as degree of polymerisation decreases and iron salts are also complexed by various simple carbohydrate molecules. Mineral complexing has many consequences for the taste, nutritional value and technological quality of foods. The taste of iron salts is masked for example, by complexing with carbohydrates at high pH, whereas the opposite occurs at low pH. Vitamin C is protected from Cu²⁺ catalyzed oxidation when the cation is complexed with various carbohydrates or their hydrogenated derivatives. Such results have implications for the design, formulation and storage of food.     

Sugar Composition Effects on Textural Parameters of Peach Jam

A series of peach jam samples was prepared using commercial glucose syrups of 38DE and 44 DE, isoglucose, maltose syrup and their mixtures with sucrose. Texture development of samples during aging was studied using an Instron machine. Jam texture was markedly affected by composition of the syrups. Consistency of jams ranged from very firm when 100% isoglucose syrup was used to very soft when 100% maltose syrup was used and three weeks aging was needed for stabilization. Principal Component Analysis showed the jams could be classified according to their mechanical and textural attributes.     

利用酶制剂提高啤酒糖浆质量

酶制剂是影响啤酒用糖浆的关键因素之一,选用合理的酶制剂组合可以生产优质辅料、营养、特种啤酒专用糖浆。正确选用酶制剂和应用技术将有助于提高啤酒糖浆的质量,降低成本,增加产量。新型酶制剂的应用将与淀粉糖和啤酒互为融合、互为促进、共同进步。     

The Production and Properties of Glucose Syrups. II. Physiological Properties of Glucose Syrups

The study indicates that when gum arabic, fat and protein are taken in conjunction with glucose syrup, changes in blood glucose profiles occur compared with glucose syrup alone. With gum arabic the effect is greatest in the 21% D.E. syrup, 30 min post ingestion (causing an elevation of blood glucose) and thereafter the effect is confined to the higher D. E. syrups. Added protein produces an elevated blood glucose peak and fat a decreased peak. Smaller loadings (10 g instead of 50 g) of different D.E. syrups showed no significant differences in blood glucose profiles.     

Action of aqueous sodium hydroxide on glucose syrups

The effect of alkali concentration on the degradation of glucose syrups is studied and alkali numbers for a series of glucose syrup fractions and commercial glucose syrups are determined.Volatile acidity produced is shown to be dependent on alkali concentration and volatile acidity values are determined on 28 samples. Again, as DE increases, so does volatile acidity.Two methods of analysis of glucose syrup are described, the first concerning the determination of the DE of glucose syrups and the second a theoretical example of the analysis of glucose syrup-sucrose mixtures.     

GAS LIQUID CHROMATOGRAPHY OF WORT AND BEER CARBOHYDRATES II. QUANTITATIVE DETERMINATION OF WORT,BEER, AND BREWING SYRUP CARBOHYDRATES

A method for the preparation and gas chromatography of the trimethylsilyl derivatives of carbohydrates was applied to the quantitative analysis of carbohydrates in worts, beers, and brewing syrups. The derivatives can be easily and quickly prepared from lyophilized worts or beers and aliquots of the reaction mixtures can be injected directly into the gas chromatograph. Gas chromatographic separations of the mono- to tetra-saccharide fractions were achieved in less than thirty minutes through the use of linear temperature programming. Recoveries of carbohydrates added to wort ranged from 97 to 105%. Quantitative data for replicate wort analyses showed relative standard deviations of from 1·7% for glucose to 5·3% for maltose. The silylation reaction can be applied to the volatilization and subsequent study of a wide variety of compounds occurring in brewing materials.     

A Novel Debranching Enzyme for Application in the Glucose Syrup Industry

Some of the properties of a novel, microbial, amylopectin debranching enzyme are described. The enzyme belongs to the class of debranching enzymes known as pullulanases (EC 3.2.1.41) and is characterized by being stable at higher temperatures and lower pH's than previously described enzymes of this type. The novel debranching enzyme can be used together with Aspergillus niger glucoamylase to improve the efficiency of starch conversion to glucose or together with cereal ß-amylases to increase the maltose level in high maltose syrups. Examples of these applications are given. It is expected that the enzyme will gain widespread acceptance in the glucose syrup industry.     

Lactose hydrolysis in acid whey with subsequent glucose isomerisation

The disposal of whey is a problem because of its high biological oxygen demand. Of the 1.8 × 10¹⁰ kg produced annually in the USA, only about half has any food or feed application (Jelen 1983). One possible approach to acid whey utilisation is the removal of the proteins either by ultrafiltration or by thermal precipitation, hydrolysis of lactose with soluble β-galactosidase (lactase, EC 3.2.1.23) and subsequent isomerisation of the glucose to fructose by the action of immobilised glucose isomerase (EC 5.3.1.5). The resulting syrup is composed of glucose, fructose and galactose plus small amounts of unhydrolysed lactose and other oligosaccharides. The syrup was found to have a predominantly sweet and slightly salty taste. Recently sucrose has been replaced in many foods by high fructose corn syrup produced by the action of glucose isomerase on glucose syrups from corn starch hydrolysates (Bucke 1981). The whey syrup also has potential as a sucrose substitute.     

Reverse Osmosis of Glucose Syrups

The paper presents data on the osmotic pressure of glucose syrup fractions obtained by reverse osmosis fractionation of a 43% D.E. commercial glucose syrup and membrane performance at different starting solids contents. Details regarding the production of glucose syrup fractions in the range 15–80% D.E. are given. The fractions produced consist of a narrower spectrum of sugars than is found in a commercial syrup of the same D.E. and thus offer new types of syrup to the industrial user of glucose syrups. Reverse osmosis and ultrafiltration seem to offer the only feasible economic means for obtaining specialised sugars from glucose syrups.     

Chemical and Physiological Properties of Glucose Syrup Components

Although glucose syrups are in wide commercial use their constitution is extremely complex and hence the physiological effects of individual components relative to their chemical structures have not been explored. Although the major components of glucose syrups are 1–4 glucosidically linked maltodextrins which may be expected to undergo normal metabolic breakdown, in whole glucose syrups fed to mammals, it is conceivable that differences could occur when glucose syrups are fractionated for different technological purposes. This paper describes experiments on the fractionation of commercial glucose syrups by two different methods and some physiological effects which are observed when these fractions are fed to both male and female rats. Although these are preliminary experiments in this field they do suggest a sex difference in the metabolism of dietary carbohydrates which accords with earlier work in humans and baboons. All rats used in these experiments were young and grew normally. Their external appearance was healthier than that of rats on a normal 41B diet.     

Apparent molar volumes and 1H-NMR relaxation values of glucose syrups

The apparent molar volumes and proton magnetic resonance ¹H-NMR pulse relaxation values of D-glucose and four commercial glucose syrups were determined in the concentration range 5–50% (w/w). The apparent molar volumes increased linearly with average degree of polymerisation (DP) of the syrups and were thus in excellent agreement with average molecular weight. These increases contrasted markedly with the known increases of specific rotation of maltooligosaccharides which reach a limiting value at about DP 7 or 8. Apparent specific volumes were all confined to the range 0.60–0.64 cm³g^?1 as expected for carbohydrates. They decreased sharply in the DP range 1–3 and showed little change thereafter. Apparent specific volumes also increased with increasing concentration of solute, as expected. Spin-spin relaxation values (T₂-values) decreased with increasing DP or increasing concentration of solute, as the proportion of ordered protons in solution increased. Consequently, within one glucose syrup, T₂ decreased with increasing apparent specific volume (increasing concentration) and, between glucose syrups, T₂ decreased with increasing DP. These results reflect the packing characteristics of the solutes among water molecules and accord with their known sweetness properties. They also underline the value of solution properties for the rapid characterisation of glucose syrups.     

Glucose infusion rates from various complex carbohydrates estimated from two models

Due to the importance of diet in the management of noninsulin dependent diabetes, we are interested in constructing a model to study the glycemic response to different foods in normal and diabetic subjects. In this study, serum glucose and insulin values from individual normal subjects (Diab. 26, 1178) following the ingestion of different foods (corn, rice, bread, potato) high in complex carbohydrate were analyzed to determine glucose infusion rates (J) into the blood from the gut as a function of time following the ingestion of the food item. A Modular Modeling Program was designed to allow selection of data, curve fit, model, and tuning of parameters. The two models used were from Ackerman et al (Phys. Med. Biol. 9, 203) and the minimal model (VI) from Bergman and Cobelli (Fed. Proc. 39,110). The models were modified so that glucose and insulin values were used as input and J was the output. There was a good correspondence between the shape of the J curves predicted by the two models. While the J curves resembled serum glucose curves, they generally reached a peak earlier and declined more rapidly. Two peaks occurred in the J curves for bread, corn and rice. The second peaks may correspond to a delay in the release of glucose during digestion. The resulting infusion rate characterization of these foodstuffs maybe useful for modeling responses in diabetic patients with normal gut function but with impaired peripheral glucose utilization and in detecting abnormal gut function.     

CHANGES OF SUGAR PROFILES IN CANNED CLINGSTONE PEACHES

The effect of post-canning storage on sugar profiles in canned clingstone peaches (Primus persica var. ‘Halford’) sweetened with various combinations of sucrose, 62 D. E. corn syrup and 42% high fructose corn syrup was investigated. The sugars in the peach syrups were monitored at 1, 20 and 30° C after storage for 0, 6, 9 and 12 months. The individual sugars in the peach syrups were separated and analyzed by high pressure liquid chromatography (HPLC). Storage of the canned peaches at 30° C resulted in a rapid decrease in sucrose and a simultaneous increase in fructose and glucose. The hydrolysis of sucrose was successively slower at 20 and 1°C. It was observed that the sugar profiles were also dependent on the initial concentration of the sugar components, time of storage and acidity of the canned peaches. The concentration of maltose showed great fluctuation during storage. The rapid loss in quality acceptance of canned clingstone peaches at high storage temperature was explained by the changes in sugar profiles and the accompanying undesirable chemical and physical changes.     

Calcium chloride complex formation of glucose syrups and their fractions

Glucose syrups react with calcium salts in aqueous solution to form complexes. As a consequence, the specific rotation, viscosity, electrical conductivity and osmotic pressure of the syrups differ from those of untreated glucose syrups. Complex formation depends on calcium ion concentration, and interaction of the glucose syrup with the calcium salt affects, in turn, the activity of the calcium ions.     

IRON-FORTIFIED SYRUP BLENDS: PREPARATION, CHARACTERISTICS, APPLICATION

Stable iron-containing syrups were developed to provide a liquid iron source that could be conveniently added to foods. Iron-fortified syrups were prepared by combining either corn syrup or sucrose, or both, with water, heating to boiling, cooling to 180–200°F and blending in an aqueous iron solution. Syrups were all-sucrose (67% solids); blends of 15% sugar (sucrose) with either regular or high-conversion corn syrups (75% solids). Iron sources were ferric ammonium citrate, ferrous sulfate, ferric choline citrate and ferrous gluconate at the available iron level of 0.015% (100 mg/pint). These iron-fortified syrups were stable during storage for 2 months at 120°F, 6 months at 100°F and 1 year at 77° except for combinations of ferrous forms with blends containing either 15% sugar and regular corn syrup or ferrous sulfate in all-sugar. Although flavor evaluations indicate that iron is readily detectable, iron-fortified syrups had satisfactory flavors before and after storage. These fortified syrups seem suitable for enrichment of infant formulas     

Replacement of Carbon-refined Corn Syrups with Ion-exchanged Corn Syrups in Ice Cream Formulations

Ice cream was manufactured utilizing ten corn syrups at 5% (dry basis) in the mix, 30 DE, 42 DE, 42 DE high maltose (HM), 55 DE HM and 64 DE, each of which was processed through the carbon-refined and ion-exchanged processes. An increase in DE of the syrup led to a decrease in mix viscosity, a decrease in the freezing point of the mix, a decrease in fat destabilization and a decrease in firmness of the ice cream. The ion-exchanged syrups decreased the mix viscosity and produced a drier ice cream with greater fat destabilization but had no influence on mix freezing point depression, overrun, firmness or meltdown. Sensory results from the 42DE HM and 55DE HM carbon-refined and ion-exchanged products evaluated in this study showed no differences in sweetness or texture. The flavor and acceptability of 42DE HM carbon-refined syrup in ice cream was preferred less than the 42DE HM or 55DE HM ion-exchanged syrups.     

THE EFFECTS OF GLUCOSE ADJUNCT IN HIGH GRAVITY FERMENTATION BY SACCHAROMYCES CEREVISIAE 2036

Laboratory fermentations of 16°Plato glucose adjunct worts by Saccharomyces cerevisiae 2036 demonstrated the absence of “glucose repression” of maltose and maltotriose uptake. However, when compared to worts in which maltose syrup was employed as an adjunct, residual glucose was present at the end of fermentation, maltose and maltotriose uptake rates were enhanced, fructose uptake was blocked and the sequence of sugar uptake was changed. These findings partially explain residual glucose and fructose that sporadically appear in commercial beers. Further research suggests that the physiological quality of the yeast is of prime importance in carbohydrate metabolism, and that critical concentrations of glucose vary with different physiological conditions for this brewing strain in 16°P wort .