Co-crystallization of Sucrose at High Concentration in the Presence of Glucose and Fructose

ABSTRACT: Co-crystallization of sucrose from a highly concentrated sucrose syrup (≤ 7% moisture, w/w) at 131 °C with 0, 5, 10, 15, and 20% of fructose, glucose, or a mixture of fructose and glucose was investigated. The crystallization of sucrose was delayed in presence of these lower molecular weight sugars. The DSC melting endotherm of co-crystallized samples exhibited a decrease in crystalline sucrose in the sample as a function of increased level of glucose and fructose. The mechanical strength of co-crystallized granules was found to be related to the moisture content and the amount of glucose or fructose content in the sample. The samples containing 10, 15, and 20% glucose in co-crystallized product demonstrated crystallization of glucose in its monohydrate form during 1 mo of storage.     

DEVELOPMENT OF A SWEETENER FROM BLACK PLUM (VITEX DONIANA) FRUIT

The Black plum (Vitex doniana) fruit was studied in respect of the chemical composition of its edible pulp, and syrup produced by concentration of extracted juice. Organoleptic evaluation was also conducted on the developed syrup. The results show that the edible pulp of the fruit is acidic (PH 5.20), high in moisture (67.9%), sucrose (12.5%) and reducing sugar (7.3%), and fairly rich in vitamin C (28.5 mg/100 g). Temperature of water used for extracting juice from the pulp correlated positively with soluble solids (r=0.86), titratable acidity (r=0.91) and negatively with vitamin C (r=?0.61). The syrup contained higher reducing sugars (51.7%), lower moisture (25.0%), but similar sucrose (12.9%) content compared to the pulp. The soluble solids of the extracted juice and consequently the yield of the syrup varied with water temperature. An optimum temperature of 80°C gave 20% (w/w) syrup per pulp. The syrup compares favorably with sucrose in sensory properties in model foods.     

Characterization of Physical and Mechanical Properties of Miscible Lactose‐Sugars Systems

Lactose‐sugars systems were produced by spray drying. They were lactose, lactose–glucose (4:1) mixtures, lactose–maltose (4:1) mixtures, lactose–sucrose (4:1) mixtures, lactose–trehalose (4:1) mixtures, and lactose–corn syrup solids (CSS) (4:1) mixtures. The physical characteristics, water sorption behavior, glass transition, and mechanical properties of miscible lactose‐sugars systems were investigated. Lactose–glucose mixtures had larger particle size than other lactose‐sugars systems after spray drying. The presence of glucose or sucrose in lactose‐sugars mixtures decreased the glass transition temperatures of amorphous systems, while the presence of maltose and trehalose had only minor impact on the glass transition temperatures. Moreover, glucose accelerated the crystallization of amorphous system at 0.44 a_w, but its presence delayed the loss of sorbed water at higher water activities (≥0.54 a_w). Mechanical property study indicated that glucose and sucrose in amorphous system could result in an increase of molecular mobility, while the presence of CSS could decrease the free volume and maintain the stiffness of the miscible systems.     

Kinetic Analysis of Osmotic Dehydration Carried Out with Reused Sucrose Syrup

ABSTRACT Processing times required to achieve a target level of soluble solids were determined in apple pieces during sequential osmotic dehydrations carried out with reused sucrose syrup, in which new loads of fruits were charged in each turn. Effective diffusivities for water and sucrose in apple pieces were experimentally determined as a function of syrup soluble solids. A computer program was written to predict soluble solids change both in apple pieces and in syrup during the sequential osmotic dehydration process. Experimental data on the change of soluble solids for apples and syrup for 10 batches arranged in 2 sets of 5 were obtained. A good agreement between observed and predicted values of soluble solids in both fruit and the syrup was obtained, with root mean square values ranging from 1.3% to 4.6%.     

Beyond Tg: optical luminescence measurements of molecular mobility in amorphous solid foods

Current research recognizes the importance of the glassy state for stabilizing amorphous solid foods and the importance of the glass transition (Tg) as an index temperature for food stability. This reflects a realization that molecular mobility modulates both physical properties such as texture and physical and chemical processes such as reaction rate, crystallization rate, solute diffusion, and collapse; the Tg is the onset temperature for cooperative translational motion in amorphous solids. The existence of complex structural features in foods with lengths ranging from nanometers to centimeters and the recognition that complex vibrational motions are activated in the glassy state, brings about the need to go beyond macroscopic measurements of product Tgs. It is now important to determine how molecular structure and mobility as well as microscopic organization modulate the macroscopic physical properties of foods.Luminescence spectroscopy provides a powerful arsenal of biophysical tools to investigate the structure and molecular mobility of amorphous solids; measurements of emission intensity, energy (wavelength), and polarization can provide direct information about molecular structure and mobility. Luminescence measurements of the effect of hydration and temperature on amorphous solid proteins and sugars reviewed here indicate that the molecular mobility due to local vibrational and rotational motions (as opposed to global translational mobility) in glassy foods is actually quite extensive with motions occurring on time scales ranging from nanoseconds to seconds. There is thus a need to identify how the rates of specific chemical and physical processes involved in food degradation are influenced by specific modes of molecular mobility in amorphous solid foods.     

Cryoprotective Effects of Some Materials on Cod-Surimi Proteins during Frozen Storage

Freeze-induced protein denaturation of cod surimi was studied as affected by carbohydrates (sucrose and glucose syrup at 8% w/w), polyols, (sorbitol and glycerol at 8% w/w), protein hydrolysates (fish protein and casein hydrolysates at 4% w/w), hydrocolloids (pectin-1% w/w, sodium alginate, lambda- and iota-carrageenan-0.5% w/w) and combinations of the above, (sucrose/sorbitol 1:1 mixture at 8% w/w, or combined with protein hydrolysates at 4% w/w). Salt extract-able protein (SEP) and heat induced denaturation by differential by differential scanning calorimetry (DSC) were used to monitor protein changes in surimi stored 16 wk at -20°C. The best cryoprotection effect was achieved from sorbitol, glucose syrup (DE = 60), sucrose and sucrose/sorbitol 1:1 w/w mixture at 8% w/w in surimi. Correlations between certain DSC parameters and SEP were high.     

Amorphous state and delayed ice formation in sucrose solutions

Phase transitions of amorphous sucrose and sucrose solutions (20–100% sucrose) were studied using differential scanning calorimetry, and related to viscosity and delayed ice formation. Glass transition temperature (Tg) was decreased by increasing water content. Ice formation and concurrent freeze concentration of the unfrozen solution increased apparent Tg. Tg could be predicted weight fractions and Tg values of components. Williams–Landel-Ferry (WLF) relation could be used to characterize temperature dependence of viscosity above Tg. Crystallization of water above Tg was time dependent, and annealing of solutions with less than 80% sucrose at –35°C led to a maximally freeze-concentrated state with onset of glass transition at –46°C, and onset of ice melting at -34°C. The state diagram established with experimental and predicted Tg values is useful for characterization of thermal phenomena and physical state at various water contents.     

Investigating the moisture sorption behavior of amorphous sucrose using a dynamic humidity generating instrument

ABSTRACT:  The moisture sorption behavior of freeze-dried amorphous sucrose was investigated using a dynamic humidity generating instrument, the Dynamic Vapor Sorption (DVS) instrument. The kinetic moisture sorption profiles of freeze-dried amorphous sucrose samples with 29% crystalline content were obtained using the DVS instrument at 9 relative humidity (RH) values, ranging from 10% to 90%, at 25 °C. Moisture-induced crystallization was observed for %RH values between 40% and 80%, where the crystallization onset time decreased as %RH increased. The moisture sorption behavior of freeze-dried amorphous sucrose with 3 crystalline contents, 23%, 29%, and 80%, was also compared, revealing that the crystalline content had a significant impact on the pseudo-sorption isotherm of freeze-dried amorphous sucrose. In general, for %RH values below 90%, samples that had a lower percent crystalline content had a higher pseudo-equilibrium moisture content, with the difference becoming most pronounced for the 60% to 80% RH values. The moisture-induced crystallization results as a function of %RH obtained in this study were compared to those previously reported in the literature, leading to an extensive discussion of both the experimental protocols used and the hypothesized mechanisms governing the long-term stability of amorphous materials. The hypothesized mechanisms discussed included the glass transition temperature boundary, the zero mobility temperature, and the hydration limit. Based on the dissimilarity in these hypothesized mechanisms, additional theoretical and experimental exploration is still merited in order to adequately predict the conditions (for example, moisture content, %RH, and temperature) required to ensure long-term stability of amorphous solids.     

Corn Syrup Oligosaccharide Effects on Sucrose Crystallization

The components of corn syrup (oligosaccharides with different degrees of polymerization) have long been hypothesized to have different effects on sucrose crystallization. Corn syrups were fractionated to produce four fractions, each containing a different range of oligosaccharides. Each fraction decreased the solubility concentration of sucrose to the same extent as the original corn syrup, except for the lowest DP fraction which caused a lower sucrose solubility in water. Each fraction also reduced the growth rate of sucrose crystals compared to the pure system. How ever, at equivalent molar levels, all corn syrup fractions had the same effects on reducing crystal growth.     

蓝莓渗透脱水的研究

在不同的渗透温度 ( 4 5～ 65℃ )条件下 ,高果糖浆和蔗糖的有效水分扩散率 (Dm)分别为( 4 90 60～ 5 2 3 66)× 1 0 - 10 m2 /s和 ( 3 5 5 1 8～ 4 0 1 0 9)× 1 0 - 10 m2 /s,有效固形扩散率 (Ds)分别为( 2 7740～ 3 691 5 )× 1 0 - 10 m2 /s和 ( 1 3 1 63～ 2 691 5 )× 1 0 - 10 m2 /s的规律。在渗透脱水处理过程中Dm 和Ds 随处理温度升高而增加。经高果糖浆 ( 70°Brix)渗透脱水的蓝莓的平均体积比随温度升高而稍微下降。其相对密度随温度的升高也略有增加     

Corn Sweeteners in Ham Formulas

Corn sweeteners were compared with sucrose in cure formulas for hams. Thirty-six hams were randomly treated with nine sweetener treatments replicated four times. Combinations of sucrose, 55% high fructose corn syrup, 42% high fructose corn syrup, and high maltose corn syrup were used in brine formulas for pumping the hams. Sensory evaluations found no significant difference between sweetener type and sensory scores on color, flavor, tenderness, and overall satisfaction. However, ham weights appeared to be affected slightly by sweetener type. Sucrose produced greater ham yields at a 3% sweetener level. However, 55% high fructose corn syrup at 3.15% equalled the yield observed for sucrose. Forty-two percent high fructose corn syrup at greater than 3.3% solid level approached the yields observed for sucrose. Since sensory factors do not appear to be affected by corn syrup solids, only economic and yield factors need bc considered for their use in commercially produced hams.     

WATER PLASTICIZATION EFFECTS ON CRYSTALLIZATION BEHAVIOR OF LACTOSE IN A CO-LYOPHILIZED AMORPHOUS POLYSACCHARIDE MATRIX AND ITS RELEVANCE TO THE GLASS TRANSITION

ABSTRACT

Crystallization of lactose in a co-lyophilized amorphous polysaccharide matrix was investigated under various hydration conditions to test the possible relation between the ability of the polymer to raise the glass transition temperature (T_g) of the lactose-pullulan blend, relative to pure lactose, and the crystallization kinetics. Both calorimetric (DSC) non-isothermal measurements and x-ray diffraction analysis of samples stored at a constant temperature revealed a marked retardation in lactose crystallization in the presence of pullulan; i.e., the rate constant values, as determined by the Avrami analysis, declined and the ‘half-time’ (t_1/2c) for lactose crystallization increased with decreasing ratio of lactose/pullulan. The inhibitory action of pullulan on crystallization of lactose could not be solely attributed to T_g-related effects on molecular mobility of the composite systems. At a pullulan weight fraction range of 0.25–0.33 (w/w of total solids) the influence of the polymeric additive on T_g was marginal over the entire water content range examined, although crystallization was delayed as compared with pure lactose. Modeling of the temperature-dependence of t_1/2c for the combined lactose-pullulan systems with the Williams-Landel-Ferry (WLF) equation was feasible only when the coefficients C₁ and C₂ were allowed to vary instead of assuming their ‘universal’ values.     

Crystallization behavior of lactose/sucrose mixtures during water-induced crystallization

The crystallization behavior of lactose/sucrose mixtures during water-induced crystallization was studied to gain more insight about their crystallization during storage. Solutions with different ratios of lactose and sucrose, 75:25 and 50:50, were spray dried to produce amorphous powders. The powders were kept at a controlled temperature and humidity to study their sorption–desorption behavior. X-ray diffraction and light microscopy analysis were performed to study their crystallization behavior. Two-step desorption was observed after sieving the powders as sample preparation. Sieving decreased the crystallization time for lactose/sucrose mixture 75:25 from 22 days to 2.5 days. Based on the X-ray diffraction analysis during this two-step process of water desorption, it was concluded that lactose crystallizes first and more quickly than sucrose. The degree of crystallization for the lactose crystals increases by 89% (relative to their final level of crystallinity), whereas sucrose crystals increase their level of crystallinity by only 28% during the first step of crystallization in the lactose/sucrose (75:25) mixtures. The light microscopy images also suggested that the crystallization of amorphous lactose/sucrose powders during water-induced crystallization may occur as a solution rather than in the solid phase.     

Development of Hydrolyzed and Hydrolyzed-lsomerized Syrups from Cheese Whey Ultrafiltration Permeate and Their Utilization in Ice Cream

Hydrolyzed lactose syrup (HLS) was produced from cheese whey ultrafiltration permeate by treatment with immobilized β-galactosidase, deionization, and evaporation. The degree of hydrolysis was 97.2%. Hydrolyzed-isomerized lactose syrup (HILS) was produced from hydrolyzed, deionized ultrafiltration permeate by treatment with immobilized glucose isomerase, deionization and evaporation. The degree of isomerization was 34.8%. HLS and HILS were substituted for 25% or 50% of the sucrose (on a solids basis) in vanilla ice cream. The mix freezing time increased when HLS or HILS was substituted for sucrose at a level of 50%. There were no significant differences in melting rates (P < 0.05) and few differences in sensory quality.     

A Computer-Assisted Method for Evaluating Ingredient Substitution in Ice Cream Formulations

Development of a computer-based system to evaluate the effect of ingredient substitution in ice cream mix on product quality and freezing requirements is described. This computer program evaluates the effect of whey powder substitution for milk solids-not-fat and three sugar systems on freezing point, viscosity, and freezing time of ice cream mix. To help to evaluate potential product quality, it is also possible to predict percent unfrozen water at different storage temperatures that might be expected for the frozen ice cream. Three sugar systems evaluated are: 100% sucrose, 70% sucrose plus 30% 36 dextrose equivalent corn syrup solids and 50% 36 dextrose equivalent corn syrup solids plus 50% 55 high-fructose corn syrup.     

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     

Determination of Lactose and Sucrose Contents of Ice Cream Mix via Enzymatic-Cryoscopic Methodology

A simple method was developed for determining the lactose and sucrose contents of ice cream mix. The method is based on measuring the freezing point depression resulting from incubating samples with invertase (EC 3.2.1.26) and β-galactosidase (EC 3.2.1.23). Sucrose and lactose concentrations are determined separately with each determination requiring 50 units of enzyme and 2 hr of incubation at 37°C. A standard curve for lactose determination was obtained using ice cream mixes containing various amounts of sucrose and corn syrup solids (R²= 0.996, C.V. = 1.2%). A standard curve for sucrose determination was obtained using ice cream mixes containing various amounts of lactose and corn syrup solids (R²= 0.996, C.V. = 1.9%).     

Changes in Electrical Energy Requirements to Operate an Ice Cream Freezer as a Function of Sweeteners and Gums

Changes in electrical energy required to operate a continuous freezer were monitored for various ice cream formulae. Ice cream formulae consisted of nine different combinations of sucrose, 36 DE corn syrup, and 42 high fructose corn syrup as well as two ratios of guar gum to locust bean gum. Within the same sweetening system, a mix high in locust bean gum tended to have a lower energy demand than mix with large amounts of guar gum. This was especially pronounced in mixes with 50% 42 high fructose corn syrup and/or 50% 36 DE corn syrup solids.     

The effect of protein types and low molecular weight surfactants on spray drying of sugar-rich foods

The effect of protein types and low molecular weight surfactants (LMS) on spray drying of sugar-rich foods has been studied using sucrose as a model sugar and sodium caseinate (NaCas) and pea protein isolate (PPI) as model proteins. Sodium stearoyl lactylate (SSL) and Polysorbate 80 (Tween-80) were chosen as model ionic and non-ionic LMS. The sucrose:NaCas and sucrose:PPI solid ratios were maintained at (99.5:0.5) and (99:1), respectively and spray-dried maintaining 25% solids in feed solutions. It was found that the proteins preferentially migrated to the air–water interface reasonably swiftly and the addition of LMS resulted into partial or complete displacement of the proteins from the air–water interface. More than 80% of amorphous sucrose powder was produced with the addition of 0.13% (w/w) of NaCas in feed solution. PPI was not as effective and produced less than 50% recovery even at 0.26% (w/w) in feed. Addition of 0.01–0.05% SSL displaced 2.0% and 29.3% of proteins from the surface of sucrose–NaCas–SSL droplet, respectively, resulting in a 6.5 ± 1.2% to 51.9 ± 1.9% reduction in powder recovery. The extent of protein displacement was higher when SSL was added into sucrose–PPI solution; however, the powder recovery was not much affected. The addition of 0.01% Tween-80 in sucrose–NaCas solution resulted in a 48.2 ± 1.5% reduction in powder recovery and at 0.05% concentration, it displaced a substantial amount or all the NaCas from the droplet surface and no powder was recovered. The addition of 0.01% and 0.05% Tween-80 into sucrose–PPI solution resulted into very low powder recoveries (24.9 ± 0.4% and 29.5 ± 1.8%, respectively). The glass transition temperature (T_g) results revealed that the amount of protein required for successful spray drying of sucrose–protein solutions depends on the amount of proteins present on the droplet surface but not on the bulk concentration. X-ray diffraction and scanning electron microscopy results showed that the powders of sucrose–NaCas/PPI and sucrose–NaCas/PPI with 0.01% SSL were mostly amorphous while those with sucrose–NaCas/PPI–Tween-80 (0.01%), sucrose–PPI–Tween-80 (0.05%) and sucrose–NaCas/PPI–SSL (0.05%) were crystalline.     

Crystallization Kinetics of Amorphous Lactose as a Function of Moisture Content Using Isothermal Differential Scanning Calorimetry

Isothermal differential scanning calorimetry (DSC) was used to study the crystallization kinetics of amorphous lactose at 3 moisture contents. Each sample was heated to several temperatures between Tg and Tm. After subtraction of an induction time, the Avrami equation was used to model the data and a Lauritzen-Hoffman like expression used to fit the crystallization rates between Tg and Tm. The highest Tm/Tg ratio and crystallization rate were observed for the sample containing the most moisture. Conversely the lowest Tm/Tg ratio and crystallization rate were observed for the sample containing the least moisture. Evidence for multiple transitions was seen. The Avrami equation may not be the best way to model such data.