Isomerization of aldo-disaccharides to keto-disaccharides in arginine solution and phosphate buffer under subcritical conditions.

Maltose, cellobiose, and lactose dissolved in 0.01 mol/L arginine solution or 0.01 mol/L phosphate buffer (pH 7.

Efficient synthesis of rare sugars from galactose in hot compressed water using eggshells as an environmentally friendly catalyst.

Aqueous galactose solutions containing eggshell was heated at 120 °C to produce calcium supplements containing rare sugars. Galactose was isomerized to rare sugars with improving rare sugar yields compared to those without eggshell. Organic acids were also formed as byproducts during the reaction.

Isomerization and epimerization of glucose and galactose in arginine solution and phosphate buffer under subcritical fluid conditions.

Reaction of glucose or galactose was performed in arginine solution or phosphate buffer (pH 7.0) using a batch reactor at 110°C. The yields of products, pH, and absorbances at 280 and 420 nm were measured during the reaction.

Isomerization of galactose to tagatose using arginine as a green catalyst.

This work investigated the isomerization of galactose to tagatose, a low caloric rare sugar, using arginine as a catalyst. Galactose (5 % w/v) and arginine (0.10 mol/mol-galactose) in water were treated at 90-120 °C.

Drying Behavior and Curcuminoids Changes in Turmeric Slices during Drying under Simulated Solar Radiation as Influenced by Different Transparent Cover Materials.

Dried turmeric is used as a spice and traditional medicine. The common drying methods for turmeric ( L.) are sun drying and solar drying.

Osmotic Dehydration, Drying Kinetics, and Quality Attributes of Osmotic Hot Air-Dried Mango as Affected by Initial Frozen Storage.

Using frozen mango for osmotic hot air drying is still uncommon due to a lack of knowledge on the effect of the freezing process on the final product's quality attributes. This study aimed to investigate the effect of the freezing method (slow and quick freezing) and frozen storage time at -18 °C (0, 1, and 2 months) on mass transfer kinetics during osmotic dehydration, drying kinetics during hot air drying, and final quality attributes of the dried mango. The results indicated that Peleg's model could describe the water loss and solid gain during the osmotic dehydration in a 38° Brix sugar solution.

Protein composition, chlorophyll, carotenoids, and cyanide content of cassava leaves (Manihot esculenta Crantz) as influenced by cultivar, plant age, and leaf position.

The variation of proximate compositions, amino acids, carotenoids, chlorophyll, and total cyanide contents in cassava leaves was studied to identify the most suitable leaves for human consumption. The cassava leaves from 4 cultivars were analysed at 3 leaf positions as well as at 2 plant ages. The leaves of 'Rayong 5' cultivar from the middle position at 6 months after planting contained the highest crude protein, amino acids, carotenoids, and chlorophyll.

Astaxanthin stability and color change of krill during subcritical water treatment.

Pacific krill () contains high amounts of astaxanthin, a carotenoid pigment with strong antioxidative activities. In this study, the effects of subcritical water temperatures (100-180 °C) and times (0-10 min) on color changes (*, *, and *) and astaxanthin degradation in Pacific krill were investigated. In addition, an aqueous solution of pure astaxanthin and that of crude astaxanthin from Pacific krill, both at a concentration of 5 mg/L, were subjected to treatment under subcritical water conditions using a flow-type reactor to compare the degradation of free astaxanthin and astaxanthin fatty acid esters.

Degradation kinetics of passion fruit pectin in subcritical water.

The degradation of passion fruit pectin by subcritical water treatment in a continuous flow-type reactor was investigated in the temperature range of 80-160 °C at a constant pressure of 5 MPa. Changes in the degree of polymerization and reducing end formation were monitored and modeled by applying the Emsley equation and zeroth-order kinetics, respectively. The results showed that both the pectin degradation rate constant and the change in the amount of reducing end were enhanced by temperature, and that the temperature dependence of these parameters obeyed the Arrhenius relationship.

Direct Treatment of Isada Krill under Subcritical Water Conditions to Produce Seasoning with Shrimp-Like Flavour.

Characterization, sensory evaluation, and astaxanthin stability of isada krill under various subcritical water conditions were investigated to optimize the quality of krill extract and residue for producing food seasoning. Raw krill (82% wet basis moisture content) without additional water was treated in a pressure-resistant vessel for 10 min at a temperature range of 100-240 °C. The yield of water-soluble protein was maximized by treatment at 200 °C and decreased with treatment at higher temperatures.

Decomposition Kinetics of Glucose and Fructose in Subcritical Water Containing Sodium Chloride.

The kinetics of the decomposition and isomerization of glucose and fructose in pure water and water containing sodium chloride (1-20 % w/w) under subcritical conditions at 180-220 °C was investigated. The addition of sodium chloride in subcritical water accelerated the decrease of glucose, and the rate was expressed by the Weibull equation. Although the isomerization of glucose to fructose was observed in parallel with decomposition, the yield of fructose was lower at higher sodium chloride concentrations.

Kinetic analysis for the isomerization of cellobiose to cellobiulose in subcritical aqueous ethanol.

The isomerization of cellobiose to cellobiulose, and other degradation reactions of cellobiose were investigated in subcritical aqueous ethanol with concentrations of ethanol ranging from 0 to 60% (w/w) and at temperatures ranging from 170 to 200 °C. The maximum yield of cellobiulose (ca. 40%) was obtained from the treatment of cellobiose in 60% (w/w) aqueous ethanol at 190 °C.

Using severity factor as a parameter to optimize krill treatment under subcritical water conditions.

The aim of this study was to optimize the conditions for subcritical water treatment of krill, as expressed with a single parameter: the severity factor (log R). Raw krill was treated under subcritical water conditions at various log R values (1.54-3.

Antioxidative Properties of Stearoyl Ascorbate in a Food Matrix System.

Stearoyl ascorbate or 6-O-stearoyl l-ascorbate is a lipophilic derivative of l-ascorbic acid and is commercially used in foods as a fat-soluble antioxidant and surfactant to overcome the disadvantages of using l-ascorbic acid. The objective of this research is to evaluate the antioxidative ability of stearoyl ascorbate, in the presence of wheat starch or gluten as a matrix, by measuring the unoxidized methyl linoleate available in the mixture of them after oxidation under accelerated conditions compared to that when using ascorbic acid. We observed that stearoyl ascorbate and ascorbic acid exhibited mutually adjacent antioxidative ability against oxidation of the methyl linoleate at a molar ratio of 0.

Degradation of caffeic acid in subcritical water and online HPLC-DPPH assay of degradation products.

Caffeic acid was subjected to degradation under subcritical water conditions within 160-240 °C and at a constant pressure of 5 MPa in a continuous tubular reactor. Caffeic acid degraded quickly at these temperatures; the main products identified by liquid chromatography-diode array detection/mass spectrometry were hydroxytyrosol, protocatechuic aldehyde, and 4-vinylcatechol. The reaction rates for the degradation of caffeic acid and the formation of products were evaluated.

Antioxidant characteristics of extracts from cereal residues by their subcritical water treatment.

Subcritical water treatment of cereal residues including okara, defatted rice bran, desalted soy sauce lees, sake lees, corn kernel hull, and defatted rapeseed was conducted at 260°C for 5 min to obtain the antioxidative extracts. The antioxidative activities of the extracts were evaluated using DPPH radical, peroxyl radical, hydroxyl radical, hypochlorite ion, and peroxynitrite ion. The results show that the extracts from the sake lees, corn kernel hull, and defatted rapeseed had differently the antioxidative activities against all radicals and ions.

Subcritical water extraction of flavoring and phenolic compounds from cinnamon bark (Cinnamomum zeylanicum).

Cinnamon bark (Cinnamomum zeylanicum) powder was treated with subcritical water at 150 and 200°C in a semi-continuous system at a constant flow rate (3 mL/min) and pressure (6 MPa). Major flavoring compounds, i.e.

Degradation kinetics of gamma-oryzanol in antioxidant-stripped rice bran oil during thermal oxidation.

Gamma-oryzanol, a group of phytosterol ferulates found in rice bran, possesses antioxidative activity and other bioactivities. The kinetics of thermal degradation of gamma-oryzanol in stripped rice bran oil (SRBO) were investigated under heating at 132, 160, 192 and 222 degrees C for 480, 140, 60 and 50 h, respectively. Losses of the overall gamma-oryzanol and its components (cycloartenyl ferulate, 24-methylene cycloartanyl ferulate, campesteryl ferulate and beta-sitosteryl ferulate) could be expressed by the first-order kinetics model.

Preparation of finely dispersed O/W emulsion from fatty acid solubilized in subcritical water.

A novel method for preparing a finely dispersed oil-in-water emulsion is proposed. Octanoic acid dissolved in water at a high temperature of 220 or 230 degrees C at 15 MPa was combined with an aqueous solution of a surfactant and then the mixture was cooled. When a nonionic surfactant, decaglycerol monolaurate (ML-750) or polyoxyethylene sorbitan monolaurate (Tween 20), was used, fine emulsions with a median oil droplet diameter of 100 nm or less were successfully prepared at ML-750 and Tween 20 concentrations of 0.

Solubility of saturated fatty acids in water at elevated temperatures.

The solubility in water of saturated fatty acids with even carbon numbers from 8 to 18 was measured in the temperature range of 60 to 230 degrees C and at a pressure of 5 or 15 MPa. The pressure had no significant effect on the solubility. The solubility of the fatty acids increased with increasing temperature.