Influences of Drying and Storage of Lycopene-Rich Carrots on the Carotenoid Content

ABSTRACT

The stability of β-carotene and lycopene was investigated during convective air and inert gas drying, microwave vacuum drying, and freeze-drying for lycopene containing carrots (Daucus carota L. cv. Nutri Red). After convection drying at temperatures below 70°C, β-carotene and lycopene contents remained unchanged independent of the drying medium. Freeze-drying did not show any advantage to convection-drying regarding carotenoid retention. Microwave vacuum–drying led to dry products with high carotenoid retention within very short drying times of about 2 h. Storage in air and in inert gas (nitrogen) containers was studied for convection-dried products, observing a better retention of carotenoids when using inert gas for a period of up to 6 months. After convection- and microwave vacuum–drying, an even better carotenoid extractability could be observed. No changes in the isomere fractions could be detected in any case.     

Application of Osmotic Dehydration Processes to Produce Apple Slices Enriched with β-Carotene

The objective of this work was the impregnation of β-carotene in apple slices by osmotic dehydration (OD) at atmospheric pressure and by pulsed vacuum osmotic dehydration (PVOD). Osmotic solutions were sucrose solutions of 30, 40, and 50 °Brix containing β-carotene (0.01 g/mL). Maximum impregnation using OD treatments was 1.5, 3.5, and 4.1 mg β-carotene/g ds. When using PVOD, significantly shorter processing times were required and impregnation reached 4.7, 5.5, and 6 mg β-carotene/g ds. Values of a_w obtained by OD were 0.973, 0.967, and 0.960 while by PVOD were 0.960, 0.930, and 0.880. Results showed that PVOD was a good option to impregnate apple with β-carotene.     

Extraction and Separation of α-lactalbumin and β-Lactoglobulin from Skim Milk by Microfiltration and Ultrafiltration at High Shear Rates: A Feasibility Study

Abstract

This paper presents a two-stage membrane filtration process for extracting and separating α-Lactalbumin (α-La) and β-Lactoglobulin (β-Lg), from UHT skim milk, using dynamic filtration. The 1st stage separates casein micelles in retentate from whey proteins in the permeate with rotating 0.2 µm pores ceramic membrane disks. Casein micelles rejection was excellent, while α-La and β-Lg transmissions remained between 80 and 90%. The permeate flux at 40°C ranged from 105 to 40 Lh^?1m^?2 at a volume reduction ratio of VRR = 4. The 2nd stage consisted of ultrafiltration of the previous permeate with a metal disk rotating at 2000 rpm near a fixed 50 kDa PES membrane, in order to concentrate β-Lg in retentate, while collecting α-La in the permeate. The flux dropped from 270 Lh^?1m^?2 at VRR = 1, and remained nearly constant at 200 Lh^?1m^?2 until a VRR of 3.3. α-La transmission increased with VRR to reach 23% at VRR = 3.3, while β-Lg transmission decayed at increasing VRR to 3%, to give a maximum selectivity of 8.     

Effects of β-carotene and lycopene thermal degradation products on the oxidative stability of soybean oil

The relative oxidative stability of soybean oil samples containing either thermally degraded β-carotene or lycopene was determined by measuring peroxide value (PV) and headspace oxygen depletion (HOD) every 4 h for 24 h. Sobyean oil samples containing 50 ppm degraded β-carotene that were stored in the dark at 60°C displayed significantly (P<0.01) higher HOD values compared with controls. Lycopene degradation products (50 ppm) in soybean oil significantly (P<0.05) decreased HOD of samples when stored in the dark. PV and HOD values for samples containing 50 ppm of either β-carotene or lycopene degradation products stored under lighted conditions did not differ significantly from controls (P<0.05). However, soybean oil samples containing 50 ppm of unheated, all-trans β-carotene or lycopene stored under light showed significantly lower PV and HOD values than controls (P<0.01). These results indicated that during autoxidation of soybean oil held in the dark, β-carotene thermal degradation products acted as a prooxidant, while thermally degraded lycopene displayed antioxidant activity in similar soybean oil systems. In addition, β-carotene and lycopene degradation products exposed to singlet oxygen oxidation under light did not increase or decrease the oxidative stability of their respective soybean oil samples.     

Computer Color Matching Procedures for Mass Colored Polypropylene

In the present investigation, attempts were made to color match mass colored polypropylene by the use of several colorimetric color matching procedures. A color matching procedure consisting of a rough match as a starting point and an iterative algorithm to achieve the exact match to any degree of accuracy was carried out. The rough match was calculated based on the Kubelka-Munk's one and two constant theories. Six different iteration procedures were utilized to achieve the exact match having ΔE₂₀₀₀ < 0.5. The results showed that the iterations based on Lab76 gave superior results showing the most potential for a recipe prediction system for a computer color matching procedure by giving the lowest average concentration difference, ΔC_AVE, and the lowest color difference, ΔE₂₀₀₀, under the reference condition, i.e., D65/10°. In general and as expected, concentration predictions based on the one-constant theory were always inferior to the prediction based on the two-constant theory.     

Kinetic Models of β-Carotene Degradation During Air Drying of Carrots

The objective of this study was to determine the kinetic parameters of models that describe the joint influence of temperature and moisture content on the thermal degradation of β-carotene in a drying process of carrots. Two models were used: a first-order decay model with an Arrhenius and a polynomial dependency on temperature and water content, respectively, and a decay model with a WLF dependency of the decimal reduction time on glass transition temperature (Tg), with the Gordon and Taylor equation describing the influence of moisture content on Tg. Carrots were dehydrated in a cabinet air dryer at 50, 60, 70, and 80°C. Carrot samples were drawn at 20-min intervals and analyzed for moisture and β-carotene content. The parameters of the two models were estimated by nonlinear regression. In addition, the models were evaluated by comparing their predictions and experimental data during drying at 80°C of carrot slices with thickness of 3, 6, and 9 mm. Both models were found suitable for modeling the β-carotene degradation, though the lower sum of squares of residuals (SSQ) of the Tg approach model and the similar WLF parameters calculated at different drying air temperatures demonstrated the higher predictive ability of the Tg model over the more common empirical dependence model.     

Effect of Calcium Salts of Glutaric Acid and Pimelic Acid on the Formation of β Crystalline Form in Isotactic Polypropylene

The effect of calcium glutarate (Cagt) and calcium pimelate (Capt) on the formation of β crystalline form in isotactic polypropylene (iPP) after isothermal crystallization at 130°C for 30 min has been investigated. The maximum K_WAXD and K_DSC values were 31.97% and 38.06%, respectively, for iPP doped with 0.2 wt.% Cagt. The maximum values of K_WAXD and K_DSC were 73.60% and 68.44% for iPP doped with 0.3 wt.% and 0.15 wt.% Capt, respectively. The crystal size of iPP doped with Capt is finer than that of iPP doped with Cagt. It is shown that the β nucleation ability of Capt is superior to that of Cagt. The difference in the β nucleation ability between Cagt and Capt is explained by the structural difference of the nucleators with β-iPP.     

The Relationship Between the Microhardness and Glass Transition Temperature of Inorganic Glasses Compared with Polymeric Glasses

ABSTRACT

In this article an attempt is undertaken to verify the approach already successfully applied to polymeric glasses for deriving a simple analytic relationship between the glass transition temperature, T_g , and Vickers microhardness, H_v , (for polymers it is H_v  = 1.57 T_g –571, H_v in MPa, T_g in K). On the basis of previously reported data for H_v and T_g of 12 inorganic glasses (lead-silicate-, alkali-silicate-, alumosilacate, and quartz glasses) a linear relationship in the form H_v  = 5.87 T _g + 1740 (H_v in MPa, T_g in K) is derived. In addition, a critical analysis of the published attempt for theoretical deriving of the relationship between H_v and T_g is also offered.     

Influence of β-Nucleators on iPP Crystallization and Morphology

In this article, the effects of the β-nucleators WBG and WOT on the crystallization behavior and morphology of isotactic polypropylene (iPP) were investigated using a combination of differential scanning calorimetry (DSC), wide-angle X-ray (WAXD), polarized optical microscopy (POM) and atomic force microscopy (AFM). The results showed that the amount of β-form and the spherulite size decreased with increasing WBG contents. At about 0.15 wt. % WBG nucleator, the formation of the β-form was evidently observed. Whereas, for the iPP with low content of WOT nucleator, the formation of the β-form was almost the same as that of pure iPP.     

SOLUBILITY OF HIPPOPHAE RHAMNOIDES L. SEED OIL IN SC CO2 AND SCFE PROCESS ENHANCEMENT BY ULTRASOUND

Dynamic method was applied to measure the solubility of oil from Hippophae rhamnoides L. seed in supercritical CO₂. The experiments were carried out at pressures and temperatures ranging from 10 to 30 MPa and 303 to 323 K, respectively. No marked changes in composition of extracted oil in the course of extraction were observed. The solubility was correlated with CO₂ density and temperature by adjusting the constants of the del Valle-Aguilera equation. In order to enhance the extraction efficiency of supercritical fluid extraction (SCFE) for natural products, the SCFE process coupled with power ultrasound (20 kHz, 150 W) was investigated. The reactor with a power ultrasound transducer was specially designed and set up. For Hippophae rhamnoides L. seed oil, soybean seed oil, and licorice root oil extraction, the extraction rate and the oil yield were increased by 16.9–33.2% and 30% respectively, with the coupling of SCFE and power ultrasound.     

Adsorption Thermodynamic and Kinetic Studies of Fluoride Aqueous Solution Treated with Waste Iron Oxide

This study uses a waste iron oxide material (BT3), which is a by-product of the fluidized-bed Fenton reaction (FBR–Fenton), for the treatment of a fluoride (F^?) solution. The purpose of this study is to investigate a low-cost sorbent as a replacement for the current costly methods of removing fluoride from wastewater. X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) are used to characterize the BT3. Contact time, F^? concentration (from 0.75 to 6 mmol L^?1), and temperature (from 303 to 323 K) are used as operation parameters to treat the fluoride. The highest F^? adsorption capacity of the BT3 adsorbent was determined to be 1.17 mmol g^?1 (22.2 mg g^?1) for a 6 mmol L^?1 initial F^? concentration at pH 3.9 ± 0.2 and 303 ± 1 K. Adsorption data were well described by the Langmuir model, and the thermodynamic constants of the adsorption process, ΔG°, ΔH°, and ΔS°, were evaluated as ?1.63 kJ mol^?1 (at 303 K), ?1.75 kJ mol^?1, and ?52.4 J mol^?1 K^?1, respectively. Additionally, a pseudo-second-order rate model was adopted to describe the kinetics of adsorption. BT3 could be regenerated with NaOH, and the regeneration efficiency reached 95.1% when the concentration of NaOH was 0.05 mol L^?1.     

A storage study of encapsulated gac (Momordica cochinchinensis) oil powder and its fortification into foods

This study investigated the effects of different storage conditions, temperatures of −20, 10, room temperature (RT), 40 and 63 °C for up to 12 months in the presence or absence of air and light, on the stability of an encapsulated gac (Momordica cochinchinensis) oil powder. A stability trial of the encapsulated oil powder incorporated into yoghurt, pasteurised milk and cake mix stored at 4 ± 0.5 °C and RT for different storage times was also carried out. The results showed that a progressive degradation of colour, β-carotene and lycopene, and a progressive increase in surface oil content and peroxide value (PV) occurred in the encapsulated powders with increasing storage temperatures and storage times. However, the degradation was much less when the encapsulated powder was stored at low temperature in the absence of air and light. The degradation of β-carotene and lycopene in all samples during storage fitted a first-order reaction. The sorption curves of the encapsulated powders at 10, 30 and 40 °C were fitted with BET and GAB models. The results also showed that the encapsulated gac oil powder could be successfully incorporated into food products in terms of retention of colour, β-carotene and lycopene, and low PV.     

Studies on the Preparation of Polystyrene Thermal Conductivity Composites

Various thermally conductive fillers including aluminum oxide(Al₂O₃), magnesium oxide(MgO), β-silicon carbide particle(β-SiCp) and β-silicon carbide whisker(β-SiCw) were used to prepare polystyrene thermal conductivity composites. Experimental results showed that, for given filler loading, the thermal conductivity of the composites was higher for PS flake than that of PS particle, and the thermal conductivity was optimal by powder blending method. The SiCw filler was more favorable to improve the thermal conductivity of the composites; a much higher thermal conductivity of 1.18 W/mK could be achieved for the composite with 40 vol% SiCw, about six times higher than that of native polystyrene. The experimental thermal conductivity values were in agreement with those predicted by lower bound of Maxwell-Eueken model. For given SiC loading, the thermal conductivity increased with the increasing shape parameter of n. The SiCw was much easier to form the thermal conductivity chains and network than that of SiCp.     

High-Purity Calycosin-7-O-β-D-glucopyranoside Recovered from Radix Astragali by Extraction,Fractionation and Recrystallization

Abstract

Calycosin-7-O-β-D-glucopyranoside (CG), one major isoflavonoid in Radix Astragali with promising pharmacological effects, was separated with a low-cost process in the present study. The sequential separation and purification procedures established involved extraction with 90% (v/v) aqueous ethanol at 75°C for 2 h twice followed by partition with ethyl acetate, elution with water, and 40% (v/v) aqueous ethanol on a styrene-based resin column and recrystallization at 4°C for 12 h with methanol. These conditions resulted in recovery of 81.6% of total CG with over 97% purity.     

Electrostatic Droplet Generator with 3-Coaxial-Nozzle Head for Microencapsulation of Living Cells in Hydrogel Covered by Synthetic Polymer Membranes

The current methods allow for encapsulation of cells inside spherical microcapsules made of a matrix covered by a permselective membrane using an electrostatic droplet generator with 1-nozzle or 2-nozzle heads. However, some potentially useful materials for the outer membranes cannot be put into direct contact with hydrophilic core filled by cells during the manufacturing process. Therefore, we designed a novel 3-coaxial-nozzle head that allows for the third fluid to separate the core material from the membrane material. The equipment was applied for manufacturing spherical microcapsules comprised of cell-friendly alginate core surrounded by semipermeable polyethersulfone membrane. The obtained microcapsules had a diameter between 0.84 mm and 1.79 mm, and the diameter correlated negatively with the applied electric voltage. The thickness of the membrane varied from 171 µm to 450 µm. The SEM images of the interior of microcapsules revealed highly porous membrane structure typical for synthetic membranes obtained by a wet phase inversion method. Bakery yeast cells encapsulated inside the alginate-polyethersulfone microcapsules retained their proliferation ability proving the effectiveness and safety of this encapsulation technique.     

DRYING TECHNOLOGY IN AGRICULTURE AND FOOD SCIENCE

ABSTRACT

The retentions of alcohol dehydrogenase (ADH) activity during drying and storage were investigated at various temperatures and relative humidities for various carbohydrate solutions. The highest retention of ADH activity after drying was obtained for the mixture of trehalose and methyl-β-cyclodextrin. For a single dried droplet, the effects of humidity on the storage stability of ADH were reversed between the trehalose solution and the blend of trehalose and methyl-β-cyclodextrin. However, the addition of methyl-β-cyclodextrin decreased the residual activity of ADH during storage. The carbohydrate matrix structure after drying might influence mainly the storage stability of ADH encapsulated in the mixed carbohydrate of trehalose and methyl-β-cyclodextrin.     

Bioactive Compounds,Antioxidant Activities and Heat Stability of Corn Oil Enriched with Tunisian Citrus aurantium L. Peel Extract

This study was designed to examine physicochemical composition, antioxidant activities and heat stability of corn oil enriched with bitter orange peel. Volatile compounds composition of corn oil flavored with Citrus aurantium peel was investigated. Flavored oil total aroma content (2.6 mg/mg oil) was mainly represented by monoterpene hydrocarbons and limonene was the major one (2.49 mg/mg oil). Flavored oil methanolic extract was characterized by total phenol content of 1.22 mg GAE/kg. Chlorogenic, ferulic and p-coumaric acids were the major phenolic components of the flavored oil extract (34.33, 30.24 and 19.39 %, respectively). It was also characterized by a higher chlorophylls and carotenoids contents than the refined one. Antioxidant activities of methanolic extracts of both samples were determined using four assays: DPPH, reducing power, β-carotene bleaching and metal chelating tests. In β-carotene bleaching and DPPH radical scavenging assays, flavored oil methanolic extract showed higher activities than the control. It was characterized by a total antioxidant activity of 4.08 mg GAE/kg and an EC₅₀ value of 3.14 mg/mg oil. Its concentration providing 50 % inhibition (IC₅₀) was 0.53 mg/mg oil in the DPPH test and 4.08 mg/mg oil in the β-carotene bleaching test. However, refined corn extract showed significantly lower antioxidant activities (p < 0.05). Results of the oxidative stability index showed bitter orange peel effectiveness against thermal oxidation based on the increased induction time observed in flavored oil (5.95).     

Carotenoid Profile of Tomato Sauces: Effect of Cooking Time and Content of Extra Virgin Olive Oil

The consumption of carotenoid-rich vegetables such as tomatoes and tomato sauces is associated with reduced risk of several chronic diseases. The predominant carotenoids in tomato products are in the (all-E) configuration, but (Z) isomers can be formed during thermal processing. The effect of cooking time (15, 30, 45 and 60 min) and the addition of extra virgin olive oil (5% and 10%) on the carotenoid extractability of tomato sauces was monitored using liquid chromatography-tandem mass spectrometry (LC-ESI-MS/MS) and LC-ultraviolet detection (LC-UV). The thermal treatment and the addition of extra virgin olive oil increased the levels of antioxidant activity, total carotenoids, Z-lycopene isomers, α-carotene and β-carotene. These results are of particular nutritional benefit since higher lycopene intake has been associated with a reduced risk of lethal prostate and a reduction of prostate-specific antigen (PSA) levels. Moreover, β-carotene has been reported to suppress the up-regulation of heme oxygenase-1 gene expression in a dose dependent manner and to suppress UVA-induced HO-1 gene expression in cultured FEK4.     

Influence of Different Solvents on the Morphology of the Hybrid Layer Using Two-Step Etch-and-Rinse Adhesives

To evaluate if different etch-and-rinse adhesive solvents influenced the hybrid layer's morphology.

Four one-bottle etch-and-rinse adhesive systems containing different solvents—Group A: Scotchbond 1XT?– 3 M ESPE, Group B: XP – Bond? – Dentsply, Group C: Prime&;Bond NT® – Dentply, and Group D: One Coat Bond® - Coltène Whaledent—were applied onto 32 dentin discs which were thermocycled, prepared, and examined using field-emission scanning electron microscopy. Micrographs were scanned and the data were processed using Statistical Package for Social Sciences. The mean value and standard deviation were calculated and the Anova Multivariant Test was used.

The hybrid layer thickness average found was 3.23 µm (±0.53) in Group A, 3.13 µm (±0.73) in Group B, 2.53 µm (±0.50) in Group C, and 1.84 µm (±0.27) in Group D. Prime&;Bond NT® presented a more inconsistent hybrid layer.

The solvent seems to play a significant role in hybrid layer structure and thickness.     

Analysis of Physical and Thermodynamic Properties of Poly(2-Phenyl-1,3-Dioxolane-4-Yl-Methyl-Methacrylate-Co-Styrene) Polymer with Inverse Gas Chromatography

In this study, physical and thermodynamic properties of poly(2-phenyl-1,3-dioxolane-4-yl-methyl-methacrylate-co-styrene) (PDMMA-ST) were investigated by using inverse gas chromatography. Two groups of solvents with different chemical natures and polarities were used to obtain information about PDMMA-ST-solvent interactions: alcohols and alkanes. The specific retention volume (V_g ⁰), the sorption enthalpy (ΔH₁ ^S), sorption free energy (ΔG₁ ^S), sorption entropy (ΔS₁ ^S), the weight fraction activity coefficients of solute probes at infinite dilution (Ω ₁ ^∞), and Flory-Huggins interaction parameters (χ ₁₂ ^∞) between polymer and solvents were determined for the interactions of PDMMA-ST with alcohols and alkanes by inverse gas chromatography in the temperature range of 333–473 K. Also, the solubility parameters of PDMMA-ST at infinite dilution were found by plotting the graph of [(δ ₁ ²/RT) - χ ₁₂ ^∞/V₁] versus solubility parameters, δ ₁, of probes.