Sorption properties, glass transition and state diagrams for pumpkin powders containing maltodextrins

State diagrams of green peas (Pisum sativum L.) powders with different maltodextrin additions

The purpose of this study was to examine the effect of maltodextrin addition on the physical stability of powdered green peas. The evaluation of the physical state of the material was based on the equilibrium water content of the monolayer (Xm) and the glass transition temperatures of the powders at room temperature (Tg) and in the frozen state (Tg'). Graphical sorption characteristic at 25°C was determined using static-gravimetric method while capacity of the monolayer values was calculated from the mathematical GAB model. Differential scanning calorimetry was carried out in order to determine glass transition lines and freezing curves which combine together were used to plot state diagrams. Relationship between Tg and solid content were shown by using Gordon-Taylor model. Freezing data were modeled employing the Clausius-Clapeyron equation and its development-Chen model. Sorption isotherms showed sigmoidal shape characteristic for high-molecular weight materials. Monolayer moisture content varied between 0.047 and 0.106 g water/g solids. The glass transition temperature of anhydrous green peas increased in from 89.9 to 175.6°C while Tg' value changed from -43.4 to -26.6°C to as a result of 75% polysaccharide addition. The ultimate maximum-freeze-concentration conditions of the powders were observed in range from 0.783 to 0.814 g solids/g sample. Monolayer capacity, Tg and Tg' values increased with increasing maltodextrin amount in the sample which indicates that the addition of starch hydrolysate has a beneficial effect on the stability of powders stored frozen and at room temperature.

Microencapsulation of phenolic compounds extracted from soybean seed coats by spray-drying

This study aimed to characterize and microencapsulate soybean seed coats phenolic compounds by spray-drying, evaluating physicochemical properties and storage stability. Different extraction methodologies were used to obtain crude extract (SCE), ethyl acetate fraction, water fraction, and bound phenolic extract. Extraction yield, total phenolic and flavonoid contents, and antioxidant capacity were determined. HPLC-electrospray ionization source-MS/MS analysis was performed on SCE. Microencapsulation by spray-drying of SCE incorporating 10%, 20%, and 30% maltodextrin (MD) was carried out. Drying yield (DY), encapsulation efficiency (EE), moisture, morphology and particle size, dry, and aqueous storage stability were evaluated on the microcapsules. SCE had 7.79 g/100 g polyphenolic compounds (mainly isoflavones and phenolic acids) with antioxidant activity. Purification process by solvent partitioning allowed an increase of phenolic content and antioxidant activity. Microcapsules with 30% MD exhibited the highest DY, EE, and stability. Microencapsulated polyphenolic compounds from soybean seed coats can be used as functional ingredients in food products. PRACTICAL APPLICATION: Soybean seed coat is a usually discarded agro-industrial by-product, which presents antioxidant compounds of interest to human health. These compounds are prone to oxidation due to their chemical structure; therefore, microencapsulation is a viable and reproducible solution to overcome stability-related limitations. Microencapsulation of soybean seed coats polyphenols is an alternative which protects and extends the stability of phenolic compounds that could be potentially incorporated into food products as a natural additive with antioxidant properties.

High-Shear Granulation of Hygroscopic Probiotic-Encapsulated Skim Milk Powder: Effects of Moisture-Activation and Resistant Maltodextrin

A fine, hygroscopic, and poorly flowable probiotic powder encapsulating Lactobacillus rhamnosus GG (LGG) was granulated using a high-shear granulation process, wherein a small amount of water (4%, w/w) was used for moisture-activation with or without 10% (w/w) resistant maltodextrin (RM). The process consisted of four steps; premixing, agglomeration, moisture absorption, and drying steps. The moisture content, water activity, and viable cell count were monitored during the granulation. The size, morphology, and flowability of the granules were determined. The powder was successfully converted to about 10-times-larger granules (mass mean diameter = 162–204 µm) by this process, and the granules had a ‘snowball’ morphology. The LGG cells were well preserved under the high-shear granulation conditions, and the viable cell count of the granules greatly exceeded the minimum therapeutic level recommended for probiotic powders. The addition of RM decreased the moisture content of the granules; improved cell resistance to drying stress; narrowed the particle size distribution, with reductions seen in both very fine and very large particles; and produced more flowable granules. Moisture sorption analysis and differential scanning calorimetry demonstrated that these positive effects of RM on granulation were primarily attributed to its water distribution ability rather than its glass transition-related binding ability.

An Equilibrium State Diagram for Storage Stability and Conservation of Active Ingredients in a Functional Food Based on Polysaccharides Blends

A functional food as a matrix based on a blend of carbohydrate polymers (25% maltodextrin and 75% inulin) with quercetin and Bacillus claussi to supply antioxidant and probiotic properties was prepared by spray drying. The powders were characterized physiochemically, including by moisture adsorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM), and modulated differential scanning calorimetry (MDSC). The type III adsorption isotherm developed at 35 °C presented a monolayer content of 2.79 g of water for every 100 g of dry sample. The microstructure determined by XRD presented three regions identified as amorphous, semicrystalline, and crystalline-rubbery states. SEM micrographs showed variations in the morphology according to the microstructural regions as (i) spherical particles with smooth surfaces, (ii) a mixture of spherical particles and irregular particles with heterogeneous surfaces, and (iii) agglomerated irregular-shape particles. The blend's functional performance demonstrated antioxidant activities of approximately 50% of DPPH scavenging capacity and viability values of 6.5 Log10 CFU/g. These results demonstrated that the blend displayed functional food behavior over the complete interval of water activities. The equilibrium state diagram was significant for identifying the storage conditions that promote the preservation of functional food properties and those where the collapse of the microstructure occurs.

Essential Oils from Some Lamiaceae Plants: Antioxidant and Anticancer Potentials besides Thermal Properties

The purpose of this study was to determine the chemical compositions, antioxidant and anticancer activities and thermal behavior of essential oils (EOs) obtained by a microwave assisted Clevenger apparatus from Mentha longifolia subsp. typhoides var. typhoides (ML), Thymus kotschyanus var. glabrescens (TK), Calamintha nepeta subsp. nepeta (CN) and Satureja cuneifolia (SC) in Osmaniye, Turkey. Nepetalactone (34.23 %), thymol (37.40 %), piperitone oxide (27.25 %), and carvacrol (28.34 %) were major compounds in the EOs of ML, TK, CN, and SC. Total phenolic content and antioxidant activity (by FRAP assay) were in the range of 0.27-3.01 mg gallic acid equivalents and 0.62-171.14 μmol trolox equivalent per g EO, respectively. IC50 values of DPPH were mostly greater than ABTS. IC50 levels of the EOs of ML, TK, CN for the cytotoxic activities were 195.7, 265.7, 442.9 μg/ml, and 218.4, 204.2, 133.9 μg/ml for 24 and 48 h, respectively. IC50 of SC-EO could not be calculated in the applied concentration range. The highest fusion enthalpies were in between 58.72 and 81.65 kJ/kg. Both the TK and SC plant EOs had comparable and significant bioactivities. CN-EO reduced cell motility and triggered apoptosis more effectively than the others.

The Thermal Characteristics, Sorption Isotherms and State Diagrams of the Freeze-Dried Pumpkin-Inulin Powders

Powders based on plant raw materials have low storage stability due to their sorption and thermal properties and generate problems during processing. Therefore, there is a need to find carrier agents to improve their storage life as well as methods to evaluate their properties during storage. Water adsorption isotherms and thermal characteristics of the pumpkin powder with various inulin additions were investigated in order to develop state diagrams. Differential scanning calorimetry (DSC) was used to obtained glass transition lines, freezing curves and maximal-freeze-concentration conditions. The glass transition lines were developed using the Gordon–Taylor model. Freezing data were modeled employing the Clausius–Clapeyron equation and its development–Chen model. The glass transition temperature of anhydrous material (Tgs) and characteristic glass transition temperature of maximum-freeze-concentration (Tg′) increased with growing inulin additions. Sorption isotherms of the powders were determined at 25 °C by the static-gravimetric method and the experimental data was modeled with four different mathematical models. The Peleg model was the most adequate to describe the sorption data of the pumpkin–inulin powders. Guggenheim-Anderson-de Boer (GAB) monolayer capacity decreased with increasing inulin concentration in the sample.

Moisture and caking resistant Tremella fuciformis polysaccharides microcapsules with hypoglycemic activity

Tremella fuciformis polysaccharides (TPs) have attracted extensive attention as functional food constituents due to their bioactivity. However, β-D-glucan obtained from TPs is readily degraded by oxidation and easy to absorb water and agglomerate. The purpose of this study was to reduce moisture adsorption and caking strength through spray drying by using maltodextrin as wall materials and explore the hypoglycemic effect and molecular mechanism of TPs microcapsules. It was observed that dextrose equivalent (DE) value and concentration of maltodextrin (MD) affect the morphology, encapsulation efficiency, loading capacity, water adsorption and caking strength of TPs microcapsules powder. The administration of TPs microcapsules powder prevented body weight and serum insulin loss, and significantly decreased the blood glucose level, serum triglycerides, as well as total cholesterol levels, which seemed to be related to increasing the glycogen synthesis and facilitating the glucose transportation by regulating the PI3K/Akt pathway.