Microencapsulation of active ingredients in functional foods: From research stage to commercial food products

Thermal properties and behavior of microencapsulated sugarcane wax phase change material

In this study, a micro-encapsulated phase change material (PCM) was composed of sugarcane wax-Al2O3composite as the core material and gelatin-gum Arabic as the polymer shell materials prepared by complex coacervation. The thermal behavior of solar panels integrated with this encapsulated PCM (EPCM) was investigated. The heat storage-dissipation performance and thermal stability of the sugarcane wax-based composite PCM layer with the heat capacity of 2.86 J/g·°C was influenced by its thickness. Increasing the composite PCM layer thickness from 4 mm to 7 mm could lower the module's front-facing glass temperature by 4% resulting in enhanced the photovoltaic power generation by 12% at the peak, because of the temperature storage ability of the composite PCM. Moreover, the thermal conductivity of the microencapsulated sugarcane wax was calculated using a steady-state one-dimensional energy balance equation. The thermal conductivities estimated across the composite PCM layer depth were found to be temperature dependent. A nonlinear regression of the power law thermal conductivity model gave a good agreement with the observed EPCM-surface temperatures.

Plant phenolics as functional food ingredients

Phenolic compounds have attracted much attention in recent times as their dietary intake has been associated with the prevention of some chronic and degenerative diseases that constitute major causes of death and incapacity in developed countries, such as cardiovascular diseases, type II diabetes, some types of cancers or neurodegenerative disorders like Alzheimer's and Parkinson's diseases. Nowadays it is considered that these compounds contribute, at least in part, for the protective effects of fruit and vegetable-rich diets, so that the study of their role in human nutrition has become a central issue in food research. This chapter reviews the current knowledge on the phenolic compounds as food components, namely their occurrence in the diet, bioavailability and metabolism, biological activities and mechanisms of action. Besides, the approaches for their extraction from plant matrices and technological improvements regarding their preparation, stability and bioavailability in order to be used as functional food ingredients are also reviewed, as well as their legal situation regarding the possibility of making "health claims" based on their presence in food and beverages.

Assessment of Ready-to-Use Freeze-dried Immobilized Biocatalysts as Innovative Starter Cultures in Sourdough Bread Making

In the present study the effect of innovative biocatalysts as starter cultures in sourdough bread making was explored. The biocatalysts consisted of Lactobacillus paracasei K5 and Lactobacillus bulgaricus ATCC 11842 (in single and mixed form), immobilized on delignified wheat bran (DWB), and freeze dried without cryoprotectants. The parameters monitored were physicochemical characteristics, mold and rope spoilage appearance, volatile composition, and organoleptic characteristics. Results obtained showed that both biocatalysts exhibit good fermentative activity. However, the best results were achieved when freeze-dried immobilized L. paracasei K5 was applied as a single culture. In particular, the produced bread had a higher acidity (8.67 mL 0.1 N NaOH) and higher organic load (2.90 g/kg lactic acid and 1.11 g/kg acetic acid). This outcome was the main reason why this bread was preserved more regarding mold spoilage (14 days) and rope spoilage (12 days), respectively. In addition, the employment of freeze-dried immobilized L. paracasei K5 led to bread with better aromatic profile in terms of concentrations and number of volatile compounds produced as gas chromatography/mass spectrometry (GC/MS) analysis proved. Finally, no significant differences were observed through sensorial tests. Last but not least, it should be highlighted that the used microorganisms were cultured in cheese whey, minimizing the cost of the proposed biotechnological procedure.

Employment of L. paracasei K5 as a Novel Potentially Probiotic Freeze-Dried Starter for Feta-Type Cheese Production

In the present study, a novel potentially probiotic Lactobacillus paracasei strain, previously isolated from dairy products, was evaluated as a starter culture of Feta-type cheese production. Targeting industrial applications, the starter culture was applied as a ready-to-use freeze-dried culture that was either free or immobilized. The immobilized biocatalyst composed of Lactobacillus paracasei K5 cells absorbed within delignified wheat bran prebiotic carrier. All produced cheeses were compared with cheese manufactured by renin enzyme. Several parameters that affect acceptability, quality and shelf-life of Feta-type cheese were investigated, including microbial populations, physicochemical characteristics and cheese volatiles through 90 days of ripening and storage. Survival of L. paracasei K5 remained in high levels (≥6.0 log cfu/g) after the 90th day of cheese production, as recorded by combining microbiological enumeration and strain-specific multiplex PCR analysis. The use of the freeze-dried novel starter culture (free or immobilized) enhanced the aromatic profile of Feta-type cheeses. Finally, the use of the potentially synbiotic immobilized biocatalyst further improved aromatic characteristics of produced cheese and decrease of possible spoilage or pathogenic microorganisms. These findings indicate the potential industrial use of freeze-dried L. paracasei K5 as starter culture for the production of good-quality functional Feta-type cheese.

Assessment of Volatile Compounds Evolution, Antioxidant Activity, and Total Phenolics Content during Cold Storage of Pomegranate Beverage Fermented by Lactobacillus paracasei K5

A recently isolate from feta type cheese, potential probiotic strain Lactobacillus paracasei K5, was applied for pomegranate juice (Punica granutum L.) fermentation. Fermentations were carried out for 24 h followed by the storage of pomegranate juices at 4 °C for 4 weeks. The parameters examined were a composition of volatile compounds, antioxidant activity, total phenolic content, and consumers’ acceptance. The results were encouraging showing that lactic acid fermentation enhanced the composition of volatile compounds even at the fourth week of storage. Increased antioxidant activity (151.44 mg TE/100 mL at the second week) and total phenolics content (285 mg GAE/100 mL at the third week) were observed for all the storage times compared to the initial pomegranate beverage. The fermented pomegranate beverage received better scores for the last 3 weeks of cold storage compared to the non-fermented one. Likewise, L. paracasei K5 was proved to be suitable for the production of functional pomegranate beverages with enhanced aromatic characteristics and high nutritional value.

Production of a Novel Functional Fruit Beverage Consisting of Cornelian Cherry Juice and Probiotic Bacteria

The present study describes the development of a novel functional beverage through the application of probiotic Lactobacillus plantarum ATCC (American Type Culture Collection) 14917 in Cornelian cherry juice fermentation. The probiotic was employed in free and immobilized in a delignified wheat bran carrier (DWB) form. Cornelian cherry juice was fermented for 24 h and then it was stored at 4 °C for 4 weeks. Several parameters were evaluated such as residual sugar, organic acid and alcohol levels, total phenolics content, and cell viability as well as consumers acceptance. Regarding sugar and organic acids analyses, it was proved that the probiotic free or immobilized biocatalyst was effective. The concentration of ethanol was maintained at low levels (0.3⁻0.9% v/v). The total phenolic content of fermented Cornelian cherry juice with immobilized cells was recorded in higher levels (214⁻264 mg GAE/100 mL) for all the cold storage time compared to fermented juice with free cells (165⁻199 mg GAE/100 mL) and non-fermented juice (135⁻169 mg GAE/100 mL). Immobilized cells retained their viability in higher levels (9.95 log cfu/mL at the 4th week) compared to free cells (7.36 log cfu/mL at the 4th week). No significant sensory differences were observed among the fermented and the non-fermented samples.

Preparation and Properties of Ginger Essential Oil β-Cyclodextrin/Chitosan Inclusion Complexes

The ginger essential oil/β-cyclodextrin (GEO/β-CD) composite, ginger essential oil/β-cyclodextrin/chitosan (GEO/β-CD/CTS) particles and ginger essential oil/β-cyclodextrin/chitosan (GEO/β-CD/CTS) microsphere were prepared with the methods of inclusion, ionic gelation and spray drying. Their properties were studied by using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermo-gravimetry analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The results showed that the particle size of GEO/β-CD composite was smaller than that of β-CD and GEO/β-CD/CTS particles were loose and porous, while the microsphere obtained by spray drying had certain cohesiveness and small particle size. Besides, results also indicated that β-CD/CTS could modify properties and improve the thermal stability of GEO, which would improve its application value in food and medical industries.