The food industry expects increasingly complex properties (such as delayed release, stability, thermal protection, and suitable sensorial profile) from food ingredients, which often would not be able ...to be achieved without microencapsulation. This paper presents the state of the art in encapsulation technology for delivery of bioactive compounds to food. It reviews common encapsulation technologies (emphasizing their advantages and limitations) versus novel, interesting approaches in emerging technologies. This review includes a presentation of benefits resulting from the use of microencapsulated ingredients in the food industry; these benefits are going to be illustrated via few case studies bringing innovative processing. Spray drying has been used for more than 60 years to protect flavor oils against degradation/oxidation/evaporation, but melt dispersion technique has been used lately to effectively stabilize an aroma compound. Microgels produced by extrusion and emulsification techniques are considered for delivering synergistic antioxidant effects of plant extract polyphenols, their off-taste masking, and improved handling. Apart from microgels, microemulsions (produced by microfluidization or micelle formation techniques) are taken into account for entrapment of extracts containing polyphenols and essential oils. Innovative and interesting coacervation processes are depicted here as they facilitate the commercialization of coacervated food ingredients. Liposomes are gaining increasing attention in the food sector as they can provide good stability even in a water surrounding and also targeted delivery. The new scalable manufacturing protocols for the production of liposomes evolved in recent years (e.g., proliposome method) are presented here. Fluidized bed technology has been offering a versatile possibility to produce encapsulates which should release ingredients at the right place and the right time. Complex systems such as lipids in hydrogels are newly developed structures for controlled release of bioactive compounds. Finally, the effect encapsulates have when incorporated into real food products will be discussed, in particular with regard to the production of innovative functional food products. As an example, textural, sensorial, and physical quality assessment of chocolates enriched with encapsulated polyphenolic antioxidants from yarrow (
Achillea millefolium
L.) will be reviewed.
In order to deactivate the health properties of bioactive compounds, they need to withstand the effects of food processing, their potential release from the food matrix, and remain bio-accessible in ...the gastrointestinal tract. Bio-actives from different plants are prone to oxidative degradation, and encapsulation is an effective method in improving their stability. In the present study, red pepper waste (RPW), a by-product of vegetable processing industry, was encapsulated in whey protein using spray and freeze-drying techniques. The aim was to evaluate the effects of in vitro gastrointestinal digestion on the release and bioactivity of encapsulated bio-actives, after each digestion step. The results showed that the release of phenolics and carotenoids, as well as antioxidants, anti-hyperglycemic, and anti-inflammatory activities are influenced by pH and intestinal fluid, with pH 7.5 exhibited at higher levels. There was a rapid initial release of carotenoids from whey protein matrices, while a more gradual increase of phenolics was observed, reaching around 50% for both encapsulates first at 6 h and 37 °C, and small intestine conditions. The encapsulation of RPW demonstrated a protective effect against pH changes and enzymatic activities along digestion, and contributed to the increase in bio-accessibility in the gut. Also, the results suggest that encapsulation is an efficient method for valorization of bio-actives from RPW, with improvements in nutrition, color, and bioactive properties.
Remodelling of collagen fibers has been described during every phase of cancer genesis and progression. Changes in morphology and organization of collagen fibers contribute to the formation of ...microenvironment that favors cancer progression and development of metastasis. However, there are only few data about remodelling of collagen fibers in healthy looking mucosa distant from the cancer. Using SHG imaging, electron microscopy and specialized softwares (CT-FIRE, CurveAlign and FiberFit), we objectively visualized and quantified changes in morphology and organization of collagen fibers and investigated possible causes of collagen remodelling (change in syntheses, degradation and collagen cross-linking) in the colon mucosa 10 cm and 20 cm away from the cancer in comparison with healthy mucosa. We showed that in the lamina propria this far from the colon cancer, there were changes in collagen architecture (width, straightness, alignment of collagen fibers and collagen molecules inside fibers), increased representation of myofibroblasts and increase expression of collagen-remodelling enzymes (LOX and MMP2). Thus, the changes in organization of collagen fibers, which were already described in the cancer microenvironment, also exist in the mucosa far from the cancer, but smaller in magnitude.
The aim of our study was to evaluate the use of Raman spectroscopy for pre-diagnostic estimation of weed response to bleaching herbicides. Model plants were Chenopodium album and Abutilon theophrasti ...treated with mesotrione (120 g a.i. ha
−1
). Raman single-point measurements were taken 1, 2, 3, and 7 days after herbicide application from different points on the leaves. Principal component analysis (PCA) was carried out on data normalized by the highest intensity band at 1522 cm
−1
and using spectral region from 950 to 1650 cm
−1
comprising mainly contributions of carotenoids. The carotenoids by intensive band at ∼1522 cm
−1
and bands with lower intensity at ∼1155 and 1007 cm
−1
in treated plants were confirmed. According to PC1 (the first principal component) and PC2 (the second principal component), the highest intensity bands responsible for treatment differentiation in C. album could be assigned to chlorophyll, lignin, and carotenes. According to PC1 in A. theophrasti leaves the treatment differences could be observed 7 days after mesotrione treatment and PC2 gave a clear separation between all control and treated leaf samples. Raman spectroscopy may be a good complement to invasive analytical methods, in assessing the plant abiotic stress induced by bleaching herbicides.
The study assessed the antimicrobial and antioxidant activities of commonly used and commercially available essential oils as an alternative to synthetic preservatives. The plant sources were as ...follows: lavender (Lavandula angustifolia), tea tree (Melaleuca alternifolia), bergamot (Citrus bergamia) and peppermint (Mentha piperita). The antioxidant activity of essential oils was tested by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2´-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods. The microdilution broth susceptibility assay revealed that lavender and bergamot essential oils were more efficient in inhibiting the bacterial growth than other tested oils, with the minimum inhibitory concentration of 5 μg/mL. This study also reports the successful implementation of an electrostatic extrusion technique for encapsulating essential oils into alginate beads, which enables the essential oils to maintain their free radical scavenging ability over time.
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•HPLC analysis showed that TTSG milk/pollen powder is good source of polyphenols.•After in vitro digestion of sample, the total polyphenols recovery was 30.71%.•TTSG milk/pollen ...powder exhibited good antioxidant properties.•TTSG milk/pollen powder could be a good functional ingredient.
The aim of research was to determine polyphenols bioaccessibility and antioxidant properties of thermally-treated skimmed goat milk enriched with sunflower bee-collected pollen through in vitro digestion. HPLC analysis confirmed that pollen-enriched milk contained flavonols as the main phenolic fraction (80.7–76.2%) followed by phenolic acids (14.2–17.4%). Among individual compounds quercetin-3-O-glucoside (155.1–197.2 μg/L) and p-coumaric acid (29.5–30.7 μg/L) were the main quantified flavonols and phenolic acids, respectively. After digestion of milk/pollen sample, total polyphenols recovery was 30.71% with higher phenolic acids recovery (40.1%) compared to flavonols (28.3%) indicating strong interactions between caprine milk casein micelles and pollen polyphenols. Applied antioxidant assays (phosphomolybdenum, ABTS•+scavenging activity and ferrous-ion-chelating capacity) have confirmed complexity of prepared product- it had high ability to quench ABTS•+ radicals and to form chelating complexes with Fe2+ ions. Digestion provoked 20% reduction in total antioxidant capacity compared to the initial sample. TTSG milk/pollen powder could be good functional ingredient.
In this study a bottom-up approach of designing functional ingredients from green tea extract is proposed by a systematic investigation of 12 different natural biopolymers and their efficiency as ...carrier materials of green tea bioactive compounds by spray drying at low temperature (130 °C). Screening of carriers revealed that inulin and whey proteins provide the highest product yields (67.04 and 65.18 %, respectively) and, accompanied with pectin, also the highest total polyphenols (67.5–82.2 %) and flavan-3-ols (93.7–75.9 %) loading capacity. Up to 162 mg/g of (−)−epigallocatechin gallate (EGCG) was achieved, while low-caffeine contents (<5 mg/g) indicated the potential of obtaining low-caffeine functional ingredients. Employing alginate, carageenan and gums (acacia gum and xanthan) enabled the best colour preservation and highest chlorophyll content. Reconstituted green tea microencapsulates comprising modified starch, inulin or carageenan exhibited the lowest bitterness and astringency and the highest green tea flavour intensity as the most favourable sensory properties. An artificial neural network (ANN) designed based on the experimentally obtained results revealed hydrocolloid gums as the best encapsulants for achieving good physical properties, high EGCG contents and prolonged dissolution/release profiles while pectin, inulin and modified starch as the optimal ones in terms of the product yields, loading capacities and sensory properties. This indicates that a formulation comprising a combination of all of those biopolymers would provide potentially functional ingredients with encapsulated green tea phytochemicals, retained colour and improved sensory properties.
Research background. Due to numerous health-promoting properties, dandelion has been used in traditional medicine as a herbal remedy, but also as a food product. Dandelion health benefits are ...ascribed to the presence of different bioactive compounds in its tissues, among which polyphenols play a significant role. However, the low stability of polyphenols is a critical parameter for their successful implementation into products. Thus, their encapsulation using appropriate carrier vehicles is highlighted as an effective technique for their stabilization and protection. The aim of this study is to microencapsulate dandelion leaf extract using spray drying and different carrier materials for the first time.
Experimental approach. In spray drying, low inlet temperature of 130 °C was employed
to preserve sensitive dandelion polyphenols, while guar gum, gum arabic, inulin, maltodextrin, pectin and alginate were used as carriers. The influence of different carriers and their content on physicochemical, morphological and colour properties, polyphenolic content and encapsulation efficiency of polyphenols in dandelion powders was examined. Specific polyphenols were determined using HPLC-PAD analysis. Their release profiles and antioxidant capacity in simulated gastrointestinal conditions were also evaluated.
Results and conclusions. Compared to plain dandelion powder, carrier-containing dandelion powders have favourably increased solubility, enhanced flow and cohesive properties, reduced particle size and prolonged release of polyphenols under simulated gastrointestinal conditions. Powders were characterized by low moisture content (~2–8 %) and high solubility (~92–97 %). Chicoric acid was the most abundant compound in dandelion powders. Pectin-dandelion powder showed to be the most effective for microencapsulation of polyphenols, especially for chicoric acid entrapment (74.4 %). Alginate-dandelion powder enabled the slowest gradual release of polyphenols.
Novelty and scientific contribution. Spray drying at 130 °C and the applied carriers
proved to be effective for microencapsulation of dandelion extract, where polyphenolic-
rich dandelion powders, due to good physicochemical and encapsulation properties,
could serve for the enrichment/production of different functional food products. Also,
due to the lack of data on dandelion encapsulation, the obtained results could be of great interest for researchers in the encapsulation field, but also for food industry, especially in the field of instant powders.
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