Carotenoids are one of the major food micronutrients in human diets and the overall objective of this review is to re-examine the role of carotenoids in human nutrition. We have emphasized the ...attention on the following carotenoids present in food and human tissues: β-carotene, β-cryptoxanthin, α-carotene, lycopene, lutein and zeaxanthin; we have reported the major food sources and dietary intake of these compounds. We have tried to summarize positive and negative effects of food processing, storage, cooking on carotenoid content and carotenoid bioavailability. In particular, we have evidenced the possibility to improve carotenoids bioavailability in accordance with changes and variations of technology procedures.
Ferulic acid (FA) and tocopherol (Toc) loaded solid lipid nanoparticles (SLN) were prepared by a hot homogenisation method. The particle size distribution, zeta potential and melting behaviour of the ...SLN as well as the stability, encapsulation efficiency and radical scavenging activity of FA and Toc in the SLN were analysed. The different formulations containing up to 2.8 mg g-1 of FA or Toc were stable during at least 15 weeks of storage at room temperature. Despite partial degradation and / or release of FA and Toc during storage, significant radical scavenging activity was maintained. DSC measurements and radical scavenging tests after different time periods revealed that the re-structuring of the lipid matrix was connected to the enhanced antioxidant activity of Toc but did not affect the activity of FA.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The development of engineered nanometre sized materials (ENM) produced with food-grade ingredients and designed as delivery systems for organic and inorganic materials has gained increasing interest. ...The major reason for this trend is the aim to overcome problems associated with the low bioavailability of many bioactive compounds (BC) which are usually claimed to benefit human health. In this review, outcomes of studies investigating the potential bioavailability enhancement of BC using ENM as delivery systems are summarised and discussed. It focuses on
in vitro
and
in vivo
studies carried out with ENM produced with food-grade materials and designed for the delivery of vitamins, other secondary plant metabolites and minerals. Furthermore, the physical and physicochemical aspects governing the preparation of the systems, the loading of the BC, the stability of the delivery systems in food applications and finally the release of the BC in the gastrointestinal tract are also considered. The mechanisms leading to an enhanced bioavailability are based on (i) improved solubility of the BC under gastrointestinal conditions, (ii) the protection of the BC from the chemical conditions in the gastrointestinal tract (GIT), (iii) the controlled release within the GIT or (iv) an improved transfer through the intestinal wall. The main outcome of the review is that particle size, surface properties and physical state of the ENM are key parameters to be controlled aiming at an enhanced nutritional value of food materials. Furthermore, the bioavailability classification scheme (BCS) can help to understand the efficacy of different ENM for the delivery of specific BC.
This review focuses on how composition and structure of food-grade nanometre sized delivery systems affect the bioavailability of bioactive compounds.
Chokeberry polyphenols could be used to design functional snacks and breakfast cereals. High-temperature, short-time extrusion processing is a unique technique to design such cereal based products. ...However, the intense amount of thermomechanical energy, which is necessary to generate crispy structures, can lead to losses of those bioactives. In order to gather information about the retention of chokeberry polyphenols in extrusion processing, the influence of process parameters, e.g. screw speed (300 and 500 1/min), barrel temperature (100 and 140 °C) and water content (15 and 22 g/100 g, wet basis), on changes of anthocyanins, procyanidins, and hydroxycinnamic acids was investigated using a model based on maize starch.
At the range investigated, changing screw speed, water content, and barrel temperature had no significant (P < 0.05) influence on the retention of procyanidins and hydroxycinnamic acids. Higher screw speed increased the specific mechanical energy, the melt temperature and resulted in the loss of anthocyanins. The retention decreased linearly with the melt temperature. A higher retention was analysed by increased water content. The highest retention (about 60%) of cyanidin glycosides in this study was achieved at the highest water content (22 g/100 g, wb), irrespective of the barrel temperature and the screw speed.
•Starch based products with high amounts of chokeberry polyphenols were produced by extrusion processing.•Improved anthocyanin retention was achieved by increasing water content.•Anthocyanin glycoside retention is depending on SME and temperature exposure.•Procyanidins and hydroxycinnamic contents were not affected by extrusion processing.
The Nutri Red carrot (Daucus carota L. cv. Nutri Red), a red carrot variety which together with β-carotene contains large amounts of lycopene, could represent an interesting alternative to tomatoes ...as a source of lycopene in the European diet. However, carotenoid retention during processing of this carrot variety has not yet been sufficiently addressed. The interest here is focused on the evaluation of the potential carotenoid degradation and/or isomerisation resulting from blanching, freezing and during the subsequent frozen storage of Nutri Red carrots. Carrots were sliced, blanched, air blast frozen and stored at −50 °C, −30 °C, −18 °C and −15 °C for up to two years. β-carotene, α-carotene, and lutein remained stable along processing and long-term frozen storage. All-trans-lycopene was degraded at all storage temperatures. A first-order and a two-first-order reaction models were applied for the description of lycopene degradation. The temperature dependence of the rate constants was adequately modelled by the Arrhenius equation at temperatures above −30 °C. Although substantial losses of all-trans-lycopene were detected, the carrot slices still exhibited lycopene contents similar to that of some tomato varieties after one year storage at −18 °C. Hence, both raw and frozen Nutri Red carrots represent an excellent alternative lycopene source.
•Frozen Nutri Red carrots represent an excellent alternative lycopene source.•The long-term frozen storage stability of β-carotene is much greater than that of lycopene.•Lycopene degradation kinetics shows Arrhenius behaviour at storage temperatures above −30 °C.
The partial substitution of starch with dietary fiber (DF) in extruded ready-to-eat texturized (RTE) cereals has been suggested as a strategy to reduce the high glycemic index of these food products. ...Here, we study the impact of extrusion processing on pure chokeberry (
) pomace powder (CPP) rich in DF and polyphenols (PP) focusing on the content and profile of the DF fractions, stability of PP, and techno-functional properties of the extrudates. Using a co-rotating twin-screw extruder, different screw speeds were applied to CPP with different water contents (c
), which resulted in specific mechanical energies (SME) in the range of 145-222 Whkg
and material temperatures (T
) in the range of 123-155 °C. High molecular weight soluble DF contents slightly increase with increasing thermomechanical stress up to 16.1 ± 0.8 g/100 g dm as compared to CPP (11.5 ± 1.2 g/100 g dm), but total DF (TDF) contents (58.6 ± 0.8 g/100 g dm) did not change. DF structural analysis revealed extrusion-based changes in the portions of pectic polysaccharides (type I rhamnogalacturonan) in the soluble and insoluble DF fractions. Contents of thermolabile anthocyanins decrease linearly with SME and temperature from 1.80 ± 0.09 g/100 g dm in CPP to 0.24 ± 0.06 g/100 g dm (222 Whkg
, 155 °C), but phenolic acids and flavonoids appear to be largely unaffected. Resulting techno-functional (water absorption and water solubility) and physical properties related to the sensory characteristics (expansion, hardness, and color) of pure CPP extrudates support the expectation that granulated CPP extrudates may be a suitable food ingredient rich in DF and PP.
Chokeberries (Aronia melanocarpa) are nowadays believed to exhibit potential cardioprotective and antidiabetic effects principally due to their high content in bioactive phenolic compounds. The ...stability of the phenolic compounds was studied during different stages of a juice production line and a method for the valorization of pomace was evaluated. Samples were taken from a commercial juice production plant, extracted and analyzed for phenolic constituents and antioxidant potential. Prototypes of functional food ingredients were produced from the pomace by wet milling and micro-milling. Alongside juice processing, the contents of phenolic berry constituents did not vary to a great extent and the overall antioxidant activity increased by about 34%. A high quality juice and a by-product still rich in polyphenols resulted from the process. The phenolic compounds content and the overall antioxidant activity remained stable when milling and micro-milling the pomace. During coarse milling, extractability of total phenolic compounds increased significantly (40% to 50%). Nanosized materials with averaged particle sizes (x50,0) of about 90 nm were obtained by micro-milling. These materials showed significantly enhanced extractability of total phenolic compounds (25%) and total phenolic acid (30%), as well as antioxidant activity (35%), with unchanged contents of total procyanidins and anthocyanins contents.
Aiming at providing prototypes for ready-to-eat texturised (RTE) cereal products with reduced glycaemic load, starch blends with chokeberry (Aronia melanocarpa) pomace powder (CPP) rich in dietary ...fibre (DF) and polyphenols (PP) were extruded using a co-rotating twin-screw extruder. The CPP ratios (25%, 50%) and processing conditions applied (barrel temperature 100 °C, screw speed 200, 400, 600, 800 min−1, water content 13%, 23%) result in specific mechanical energies of 87–336 Whkg−1 and material temperatures of 111–155 °C. Extrudates containing 25% CPP still offer acceptable techno-functional and sensory related physical properties, while higher CPP ratios result in decreased expansion and cell pore size of the slightly darker and softer extrudates. The in vitro glucose release of both extruded blends is reduced by 25% and 50%, respectively. The DF contents are unaffected. As expected, anthocyanins are degraded by about 70% in both blends while phenolic acids and flavonols are fully retained. All PP are already accessible during the stomach phase of an in vitro digestion and are not changed significantly in the intestinal phases. Overall, these data substantiate, that marketable texturised RTE extruded cereals may be developed based on the results presented and on further sensory analysis.
•Texturised cereal prototypes containing dietary fibre-rich chokeberry pomace (CPP).•Starch-CPP blends extruded using a co-rotating twin-screw extruder.•25% CPP extrudates: Good techno-functional and sensory related physical properties.•Reduced in vitro glucose release from extruded blends according to the CPP content.•CPP polyphenols accessible and available for absorption during in vitro digestion.
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•Chokeberry pomace – a promising ingredient in the reformulation of cereal products.•Good source of dietary fiber (DF) with the potential to partially substitute starch.•No remarkable ...DF alterations due to extrusion-like thermomechanical treatment.•Polyphenols degraded but fully bioaccessible after treatment.
Dietary fiber is a potential replacement for other ingredients such as starch in reformulated extruded breakfast cereals. Analysis of chokeberry pomace powder revealed a total dietary fiber content of 57.8 ± 2 g/100 g with 76% being insoluble, 20% high molecular soluble and 4% low molecular soluble dietary fiber. The fiber polysaccharide composition was analyzed in detail by using a variety of analytical approaches. Extrusion-like processing conditions were studies in a Closed Cavity Rheometer enabling the application of defined thermal (temperature range 100–160 °C) and mechanical treatments (shear rates between 0.1 s−1 and 50 s−1) to chokeberry pomace powder. Application of temperatures up to 140 °C irrespective of the mechanical treatment does not remarkably alter dietary fiber structure or content, but reduces the initial content of total polyphenols by about 40% to a final content of 3.3 ± 0.5 g/100 g including 0.63 ± 0.1 g/100 g of anthocyanins, 0.18 ± 0.02 g/100 g of phenolic acids and 0.090 ± 0.007 g/100 g of flavonols, respectively. The retained polyphenols are fully bioaccessible after in vitro digestion, and antioxidant capacity remains unchanged as compared to the untreated pomace powder. Glucose bioaccessibility remains unaffected, whereas glucose content is reduced. It is concluded that chokeberry pomace powder is a good source of dietary fiber with the potential to partially substitute starch in extruded breakfast cereals.
Actinobacteria are involved in many soil processes related to plant growth, including the secretion of various bioactive products and nutrient cycling. The aim of this study was to characterize the ...plant growth promoting traits (phosphate solubilizing activity, phytate degradation ability and indolic compounds production, and organic acids secretion) of seven actinobacteria isolates and evaluate the effect of two selected rhizospheric Streptomyces on growth and phosphorus content of maize in presence of different phosphorus (P) sources (tri-calcium phosphate, triple super phosphate and calcium phytate). Phylogenetic analysis of partial 16S rRNA sequences showed that the Streptomyces isolates were clustered in two distinct separated groups. All Streptomyces isolates produced 2-ketogluconic acid and oxalic acid in fermentation medium supplemented with inorganic P sources, while in the presence of phytate, all isolates secreted 2-ketogluconic acid and malic acid. All the isolates were able to release inorganic P from insoluble phosphate sources and this behavior was negatively correlated with pH reduction. Phytate degradation raged from 1.65% to 95.2%, and total indole compound production ranged from 6.3 to 27.8 µg ml
−1
. The shoot dry weight, root dry weight, plant height, chlorophyll content and tissue P concentration were significantly (p < 0.05) increased by both inoculations with Streptomyces isolates and by the addition of different phosphorus sources, compared to their appropriate controls. The inoculation of Streptomyces isolates resulted in a significant increase in plant phosphorus content from different phosphate sources. Streptomyces sp. UTMC 1478 (Streptomyces sp. 63) and Streptomyces sp. 47 were suitable inoculants for increasing maize growth and P from soil amended with different phosphorus sources, indicating their potential use as plant growth-promoting phospho-bacteria.
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