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1.
The objective of this study was to study the influence of purification of sour cherry pomace extract on particle size distribution of suspension and on encapsulation efficiency of powders. In addition, antioxidant activity, surface morphology, and color of powder and capsules were determined. Extraction of phenolic compounds was performed at 30 °C with shaking at 70 rpm for 24 h with 1:20 solid–solvent ratio. Ethanol–water (1:1) was used as the solvent. Filtered extract was concentrated in a rotary evaporator and freeze dried to produce extracted phenolic powder (EPP). Purified extracted phenolic powder (PEPP) was obtained by degritting at 10,000 rpm for 2 min and then by freeze drying for 48 h. Purification reduced Sauter mean diameter (D [32]) of concentrated extract from 5.76 μm to 0.41 μm. In encapsulation, two types of coating materials were used. The first one contained 10 % maltodextrin (MD) and 90 % distilled water, while the second one contained 8 % MD, 2 % gum arabic (GA), and 90 % distilled water. Samples were homogenized using ultrasound (160 W, 50 % pulse) for 20 min. Microsuspensions containing EPP had D [32] of 1.65 and 1.61 μm when 10 % MD and 8 % MD-2 % GA aqueous solutions were used for coating, respectively. It was possible to obtain nano-suspensions when purification step was performed. Suspensions prepared with PEPP and 10 % MD and 8 % MD–2 % GA for coating had D [32] of 0.396 and 0.334 μm, respectively. As a result of purification, encapsulation efficiency of the capsules increased significantly from 86.07–88.45 % to 98.01–98.29 % (P?<?0.001).  相似文献   

2.
Mangosteen pericarp anthocyanin-rich extract (MPA) was encapsulated by maltodextrin dextrose equivalent 20 (MD20) combined with gum arabic (GA), inulin (IN) or pectin (PEC) using spray drying. The highest encapsulation efficiency and anthocyanin content exhibited MD20:PEC and MD20:IN combinations. The MPA-encapsulated powders had a crystalline-mixed amorphous structure. Scanning electron microscopy (SEM) analysis showed smooth, round, fine particles. Fourier transform infrared spectroscopy (FTIR) analysis confirmed entrapment of anthocyanins by carrier agents. Thermogravimetric analysis (TGA) revealed a high thermal stability of encapsulated powders at temperatures <200°C and found that encapsulation reduced thermal degradation of anthocyanins. Incorporation of MPA-encapsulated powders into natural yoghurt produced shelf-stable naturally coloured product but slightly suppressed the multiplication of Lactobacillus bulgaricus. Encapsulation of anthocyanin-rich mangosteen pericarp extract using spray drying presents a viable opportunity for food technologists to utilise this source in the development of functional food products.  相似文献   

3.
In this study, the oxygen barrier and physical properties of two maltodextrin/gum Arabic (MD/GA) (3:1 w/w) microcapsules with dextrose equivalence (DE) 26 and 6 were assessed with or without the incorporation of cellulose nanofibres (CNF). The oxygen diffusion coefficient (Deff) was between 10.6 × 10−15 m2 s−1 and 17.3 × 10−15 m2 s−1 for all microcapsules. The addition of CNF improved the oxygen barrier of MD/GA microcapsules. The incorporation of CNF did not significantly impact Tg due to the low quantity of CNF present in the microcapsules. Wettability was higher in CNF incorporated microcapsules, and dispersibility was lower only for microcapsules with maltodextrin of DE 26. Spray-dried microcapsules exhibited poor flowability and high cohesiveness due to the moisture content (2.0–2.5%) of the powders. The results suggest that incorporation of CNF can increase the oxygen barrier of MD/GA microcapsules which may lead to better oxidative stability of micronutrients incorporated in the microcapsules.  相似文献   

4.
The flow characteristics of molten milk chocolate, like most dense suspensions, are a function of the maximum packing fraction ((m) of the suspended solids. Milk chocolates were prepared from mixtures of two relatively narrow coarse (d4,3 = 17 μm) and fine (d4,3 = 8.5 μm) size distributions of non‐fat solids to contain 0, 25, 50, 75, and 100% of the coarse component. Solids bed density (a measure of maximum packing fraction) correlated with the apparent viscosity of milk chocolates (r = ‐0.98). The highest value for solids bed density and lowest value for apparent viscosity were measured for size distributions with 75% of solids from the coarse fraction. Casson yield value correlated with d4,3 (r = ‐0.98) and specific surface area (r = 0.93). The maximum packing fraction of binary mixtures of two distinct sizes of non‐fat chocolate solids attained a maximum value for a specific volume ratio of the components. The maximum in m corresponded with the minimum viscosity in molten chocolate at a given solids volume concentration.  相似文献   

5.
In this study, a novel chrysanthemum polysaccharide (CP) was obtained and investigated from Chrysanthemum morifolium tea in Hubei province, China. Molecular characterisation and emulsifying properties of the CP were elucidated. The effects of different factors, including storage time, metal ions, pH value and heat treatment, were studied on the stability of emulsion. Results showed that the mean particle diameter (MPD) (d32) varied from 5.54 to 0.49 μm with the polysaccharide concentration ranging from 0.5wt% to 3.0wt%. The MPD (d32) of emulsions stabilised by chrysanthemum tea polysaccharide (ECP) was smaller than that of GA at 2wt%, and the MPD (d32) of ECP remained stable with no stratification occurred at 25 °C for 10 days. ECP also showed good stability under acidic conditions (3.0–7.0). With increase of Na+ and Ca2+ concentration, MPD(d32) and zeta potential values raised significantly, from 2.24 to 7.24 μm and from −40.52 to −35.35 mV respectively. After high-temperature heat treatment, MPD (d32) and zeta potential showed no significant change, indicating ECP presented good storage stability. In conclusion, CP helped stabilised emulsions that could be used as a natural emulsifier for future application.  相似文献   

6.
The aim of this research was to study spray drying as potential action to protect chlorophyllide from environmental conditions for shelf‐life extension and characterisation of the powders. Six formulations were prepared with 7.5 and 10 g of carrier agents [gum Arabic (GA), maltodextrin (MA) and soybean protein isolate (SPI)]/100 mL of chlorophyllide solutions. The powders were evaluated for morphological characteristics (SEM), particle size, water activity, moisture, density, hygroscopicity, cold water solubility, sorption isotherms, colour and stability, during 90 days. All the powders were highly soluble, with solubility values around 97%. A significant lower hygroscopicity was observed for GA powders, whilst the lower Xm values obtained by GAB equation fitting of the sorption isotherms was observed for the 7.5 g MA/100 mL samples. All formulations, but the 1 (7.5 g SPI/100 mL of chlorophyllide), provided excellent stability to the chlorophyllide during 90 days of storage even at room temperature.  相似文献   

7.
Three different milk proteins — skim milk powder (SMP), sodium caseinate (SC) and whey protein concentrate (WPC) — were tested for their ability to stabilize microencapsulated L. acidophilus produced using spray drying. Maltodextrin (MD) was used as the primary wall material in all samples, milk protein as the secondary wall material (7:3 MD/milk protein ratio) and the simple sugars, d-glucose and trehalose were used as tertiary wall materials (8:2:2 MD/protein/sugar ratio) combinations of all wall materials were tested for their ability to enhance the microbial and techno-functional stability of microencapsulated powders. Of the optional secondary wall materials, WPC improved L. acidophilus viability, up to 70 % during drying; SMP enhanced stability by up to 59 % and SC up to 6 %. Lactose and whey protein content enhanced thermoprotection; this is possibly due to their ability to depress the glass transition and melting temperatures and to release antioxidants. The resultant L. acidophilus powders were stored for 90 days at 4 °C, 25 °C and 35 °C and the loss of viability calculated. The highest survival rates were obtained at 4 °C, inactivation rates for storage were dependent on the carrier wall material and the SMP/d-glucose powders had the lowest inactivation rates (0.013 day?1) whilst the highest was observed for the control containing only MD (0.041 day?1) and the SC-based system (0.030 day?1). Further increase in storage temperature (25 °C and 35 °C) was accompanied by increase of the inactivation rates of L. acidophilus that followed Arrhenius kinetics. In general, SMP-based formulations exhibited the highest temperature dependency whilst WPC the lowest. d-Glucose addition improved the storage stability of the probiotic powders although it was accompanied by an increase of the residual moisture, water activity and hygroscopicity, and a reduction of the glass transition temperature in the tested systems.  相似文献   

8.
The influence of temperature (10–45 °C), feed flow rate (300–500 L/h) and sweeping gas flow rate (1.2–2 m3/h) on the recovery of berry fruit juice aroma compounds by sweeping gas membrane distillation (SGMD) was examined on an aroma model solution and on black currant juice in a lab scale membrane distillation set up. The data were compared to recovery of the aroma compounds by vacuum membrane distillation (VMD). The flux of SGMD increased with an increase in temperature, feed flow rate or sweeping gas flow rate. Increased temperature and feed flow rate also increased the concentration factors (Cpermeate/Cfeed) of the aroma compounds. At 45 °C the most volatile and hydrophobic aroma compounds obtained the highest concentration factors: 12.1–9.3 (black currant juice) and 17.2–12.8 (model solution). With black currant juice a volume reduction of 13.7% (vol.%) at 45 °C, 400 L/h, resulted in an aroma recovery of 73–84 vol.% for the most volatile compounds. Compared to VMD, the aroma recovery with SGMD was less influenced by the feed flow rate but more influenced by the temperature. Higher fluxes were achieved during concentration by VMD and this reduced the operation time, which in turn reduced the degradation of anthocyanins and polyphenolic compounds in the juice.

Industrial relevance

High temperature evaporation is the most widely used industrial technique for aroma recovery and concentration of juices, but membrane distillation (MD) may provide for gentler aroma stripping and lower energy consumption. This study gives important clues about the fate of berry juice aroma compounds and polyphenols during concentration by MD, and identifies the main factors influencing the aroma recovery efficiency with MD. Both SGMD and VMD are promising techniques for gentle stripping of berry juice aroma compounds and deserve further consideration as alternative techniques for gentle aroma stripping in industrial fruit juice processing.  相似文献   

9.
Antioxidant and antiproliferative activities of three rosemary extract formulations (VivOX 20, VivOX 40 and Inolens 50) with different contents of carnosic acid, carnosol and methylcarnosol were tested in vitro. Electron spin resonance measurements revealed that Inolens 50 extract that contained highest amount of carnosic acid was the most potent scavenger of hydroxyl (concentration of extract where 50% of its maximal scavenging activity is observed, that is, EC50, 109.54 μg mL?1), superoxide anion (EC50 = 7.94 μg mL?1) and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) (EC50 = 27.4 μg mL?1)‐free radicals. Comparison of the radar charts of standard antioxidants and rosemary extracts showed similarity between antioxidant characteristics of Inolens 50 and chlorogenic and caffeic acids. Tested rosemary extracts exhibited significant (P ≤ 0.01) antiproliferative effect in cervix epitheloid carcinoma (HeLa), breast adenocarcinoma (MCF7) and colon adenocarcinoma (HT‐29) cell lines. In both MCF7 and HeLa cell lines, the extracts yielded very low IC50 values (concentration of extract needed to inhibit cell growth by 50%), the most pronounced being for Inolens 50 in MCF7 (IC50 = 9.95 μg mL?1) and VivOX 20 in HeLa cell line (IC50 = 10.02 μg mL?1). The obtained results may provide support for the use of tested rosemary extracts as nutraceuticals and phytopharmaceuticals.  相似文献   

10.
During the encapsulation of aromas by spray-drying, some volatile components may be lost; consequently, the sensory profile could be modified in the final product. Therefore, the selection of the carrier matrix for the encapsulation is crucial to obtain high aroma retention and long shelf-life stability, reduce aroma oxidation and increase physical stability of the powder. With the aim of studying the use of trehalose for the encapsulation of orange essential oil, emulsions were prepared containing mixtures of trehalose–maltodextrin (TMD) and sucrose–maltodextrin (SMD). Two modified starches were used as emulsifiers. The emulsions were spray-dried and stored at 25 and 37 °C. The aroma retention was evaluated using head space–solid phase microextraction/gas chromatography–mass spectrometry (HS-SPME/GC-MS) and by sensory evaluation. In addition, some physical properties of orange essential oil powders, such as water sorption and glass transition temperature (T g), were determined. The sensory profiles obtained for TMD and SMD were different: TMD formulations retained mainly limonene, while SMD retained mostly α-pinene and myrcene. The modified starches (Capsul and Hi Cap) used as emulsifiers also affected the retention of certain volatiles. Therefore, the selection of components in the carrier matrix is relevant to the retention of aromas in orange oil powders. Regarding the physical properties, TMD formulations presented better characteristics in comparison to SMD, particularly due to the higher T g values. The high aroma retention levels and the good physical characteristics are promising results in relation to the inclusion of the developed formulations in dehydrated citric juices.  相似文献   

11.
The effectiveness of two drying agents, namely whey protein isolate (WPI) and maltodextrin (MD), was evaluated during spray-drying of strawberry puree. With the increase of WPI substitution in the feed material, the surface tension of strawberry puree decreased, and powder recovery increased. Powder recovery (Rp) increased from 39.2 ± 2.3% (S:MD:WPI = 60:40:0) to 56.5 ± 2.8% when MD was replaced by WPI (S:MD:WPI = 60:39:1). Surface morphology of powders showed that the addition of WPI resulted in shrunken particle surface, which gave rise to smaller DB and particle size. The particles were not spherical, and even with the addition of 0.5% WPI, the particle morphology was altered. The surface shrinkage of strawberry powder increased with increase in WPI from 0.5% to 10%. The production efficiency of strawberry powder could be greatly improved when MD was replaced by 1% WPI.  相似文献   

12.
Muitle (Justicia spicigera), a Mexican native plant, produces a purple aqueous extract (MAE) because of its anthocyanin content. The aim of this work was to microencapsulate MAE by spray‐drying in two different protective colloids blends in a 1:1 weight ratio: gum Arabic‐mesquite gum (GA50‐MD50) and mesquite gum‐maltodextrin DE10 (MG50‐MD50), yielding the microcapsules MGA50‐MD50 and MMG50‐MD50. The minimum integral entropy of the microcapsules was determined at 20, 35 and 40 °C, and the resulting water activities (aW) were 0.555, 0.592, 0.627 for MGA50‐MD50 and 0.581, 0.587, 0.648 for MMG50‐MD50, respectively. These aW temperature sets were considered as the most adequate conditions for achieving maximum storage stability of the microcapsules. Total anthocyanin content (TAC) and total colour change (ΔE) suffered considerable degradation at all storage conditions, but that degradation was significantly inhibited by encapsulating MAE in the biopolymers blends especially that made up by MG50‐MD50.  相似文献   

13.
Three types of emulsions (β-Lg-, β-Lg-pectin-, and β-Lg-ι-carrageenan-coated emulsions) with controlled electrostatic and/or steric interactions were prepared, and then examined for their freeze-dry stability in the absence or presence of 6% maltodextrin (MD). In the absence of MD, all emulsions were highly unstable to freeze-drying, nevertheless, the β-Lg-pectin-coated emulsions (d 32 =5.37, d 43 =35.11 μm) that were stabilized mostly by steric repulsion showed better stability than the other 2 emulsions (no dried power was obtained). The freeze-dry instability of all emulsions was improved with MD addition, particularly in the β-Lg- (d 43 =1.10 μm) and β-Lg-ι-carrageenan-coated emulsions (d 43 =0.58 μm) that were stabilized by electrostatic repulsive force. In the presence of MD, the β-Lg-ι-carrageenan-coated emulsions showed the highest stability to freeze-drying, which was attributed to the cooperative impact of steric and electrostatic repulsion. This study implicates that the major mechanism for stabilizing emulsions against freeze-drying could be different depending on the absence or presence of MD.  相似文献   

14.
Changes in the coefficient of variation of fibre diameter (V d ) were made by blending top qualities (a) 70s and 56s, and (b) 60s and 56s, and comparing these with a 58s. In this way, a range of values of V d from 21.4 to 24.9% was obtained over three top samples whose mean fibre diameters and fibre lengths were closely similar. These tops were worsted-spun to determine their performance at the spinning limit and other yarn counts and to measure the yarn properties. The three samples did not give any important differences in chemical composition or in spinning limit, but did show a trend to significant differences in yarn breaking strength and elongation, the lower-V d sample being favoured. Over this range of values of V d at mean diameters of 25–26 μm, although there are hints of slight differences in spinning and in the product, the trend is not important. The range of V d values for European tops of mean fibre diameter 25.3 μm appears to lie between 22 and 28%. The Australian tops investigated gave V d values over the lower half of this range.  相似文献   

15.
In this study, the effect of different carriers including maltodextrin (MD), gum arabic (GA) and whey protein concentrate (WPC) and their combination on the production yield, moisture content, bulk and tapped density, solubility, wettability, flowability indexes (Hausner ratio, compressibility, angle of repose), hygroscopicity and deliquescence process, color index and microstructure of spray dried sour cherry juice concentrate was investigated. The results showed increased powder production yield with a mixture of MD and GA (40:10 weight ratio). Use of 5% WPC in combination with the GA and MD increased powder production yield from 45.66 to 55.66% and 42.23 to 52.86%, respectively. Bulk density, tapped density, solubility and wettability significantly decreased with increasing concentration of WPC. Also, the use of 30% WPC in combination with the MD or GA increased particle size substantially. The surface morphology of the particles (with a smooth, shrunk and dented surfaces) was affected by feed composition.  相似文献   

16.
采用喷雾干燥法以两种葡萄糖当量(DE值)的麦芽糊精(MD)为助干剂和限制性淀粉酶解法,考察了处理方法对小米速溶粉的璃化转变温度、集粉率、水分含量、水分活度、堆积密度、结块性和颗粒微观形态的影响。结果表明,较低的DE值、较高的MD使用量和较低的淀粉酶解度可以提高喷雾干燥的集粉率,提高小米速溶粉的玻璃化转变温度和堆积密度,降低小米速溶粉的水分含量和水分活度,同时使其结块性下降;以DE8的MD为助干剂的喷雾干燥效果优于以DE20的MD为助干剂的喷雾干燥效果;相同DE值条件下,限制性淀粉酶解法获得的产品性质均优于添加MD助干剂法,但会引起集粉率的降低。不同的处理对颗粒的微观形态也有显著的影响。   相似文献   

17.
This study aimed at evaluating the potential of maltodextrin combination with different wall materials in the microencapsulation of flaxseed oil by spray drying, in order to maximize encapsulation efficiency and minimize lipid oxidation. Maltodextrin (MD) was mixed with gum Arabic (GA), whey protein concentrate (WPC) or two types of modified starch (Hi-Cap 100TM and Capsul TA®) at a 25:75 ratio. The feed emulsions used for particle production were characterized for stability, viscosity and droplet size. The best encapsulation efficiency was obtained for MD:Hi-Cap followed by the MD:Capsul combination, while the lowest encapsulation efficiency was obtained for MD:WPC, which also showed poorer emulsion stability. Particles were hollow, with the active material embedded in the wall material matrix, and had no apparent cracks or fissures. During the oxidative stability study, MD:WPC combination was the wall material that best protected the active material against lipid oxidation.  相似文献   

18.
Coffee oil microcapsules were produced by spray‐drying using as encapsulating agents gum Arabic, whey protein isolate (WPI) and mixtures of maltodextrin (MD) and WPI, at three different proportions (3:1, 1:1 and 1:3). Sorption isotherms were determined by the gravimetric method, and the glass transition temperature (Tg) was measured by differential scanning calorimetry. Microcapsules produced with gum Arabic showed the highest water adsorption and underwent a stronger water plasticising effect. At the highest water activity (0.843), this sample had a Tg value of ?18.3 °C, while those produced with WPI at higher proportions showed values around 25 and 30 °C. The good fit of experimental data by Guggenheim‐Anderson‐de Boer and Gordon–Taylor models allowed the determination of the critical storage conditions, at which powders are not susceptible to deteriorative physical changes. The samples produced with 1:1 and 1:3 of MD/WPI were the most stable ones, showing critical water activity values of 0.890 and 0.938, respectively.  相似文献   

19.
Continuous vacuum-belt drying was studied as a means to produce high-quality powders from blueberry slurries, with limited degradation of anthocyanins. Drying was performed at three different temperatures (80, 95, 110 °C) and the resulting dried material (a w?~?0.2) ground into powders. Drying times ranged from 70 min at 80 °C to 50 min at 110 °C. Maltodextrin (MD) was used as a drying agent at three levels (0.3, 0.45, and 0.6 kg/kg dry blueberry solid). Powders were purple, with no signs of browning, and similar in appearance to those produced by freeze-drying. Increasing MD level and drying temperature decreased the hygroscopicity of the powders. Moisture isotherms showed type 3 behavior and were well-fit with the Guggenheim–Anderson–de Boer equation. Higher levels of MD improved flowability of the powders, with >93 % of the powders with MD flowing from the test fixture after 30 s, compared to only 62.1 % emerging for powders without MD. Powders dried at 80 °C were slightly darker (L*?=?25.73–28.4) than those produced 110 °C (L*?=?27.10–28.53), presumably due to less degradation of anthocyanins. Total monomeric anthocyanins (TMA) for MD dried at 80 °C (13.1 mg C3G/g) were not different than for freeze-dried blueberries. Higher drying temperatures caused some loss of TMA. Higher levels of MD result in lower TMA by increasing the amount of dry matter in the powders. Vacuum-belt drying at 80 °C with 0.3 kg MD/kg dry solids produced non-sticky powders with anthocyanin content similar to freeze-dried powders.  相似文献   

20.
Friesian steers (n=5), aged 26–27 months, were fed a diet containing 2000 (supplemented) IU α-tocopheryl acetate/head/day for approximately 50 days prior to slaughter. Muscularis semimembranosus muscles from supplemented cattle were held in frozen storage (−20°C×12 weeks) following which they were minced and divided into five batches. The batches contained: (1) control, containing only vitamin E supplemented beef (C); (2) vitamin E supplemented beef with 4% soya oil (S); (3) vitamin E supplemented beef mixed with 0.2% Duralox NMC dissolved in 4% soya oil (R1); (4) vitamin E supplemented beef mixed with 0.25% Herbalox type 25 (containing 25 natural antioxidant extracts of rosemary) dissolved in 4% soya oil (R2); and (5) vitamin E supplemented beef mixed with a 1:1 mixture of 0.01% (w/w) BHA and 0.01% (w/w) BHT dissolved in 4% soya oil (B). The meat was then aerobically packaged (A) or packaged under the following modified atmospheres (MAP); 30:70 (M1); 70:30 (M2) or 80:20 (M3) (O2:CO2). Oxidative stability (TBARS) and Hunter ‘a’ values (redness) were determined in all beef patties over 8 days of refrigerated (4°C) storage. Under MAP or aerobic packaging conditions, elevated oxygen levels brought about increased (P<0.05) TBARS numbers during refrigerated storage. However, the addition of rosemary extracts or BHA/BHT significantly (P<0.05) improved the oxidative stability of dietary α-tocopheryl acetate supplemented beef. Rosemary extracts were as effective in reducing TBARS as the combination of synthetic antioxidants, BHA/BHT.  相似文献   

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