Search

Soursop is seasonal and highly perishable fruit, which limits its commercialization. Thus it is necessary to conserve its pulp so that it is available throughout the year. One of the most common forms of fruit preservation is by dehydration. This work had an objective to dehydrate soursop pulp by spray drying at optimum conditions and to analyze the retention of bioactive and volatile compounds in soursop powder, besides analyzing its antioxidant capacity. The total phenolics, carotenoids and flavonoids contents were determined, while volatile compounds were analyzed by Stir Bar Sorptive Extraction (SBSE) coupled with GC–MS system. The total content of the phenolic compounds and flavonoids in the fresh pulp were 160.28 mg of GAE/100 g and 87.17 mg of quercetin/100 g, respectively while for rehydrated dried powder their values were 158.95 mg of GAE/100 g and 85.17 mg of quercetin/100 g, respectively. The total phenolic compounds, flavonoids and antioxidant capacity did not show any significant difference (p <.05) between the fresh fruit pulp and dehydrated powder. A total of 85 volatile compounds were identified, of which 33 were esters, representing the major class of organic compounds, 15 were terpenes, 10 aldehydes, 7 acids, 5 alcohols, 5 lactones, 3 ketones, and 6 other compounds. Of the total 85 compounds, identified in soursop pulp, 58 compounds were identified in the rehydrated dried powder. The principal compounds for both samples were methyl (E)-2-hexenoate, methyl hexanoate and methyl (E)-2-butanoate, which contribute to soursop aroma according to their Odor Active Values (OAV). Considering that there was no significant difference (p <.05) between fresh pulp and the rehydrated dried powder in concentrations of bioactive compounds and even with the reduction in the concentration of the main volatile compounds while the OAVs of these compounds were relatively high, it is concluded that spray dried powder of soursop pulp retains its nutritional and aroma quality, besides maintaining the antioxidant capacity. Unlabelled Image • The drying process showed good retention of bioactive compounds and antioxidant capacity. • A SBSE-GC/MS identified a total of 85 and 58 compounds in soursop pulp and powder respectively. • Thirty one volatiles were selected as key aroma compounds in soursop pulp. • Most of the key aroma compounds of soursop were retained in the dehydrated powder. [ABSTRACT FROM AUTHOR]

Spray drying was applied for the production of kefir powder. The survival of microorganisms after drying, storage and simulated gastrointestinal (GI) conditions was investigated. Kefir was obtained by fermentation of milk and whey permeate, and was dehydrated directly (traditional kefir) or using different carriers (skim milk, whey permeate and maltodextrin). Low survival (5.5 log and <2 log CFU/g for lactic acid bacteria and yeast respectively) of microorganisms was achieved when kefir was dehydrated without thermoprotectants (carriers). In contrast, survival of the microorganisms was significantly improved in the presence of different carriers. When skim milk (SM) was used as the carrier medium, lactic acid bacteria (LAB) survival was above 9 log CFU/g. In contrast, viability of yeast was dramatically reduced after spray drying in these conditions. When whey permeate was used as the carrier medium, LAB survival was 8 log CFU/g and yeast survival was above 4 log CFU/g. LAB in the kefir powder survived better the simulated GI conditions when spray drying was conducted in SM. LAB in kefir powder sample dehydrated in SM and SM plus maltodextrin remained stable for at least 60 days at 4 °C. Our results demonstrated that spray drying of kefir is a suitable approach to obtain a concentrated kefir-derived product. [ABSTRACT FROM AUTHOR]

Abstract This study investigated spray drying of food-grade solid lipid particles (SLN) and nanostructured lipid carriers (NLC) containing ω-3 fish oil. Stable SLN and NLC dispersions with tristearin as carrier lipid were formed by using a combination of Quillaja saponins and high-melting lecithin as emulsifiers. Our specific goal was to study the influence of four different spray drying inlet and outlet temperatures (T inlet/outlet = 140–170 °C/65–95 °C) and two different maltodextrin types (DE 6 and DE 21) with different molecular weights as protective wall materials on the physical and polymorphic stability of the solid lipid particles. The results revealed that the low molecular weight maltodextrin DE 21 was a superior wall material in stabilizing the solid lipid particles. Moreover, the lipid particles spray dried at T inlet/outlet of 140/65 °C exhibited the highest physical and polymorphic stability, whereas using higher T inlet/outlet led to bigger particles which were more prone to polymorphic transition. This was also verified in a 71-day storage test. The findings were explained that by preventing the melting of the tristearin carrier lipid during spray drying, the crystallized lipid particles remained intact inside the amorphous maltodextrin layer and exhibited high physical and polymorphic stability. These findings are important for generating stable food-grade spray dried powders. Graphical abstract Unlabelled Image Highlights • Spray drying of food-grade solid lipid particles was investigated. • Impact of inlet temperature and wall material type upon spray drying was studied. • Low molecular weight maltodextrin was better in stabilizing the solid lipid particles. • The highest physical and polymorphic stability was achieved at T inlet of 140 °C. [ABSTRACT FROM AUTHOR]

Soybean Protein Isolate (SPI) is a by-product from soybean oil industries with good nutritional and functional properties. Denaturation of hydrated SPI can change its properties, allowing the formation of gel-like particles, which can be used to stabilize emulsions without addition of surfactants. SPI microgel particles were produced by denaturation of hydrated SPI, followed by high pressure homogenization or sonication, with different NaCl or NaF contents, aiming the formation of small particles capable to stabilize O/W emulsions and acting as wall material for microencapsulation of soybean oil by spray drying. The presence of NaF in the suspensions decreased the charge intensity of SPI microgels, leading to formation of significantly bigger SPI microgel particles. Based on Creaming Index (CI), all the emulsions were stable for, at least, 21 days at room temperature. The presence of salt affected minimally the droplet size of the emulsions, though there has been an increase in flocculation. All the emulsions presented shear-thinning behavior and a strong shear rate dependence when salt was present in the system. The microspheres produced by spray drying of the emulsions were spherical and showed few aggregate formation. In addition, they presented high values of oil retention (> 80 wt%) and acceptable values of moisture content (< 4 wt%). SPI microgel particles produced by high-pressure homogenization or sonication may be used to stabilize emulsions with low oil contents. These emulsions can be further spray dried to microencapsulate lipophilic compounds using SPI microgels as wall material. Unlabelled Image • Soybean protein microparticles were produced at different ionic strength. • O/W emulsions were produced under sonication and high pressure homogenization. • Emulsions presented good stability against creaming. • Microspheres were produced from Pickering emulsions by spray drying. • Soybean protein microparticles showed ability to encapsulate lipid compounds. [ABSTRACT FROM AUTHOR]

Graphical abstract Unlabelled Image Highlights • Chemical and physical properties of native starch achira were modified. • Modified achira starch had good characteristics as an encapsulating material. • For the Hibiscus sabdariffa extract, an encapsulation efficiency of 70% was obtained by spray drying. • Microcapsules of approximately 10 μm were obtained by spray drying. • The microcapsules had excellent antimicrobial activity. [ABSTRACT FROM AUTHOR]

Abstract The stabilizing capacity of crystalline inulin during spray-drying and storage of Lactobacillus plantarum CIDCA 83114 was assessed. In a first step, the physical properties of the matrices were investigated, using amorphous inulin as control. Melting and glass transition temperatures, water sorption isotherms, water activity, and infrared spectra were determined. Microorganisms were spray-dried at a pilot scale in both amorphous and crystalline matrices. After that, scanning electronic and confocal microsopies provided a full landscape about the interactions between microorganisms and crystals, and also the bacterial location within the amorphous matrices. The technological properties of the dehydrated microorganisms (culturability and acidification capacity) during storage at different water activities were also evaluated. Both amorphous and crystalline inulins were adequate matrices to stabilize microorganisms. However, crystalline inulin was more stable than amorphous one, especially when the storage temperature was close to the glass transition temperature, resulting in a better matrix to protect microorganisms during pilot spray-drying and storage. Furthermore, no accumulation of insoluble inulin was observed after resuspending the dehydrated microorganisms in crystalline inulin matrices, which appears as a clear technological advantage with regard to the amorphous one. Considering the prebiotic character of inulin and the probiotic properties of L. plantarum CIDCA 83114, this work developed an integrated approach, both from a fundamental and from an applied viewpoint, supporting the incorporation of such ingredients in the formulation of food products. Graphical abstract Unlabelled Image Highlights • Crystalline and amorphous inulins were used to stabilize L. plantarum CIDCA 83114 during spray-drying at a pilot scale. • Tm and Tg, water sorption isotherms, a w and FTIR were determined to explain the protecting effect. • Both amorphous and crystalline inulin matrices were adequate to stabilize micro-organisms. • Crystalline inulin was more stable than amorphous one, especially when T was close to Tg. • Such behavior explained the better stabilizing capacity of crystalline inulin during storage. [ABSTRACT FROM AUTHOR]

Abstract In this work, the aqueous extract obtained from Brazilian ginseng (Pfaffia glomerata) roots (BGR), rich in beta-ecdysone and fructooligosaccharides (FOS), was powdered by spray drying and freeze drying techniques aiming to obtain a novel functional food product. The effects of these drying techniques on the chemical and nutritional quality, morphological and redispersion properties of the BGR powders were evaluated. The BGR powders obtained by both spray drying and freeze drying techniques maintained their beta-ecdysone and FOS contents after drying, demonstrating the stability of these functional compounds. It was found that the wettability of the powders obtained by different treatments was affected by the drying technique because freeze-dried particles reached the lower values (66 ± 5 s) while spray-dried particles showed a greater time for dispersion into water (150 ± 25 s). This behavior was mainly associated with differences between powder morphological properties since the freeze-dried particles presented a more porous structure, resulting in a greater water diffusivity into microstructure during the redispersion process. Drying process did not affect the storage stability of powders because the glass transition temperature (Tg) for both samples was approximately 160 °C at a relative humidity of 56%. Thus, both BGR powders presented adequate redispersion properties to constitute a new functional tea or even to be used as a functional ingredient in food products. Graphical abstract Unlabelled Image Highlights • An instant powder rich in bioactive compounds was obtained in this work. • Brazilian ginseng extract was dried by spray drying and freeze drying. • The dried powders maintained their fructooligosaccharides and beta-ecdysone contents. • The powders presented satisfactory redispersion properties. [ABSTRACT FROM AUTHOR]

Abstract: Incorporation of bifidobacteria into probiotic formulations is promoted worldwide due to the health benefits associated with their application. For the manufacturing of such probiotic formulations, drying of microorganisms is an important process. Spray drying is a well-established and economical method for this purpose. Using spray drying, however, cells are exposed to stress, affecting their viability. The aim of this study was to generate a systemic knowledge about the impact of spray drying on the viability of B. bifidum BB-12. First, the effect of thermal stress was investigated by exposure of B. bifidum BB-12 to different temperatures in defined time intervals. The alterations in cell membrane integrity and esterase activity were studied using fluorimetry and compared to the heat response of the robust strain E. faecium M-74. Exposing microorganisms to the same temperatures, alterations in the viability of B. bifidum BB-12 occurred after shorter time intervals. Moreover, cell membrane damage and changes in the esterase activity were more rigorous, indicating the higher sensitivity of B. bifidum BB-12. Then, B. bifidum BB-12 was spray dried. The impact of spray drying on the changes in the membrane integrity and membrane potential was investigated using flow cytometry. Culturability was investigated using plate count method. Unprotected B. bifidum BB-12 was markedly harmed by the drying process, drastic membrane damage, depolarization and reduced culturability were observed. The protective impact of excipients on the cell damage during spray drying and one month storage was evaluated. Gum arabic, gelatin and pectin showed the best protective impact. Cells pre-treated with these excipients showed reduced membrane damage, enhanced stability and improved culturability during the storage time. Application of the gathered knowledge may contribute to develop rapid tools for investigation of the cell viability and to improve the production yield. [Copyright &y& Elsevier]

Lipid peroxidation induced by oxidative stress plays an important role in reducing probiotic survival during spray drying. In this study, the probiotic Lactobacillus reuteri KUB-AC5 was co-encapsulated with holy basil essential oil, HBEO (0, 6, and 12 mg/ml), by spray drying using skim milk at inlet air temperatures of 130, 140, and 150 °C. The microcapsule properties in terms of morphology, size, moisture content, water activity, surface oil, microencapsulation efficiency, antioxidant activity, lipid peroxidation, and cell survival were determined. The result showed that the microcapsules with HBEO had much higher antioxidant activity than the ones without HBEO. The optimal condition of HBEO (6 mg/ml) with inlet temperature (130 °C) was effective in reducing malondialdehyde (MDA) level and enhancing survival of probiotics. This study indicates the potential role of HBEO in decreasing oxidative stress in probiotics during spray drying, which contributed to an increase in cell survival and health benefits. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this work was to produce microparticles of green coffee oil by spray drying using emulsions stabilised by lecithin and chitosan through electrostatic layer-by-layer deposition technique. The emulsions were prepared using only corn syrup and the modified starch Hi-Cap 100 and the combination of the corn syrup with the Hi-Cap 100 or modified starch Snow-Flake at a 50:50 ratio. The feed emulsions were characterised for stability, droplet size, ζ-potential and optical microscopy. The microparticles obtained after the drying process were characterised regarding encapsulation efficiency, moisture content, water activity, particle size distribution, microstructure, in vitro sun protection factor and lipid oxidation by Rancimat. The emulsions stabilised by lecithin–chitosan were highly stable, with droplet size ranged from 1.35 to 3.70μm and ζ-potential varied from −2.24 to +40.40mV. All microparticles presented high encapsulation efficiency values, above 86%. The microparticles produced with the modified starches showed spherical shape without cracks or holes and those produced with only corn syrup showed some holes and cracks that caused lower oxidative stability. Microparticles produced with Hi-Cap 100 and corn syrup/Hi-Cap 100 stabilised by lecithin–chitosan exhibited the highest oxidative stability among the microparticles. The sun protection factor of microparticles ranged from 1.52 to 2.45, close to the pure green coffee oil. [Copyright &y& Elsevier]

Abstract: Commercial probiotic bacteria are delivered mainly as frozen or freeze-dried cultures. However, spray drying is a lower cost technology that could be used for the production of probiotic cultures. In this work we aimed at screening among lactobacilli strains for candidates able to survive to spray drying and to study the effects of a preliminary mild heat treatment and different food matrices on post-drying survival and simulated gastric acid resistance. Heat resistance (survival to exposure at 60°C for 5min) in MRS broth or in 10% (wt/vol) skim milk was assessed in 22 strains of Lactobacillus casei, Lactobacillus paracasei, Lactobacillus acidophilus and Lactobacillus plantarum. Five strains (L. casei Nad, L. plantarum com, L. paracasei A13, L. plantarum 8329 and L. acidophilus A9) were selected for spray drying in 20% (wt/vol) skim milk and storage at 5, 25 or 37°C for 75days. For L.p. A13, L.p. com and L.a. A9 no differences in cell viability were observed due to spray drying. However, for L.c. Nad and L.p. 8329 cell death due to spray drying was 0.16 and 0.49 log orders CFUml−1 when a mild heat treatment (52°C for 15min) was applied and 0.85 and 0.95 log cycles, respectively, without preliminary mild heat treatment, showing that heat treatment enhanced survival to spray drying. The application of a heat treatment was effective for enhancing survival during storage of L.p. 8329, irrespective of the storage temperature and period. No significant cell loss at 5 and 25°C was observed for L.c. Nad. For this strain, at 37°C no cell counts of lactobacilli were observed after 30days of storage. For L.a. A9, L.p. com and L.p. A13 a reduction in cell viability was observed along storage as temperature increased. Resistance to simulated gastrointestinal digestion was enhanced by spray drying. The application of a mild heat treatment before spray drying may enhance cell survival during storage and the resistance to gastrointestinal digestion. Spray drying might be used for enhancing cell functionality in a strain-dependant way. [Copyright &y& Elsevier]

Protective solid carriers are commonly added to probiotic cultures prior to drying. Their formulation is not trivial and depends on the drying conditions applied. In this study, we systematically investigated the influence of formulation parameters on the survival of Lactobacillus plantarum WCFS1 after drying. Low molecular weight carbohydrates (less than 2kDa) with high glass transition temperatures provided the highest level of protection at both low (25°C) and high (50°C or higher) drying temperatures. Low molecular weight carbohydrates may provide stabilization by closely interacting with the lipid bilayer of the cell membranes. Meanwhile, carbohydrates with high glass transition temperatures probably provide stabilization via fixation of the cells in a glassy powder. Furthermore, adequate amounts of solid carrier are required to sufficiently stabilize the cells during drying. During drying, crystallization of solid carriers may occur. Depending on the crystal geometry, crystallization can be either beneficial (e.g. with mannitol or sorbitol) or detrimental (e.g. with lactose) to cell survival. Finally, the effect of formulation on cell viability during storage was studied. A decimal reduction time of approximately 300days was observed when spray dried L. plantarum WCFS1 was stored at temperatures below 40°C. The outcome of this study was used as a basis to construct a generalized diagram to indicate the combinations of formulation and drying conditions to maximally retain viability and operate dryers at high efficiency. [ABSTRACT FROM AUTHOR]

Abstract: Spray-drying process has been used for decades to encapsulate food ingredients such as flavors, lipids, and carotenoids. During this drying process, the evaporation of solvent, that is most often water, is rapid and the entrapment of the interest compound occurs quasi-instantaneously. This required property imposes a strict screening of the encapsulating materials to be used in addition to an optimization of the operating conditions. Likewise, if the encapsulated compound is of hydrophobic nature, the stability of the feed emulsion before drying should also be considered. Thus, spray-drying microencapsulation process must rather be considered as an art than a science because of the many factors to optimize and the complexity of the heat and mass transfer phenomena that take place during the microcapsule formation. This paper reports the main process engineering information that are considered useful to the success of a microencapsulation operation by spray-drying. Besides, a summary of the most commonly used wall materials and the main encapsulated food compounds are presented. [Copyright &y& Elsevier]

Abstract: The aqueous extract of pink-fleshed guava fruit was encapsulated by spray-drying with maltodextrin (MD), arabic gum (AG), and their mixtures. The use of AG improves the fluidity during the drying process but produces an undesirable residual taste and decreases the thermal stability in the final microencapsulated powders. Retention of some aroma-active guava volatiles in the powders was confirmed by using HS-SPME–GC–MS analyses. The sensory analyses performed by two sets of non-trained panellists (adults and children) allow to select the most promising powders (MD and AGMD-1). They were physicochemically characterised and subjected to thermal (TGA and DSC) and morphologic (SEM) analyses. The successful production of spherical microencapsulates was also confirmed. From a storage stability study at two relative humidity (RH) conditions (74% and 94%), a strong influence of this parameter in the structure stability of microencapsulates and aroma release was found. The solids developed in this study represent an innovative and natural processed product from guava fruits which can be incorporated into different food products due to their sensory properties. [Copyright &y& Elsevier]

Lipophilic compounds such as polyunsaturated fatty acids (PUFAs) and antioxidants can be encapsulated by spray drying in order to protect and prolong their functionalities and get new handling properties. The aim of this work was to study the effect of both the spray drying stage and storage (60 °C — 50% RH) on the oxidation of lipophilic compounds encapsulated in spray dried oil-in-water emulsions (10% w/w oil in dry matter) using maltodextrin as matrix and Tween® 20 as emulsifier. Emulsions were prepared with oil containing or not containing α-tocopherol (482 ppm in oil) in order to also demonstrate the influence of the antioxidant. Results showed that there is a beginning of oxidation during spray drying, evidenced by a slight increase of markers of rancidity, i.e. conjugated dienes and volatile organic compounds. During storage, the oxidative degradation of PUFAs and α-tocopherol started quickly under the conditions of aging. This was shown to be due to the negative effect of the process and to the porosity of the solid matrix to oxygen, associated with the hollow structure of the particles. An inhibitory action of maltodextrin on α-tocopherol was also hypothesized, but it has to be confirmed. [ABSTRACT FROM AUTHOR]