Technological performance of new bio-based wall materials combining starch and mucilage for encapsulation of fruit juice by spray drying

Enzymatic hydrolysis of granular starch is an important tool to provide information about granule structure. Cassava, sweet potato, Peruvian carrot, and potato starches were hydrolyzed by bacterial α-amylase at 37 °C for 48 hours, and the physicochemical properties of the residues from hydrolysis were determined. Cassava starch was the most susceptible to enzyme displaying 20.9% of hydrolysis, whereas potato starch was the most resistant with 5.9%. The granule average size varied from 10.8 to 23.4 μm for Peruvian carrot and potato starches, respectively. With the use of SEM, a smooth granule surface was observed for all native starches. Cassava and sweet potato starches displayed an A-type X-ray diffraction pattern, while Peruvian carrot and potato starches showed a B-type pattern. After hydrolysis, cassava, sweet potato, and Peruvian carrot starches showed some well degraded granules, whereas potato starch presented a slight sign of degradation. The amylose content of the starches decreased with hydrolysis for cassava, sweet potato, and Peruvian carrot starches and was kept unchanged for the potato starch. As expected, intrinsic viscosity and pasting properties decreased for all hydrolyzed starches. There is no difference between thermal properties of native and hydrolyzed starches. These results suggested that hydrolysis occurred in amorphous and crystalline areas of the granules. The B type diffraction pattern in conjunction with the big granule size of the potato starch may have contributed to the greatest resistance of this starch to hydrolysis.

Physicochemical characteristics and in vitro digestibility of potato and cassava starches under organic acid and heat-moisture treatments

Starches from cassava tubers, sweet potato, and mango seeds were isolated and characterized. The starches' proximate, elemental composition, physicochemical and physical properties, were studied. Cassava tuber yielded 93.45 percent, while Potato and Mango seed yielded 88.65 and 78.45 percent, respectively, in the proximate composition. When compared to cassava at 5.49 and potato starch 5.72, which have a highly acidic pH, mango starch had a neutral pH of 6.9. The moisture content of starch extracted from cassava and mango was significantly closed values at 6.00 and 6.5 percent, respectively, when compared to potato, which had a moisture content of 4.5 percent. Cassava starch (0.0012±0.003, 0.08 ±0.01) had significantly lower protein and nitrogen levels than Potato (0.35±0.00001) and (0.06±0.03), and was significantly lower than Mango starch (0.35±0.01) and (0.06±0.01) (p <0.005). Cassava starch had the highest swelling capacity of 0.940 cm3 compared to 0.285 and 0.250 cm3 for mango and potato, respectively. Cassava and potato starches have significantly higher swelling capacities of 92.00 and 93.00 percent, respectively, than mango starch, which has a swelling capacity of 75.2 percent. Cassava starch had a greater moisture absorption index of 36.00, compared to Potato 24.10 and Mango starch 23.65 percent, which showed no significant difference. Mango starch had significantly higher sodium, potassium, and calcium concentrations than cassava and potato starch, but magnesium and phosphorus concentrations were significantly higher in mango starch than cassava and potato starch. All of the starches have outstanding characteristics and can be used interchangeably, especially in food and pharmaceuticals.

Debranching starch by pullulanase is considered to improve the RS content of starch which is widely used to produce the starch‐based foods with high‐health benefit impacts. In this study, the cassava and potato starches were debranched by pullulanase, followed by an autoclave treatment and storage at −18°C, 4°C, or 25°C to investigate their crystallinity and functional properties. After debranching, the potato starch contained significantly higher CL (35.4 glucose units) than did the cassava starch (32.4 glucose units). The debranched cassava and potato starches after retrogradation at the storage temperatures had a typical B‐type crystalline structure although the native cassava and potato starches exhibited the different crystalline forms (A‐ and B‐type, respectively). The RS contents of the debranched cassava and potato starches significantly improved with higher RS content of the debranched potato starch than that of the debranched cassava starch at the same storage condition. The storage temperature significantly affected the RS formation of the debranched starches with the highest RS content at storage temperature of −18°C (35 and 48% for the debranched cassava and potato starches, respectively). The debranched starches had significantly lower viscosities and paste clarities but higher solubilities than did the native starches. As a result, the debranched cassava and potato starches can be considered for use not only in functional foods with enhanced health benefits but also in pharmaceutical and cosmetic industries.

Spray drying is a widely used method for producing milk powder. This process is not aimed to cause microbial inactivation, thus sporeforming bacteria may be abundant in the microbiota of milk powder. The first aim of this study was to determine the inactivation kinetics parameters in capillary tubes of three Bacillus cereus strains (436, B63, 540) in three menstrua (whole milk, phosphate buffer, and talc suspension) at 90, 100, and 110°C. D-values for B. cereus in the three menstrua were not significantly different at the highest tested temperature (p > 0.05). Thus, talc was chosen as a carrier agent to allow the recovery of B. cereus from spray dried materials given its low interference on inactivation kinetics. B. cereus spores were also inoculated in whole milk and skim milk following spray drying at 95, 105, and 110°C (outlet temperature). After the spray drying runs, B. cereus spores were counted and the number of decimal reductions (γ) calculated. A correlation between the small diameter of the particles with the survival of spores of three B. cereus strains was found, and B. cereus 436 presented consistently the lowest γ no matter temperature and a carrier agent. The highest γ was found when talc powder was used, which suggest that this carrier agent does not protect B. cereus spores during spray drying. Spray drying of milk can lead to up to 4 γ (strain 540) of B. cereus spores but depending on the strain less than one γ (strain 436) could be observed. This study contributes to the knowledge on the microbiology of low water activity foods by providing novel findings regarding the fate of three B. cereus strains to different spray drying conditions. Acknowledging the variability of inactivation of B. cereus during spray drying is key in the current context of food safety in which the quantification of effects of unit operations must be known for the validation of processes and development of more robust formulations.

The blue butterfly pea (Clitoria ternatea L.) flowers have been traditionally used as food colorants and source of anthocyanins and other flavonoids, particularly as antioxidants. Encapsulation aims at preserving natural pigments from several factors that cause their degratation. This work aimed at producing powdered butterfly pea flower extract by spray drying, using maltodextrin, cassava starch, and gelatin as carrier agents, generating a product ready to use, easy to handle, and with long shelf life. Physicochemical and colorimetric properties of the powders were assessed, resulting in high anthocyanin retention (>90%), good solubility (around 99%), low moisture (less than 5%), and good reconstitution property, with color attributes very similar to the original extract at different pHs. Gelatin-maltodextrin blended formulations resulted in powders with the best physicochemical and morphological characteristics, as well as better color preservation. Practical applications This study investigated the production by spray drying of a powdered, natural blue dye extracted from butterfly pea (Clitoria ternatea L.) flowers, using maltodextrin, cassava starch, and gelatin as carrier agents, obtaining a product that is easy to handle, ready to use, and with a long shelf life. The produced powders showed high anthocyanin retention, good solubility, low moisture and good reconstitution properties, with color attributes very similar to the original extract at different pHs. The formulation using maltodextrin-gelatin blend resulted in the powder with the best physicochemical and morphological characteristics, in addition to better color preservation, enabling its application as natural colorant in food, beverages, pharmaceuticals, and cosmetics.

The oxidising effects of organic (acetic, citric and lactic) acids on the physicochemical properties of starches from cassava, potato and jicama were investigated. Cassava starch oxidised with lactic and citric acids had the highest carbonyl contents (5.43 and 5.84 g kg−1 respectively), while oxidised potato starch had the highest carboxyl contents. Oxidised jicama starch showed the lowest carbonyl and carboxyl contents. Oxidation increased the maximum viscosity of cassava starch (from 426.61 to 670.11 relative viscosity units (RVU)) and jicama starch (from 160.17 to 561.50 RVU) but decreased that of potato starch (from 669.44 to 206.92 RVU). When carbonyl and carboxyl groups were incorporated into jicama starch granules, the resistance of these granules to stirring at constant temperature (holding) increased, as did their final and retrogradation viscosities. However, the behaviour of oxidised cassava and potato starches, as indicated by a Rapid Visco Analyser, was different. The highest values of endotherm enlargement were found for native and oxidised jicama starch, while the lowest values were found for native and oxidised cassava starch. Native and oxidised potato starch had the highest enthalpy values (14.30–18.30 J g−1), while jicama starch had the lowest (9.50–11.9 J g−1). The high intrinsic viscosity of native potato starch was attributed to B‐type starch with a longer‐than‐average amylopectin chain length and a lower degree of crystallinity. Oxidised granules showed little erosion in the form of grooves; on the contrary, oxidation left the grains with a very smooth surface. Copyright © 2007 Society of Chemical Industry

Trends of spray drying: A critical review on drying of fruit and vegetable juices

From sub-microsized MgAl2O4 powder to MgAl2O4-Si3N4 nanocomposite powder by spray drying of ultrasonicated suspensions

Background: The carrot (Daucus carota L.) is a popular root vegetable grown throughout the world. In the present study, an attempt was made to use the carrot outgrades, which are purely rejected for aesthetic reasons, not meeting the standards based on size and shape. Further enzymes (Pectinase and Cellulase) are used to extract the carrot coagulum from carrot outgrades. Carrier agents were mixed into carrot coagulum and spray dried at three different inlet air temperatures (160, 170, and 180 °C) to encapsulate enzyme-extracted carrot coagulum. Aim: Carrots are nutritious and mainly rich in carotenoids. Often, very high losses are incurred during post-harvesting operations. A significant proportion of carrots are rejected due to bad aesthetics. Therefore, the objective of the study was to utilise such non-commercial carrot out-grades to recover carotenoids and produce encapsulated powder using spray drying. Methodology: The process of spray drying of enzymatically extracted carrot coagulum was standardised by varying carrier agents (maltodextrin and gum arabica) concentration and at different inlet temperatures. Pectinase (Pectinex Ultra SPL from Aspergillus aculeatus aqueous solution, ≥3,800 units/mL) and cellulose (Celluclast 1.5L from Trichoderma reesei aqueous solution, ≥700 units/g) were obtained from Novozymes, Bangalore. Trans-β-carotene was obtained from Sigma Chemical Company. All other chemicals used were of analytical grade. Results: All physicochemical properties were significantly affected by the carrier agents and temperature. Carotenoid content was highest (9.80%) at an inlet temperature of 170 °C with MD100. Overall moisture content was reduced, while other physical properties were enhanced when the temperature increased. Increasing the gum Arabica content showed a significant increase in moisture content and wettability time, as well as poorer physical properties. Results showed that the physicochemical and microstructural properties of encapsulated carrot coagulum powder (ECCP) were affected by inlet temperatures and carrier agents. Conclusion: Among all the spray-dried powders, the powder dried at 170 °C using maltodextrin at 15% alone had comparatively lower moisture content, good flowability, higher solubility, and less wetting time compared to other combination treatments and inlet temperatures, and thus fulfills the requirement of good quality spray-dried powders. Certainly, carrot out grades have a significant content of total carotenoids, which makes the utilisation of such material worthwhile for processing.

Cassava starch was partially hydrolyzed in 6% HCl solution at room temperature for 192 h, dried using oven- and spray-drying techniques and subsequently evaluated as a direct compression excipient in pharmaceutical tablet formulations. Acid modification enhanced the crystallinity while the amylose content decreased from 15.24% to 5.14%. Native cassava starch (NCS) and oven -dried acid modified cassava starch (AMCS) exhibited poor flow characteristics, whereas spray dried AMCS was found to be free flowing powder with 25.12 ± 2.88° angle of repose and 13.63 ± 0.52 g/sec flow rate. Lubricant sensitivity and dilution potential of spray dried NCS and spray dried AMCS were investigated by incorporating magnesium stearate and paracetamol, respectively, in tablet formulations. Spray dried AMCS and Starch 1500® tablets were produced with acceptable tablet characteristics (a minimum of 50 N crushing strength and < 1% friability) up to 0.75% and at 0.25% magnesium stearate concentrations, respectively. The spray dried AMCS was able to accommodate up to 40% paracetamol by weight with crushing strength of 55.90 ± 2.84 N and friability of 0.80 ± 0.06%. Starch 1500® tablets were more friable and exhibited lower crushing strengths at all paracetamol concentrations as compared to the spray dried AMCS tablets (P < 0.05). The dilution potential and lubricant sensitivity of the spray-dried AMCS were significantly higher than those of spray dried NCS and Starch 1500®. Hence, spray dried AMCS has the potential for application as a directly compressible tablet excipient.Keywords: cassava starch, acid modification, spray drying, direct compression, tablet excipient

Natural fermentation of potato (Solanum tuberosum L.) starch: Effect of cultivar, amylose content, and drying method on expansion, chemical and morphological properties

Hibiscus Sabdariffa has high antioxidant capacity, but as the fruit in natura can degrade, the drying process can assist in the conservation and the spray drying is a widely used technique. The objective was to evaluate the drying of H. sabdariffa by spray dryer, employing different diameter nozzles and carrier agents. The process yield and the powder properties such as moisture content, water activity, hygroscopicity, solubility, anthocyanins, antioxidant capacity, and color were determined. Regardless of the formulation, the powders showed low water activity (<0.27) and hygroscopicity (<20%), which guarantees good handling and showed a high solubility (>77%). In relation to the antioxidant compounds, the powder obtained from the interaction of gum arabic and chitosan presented higher anthocyanin content and antioxidant capacity. Therefore, it was concluded that both carrier agents and the diameter of the sprinkler nozzle influenced the yield and the chemical and antioxidant properties of H. sabdariffa. Practical applications Hibiscus sabdariffa is widely consumed and its health benefits are due to the presence of antioxidant compounds. However, during the drying process by spray dryer, different factors can lead to the degradation of the antioxidant compounds. Thus, controlling the drying parameters is necessary to evaluate how the process affects the content of antioxidant compounds. The obtained H. sabdariffa extract presented a retention of anthocyanins and antioxidant compounds, which makes its application possible in different products.

Starches from cassava, potato and maize were hydrolysed by locally sourced crude amylases to assess and compare the performance of the enzymes in converting root and cereal starches to glucose syrup. Standard amylases (Sigma USA) served as the reference enzymes. Selected physical and sensory characteristics of the syrups produced were evaluated simultaneously with the syrups produced by the standard amylases. The crude amylases showed higher (P < 0.05) activity on maize starch than on cassava and potato starches. The hydrolytic performance of the crudeamylases increased with increase in substrate concentration up to a maximum substrate concentration of 10%. The crude alpha amylase exhibited a dextrinization time of 2.5h, 2.75h and 3.0h for maize, cassava and potato starches and produced 13%, 12% and 11.8% glucose respectively. The crude gluco-amylase had maximum saccharificationtime of 72h for cassava and potato starches, 84h for maize and produced 24.37%, 21.8% and 21% glucose respectively. The crude amylases produced syrups in the type II category with Dextrose Equivalent (DE) of 47 and 50 from potato and cassava starches respectively, while syrup from maize starch fall within type III category with DE of 61. Potato starch syrup exhibited higher (P < 0.05) apparent viscosity and low (P < 0.05) mean score for colour and taste than cassava and maize syrups.

The effect of sodium chloride on the glass transition of potato and cassava starches at low moisture contents