Optimization of the color masking and coating unit operations for microencapsulating ferrous fumarate for double fortification of salt.

A new coating formulation was developed to eliminate the factor that caused black spots on the iron premix surface, used for making Double Fortified Salt. The formulation is a suspension of titanium dioxide in soy stearin, prepared with ethanol and dichloromethane and applied with a glass sprayer and pan coater. 0-20% w/w titanium dioxide was suspended in 10% w/w soy stearin/hydroxypropyl methylcellulose. Coating with a suspension of 15% w/w TiO2 in 10% w/w soy stearin ensured that all the TiO2 adheres to the premix surface, giving no chance for the recycling of iron contaminated TiO2, which caused the black spot. The new coating formulation ensured that over 90% iodine in Double Fortified Salt was retained after 6 months at 45 °C, 60-70% RH. The whiteness of the premix (L* = 86.4) matched the Double Fortified Salt whiteness (L* = 86.8). Thus, making the new coating method as effective as the previous in desirable characteristics. More so, the new coating method simplifies the existing method by merging the previous color masking, and double coating steps into one step.

Hesperetin (citrus peel flavonoid aglycone) encapsulation using pea protein-high methoxyl pectin electrostatic complexes: complex optimization and biological activity.

BACKGROUND: Orange pomace polyphenols have potential for use as nutraceutical ingredients in functional foods and beverages. However, owing to their low water solubility and bioaccessibility, they are not being utilized to their full potential. The goal of this research is to assess the impact of encapsulation on hesperetin (HT - a model orange polyphenol) water solubility, antioxidant activity, and in vitro bioaccessibility. RESULTS: In this study, a citrus flavonoid aglycone, HT, was encapsulated within water-dispersible colloidal complexes (d = 350 ± 8 nm) formed by electrostatic attraction of pea protein isolate and high-methoxyl pectin at a mixing ratio of 1:1 (v/v) and pH 4. The maximum amount of HT that could be dispersed in water was much higher for the encapsulated form (99 ± 7 µg mL-1 ) than the non-encapsulated form (<10 µg mL-1 ). The radical scavenging activity of the encapsulated HT (>90%, pH 4) was much higher than the non-encapsulated form (<15% at pH 4 or 7). The in vitro bioaccessibility of encapsulated HT (27 ± 7%) was also much higher than the non-encapsulated form (<7%). CONCLUSION: These results suggest that a well-designed, biopolymer-based delivery system may improve the effective incorporation of HT, and potentially other orange pomace polyphenols, into food and beverage products. This could provide an additional high-value use for orange juicing by-products while introducing a new nutraceutical product to the food and beverage industry. © 2022 Society of Chemical Industry.

Encapsulation and delivery of bioactive citrus pomace polyphenols: a review.

Citrus pomace consists of the peel, pulp, and membrane tissues remaining after juice expression. Globally, around one million tons of citrus pomace are generated annually, which contains a variety of bioactive constituents that could be used as value-added functional ingredients in foods. However, the polyphenols in citrus pomace are not currently being utilized to their full potential, even though they can be used as nutraceuticals in functional foods and beverages. Citrus phenolics face significant roadblocks to their successful incorporation into these products. In particular, they have poor water solubility, chemical stability, and bioavailability. This review describes the diverse range of colloidal systems that have been developed to encapsulate and deliver citrus phenolics. Examples of the application of these systems for the encapsulation, protection, and delivery of polyphenols from citrus pomace are given. The use of colloidal delivery systems has been shown to improve the stability, dispersibility, and bioaccessibility of encapsulated polyphenols from citrus pomace. The selection of an appropriate delivery system determines the handling, storage, shelf life, encapsulation efficiency, dispersibility, and gastrointestinal fate of the citrus polyphenols. Furthermore, the purity, solubility, and chemical structure of the polyphenols are key factors in delivery system selection.

Encapsulation of Lutein in Nanoemulsions Stabilized by Resveratrol and Maillard Conjugates.

Lutein is incorporated into foods as a natural yellow pigment and nutraceutical. The introduction of lutein into many foods and beverages, however, is problematic because of its strong hydrophobicity and poor chemical stability. In this research, lutein-loaded nanoemulsions were prepared to overcome this problem. Casein-dextran Maillard conjugates or physical complexes were utilized as emulsifiers, while either medium chain triglycerides (MCT) or grape seed oil (GSO) were used as carrier oils. The impact of resveratrol addition on nanoemulsion stability was also examined. The influence of storage temperature, pH, and CaCl2 concentration on the chemical and physical stability of the nanoemulsions was measured. The casein-dextran conjugates were highly effective at improving the physical resistance of the nanoemulsions to environmental stresses, but had a detrimental effect on their color stability. Conversely, nanoemulsions prepared from casein-dextran physical complexes were unstable around the protein's isoelectric point (pH 4.6), as well as upon addition of CaCl2 . Incorporation of resveratrol and GSO into the nanoemulsions decreased lutein degradation and color fading at all temperatures. This study shows that casein-dextran conjugates are highly effective at improving the physical stability of lutein-loaded nanoemulsions, while resveratrol and GSO are effective at improving their chemical stability. PRACTICAL APPLICATION: Lutein can be used by the food industry to create "clean label" and functional food products. The major challenges in incorporating lutein in foods are its poor chemical stability and its high hydrophobicity, which makes it difficult to incorporate. Emulsion-based delivery systems assembled from natural ingredients may address these challenges. In this study, the impact of Maillard conjugates fabricated from caseinate and dextran, as well as resveratrol addition, on the formation and stability of lutein-enriched nanoemulsions was determined. The information obtained from this study will help the formulation of more effective functional foods and beverage products.

Biosynthesis of selenium rich exopolysaccharide (Se-EPS) by Pseudomonas PT-8 and characterization of its antioxidant activities.

Biosynthesis of organo-selenium is achieved by submerged fermentation of selenium-tolerant Pseudomonas PT-8. The end product of metabolic process is selenium-bearing exopolysaccharide (Se-EPS), which contains a higher content of uronic acid than the exopolysaccharide (EPS) by the strain without selenium in the culture medium. Selenium content in Se-EPS reached a maximum yield of 256.7 mg/kg when using an optimized culture condition. Crude Se-EPS was purified into two fractions-a pH neutral Se-EPS-1 and an acidic Se-EPS-2. Structure and chemical composition of Se-EPS-2 were investigated by chromatographic analyses. Results showed that Se-EPS-2 was a homogenous polysaccharide with molecular weight of 7.3 kDa, consisting of monosaccharides, rhamnose, arabinose, xylose, mannose, glucose and galactose with a molar ratio of 19.58:19.28:5.97:18.99:23.70:12.48, respectively. Compared to the EPS, the content of rhamnose in Se-EPS increased and molecular weight decreased. The Se-EPS had strong scavenging actions on DPPH•, •OH and •O2(-), which is much higher than the EPS.

Feasibility and optimization study of using cold-forming extrusion process for agglomerating and microencapsulating ferrous fumarate for salt double fortification with iodine and iron.

A microencapsulation-based technology platform has been developed for salt double fortification with iron and iodine, aiming to address two globally prevalent micronutrient deficiencies simultaneously. Specifically, ferrous fumarate was microencapsulated into a form of salt grain-sized premix, and then added into iodised salt. The earlier process involved fluidised-bed agglomeration followed by lipid coating. To improve physico-chemical properties of the iron premix, the use of cold-forming extrusion for agglomerating and microencapsulating ferrous fumarate was investigated and optimized in this study, leading to optimal formulations and operation parameters. Grain flours were suitable for forming an extrudable dough incorporating high percentages of ferrous fumarate. All extruded iron particles, regardless of binders used, were rich in iron and had excellent iron in vitro digestibility. The extruded iron particles formed the basis of the final, microencapsulated iron premixes with desired particle size (300-700 µm), and other physical, chemical, nutritional, and organoleptic properties suitable for salt fortification.

Folic acid fortification through existing fortified foods: iodized salt and vitamin A-fortified sugar.

BACKGROUND: Folic acid fortification of cereal-grain products has markedly improved folate status and reduced the risks of neural tube defects and other chronic diseases in the populations participating in fortification programs. To more broadly extend its benefit to affected populations in developing countries, it would seem logical to incorporate folic acid fortification into existing or planned programs to minimize the incremental cost of this intervention. OBJECTIVE: To examine the feasibility of providing folic acid through ongoing programs for salt iodization and vitamin A fortification of sugar. METHODS: Folic acid was added to iodized salt and vitamin A-fortified sugar by various methods--direct blending as a powder, spraying onto the carriers as aqueous solution or suspension, or blending as a microencapsulated premix. The multiple fortified samples were subjected to a prolonged storage stability test, and the retentions of the added micronutrients were followed. RESULTS: Folic acid was generally stable when incorporated into Guatemalan iodized salt and vitamin A-fortified sugar. Even in the presence of encapsulated ferrous fumarate as an iron fortificant, samples retained > 80% in salt and approximately 70% in sugar samples respectively, after 9 months of storage at 40 degrees C and 60% relative humidity. The addition of folic acid as a dry premix made by extrusion was most effective in retaining both folic acid and the other added micronutrients. CONCLUSIONS: The fortification method had a pronounced impact on the stability of both folic acid and the other added micronutrients. Proper encapsulation may be required to ensure the stability of multiple fortified foods.

Antioxidant system for the preservation of vitamin A in Ultra Rice.

BACKGROUND: Ultra Rice grains are micronutrient-fortified, extruded rice grains designed to address specific nutritional deficiencies in populations where rice is a staple food. Vitamin A and some of the B vitamins, as well as iron and zinc, are target nutrients for fortification through Ultra Rice technology. Vitamin A is sensitive to degradation. Therefore, the original Ultra Rice formulations included stabilizers, some of which were not approved as food additives in all of the receiving markets. OBJECTIVE: To develop a new antioxidant system for improving vitamin A storage stability in Ultra Rice grains, while complying with international food regulations. METHODS: Ten formulations were prepared containing various combinations of hydrophilic and hydrophobic antioxidants, as well as moisture stabilizers. Accelerated vitamin A storage stability tests were conducted at 25 degrees, 35 degrees, and 45 degrees C with 70% to 100% relative humidity. RESULTS: The most stable samples contained one or more phenolic antioxidants, a water-soluble antioxidant, and stabilizing agents. The best results were obtained by using butylated hydroxyanisole (BHA) in combination with butylated hydroxytoluene (BHT) as the hydrophobic antioxidants and ascorbic acid as the hydrophilic antioxidant. Citric acid and sodium tripolyphosphate (STPP) were used to chelate metal ions and to stabilize moisture, respectively. The best formulations retained more than 85% and approximately 70% of the added vitamin A at 25 degrees and 45 degrees C, respectively, after 24 weeks storage. CONCLUSIONS: The best antioxidant system, composed of generally accepted food additives, improved vitamin A stability while reducing the price, thus greatly improving the commercial viability of Ultra Rice grains for use as a ricefortificant.

Iron in vitro bioavailability and iodine storage stability in double-fortified salt.

BACKGROUND: Ferrous fumarate is useful in iron fortification because of its high bioavailability, mild taste, and relatively low cost. A ferrous fumarate premix for incorporation into salt has been developed by agglomerating ferrous fumarate with appropriate binder materials into salt-size particles followed by microencapsulation. OBJECTIVE: The bioavailability of iron is critical for the usefulness of double-fortified salt. This study examined the in vitro bioavailability of various iron forms in double-fortified salt and microencapsulated ferrous fumarate premixes prepared by various techniques in an effort to identify key processing factors affecting iron bioavailability. METHODS: Iron in vitro bioavailability was approximated through the rate of dissolution of iron in 0.1 N HCl, which closely approximates the acid in gastric juice. Iron in vivo bioavailability was tested using the hemoglobin repletion assay in rats. RESULTS: The materials and techniques used in microencapsulating ferrous fumarate had little effect on iron in vitro bioavailability: more than 90% of iron in the premixes was released during 2 hours of digestion in the simulated gastric fluid. By incorporating titanium dioxide in the coating materials, the dark reddish-brown color of ferrous fumarate was effectively masked, resulting in acceptable sensory qualities, while maintaining the stability of iodine in the salt. Iron in vivo tests in rats have confirmed that the ferrous fumarate microencapsulated in a lipid is highly bioavailable, with a bioavailability of 95% relative to ferrous sulfate. CONCLUSIONS: These findings were corroborated by field tests in southern India which demonstrated that double-fortified salt containing microencapsulated ferrous fumarate was effective in reducing the prevalence of iron-deficiency anemia and iodine-deficiency disorders.

Microbial remediation and optimization of oil polluted wetlands at Dalian Bay in China.

OBJECTIVE: The wetland at Dalian Bay in the Northeast of China has been polluted by oil severely. The effect of various microbes and operation parameters on the bioremediation of oil-polluted wetlands at Dalian Bay was investigated and reported previously. In the study, other operation conditions related to the status of medium were investigated via statistical experimental design and analysis and a necessary information is involved to use micro-technology in the application. METHODS: The method used involved the direct inoculation of selected bacteria, which were capable of degrading oil. The operation conditions were further optimized and evaluated by gravimetrical assay. RESULTS: The optimal pH and temperature for the studied bacteria to degrade the existing oil pollutants were established as pH 8.0 and 27 degrees C. The mixed of various bacteria showed better results in terms of oil degradation than any single one. Among the selected four factors, disturbance, oxidant, nutrients, and biosurfactant, the former two contributed more impacts on the oil degradation in the early stage of process, while the latter two became the limiting factors in the late stage. Three sets of optimal conditions were obtained for each individual stage, but no one was suitable for the overall process. CONCLUSION: The study demonstrated the technical feasibility of using direct inoculation into the contaminated soil samples to remove oil pollutants. It suggested that the operation conditions should be monitored and adjusted during the different stages of bio-reactions in the process to achieve the best result of oil degradation.

Investigation on bioremediation of oil-polluted wetland at Liaodong Bay in northeast China.

An investigation on the effect of various microbes on degradation was carried out as part of the study on bioremediation of oil-polluted wetland at LiaoDong Bay in northeast China. The method used involved direct inoculation of selected bacteria, which were capable of degrading oil, to the soil samples. The combination of various bacteria showed better results in terms of oil degradation than any single ones due to their synergetic effects. The operation conditions [pH 8.0, 25 degrees C, C/N/P (40:5.6:1)] for these bacteria to degrade the oil content in the soil samples were also studied and optimized. Addition of appropriate surfactants was helpful for bacteria growth, thus favoring the oil degradation. For instance, after adding Tween 80 (300 mg/kg) for 8 days, the number of bacteria was amplified 6.22 times and the rate of oil degradation increased by 20%. Adequate amount of H2O2 was also beneficial for microbes to decompose oil. However, overdosage may cause the death of the bacteria. The addition of 400 mg/l H2O2 each time was suitable. Seven thousand milligrams of H2O2 was added entirely in 11 days, and the rate of oil degradation increased significantly from 27% (without H2O2) up to 67%. The study clearly demonstrated that the direct soil inoculation was an effective method for environmental bioremediation.