Kafirin structure and functionality

Food Protein-Based Nanodelivery Systems for Hydrophobic and Poorly Soluble Compounds

The hydrophobicity of bioactive molecules poses a considerable problem in the pharmaceutical and the food industry. Using food-based protein nanocarriers is one promising way to deliver hydrophobic molecules. These types of protein possess many functional properties such as surface activity, water-binding capacity, emulsification, foaming, gelation, and antioxidant activity, as well as their incorporation in the food industry as ingredients. Besides, they express low toxicity, are less expensive compared to synthetic polymers, and are biodegradable. This review aims to give a brief overview of the recent studies done using food proteins as colloidal delivery systems for hydrophobic and poorly soluble compounds.

Protein digestion of different protein sources using the INFOGEST static digestion model

In vitro digestion systems are valuable tools for understanding and monitoring the complex behavior of food degradation during digestion, thus proving to be good candidates for replacing in vivo assays. The aim of the present work was to study protein hydrolysis in a selection of different protein sources using the harmonized INFOGEST static protocol: three isolated proteins (collagen, zein, and whey protein) and five foods (sorghum flour, wheat bran cereals, peanuts, black beans, and pigeon peas). The proteins of all the substrates were analyzed by SDS-PAGE and HPLC-MS/MS. Individual amino acid composition was analyzed by high-performance liquid chromatography (HPLC). EAA/NEAA (essential amino acids/ nonessential amino acids) ratios in the substrates from low to high were as follows: wheat bran cereals, peanuts, collagen, zein, whey protein, sorghum, pigeon peas, and black beans. The results revealed sorghum, whey protein, and zein as good sources of BCAA. In all substrates, no intact protein from the substrates was visually detected by SDS-PAGE after the intestinal phase of in vitro digestion with the INFOGEST protocol. However, digestion-resistant peptides were detected in all substrates after the intestinal digestion phase. Protein hydrolysis was high in whey protein isolate and pigeon pea and low for wheat bran cereals and bovine collagen.

Effect of wet and dry milling on the functional properties of whole sorghum grain flour and kafirin

The effect of wet and dry milling on the functional properties of whole sorghum grain flour (SF) and extracted kafirin were assessed. White sorghum landrace was used to prepare two SFs by wet milling (SF1) or dry milling (SF2) and to extract their respective kafirins SK1 and SK2. Protein contents of SK1 and SK2 were 90.07 and 94.23%. Wet milling of SF allowed increasing the oil binding capacity, the least gelling concentration and the instant foam capacity and decreasing the water binding capacity and foam stability. The emulsifying activity index of SF1 and SF2 were in the same range, while emulsion stability was two time higher in SF2. Functional properties of SK1 and SK2 showed an appropriate water binding capacity of 2.20 ± 0.10 and 1.82 ± 0.22 (g water/g dry mater), respectively. Both SK1 and SK2 showed higher oil binding capacity than SF1 and SF2 with no gel and foam formation. The wet milling improved water and oil binding capacities of SK1 by 17 and 5%. The emulsifying activity indexes were approximately similar for SK1 and SK2 with emulsion stability exceeding 60%. Fourier transform infrared spectroscopy of SK1 and SK2 showed that wet milling induced a decrease of α-helical structure and an increase of intermolecular β-sheet and β-turns and no change in the anti parallel β-sheet. This study showed that wet milling could allow extracting kafirin with preserving the most important functional properties of SF and kafirin and could constitute an interesting method for protein recovery and starch isolation.

Sorghum Grain: From Genotype, Nutrition, and Phenolic Profile to Its Health Benefits and Food Applications

Globally, sorghum is one of the most important but least utilized staple crops. Sorghum grain is a rich source of nutrients and health-beneficial phenolic compounds. The phenolic profile of sorghum is exceptionally unique and more abundant and diverse than other common cereal grains. The phenolic compounds in sorghum are mainly composed of phenolic acids, 3-deoxyanthocyanidins, and condensed tannins. Studies have shown that sorghum phenolic compounds have potent antioxidant activity in vitro, and consumption of sorghum whole grain may improve gut health and reduce the risks of chronic diseases. Recently, sorghum grain has been used to develop functional foods and beverages, and as an ingredient incorporated into other foods. Moreover, the phenolic compounds, 3-deoxyanthocyanidins, and condensed tannins can be isolated and used as promising natural multifunctional additives in broad food applications. The objective of this review is to provide a comprehensive understanding of nutrition and phenolic compounds derived from sorghum and their related health effects, and demonstrate the potential for incorporation of sorghum in food systems as a functional component and food additive to improve food quality, safety, and health functions.

Is the kafirin profile capable of modulating the ileal digestibility of amino acids in a soybean meal-sorghum diet fed to pigs?

The effects of kafirins on protein and amino acid ileal digestibility have not been evaluated in vivo in pigs. The aim of this study was to determine the effects of protein profile on apparent ileal digestibility (AID) of amino acids. We used a sorghum hybrid with low tannin content (<0.5%). The same hybrid was harvested from 2 different plots with different kafirin profile. Sorghum with greater content of total kafirins had less content of γ- and α1-kafirins and higher content of β- and α2-kafirins than that with lower content of total kafirins. Two sorghum-soybean meal (SBM) diets were formulated: 1) low kafirin (LK) content (32.2 g/kg) and 2) high kafirin (HK) content (48.1 g/kg). A control diet (maize-SBM) and a reference SBM-diet were also prepared. The reference diet was fed to all pigs following the experimental period and was used to estimate the AID of cereals by the difference method. "T" cannulas were fixed in the distal ileum of 18 barrows (6 by treatment), divided into 2 groups of 9 pigs. The pigs were fed 2.5 times their maintenance requirement of digestible energy (110 kcal/kg BW^0.75). The AID of dry matter, protein, amino acids, and energy of the experimental diets was measured; the AID of cereals (maize, LK sorghum and HK sorghum) was estimated by the difference method. The maize-SBM diet was more digestible than the sorghum-SBM diets, only with respect to valine (P < 0.05). The AID of valine in the maize-SBM diet was higher than that in sorghum-SBM diets. The changes in kafirin profile between the diets only affected the AID of threonine (P < 0.01), which decreased by 9.5 percentage units in LK diet compared with HK diet. Regarding the AID of cereals, maize exhibited greater AID than sorghum, with respect to valine (P < 0.01) and serine (P < 0.10). A comparison of sorghum with LK and HK content showed that the AID of threonine and serine increased by 50.5 (P < 0.001) and 19.2 percentage units (P < 0.05) in the latter, respectively. The higher content of γ-kafirins in LK sorghum negatively affected threonine and serine digestibility, implying that the AID of amino acids is affected more by the profile than the content of kafirins.

Genetic and genomic resources of sorghum to connect genotype with phenotype in contrasting environments

With the recent development of genomic resources and high-throughput phenotyping platforms, the 21st century is primed for major breakthroughs in the discovery, understanding and utilization of plant genetic variation. Significant advances in agriculture remain at the forefront to increase crop production and quality to satisfy the global food demand in a changing climate all while reducing the environmental impacts of the world's food production. Sorghum, a resilient C₄ grain and grass important for food and energy production, is being extensively dissected genetically and phenomically to help connect the relationship between genetic and phenotypic variation. Unlike genetically modified crops such as corn or soybean, sorghum improvement has relied heavily on public research; thus, many of the genetic resources serve a dual purpose for both academic and commercial pursuits. Genetic and genomic resources not only provide the foundation to identify and understand the genes underlying variation, but also serve as novel sources of genetic and phenotypic diversity in plant breeding programs. To better disseminate the collective information of this community, we discuss: (i) the genomic resources of sorghum that are at the disposal of the research community; (ii) the suite of sorghum traits as potential targets for increasing productivity in contrasting environments; and (iii) the prospective approaches and technologies that will help to dissect the genotype-phenotype relationship as well as those that will apply foundational knowledge for sorghum improvement.

Maize 16-kD γ-zein forms very unusual disulfide-bonded polymers in the endoplasmic reticulum: implications for prolamin evolution

In the lumen of the endoplasmic reticulum (ER), prolamin storage proteins of cereal seeds form very large, ordered heteropolymers termed protein bodies (PBs), which are insoluble unless treated with alcohol or reducing agents. In maize PBs, 16-kD γ-zein locates at the interface between a core of alcohol-soluble α-zeins and the outermost layer mainly composed of the reduced-soluble 27-kD γ-zein. 16-kD γ-zein originates from 27-kD γ-zein upon whole-genome duplication and is mainly characterized by deletions in the N-terminal domain that eliminate most Pro-rich repeats and part of the Cys residues involved in inter-chain bonds. 27-kD γ-zein also forms insoluble PBs when expressed in transgenic vegetative tissues. We show that in Arabidopsis leaves, 16-kD γ-zein assembles into disulfide-linked polymers that fail to efficiently become insoluble. Instead of forming PBs, these polymers accumulate as very unusual threads that markedly enlarge the ER lumen, resembling amyloid-like fibers. Domain-swapping between the two γ-zeins indicates that the N-terminal region of 16-kD γ-zein has a dominant effect in preventing full insolubilization. Therefore, a newly evolved prolamin has lost the ability to form homotypic PBs, and has acquired a new function in the assembly of natural, heteropolymeric PBs.

Qualitative assessment of 'highly digestible' protein mutation in hard endosperm sorghum and its functional properties

Sorghum mutants with altered protein body structure have improved protein nutritional quality; however, practical methods to accurately track heritability of the trait are lacking. We evaluated suitability of the in vitro pepsin assay, and a new high-resolution field emission electron microscopy (FE-SEM) method to detect the mutation (HD) in hard-endosperm sorghum; and compared the physicochemical properties of experimental HD sorghums to wild type (LD) lines. FE-SEM reliably resolved sorghum protein body structure, allowing for qualitative classification of sorghum as HD or LD. The pepsin assay was less reliable, with significant variations across environments. Nevertheless, HD lines averaged higher protein digestibility (69.4% raw, 57.6% cooked) than LD lines (61.7% raw, 45.6% cooked). The HD lines also had better water solubility and starch pasting profiles than LD lines. FE-SEM, but not pepsin assay, reliably detects HD nutation in sorghum. The HD trait may improve food-use functionality of sorghum.

A Comparative Study of Selected Physical and Biochemical Traits of Wild-Type and Transgenic Sorghum to Reveal Differences Relevant to Grain Quality

Transgenic sorghum featuring RNAi suppression of certain kafirins was developed recently, to address the problem of poor protein digestibility in the grain. However, it was not firmly established if other important quality parameters were adversely affected by this genetic intervention. In the present study several quality parameters were investigated by surveying several important physical and biochemical grain traits. Important differences in grain weight, density and endosperm texture were found that serve to differentiate the transgenic grains from their wild-type counterpart. In addition, ultrastructural analysis of the protein bodies revealed a changed morphology that is indicative of the effect of suppressed kafirins. Importantly, lysine was found to be significantly increased in one of the transgenic lines in comparison to wild-type; while no significant changes in anti-nutritional factors could be detected. The results have been insightful for demonstrating some of the corollary changes in transgenic sorghum grain, that emerge from imposed kafirin suppression.

Nutrient content and nutrient availability of sorghum wet distiller's grain in comparison with the parental grain for ruminants

BACKGROUND

The present study aimed to compare wet sorghum distiller's grain (WSDG) with sorghum grain (SG) in terms of: (i) chemical composition; (ii) in situ rumen degradation kinetics of organic matter (OM) and neutral detergent fiber (NDF); (iii) crude protein (CP) sub-fractions; (iv) in situ disappearance at 12 and 48 h; and (v) energy values. The WSDG intestinal digestibility (ID) of undegradable crude protein (UCP) was compared to soybean meal (SBM).

RESULTS

Compared to SG, WSDG exhibited: (i) lower (P < 0.01) dry matter and non-fiber carbohydrate content, whereas the other chemical components were higher (P < 0.01); (ii) higher (P < 0.01) degradation rates of OM and NDF and lower (P < 0.01) degradable fraction of OM and NDF; (iii) lower (P < 0.05) contents of CP sub-fractions A, B1 and B2, and higher (P < 0.05) contents of B3 and C; (iv) lower (P < 0.05) protein disappearance at 12 and 48 h and higher UCP; and (v) lower (P < 0.05) energy content. The ID of UCP for WSDG was lower (P < 0.05) compared to SBM.

CONCLUSION

The WSDG as a supplement provides a good source of energy. To enable its use as a protein supplement, further studies should be performed. © 2016 Society of Chemical Industry.

Optimizing Prednisolone Loading into Distiller's Dried Grain Kafirin Microparticles, and In vitro Release for Oral Delivery

Kafirin microparticles have potential as colon-targeted delivery systems because of their ability to protect encapsulated material from digestive processes of the upper gastrointestinal tract (GIT). The aim was to optimize prednisolone loading into kafirin microparticles, and investigate their potential as an oral delivery system. Response surface methodology (RSM) was used to predict the optimal formulation of prednisolone loaded microparticles. Prednisolone release from the microparticles was measured in simulated conditions of the GIT. The RSM models were inadequate for predicting the relationship between starting quantities of kafirin and prednisolone, and prednisolone loading into microparticles. Compared to prednisolone released in the simulated gastric and small intestinal conditions, no additional drug release was observed in simulated colonic conditions. Hence, more insight into factors affecting drug loading into kafirin microparticles is required to improve the robustness of the RSM model. This present method of formulating prednisolone-loaded kafirin microparticles is unlikely to offer clinical benefits over commercially available dosage forms. Nevertheless, the overall amount of prednisolone released from the kafirin microparticles in conditions simulating the human GIT demonstrates their ability to prevent the release of entrapped core material. Further work developing the formulation methods may result in a delivery system that targets the lower GIT.

Mechanisms of starch digestion by α-amylase-Structural basis for kinetic properties

Recent studies of the mechanisms determining the rate and extent of starch digestion by α-amylase are reviewed in the light of current widely-used classifications for (a) the proportions of rapidly-digestible (RDS), slowly-digestible (SDS), and resistant starch (RS) based on in vitro digestibility, and (b) the types of resistant starch (RS 1,2,3,4…) based on physical and/or chemical form. Based on methodological advances and new mechanistic insights, it is proposed that both classification systems should be modified. Kinetic analysis of digestion profiles provides a robust set of parameters that should replace the classification of starch as a combination of RDS, SDS, and RS from a single enzyme digestion experiment. This should involve determination of the minimum number of kinetic processes needed to describe the full digestion profile, together with the proportion of starch involved in each process, and the kinetic properties of each process. The current classification of resistant starch types as RS1,2,3,4 should be replaced by one which recognizes the essential kinetic nature of RS (enzyme digestion rate vs. small intestinal passage rate), and that there are two fundamental origins for resistance based on (i) rate-determining access/binding of enzyme to substrate and (ii) rate-determining conversion of substrate to product once bound.

Sorghum (Sorghum bicolor L.): Nutrients, bioactive compounds, and potential impact on human health

Sorghum is the fifth most produced cereal in the world and is a source of nutrients and bioactive compounds for the human diet. We summarize the recent findings concerning the nutrients and bioactive compounds of sorghum and its potential impact on human health, analyzing the limitations and positive points of the studies and proposing directions for future research. Sorghum is basically composed of starch, which is more slowly digested than that of other cereals, has low digestibility proteins and unsaturated lipids, and is a source of some minerals and vitamins. Furthermore, most sorghum varieties are rich in phenolic compounds, especially 3-deoxyanthocyanidins and tannins. The results obtained in vitro and in animals have shown that phenolics compounds and fat soluble compounds (polycosanols) isolated from sorghum benefit the gut microbiota and parameters related to obesity, oxidative stress, inflammation, diabetes, dyslipidemia, cancer, and hypertension. The effects of whole sorghum and its fractions on human health need to be evaluated. In conclusion, sorghum is a source of nutrients and bioactive compounds, especially 3-deoxyanthocyanidins, tannins, and polycosanols, which beneficially modulate, in vitro and in animals, parameters related to noncommunicable diseases. Studies should be conducted to evaluate the effects of different processing on protein and starch digestibility of sorghum as well as on the profile and bioavailability of its bioactive compounds, especially 3-deoxyanthocyanidins and tannins. Furthermore, the benefits resulting from the interaction of bioactive compounds in sorghum and human microbiota should be studied.

Physicochemical properties of kafirin protein and its applications as building blocks of functional delivery systems

The unique physicochemical properties of kafirin highlight its potential as an attractive resource for gluten-free products and building blocks for functional delivery systems.

Cereal Crop Proteomics: Systemic Analysis of Crop Drought Stress Responses Towards Marker-Assisted Selection Breeding

Sustainable crop production is the major challenge in the current global climate change scenario. Drought stress is one of the most critical abiotic factors which negatively impact crop productivity. In recent years, knowledge about molecular regulation has been generated to understand drought stress responses. For example, information obtained by transcriptome analysis has enhanced our knowledge and facilitated the identification of candidate genes which can be utilized for plant breeding. On the other hand, it becomes more and more evident that the translational and post-translational machinery plays a major role in stress adaptation, especially for immediate molecular processes during stress adaptation. Therefore, it is essential to measure protein levels and post-translational protein modifications to reveal information about stress inducible signal perception and transduction, translational activity and induced protein levels. This information cannot be revealed by genomic or transcriptomic analysis. Eventually, these processes will provide more direct insight into stress perception then genetic markers and might build a complementary basis for future marker-assisted selection of drought resistance. In this review, we survey the role of proteomic studies to illustrate their applications in crop stress adaptation analysis with respect to productivity. Cereal crops such as wheat, rice, maize, barley, sorghum and pearl millet are discussed in detail. We provide a comprehensive and comparative overview of all detected protein changes involved in drought stress in these crops and have summarized existing knowledge into a proposed scheme of drought response. Based on a recent proteome study of pearl millet under drought stress we compare our findings with wheat proteomes and another recent study which defined genetic marker in pearl millet.

A new allele of γ-kafirin gene coding for a protein with high lysine content in Mexican white sorghum germplasm

BACKGROUND

Low protein digestibility and lysine content of white sorghum grain limit its use as a foodstuff. The increase in γ-kafirin cross-linking, has an important role in the reduction of protein digestibility. The objective of this study was to characterize the γ-kafirin gene in 12 Mexican tannin-free white sorghum genotypes and its relationship with protein digestibility and lysine content.

RESULTS

Two alleles of γ-kafirin gene were identified: alleles 1 and 7. The predicted amino acid sequence of allele 7 showed seven point mutations; six were silent, and one missense (C235G), causing the substitution P79A in the deduced amino acid sequence. In silico analysis showed that γ-kafirin codified by allele 1 has five α-helixes without disulfide bonds, while γ-kafirin coding by allele 7 has four α-helixes and three disulfide bonds. Genotypes with allele 7 had higher lysine content than those with allele 1, showing no differences in the kafirin electrophoretic profile, neither a correlation with the protein content nor the in vitro pepsin digestibility.

CONCLUSIONS

Mexican tannin-free white sorghum genotypes showed two γ-kafirin alleles, 1 and 7. Allele 7 was associated with higher lysine content; in silico analysis showed that the substitution of P79A in this allele could modify γ-kafirin secondary structure. © 2015 Society of Chemical Industry.

Protein structural changes during processing of vegetable feed ingredients used in swine diets: implications for nutritional value

Protein structure influences the accessibility of enzymes for digestion. The proportion of intramolecular β-sheets in the secondary structure of native proteins has been related to a decrease in protein digestibility. Changes to proteins that can be considered positive (for example, denaturation and random coil formation) or negative (for example, aggregation and Maillard reactions) for protein digestibility can occur simultaneously during processing. The final result of these changes on digestibility seems to be a counterbalance of the occurrence of each phenomenon. Occurrence of each phenomenon depends on the conditions applied, but also on the source and type of the protein that is processed. The correlation between denaturation enthalpy after processing and protein digestibility seems to be dependent on the protein source. Heat seems to be the processing parameter with the largest influence on changes in the structure of proteins. The effect of moisture is usually limited to the simultaneous application of heat, but increasing level of moisture during processing usually increases structural changes in proteins. The effect of shear on protein structure is commonly studied using extrusion, although the multifactorial essence of this technology does not allow disentanglement of the separate effects of each processing parameter (for example, heat, shear, moisture). Although most of the available literature on the processing of feed ingredients reports effects on protein digestibility, the mechanisms that explain these effects are usually lacking. Clarifying these mechanisms could aid in the prediction of the nutritional consequences of processing conditions.

In vitro starch digestibility and in vivo glycemic response of foxtail millet and its products

Foxtail millet, as a leading variety in arid and semi-arid areas of Asia and Africa, can provide broad potential benefits to human health.

Controlled Release from Zein Matrices: Interplay of Drug Hydrophobicity and pH

Purpose

In earlier studies, the corn protein zein is found to be suitable as a sustained release agent, yet the range of drugs for which zein has been studied remains small. Here, zein is used as a sole excipient for drugs differing in hydrophobicity and isoelectric point: indomethacin, paracetamol and ranitidine.

Methods

Caplets were prepared by hot-melt extrusion (HME) and injection moulding (IM). Each of the three model drugs were tested on two drug loadings in various dissolution media. The physical state of the drug, microstructure and hydration behaviour were investigated to build up understanding for the release behaviour from a zein based matrix for drug delivery.

Results

Drug crystallinity of the caplets increases with drug hydrophobicity. For ranitidine and indomethacin, swelling rates, swelling capacity and release rates were pH dependent as a consequence of the presence of charged groups on the drug molecules. Both hydration rates and release rates could be approached by existing models.

Conclusion

The drug state and pH dependant electrostatic interactions are hypothesised to influence release kinetics. Both factors can potentially be used to influence release kinetics release, thereby broadening the horizon for zein as a tuneable release agent.

Electronic supplementary material

The online version of this article (doi:10.1007/s11095-015-1818-8) contains supplementary material, which is available to authorized users.

Influence of Sorghum Kafirin on Serum Lipid Profile and Antioxidant Activity in Hyperlipidemic Rats (In Vitro and In Vivo Studies)

The aim of this study was to compare in vitro the antioxidant potential of sorghum kafirin and sorghum flour and their influence on lipids and antioxidant capacity in rats. The antioxidant activity in sorghum kafirin extract measured by the DPPH and TEAC methods was increased 30 and 65 times, respectively, compared to that of its counterpart, sorghum flour. According to electrophoresis assay, the kafirins tert-butanol extract showed a high proportion of α-kafirin monomers, and its amino acid composition revealed higher hydrophobic amino acid content such as alanine, isoleucine, leucine, tyrosine and phenylalanine than sorghum flour extract. Diets supplemented with sorghum kafirin extract have improved lipid metabolism and increased the serum antioxidant potential (67%) especially in rats fed with added cholesterol. The bioactive peptides generated from kafirin in vivo hydrolysis appear to be associated with the positive effect on serum lipids and antioxidant activity. According to these results, sorghum kafirin extract at the levels used in this study apparently could be used for prevention of atherosclerosis and other chronic diseases.

Structure, morphology, and assembly behavior of kafirin

Prolamins from grains have attracted intensive attention in recent years due to their potential in satisfying the demand for environmentally friendly (biodegradable), abundantly available (sustainable), and cost-effective biomaterials. However, for kafirin, the prolamin from sorghum, its composition, structure, morphology, and self-assembly behaviors have not been fully characterized. In this paper, kafirin was extracted from the whole sorghum grain and found to contain 68, 14, 6, and 12% of α-, β-, and γ-fractions and cross-linked kafirin, respectively. Freeze-dried kafirin contained ∼49% α-helix in the solid state. When dissolved in 65% (v/v) isopropanol, 60% (v/v) tert-butanol, and 85% (v/v) ethanol aqueous solvents, the relative α-helix content in kafirin increased with the decrease of solvent polarity. Structural analysis using small-angle X-ray scattering (SAXS) indicated that kafirin (2 mg/mL) took stretched and extended conformations with dimensions of 118 × 15 × 15 and 100 × 11 × 11 Å in 60% tert-butanol and 65% isopropanol, respectively. More elongated conformation of individual kafirin with high-order assembly was observed in 85% ethanol. Protein aggregation occurred as protein concentration increased in its good solvent. The morphology of kafirin assemblies captured by atomic force microscopy (AFM) revealed that kafirin protein took uniform particle morphology at low concentration, and disk-like or rod-like structures resulting from solvent evaporation induced particle interactions emerged at high concentrations. These results suggest that both protein concentration and solvent polarity can effectively regulate kafirin assemblies from thick rod-like to slim rod-like structures, a convenient way to tune the fibrillation of prolamin-based biomaterials.

Preparation andIn VitroRelease of Drug-Loaded Microparticles for Oral Delivery Using Wholegrain Sorghum Kafirin Protein

Kafirin microparticles have been proposed as an oral nutraceutical and drug delivery system. This study investigates microparticles formed with kafirin extracted from white and raw versus cooked red sorghum grains as an oral delivery system. Targeted delivery to the colon would be beneficial for medication such as prednisolone, which is used in the management of inflammatory bowel disease. Therefore, prednisolone was loaded into microparticles of kafirin from the different sources using phase separation. Differences were observed in the protein content,in vitroprotein digestibility, and protein electrophoretic profile of the various sources of sorghum grains, kafirin extracts, and kafirin microparticles. For all of the formulations, the majority of the loaded prednisolone was not released inin vitroconditions simulating the upper gastrointestinal tract, indicating that most of the encapsulated drug could reach the target area of the lower gastrointestinal tract. This suggests that these kafirin microparticles may have potential as a colon-targeted nutraceutical and drug delivery system.