Corn Protein Research Articles

Effect of substituting fishmeal with corn protein concentrate on growth performance, nutrient utilization and skin coloration in red hybrid tilapia, Oreochromis sp.

Effect of substituting fishmeal with corn protein concentrate on growth performance, nutrient utilization and skin coloration in red hybrid tilapia, <i>Oreochromis</i> sp.

Bioadhesive Food Protein Nanoparticles as Pediatric Oral Drug Delivery System.

The goal of this study was to develop bioadhesive food protein nanoparticles using zein (Z), a hydrophobic corn protein, as the core and whey protein (WP) as the shell for oral pediatric drug delivery applications. Lopinavir (LPV), an antiretroviral drug, and fenretinide, an investigational anticancer agent, were used as model drugs in the study. The particle size of ZWP nanoparticles was in the range of 200-250 nm, and the drug encapsulation efficiency was >70%. The nanoparticles showed sustained drug release in simulated gastrointestinal fluids. ZWP nanoparticles enhanced the permeability of LPV and fenretinide across Caco-2 cell monolayers. In both ex vivo and in vivo studies, ZWP nanoparticles were found to be strongly bioadhesive. ZWP nanoparticles enhanced the oral bioavailability of LPV and fenretinide by 4 and 7-fold, respectively. ZWP nanoparticles also significantly increased the half-life of both drugs. The nanoparticles did not show any immunogenicity in mice. Overall, the study demonstrates the feasibility of developing safe and effective food protein-based nanoparticles for pediatric oral drug delivery.

Neem oil based nanopesticide as an environmentally-friendly formulation for applications in sustainable agriculture: An ecotoxicological perspective

Sustainable agriculture encourages practices that present low risks to the environment and human health. To this end, zein (corn protein) can be used to develop nanocarrier systems capable of improving the physicochemical properties of biopesticides, reducing their possible toxicity. Neem oil extracted from the Azadirachta indica tree contains many active ingredients including azadirachtin, which is the active ingredient in multiple commercially available biopesticides. In this study, we describe the preparation and characterization of neem oil-loaded zein nanoparticles, together with evaluation of their toxicity towards nontarget organisms, using Allium cepa, soil nitrogen cycle microbiota, and Caenorhabditis elegans aiming to achieve the safer by design strategy. The spherical nanoparticles showed an average diameter of 278 ± 61.5 nm and a good stability during the experiments. In the toxicity assays with A. cepa, the neem oil-loaded zein nanoparticles mitigated the increase in the DNA relative damage index caused by the neem oil. Molecular genetic analysis of the soil nitrogen cycle microbiota revealed that neem oil-loaded zein nanoparticles did not change the number of genes which encode nitrogen-fixing enzymes and denitrifying enzymes. In C. elegans, the neem oil-loaded zein nanoparticles had no toxic effect, while neem oil interfered with pharyngeal pumping and GST-4 protein expression. These neem oil-loaded zein nanoparticles showed promising results in the toxicity studies, opening perspectives for its use in crop protection in organic agriculture.

Nitrogen Use Efficiency and Grain Protein of Corn as Affected by Applying Different N Levels

Nitrogen use efficiency (NUE) is one of the most important physiological traits related to low N tolerance. The present investigation was carried out during 2016 and 2017 seasons at the Agricultural Research and Experiment Station, Faculty of Agriculture, Cairo University, Giza, Egypt. The objectives were to study the effect of low N level on NUE, yield and grain composition as well as to determine the relationship between physiological traits (N accumulated in grain, Ng; NUE and grain produced per unit of grain N, Gw/Ng) and grain yield/plant (Gw). Two single cross hybrids were evaluated under three N levels, namely low N level (216kg N/ha), control (288kg N/ha) and high N level (360kg N/ha). Therefore, the amounts of applied nitrogen in the soil were 3.75, 5.0 and 6.25g/plant under low N, medium N (control) and high N, respectively. A split-plot design in a randomized complete block arrangement was used with four replications. The percent change relative to control showed that high N level caused a significant increase in grain yield/plant, grain yield/ha, kernels/row, ear length, N% in grain, Ng and grain protein % by 13.8, 14.53, 9.12, 6.99, 8.25, 22.85 and 7.2%, respectively. On the other hand, low N level caused a significant increase in NUE by 27.53% and Gw/Ng by 3.70%. Results of the simple regression analyses revealed that the superior traits in their contributions to Gw were NUE where R2 values were 0.99, 0.98 and 0.96 along with Ng where R2 values were 0.95, 0.66 and 0.94 under low N, medium N and high N, respectively.

Edible water barrier films prepared from aqueous dispersions of zein nanoparticles

Zein, a corn protein, is often used for preparing edible films and coatings. Since zein is insoluble in water, zein films and coatings are usually prepared by spraying or casting its aqueous ethanol solutions to a contact surface (Zsol films). However, the use of organic solvents in many food applications is unwanted. In this work, aqueous dispersions of zein nanoparticles were prepared by antisolvent precipitation from 90% v/v aqueous ethanol zein solutions. Zein films were then prepared by casting the dispersions in silicone molds and air–drying at 50 °C (Zdis films). The obtained films were characterized for morphology, FTIR analysis, mechanical, water barrier and optical properties, and were benchmarked against Zsol films. It was found that continuous zein films can be prepared out of aqueous dispersions of zein nanoparticles. Zdis films proved to have grainy morphology and higher surface roughness when compared to Zsol. Surface roughness of Zdis films was decreased when plasticizer was added. Water barrier properties of Zdis films were found to be comparable to Zsol films. No differences in mechanical properties were found between Zsol and Zdis film. Size of zein particles influenced morphology and optical properties of zein dispersion films.

Using high protein distiller's dried grain product to replace corn protein concentrate and fishmeal in practical diets for the Pacific white shrimp Litopenaeus vannamei

An 8‐week growth trial was conducted to evaluate the use of a high protein distiller's dried grain (HPDDG, NexPro®, Flint Hills Resources, LP, Wichita, KS) on the growth performance of juvenile Pacific white shrimp Litopenaeus vannamei. In the growth trial, graded levels of HPDDG (0.00, 10.00, 15.00, and 20.00%) were used to replace corn protein concentrate (CPC: 12.60, 6.30, 3.15, and 0.00%) or fishmeal (FM: 17.40, 9.79, 6.00, and 2.21%). A commercially produced open‐feed formulation was also included in the trial as a reference. Each diet was randomly assigned to four replicate groups of 30 shrimp stocked in 0.8 m3 culture tanks. Under green water conditions, in the presence of natural foods, the results indicated that growth performance and feed conversion ratio were not statistically influenced by increasing levels of HPDDG when used to replace CPC. The FM replacement series trial results showed that shrimp fed a diet with 20% HPDDG exhibited significantly decreased trend of biomass. Results of this study demonstrate that HPDDG is a good protein source, and 20% HPDDG can be used to replace CPC in shrimp diets, or up to 15% when replacing FM.

Anti-cancer targets of formononetin and molecular mechanisms in osteosarcoma: Findings of bioinformatic and experimental assays.

In current study, a bioinformatic‐based network pharmacology was used to identify the osteosarcoma (OGS)‐pathological targets and formononetin (FN)‐treated targets before the main core predictive biotargets were screened. In addition, all core targets were selected through a number of bioinformatic databases, followed by identification of predominant biological processes and signalling pathways of FN anti‐OGS. Further, top three core targets of FN anti‐OGS were determined as oestrogen receptor 1 (ESR1), tumour protein p53 (TP53), receptor tyrosine‐protein kinase erbB‐2 (ERBB2) respectively. In clinical biochemical data, the plasma samples of OGS showed the increased trends of alkaline phosphatase, triglyceride, blood glucose, lactate dehydrogenase, high‐sensitive C‐reactive protein and some immune cell counts when referenced to medical criteria. In clinicopathological examination, histological OGS sections resulted in increased positive cell counts of neoplastic ESR1, TP53, ERBB2. To further validate these corn proteins in experimental study in vivo, FN‐treated tumour‐bearing nude mice showed intracellular reductions of ESR1, TP53, ERBB2 positive expressions, accompanied with visibly reduced tumour weights. Collectively, our bioinformatic and experimental findings disclosed main core targets, biological processes and signalling pathways of FN anti‐OGS. Interestingly, the top core targets were representatively validated following FN treatment in vivo. Therefore, we reasoned that these predictive targets might be the potential biomarkers for screening and treating osteosarcoma.

Partial or total replacement of fish meal in the diets of Florida pompano Trachinotus carolinus

Two trials were conducted to evaluate the efficacy of commercial enzyme-treated soy (ESBM) to replace the use of fish meal (FM) in practical diets for Florida pompano Trachinotus carolinus. The reference diet which has been run in numerous trials for Florida pompano was formulated using 150, 466 and 80 g/kg of FM, soybean meal and corn protein concentrate respectively. In trial 1, test diets were produced by replacing FM with 30.8, 61.4 and 92.1 g/kg of ESBM. In trial 2, test diets were produced by replacing FM with 28.9, 89.8, 120.1 g/kg of ESBM. Triplicate group of fish in trial 1 (mean weight = 13.05 ± 0.34 g) and trial 2 (mean weight = 18.45 ± 0.49 g) was fed these diets to apparent satiety for 8 weeks. Growth performance was affected as the dietary FM was replaced with ESBM. In trial 1, final weight (FW), percentage weight gain and thermal growth coefficient were lower in 6 g/kg of FM compared to 15 g/kg, while feed conversion ratio significantly higher in fish fed the lowest inclusion level of FM (6 g/kg). In trial 2, FW was significantly lower when FM completely replaced by ESBM and no significant differences in other growth parameters. In all trials, no significant differences were observed in terms of crude protein, moisture, fat, crude fibre, dry matter and ash content of the fish. No significant differences in serum levels of total protein, albumin, alkaline phosphatase, alanine transaminase, aspartate transaminase, glucose and bile acids were observed in either trial. However, in trial 1, serum cholesterol level was higher in fish fed 150 g/kg FM compared to other dietary treatments. The histomorphological structure of liver and distal intestine was slightly affected by lower inclusion level of FM. Overall, there was a decreasing trend in pompano growth performance as the inclusion of FM decreased. All parameters indicated that ESBM could be used to reduce the inclusion of FM from 150 to 90 g/kg.

Foaming properties and air-water interfacial behavior of corn protein hydrolyzate-tannic acid complexes.

The complexation of corn protein hydrolyzate (CPH) with tannic acid (TA) was utilized to improve the foaming properties of CPH itself, and the air-water interfacial behavior of CPH-TA complex was also investigated. The results showed that the surface hydrophobicity of pure CPH was significantly decreased in bulk solution after the complexation with TA. Compared with pure CPH, the foams stabilized by CPH-TA complex showed higher interfacial thickness between the bubbles, which well explained the better long term stability of the corresponding foams. Therefore, the complexation maintained the good foaming capacity of CPH itself, but considerably increased its foam stability. Moreover, the air-water interfacial behavior study demonstrated that the complexation slightly decreased the interfacial activity of CPH itself, but considerably increased its interfacial viscoelasticity, suggesting more stable of the air-water interface stabilized by CPH-TA complex compared with that stabilized by CPH alone. These findings indicated that foaming properties of the surface active components were closely related with its air-water interfacial behavior. The study suggested that CPH-TA complex could be used as a stabilizer in constructing the peptides-based foams.

Spatial distribution and control levels of Anastrepha spp. (Diptera: Tephritidae) in guava orchards.

This study aimed to know the patterns of spatial distribution of Anastrepha spp. and establish a criterion for determining the appropriate time for pest control. For this, 90 McPhail traps were used as Sampling Units (SU) divided into three commercial orchards of Novo Milênio guava with a total area of 14 ha. Traps were interspersed between the rows of plants, systematically in the orchards, hung and baited with 5% hydrolyzed corn protein with weekly collections. We caught 8,170 Anastrepha spp. in 840 SU. The mean infestation index was compared to the three types of distribution: random, uniform, aggregate, and fit by the theoretical frequency distributions of Poisson, negative binomial and positive binomial. The populations of Anastrepha presented aggregate distribution according to the mean variance method (I), tested by distance from randomness. The economic damage risk potential of Anastrepha spp. was associated with the aggregate distribution behavior. The most appropriate moment for the use of control techniques is when reaching 20 flies by the negative binomial. On the other hand, number of fruit fly adults per trap per day (FTD), underestimates population index, which will allow population growth, leading to risk of crop production loss.

Fruit flies (Diptera: Tephritidae) in commercial mango orchards in a semiarid region of Brazil

Abstract Fruit flies (Diptera: Tephritidae) are important mango (Mangifera indica L.) pests in several parts of the world. Therefore, the main objective of this study was to know the species of fruit flies associated with commercial mango orchards in a semiarid region of Rio Grande do Norte state, Brazil; report the species of quarantine importance; discuss the influence of the semiarid environment on the distribution of the species and verify their faunistic indices. The study was carried out between July 2011 and June 2014 in ten commercial orchards of mango cultivar Tommy Atkins in the semiarid region of the state of Rio Grande do Norte, Northeastern Brazil. Fruit flies were captured in McPhail traps baited with 5% hydrolyzed corn protein (Bio Anastrepha®). Mangoes fruits were also collected. Faunistic analysis was performed to characterize the populations. Eight fruit fly species (Anastrepha spp. and C. capitata) were captured. The species C. capitata had the highest geographic distribution and was the only one to infest mangoes. The faunistic analysis showed that most of the orchards had low species richness and that C. capitata was the most frequent and predominant species.

A Comprehensive Review of Corn Protein-derived Bioactive Peptides: Production, Characterization, Bioactivities, and Transport Pathways.

Bioactive peptides are specific peptide fragments that positively exert various functional and biological activities and ultimately influence health. Corn protein are potential precursor proteins for bioactive peptides. This review encompasses the studies reported to date on the production, isolation, purification, and characterization technologies of bioactive corn peptides (CPs), with particular attention being devoted to these peptides' different health effects, including antioxidant, antihypertensive, hepatoprotective, alcohol-metabolism-facilitating, anti-inflammatory, anticancer, antimicrobial, and dipeptidyl peptidase IV (DPP-IV) inhibitory activities. The review also describes studies examining the potential mechanisms believed to be involved in these bioactivities, and the possible absorption and transport pathways of CPs are summarized.

Functions and Applications of Bioactive Peptides From Corn Gluten Meal.

Corn protein has been identified as an important source of bioactive peptides. Such peptides can be released during hydrolysis induced by proteolytic enzymes or microbial fermentation. Corn peptides have been found to exhibit different functions in vitro and in vivo such as antihypertensive, hepatoprotective, anti-obesity, antimicrobial, antioxidative, mineral-binding and accelerating alcohol metabolism. To date, 22 sequences of bioactive corn peptides have already been identified. There is an increasing commercial interest in the production of corn peptides with the purpose of using them as active ingredients, which may find use in the treatment of liver injury, hypertension, dental carries, oxidative stress, mineral malabsorption and obesity. These bioactive peptides may be used in formulation of functional foods, nutraceuticals, and natural drugs because of their health benefit effects.

Protein content and amino acid composition of commercially available plant-based protein isolates

The postprandial rise in essential amino acid (EAA) concentrations modulates the increase in muscle protein synthesis rates after protein ingestion. The EAA content and AA composition of the dietary protein source contribute to the differential muscle protein synthetic response to the ingestion of different proteins. Lower EAA contents and specific lack of sufficient leucine, lysine, and/or methionine may be responsible for the lower anabolic capacity of plant-based compared with animal-based proteins. We compared EAA contents and AA composition of a large selection of plant-based protein sources with animal-based proteins and human skeletal muscle protein. AA composition of oat, lupin, wheat, hemp, microalgae, soy, brown rice, pea, corn, potato, milk, whey, caseinate, casein, egg, and human skeletal muscle protein were assessed using UPLC–MS/MS. EAA contents of plant-based protein isolates such as oat (21%), lupin (21%), and wheat (22%) were lower than animal-based proteins (whey 43%, milk 39%, casein 34%, and egg 32%) and muscle protein (38%). AA profiles largely differed among plant-based proteins with leucine contents ranging from 5.1% for hemp to 13.5% for corn protein, compared to 9.0% for milk, 7.0% for egg, and 7.6% for muscle protein. Methionine and lysine were typically lower in plant-based proteins (1.0 ± 0.3 and 3.6 ± 0.6%) compared with animal-based proteins (2.5 ± 0.1 and 7.0 ± 0.6%) and muscle protein (2.0 and 7.8%, respectively). In conclusion, there are large differences in EAA contents and AA composition between various plant-based protein isolates. Combinations of various plant-based protein isolates or blends of animal and plant-based proteins can provide protein characteristics that closely reflect the typical characteristics of animal-based proteins.

Stability and antioxidant activities of corn protein hydrolysates under simulated gastrointestinal digestion

AbstractBackground and objectivesBioactive peptides are expected to be ingested orally; it is important to study the effect of simulated gastrointestinal (GI) digestion on the stability and antioxidant activity of these peptides.FindingsAfter simulated GI digestion, degree of hydrolysis of corn protein hydrolysates (CPH) significantly increased from 22.7% to 39.4% while 77.5% peptides were still retained. Compared to the undigested CPH, the final CPH digests exhibited excellent antioxidant activity, including 1,1‐diphenyl‐2‐picrylhydrazyl radical 2,2‐diphenyl‐1‐(2,4,6‐trinitrophenyl) hydrazyl radical scavenging activity (12.9% increase), hydroxyl radical scavenging activity (4.1% increase), and reducing power (50.9% increase), but lower inhibition rate of linoleic acid peroxidation (41.5% decrease). The free amino acids including Pro, Asp, and Glu maintained at a low proportion during the entire course of digestion. Two GI‐resistant antioxidant peptides (Tyr‐Pro‐Gln, 406.45 Da; Ala‐Tyr‐Leu, 365.43 Da) were purified with multistep chromatography and identified by UPLC‐ESI‐MS.ConclusionsThe CPH digests exhibited excellent antioxidant activity after simulated GI digestion. The results suggested that CPH obtained by alcalase digestion are potential functional foods or nutraceuticals due to their content of bioactive peptides.Significance and noveltySome peptides containing Pro, Asp, and Glu had a strong ability to resist digestion. Two novel antioxidant peptides have been purified and identified from the CPH digests.

Extraction and identification of the chyme proteins in the digestive tract of growing pigs.

This study aimed to explore the rule of degradation of dietary proteins by identifying chyme proteins in different segments of the digestive tract of growing pigs, using proteomics techniques. Six growing pigs were fed a corn-soybean meal-based diet for 7 days. The feedstuff and chyme proteins were separately extracted and separated with SDS-PAGE. 2D LCMS/MS combined with protein database searching identified 1,513 proteins in different segments of the gastrointestinal tract, the number of identified exogenous proteins gradually decline from the stomach to colon, with large amounts in the duodenum to the large intestine. More corn proteins than soybean proteins were identified both in the feedstuff and chyme, and these were significantly decreased after digestion in the stomach. More membrane proteins than non-membrane proteins were identified in whole digestive tract. These results regarding the profiles of chyme proteins in different segments of the gastrointestinal tract would provide useful information for optimizing feed formula in pigs.

Fabrication and characterization of PCL/zein/gum arabic electrospun nanocomposite scaffold for skin tissue engineering

The main role of tissue engineering is to produce the artificial tissue for replacing the biological functions in tissue regeneration and wounds healing. The purpose of this research was to produce porous nanofiber scaffold by electrospinning to compensate deep skin damages. In order to simulate a scaffold similar to the natural extracellular matrix of the skin, a mixture of corn protein (Zein), polycaprolactone (PCL) and gum arabic (GA) was used with different concentrations and ratios. Zein and GA polymers were used as a protein and polysaccharide component of the scaffold and PCL polymer for elasticity, strength and time setting of scaffold degradability. For investigating morphology and scaffold compounds, scanning electron microscopy (SEM) and Fourier transform infrared techniques were used. Furthermore, mechanical properties, porosity, water absorption and degradability in phosphate buffered saline (PBS) were investigated. Antibacterial properties, cell adhesion and proliferation were also evaluated. SEM results showed that fabricated PCL/Zein/GA scaffolds had a porous structure with bimodal diameters distribution. PCL/Zein/GA scaffolds showed high hydrophilic properties, favorable porosity (about 80%) and tensile strength of 1.36–3 MPa with an elongation of 19.13–44.06% desirable for skin tissue engineering. SEM images of degraded specimens show that the scaffold retains its fibrous structure during its destruction. The results of bacterial culture indicated that the scaffold containing GA had antibacterial properties. Moreover, in vitro assays revealed favorable L929 cells proliferation compared to tissue culture polystyrene (control). Hence, the PCL/Zein/GA scaffold shows a good potential for application in skin tissue engineering.

Comparative effect of advanced soy products or corn protein concentrate with porcine meal on growth, body composition, and distal intestine histology of Florida pompano, Trachinotus carolinus

The present study was designed to investigate the effects of diets containing advanced soy products (enzyme‐treated soy and fermented soy) or corn protein concentrate (CPC) in combination with porcine meal (PM) to completely replace poultry byproduct meal (PBM) on growth performance, body composition, and distal intestine histology of Florida pompano, Trachinotus carolinus. Four experimental diets were formulated to be isonitrogenous and isolipidic, to contain 400 g/kg crude protein and 80 g/kg lipid. A reference diet (PBM diet [PBMD]) contained 150 g/kg PBM and 495 g/kg soybean meal (SBM), and three test diets were formulated replacing PBM with 15 g/kg of CPC (CPC diet [CPCD]) or replacing all SBM and PBM with 535 g/kg fermented soy (fermented soybean meal diet [FSBMD]) or 451.3 g/kg enzyme‐treated soy (enzyme‐treated soybean meal diet [ESBMD]). All three test diets were supplemented with 38 g/kg of PM. Diets were fed based on a percentage of bodyweight adjusted after sampling the fish every 2 weeks to triplicate groups of Florida pompano juveniles (mean weight 8.06 ± 0.22 g). After 8 weeks of feeding, fish fed CPCD and ESBMD performed equally well in terms of final body weight, thermal growth coefficient, and percentage weight gain in comparison to fish fed PBMD. In all cases, feeding FSBMD resulted in poor feed conversion and lower feed intake compared to other treatments. Protein retention efficiency, whole‐body proximate composition, phosphorus, sulfur, potassium, magnesium, calcium, sodium, and zinc contents were not significantly influenced by the dietary treatments. The results obtained in the present histological study showed no significant differences in the thickness of serous layer, muscular layer, and submucosal layer of the intestine among treatments. Fish fed CPCD showed a significant widening of the lamina propria with an increase of cellular infiltration and higher presence of goblet cells compared to other dietary treatment. Based on these results, 451 g/kg ESBM or combination of 150 g/kg of CPC and 495 g/kg SBM supplemented with 38 g/kg PM can be utilized to develop a practical diet for juvenile Florida pompano without impacting growth, nutritive parameters, and several distal intestine health parameters.

Flutamide-Loaded Zein Nanocapsule Hydrogel, a Promising Dermal Delivery System for Pilosebaceous Unit Disorders.

Zein is a naturally occurring corn protein having similarity to skin keratin. Owing to its hydrophobicity and biodegradability, zein nanocarriers are promising drug delivery vehicles for hydrophobic dermatological drugs. In this study, zein-based nanocapsules (ZNCs) were exploited for the first time as dermal delivery carriers for flutamide (FLT), an antiandrogen used for the management of pilosebasceous unit disorders. FLT-loaded ZNC of appropriate particle size and negative surface charge were prepared by nanoprecipitation method. The dermal permeation and skin retention of FLT from ZNCs were studied in comparison to corresponding nanoemulsion (NE) and hydroalcoholic drug solution (HA). ZNCs showed a significantly lower permeation flux compared to NE and HA while increasing the skin retention of FLT. Confocal laser scanning microscopy (CLSM) demonstrated the follicular localization of the fluorescently labeled NCs. The incorporation of NCs in chitosan gel or Carbomer® 934 gel was studied. Carbomer® gel increased the skin retention of FLT compared to chitosan gel. Accordingly, Carbomer® hydrogel embedding FLT-loaded ZNCs is a promising inexpensive, biocompatible dermal delivery nanocarrier for localized therapy of PSU disorders suitable for application on oily skin.

Changes in Corn Protein Content During Storage and Their Relationship with Dry Grind Ethanol Production

AbstractChanges in corn grain during storage can cause variations in dry grind ethanol yields. The first objective of this study was to determine the effects of postharvest storage on dry grind ethanol concentrations. Ethanol concentrations for corn stored under ambient and refrigerated conditions were measured every 4 weeks for 1 year. Ethanol concentrations had a decreasing trend for corn stored from 0 to 16 weeks and an increasing trend from week 16 to 24. These trends were similar for corn stored at refrigerated and ambient conditions. The effects of postharvest storage on soluble protein content and their relationship with ethanol concentration were also evaluated. Stored corn was sampled at weeks 0, 8, 16, 24, and 40. Soluble proteins were extracted using a sequential extraction procedure and expressed with respect to the total crude protein of corn, and the total values were not affected by storage temperature (ranging from −7 to 23°C). During 8 to 40 week storage at ambient and refrigerated temperature, the albumin content of corn decreased by 43.6% and 48.5% while the prolamin content increased by 37.9% and 43.0%, respectively. Ethanol yield at 72 hours of fermentation had no correlation with soluble protein content; however, ethanol yield at 24 hours correlated negatively with glutelin (r = −0.76) and positively with prolamin (r = +0.74) contents.