Adaptabilidad de granos de híbridos de maíz super dulce sh2 al procesamiento industrial. II Enlatado / Super sweet corn hybrid sh2 adaptability for industrial canning process

The super sweet corns Krispy king, Victor and 324 (sh2 hybrids) were evaluated to determine their adaptabilities to the industrial canning process as whole kernels. All these hybrids and Bonanza (control) were sown in San Joaquín (Carabobo, Venezuela), harvested and canned. After 110 days storage at room temperature they were analyzed to be compared physically, chemically and sensorially with Bonanza hybrid. Results did not show significant differences among most of the physical characteristics, except for percentage of broken kernels which was higher in 324 hybrid. Chemical parameters showed significant differences (P < 0.05) comparing each super sweet hybrid with Bonanza. The super sweet hybrids presented a higher sugar content and soluble solid of the brine than Bonanza, also a lower pH. The super sweet whole kernel presented a lower soluble solids content than Bonanza but they were not significant (Krispy king and 324). Appearance, odor and overall quality were the same for super sweet hybrids and Bonanza (su). Color, flavor and sweetness were better for 324 than all the other hybrids. Super sweet hybrids presented a very good adaptation to the canning process, having as an advantage that doesn't require sugar addition in the brine and a very good texture (firm and crispy).

[Suitability study for super sweet corn on the ears hybrids under refrigerated conditions evaluating chemicals microbiological and sensorial characteristics]. / Estudio de la estabilidad de las características químicas, microbiológicas y sensoriales de mazorcas refrigeradas de híbridos de maíz super dulce.

Krispy King, Víctor and 324, super sweet hybrids (sh2) were cultivated in San Joaquín, estado Carabobo, Venezuela. The scheme was stablished to produce refrigerated fresh ears to be commercialized. The chemistry, microbiology and sensorial characteristics were evaluated at 0; 7; 14; 21 and 28 days of storage. One hundred ears of each hybrid were picked at the ripe fresh stage and packed in polystyrene trays covered with polyethylene. The storage temperature was 4 degrees C +/- 1 degree C. The scheme used was well adapted, allowing a good stability of the ears until 28 days of storing. The plastic cover avoid the lost of humidity. The soluble solids, total sugars and pH went down during the storage. The acidity and the microorganisms increased as expected. The sensorial variables kept the same for Krispy king and Víctor, while the hybrid 324 shown the lowest humidity content, the highest count of microorganisms and the poorest sensorial quality.

[Characteristics of Canavalia proteins]. / Estudio de algunas características de las proteínas de Canavalia.

The purpose of this work was the isolation and characterization of grain protein from five Venezuelan Genotypes (U-02, Yaracuy, Valle De La Pascua, Originally Tovar) of Jack Bean (Canavalia ensiformis). The average protein content from these genotypes was 31.37%, it ranged between 28.44% and 33.05%. The protein isolation was performed by solubility extraction procedures, showed: 84.57% of albumins, globulins and non proteic nitrogen and 15.43% of alcohol insoluble reduced glutelin (AIG). The content of anti-nutritional factors (canavanine and hemagglutination title) found in protein fractions were respectively: Albumins 1.96%, +4; globulins 0.17%, +5 and AIG 0.22%, +1. It was observed that protein fractions of genotype Tovar had the lowest canavanine values (0.79%, 0.02% and 0.00% respectively). The globulins gave the highest in vitro protein digestibility (65.20%) followed by Albumins (58.90%) and AIG (37.28%).

[Electrophoretic study of albumins and globulins of 4 genotypes of Canavalia ensiformis]. / Estudio electroforético de las albúminas y globulinas de cuatro genotipos de Canavalia ensiformis.

Polyacrylamide gel electrophoresis (PAGE) and PAGE-SDS were used to study seed albumins and globulins of Canavalia ensiformis. In PAGE the concentration of acrylamide used in the upper gel was 4.0% with a pH of 6.7 and in the lower gel 7.5% and 10% of acrylamide were used with a pH of 8.9. In PAGE-SDS the concentration of acrylamide was 4.4% with a pH of 6.8 in the upper gel and 7.5% and 12.6% with a pH of 8.8 in the lower gel. The material used were the Venezuelan genotypes Tovar, Yaracuy, Original and U-02. The albumins and globulins were extracted with a 0.5 M NaCl solution and then separated by dialysis against water and lyophilized. These protein fractions represented 84.85% of the total amount of protein in seeds. The albumins were separated in PAGE with 7.5% acrylamide into five fractions and globulins into six, with similar electrophoretic patterns between genotypes. In a similar manner, the patterns obtained in PAGE with 10% acrylamide were the same for all genotypes, showing five bands for albumins and three bands for globulins. With PAGE-SDS containing 7.5% of acrylamide, albumins were separated into as many as eight components, and globulins into as many as seven bands with mobilities between 0.2981 and 0.9932, with different patterns for each genotype. Also the patterns PAGE-SDS at 12.6% of acrylamide were different for the genotypes, separating proteins into a greater number of bands. The albumins showed as many as twenty-one bands with mobilities between 0.2603 and 0.7398, and globulins as many as sixteen bands with mobilities between 0.2454 and 0.7390. The PAGE patterns of the genotypes analyzed did not show differences between them. However, with PAGE-SDS different electrophoretic patterns were obtained which varied in the number and intensity of the bands, making it possible to distinguish the genotypes studied. The molecular weight of the albumins varied between 76,000 and 12,000 daltons and of the globulins between 80,000 and 12,000 daltons.

[Chemical and nutritional characteristics from grains of five genotypes of Canavalia ensiformis]. / Características químicas y nutricionales del grano de cinco (5) genotipos de Canavalia ensiformis.

This study evaluated the raw meals from grains of five genotypes of Canavalia ensiformis, by means of the chemical composition, the presence of antinutritional factors (Canavanine and hemaglutination activity) and in vitro protein digestibility. The genotypes studied were: Original, Yaracuy, Tovar, Valle de la Pascua and U-02. The results of chemical composition, showed significance difference between them, except moisture content, found the following average values: Protein 31.37%, fiber: 8.10%, ash: 2.93% and moisture: 11.68%. The canavanine content of the genotypes was variable oscillating between 2.02 and 4.86%, the genotype U-02 presented the higher value, respect to the hemaglutination title changed between: +2 and +5. The in vitro protein digestibility of the raw meals showed significance differences between the genotype, it changed between 47.51% and 51.84%, these values were lower than the casein (97.3%).

[Extraction and characterization of zeins from kernels of 10 maize cultivars]. / Extracción y caracterización de las zeínas del grano de diez cultivares de maíz.

The study consisted in the extraction and characterization of zeins of Venezuelan maizes, according to their solubility and molecular properties. The cultivars analyzed were the hybrids Ceniap PB8, Tocoron 127, Arichuna, Obregón, Ceniap 3, Corocito 101 and the varieties Máquina del Ceniap, Venezuela-1 and Venezuela-1 Opaco-2. Zeins were extracted with 70% ethanol and fractionated by two methods: 95% ethanol and column filtration with Sephadex G-200. The molecular weight was determined by electrophoresis in a discontinuous polyacrilamide gel with sodium dodecyl sulfate (PAGE-SDS). The results demonstrated that zeins account for 36.57% of the total protein present in normal corn grain and 9.38% in Opaque-2 corn. Prolamines presented a soluble fraction in 95% ethanol (alpha zeins) which represented 33,12% of zeins and another insoluble (beta zeins) the 66.88%. In column fractionation, three fractions were obtained, two major A and C and another B in minor quantity, which varied in proportion between cultivars. Zeins which were reduced with 2-mercaptoethanol separated into two subunits with molecular weights of 21,300 and 24,300 daltons, whereas unreduced zeins presented large sized aggregates which remained at the origin and large numbers of bands (nine) whose molecular weights oscillated between 24,300 and 87,000 daltons. The electrophoretic patterns of normal maizes were similar, but differ from the pattern of the Opaque-2. In this maize, zeins reduced presented only the band with molecular weight 24,300 daltons and the unreduced zeins showed those with molecular weights of 87,000; 78,500; 48,500 and 24,300 daltons. Reduced alpha and beta are made up of the same basic components of zeins. Likewise unreduced alpha zeins are made up of the same polypeptides as unreduced zeins. The difference between Opaque-2 zeins and normal ones in that they contain more alpha zeins and less polypeptides of high molecular weight.

[Extraction and characterization of grain prolamins of 6 sorghum Sorghum bicolor L. Moench cultivars]. / Extracción y caracterización de las prolaminas del grano de seis cultivares de sorgo Sorghum bicolor L. Moench.

The purpose of this work was to isolate and characterize prolamines from grains of sorghum, by their solubility and molecular properties. One variety, Zaraza-1 (SV-V51), and five hybrids (Dekalb-55, Dekalb-64, Wac-5005, Pioneer-815B and Savanna-5) were used. The prolamines, called kafirins, were extracted with 70% isopropanol at 60 degrees C, and then fractionated by two methods: 95% ethanol and gel filtration with Sephadex G-200. The molecular weight was determined by electrophoresis in a discontinuous polyacrylamide gel with sodium dodecyl sulfate (PAGE-SDS). The alpha kafirin (soluble fraction in 95% ethanol), and 7.13% of the grain's total protein, and the beta kafirin represents 21.64% of kafirin (the insoluble fraction), represents 78.36% of the kafirin and 25.39% of total protein. Three fractions were obtained from the column fractionation, two important ones (A and C), and one (B) in a lesser amount. The proportion of these fractions varied between cultivars, so that in SV-V51, D-64 and Wac-5005, A is predominant, and in high tannin sorghum, C is the predominant one. Kafirins reduced with 2-mercaptoethanol were separated in four subunits with molecular weights of: 15,000, 21,300, 24,300 and 51,500 daltons. Unreduced kafirin showed a larger number of subunits (six) whose molecular weights were: 15,000, 24,300, 48,500, 69,000, 80,000 and 93,500 daltons. Reduced and kafirin showed the same number of subunits as those of nonfractioned kafirin reduced with 2-mercaptoethanol.

[Characterization of corn proteins of the cultivars Venezuela-1, Arichuna, Obregon and Venezuela-1 Opaque-2]. / Caracterización de las proteínas de los maíces Venezuela-1, Arichuna, Obregón y Venezuela-1 Opaco-2.

A study is presented on the protein composition of the Venezuelan corn cultivars Venezuela-1, Arichuna, Obregón and Venezuela-1 Opaque-2. The proteins were isolated and analyzed for their molecular weight and lysine and tryptophan content. Protein fractionation showed significant differences between normal corn cultivars and Opaque-2. The latter showed a low level of zein and a high content of alcohol-insoluble reduced glutelins (AIG), albumins and globulins in relation to the normal kernel. The relative increase of these protein fractions, rich in lysine and tryptophan, results in a higher concentration of these amino acids in the Opaque kernel, as revealed by the analysis of these compounds carried out in different cultivars. Electrophoretic analysis showed only small differences in the number and intensity of bands from the protein fractions of the maize cultivars under study.