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Isolated sorghum (Sorghum bicolor) storage proteins (kafirins) have been successfully used in the production of several bio-materials including adhesives, films, micro-particles, fibers, and biological scaffold material. Comparatively little research has been conducted on the use of isolated kafirins in food products or to produce bioactive peptides via hydrolysis for nutritional uses. To support such research, the aim of this study was to compare existing methods for bulk isolation of sorghum kafirins with the goal of identifying a solvent with the least toxicity that maintained a high extraction rate from food grade sorghum flour. A secondary goal was to characterize the kafirin isolates produced from various extraction methods to provide some information on their potential use in food products to guide future research in this area. Five different extraction methods were compared including 1) aqueous ethanol containing NaOH and sodium metabisulfite, 2) glacial acetic acid, 3) aqueous ethanol with sodium metabisulfite, 4) aqueous ethanol at acidic pH, and 5) alkaline pH alone. The protein contents of the kafirin isolates obtained by the five methods ranged from 49.76% to 56.83%. Kafirin isolates were characterized using reversed phase (RP)-high performance liquid chromatography (HPLC), which revealed substantial variability in the various kafirin patterns among the extraction methods tested. However, characterization of the kafirin isolates by size exclusion chromatography (SEC) did not show a high degree of variability among the methods tested. Likewise, analysis of the samples using sodium dodecyl sulphate - polyacrylamide gel electrophoresis (SDS-PAGE) showed essentially the same band profiles but with different band intensities among kafirin extraction methods. Surface hydrophobicity of the kafirin isolates varied considerably with isolates extracted with glacial acetic acid and aqueous ethanol plus sodium metabisulfite the most hydrophobic as indicated by hydrophobic dye binding.

A non classical approach to the logic synthesis of Boolean functions based on switching lattices is considered, for which deriving a feasible layout has not been previously studied. All switches controlled by the same literal must be connected together and to an input lead of the chip, and the layout of such connections must be realized in superimposed layers. Inter-layer connections are realized with vias, with the overall goal of minimizing the number of layers needed. The problem shows new interesting combinatorial and algorithmic aspects. Since the specific lattice cell where each switch is placed can be decided with a certain amount of freedom, and one literal among several may be assigned for controlling a switch, we first study a lattice rearrangement (Problem 1) and a literal assignment (Problem 2), to place in adjacent cells as many switches controlled by the same literal as possible. Then we study how to build a feasible layout of connections onto different layers using a minimum number of such layers (Problem 3). We prove that Problem 2 is NP-hard, and Problems 1 and 3 appear also intractable. Therefore we propose heuristic algorithms for the three phases that show an encouraging performance on a set of standard benchmarks.

A non classical approach to the logic synthesis of Boolean functions based on switching lattices is considered, for which deriving a feasible layout has not been previously studied. The problem presents new interesting combinatorial and algorithmic aspects. Our basic assumptions are that the positions of the switches in the lattice are fixed in the synthesis stage, and the layout for connecting the subsets of switches with the same input literal must be realized in superimposed planes through vias that take the same switch area. The overall goal is to minimize the number of layers needed. Since multiple choices of input literals are possible for each switch, we first study how to assign a single literal to each switch, to minimize the number of lattice portions of adjacent cells associated to the same literal (Problem 1). Then we study how to derive a feasible layout by building connections onto different layers, to minimize the number of layers (Problem 2). Problem 1 is NP-hard. Problem 2 seems to be also intractable, and exhibits limit instances that require an exceedingly number of layers or are even unsolvable. Heuristic algorithms are then developed for both problems and their encouraging performances are proved on a set of known benchmarks.

Grain sorghum [Sorghum bicolor (L.) Moench] is a gluten-free grain that is gaining attention as a food crop that can be used in the management of celiac disease. At present, sorghum is widely grown in many semiarid regions of the world. New food-grade sorghum cultivars are of particular interest in Mediterranean countries due to improved quality characteristics and gluten-free status of the grains. Until now very few studies have examined the grain yield (GYLD) and agronomic performance characteristics of food-grade sorghum hybrids in Italy. A 2 year study was conducted to evaluate the agronomic performance of eight food-grade sorghum hybrids representing different maturity classes in trials conducted in Southern Italy. The results showed wide variation in adaptation of these hybrids as measured by differences in GYLD (2.35-8.50 t ha(-1)) and other phenomorphological characteristics. Of particular interest was the fact that many of the early-flowering hybrids (e. g. SP-X303) performed better than the later-flowering hybrids (e. g. ArchX-02). These results demonstrated that flowering time of hybrid and crop cycle length are important factors to consider in selecting cultivars for production in the Mediterranean region.

Sorghum has been grown as a food crop for many centuries in Africa and Asia and it is a cereal option for celiac patients. Due to its properties as a wheat-free food, interest is increasing in cultivating sorghum in Mediterranean countries. To evaluate the agronomic characteristics of growth in the Mediterranean area, six hybrids of sorghum (Sorghum bicolor L. Moench), representing different maturity classes, were selected and tested in experimental trials for 2 years in San Bartolomeo in Galdo (BN) hill, South Italy. The results showed moderate variation in adaptation of these hybrids as measured by differences in grain yields (4.60 to 7.30 t ha-1) and other pheno-morphological traits. In particular, the hybrid SW6129W from Bolivia and the hybrid SASG05W from Argentina had grain yields higher than others tested in these trials. Our results demonstrated that selected food-grade hybrids from South America, have agronomic characteristics well-suited for cultivation in Mediterranean countries.

Mineral nutrients play a fundamental role in the biochemical and physiological functions of biological systems. Cereals may especially be an important source of essential minerals in view of their large daily intake both for human health and nutrition. Sorghum, among the cereals, is a major crop being used for food, feed and industrial purposes worldwide. The objective of this study was to determine the mineral contents in grains of seven white food-grade sorghum hybrids, bred and adapted for growth in the central USA and grown in a Mediterranean area of Southern Italy. The seven hybrids were analyzed for grain ash and for minerals contents. Nutritionally, essential macro-, micro- and trace elements content were investigated. The analysis of essential elements was performed by mass spectrometry using a mix solution of internal isotopes standard. The results demonstrated that food-grade sorghum was characterized by high Mg, Fe and Zn content, high K:Na ratio and low Ca:P ratio, compared to other crops, due to the fact that the grain mineral contents of crop species are influenced by the effects of genotypes and environments. Significant variations in the essential elements content were found among the hybrids which allowed us to divide them into three distinct groups on the basis of their mineral profile by cluster analysis. These results are discussed with reference to the importance of minerals in human nutrition and suggest that, like wheat, it is possible to plan research programs for the improvement and selection of sorghum hybrids with high micronutrients content