Physical aging of starch, maltodextrin, and maltose

The physical aging of low water content, amorphous starch/water, maltodextrin/water, and maltose/water mixtures in the glassy state was examined using mechanical testing and calorimetry. Stress relaxation measurements showed that upon storage of the glassy materials there was a time-dependent increase in both flexural modulus and mechanical relaxation time. The mechanical relaxation time increased with depth of quench below the calorimetric glass transition temperature and with aging time at the quench temperature. Calorimetry of the aged materials showed an overshoot in heat capacity in the vicinity of the glass transition. The logarithm of the mechanical relaxation time showed a simple linear relationship with the size of the overshoot expressed as an enthalpy change. The calorimetric behavior could be modeled using the Tool-Narayanaswamy-Moynihan method.     

Assessment of genetic variability in hexaploid wheat landraces of Pakistan based on polymorphism for HMW glutenin subunits

Summary Sixty hexaploid wheat landraces collected from five regions of Pakistan were assessed for genetic variability in terms of high molecular weight (HMW) glutenin subunits as revealed by SDS-PAGE. The germplasm appeared to be diverse and unique on the basis of HMW glutenin subunit compositions. Out of 24 alleles detected at all the Glu-1 loci, four belonged to Glu-A1, 12 to Glu-B1 and eight to Glu-D1 locus. The number of novel HMW glutenin subunits detected were 1, 4 and 6 at the three loci (Glu-A1, Glu-B1, Glu-D1), respectively. The frequency distribution patterns of 24 allelic variants detected at the three Glu-1 loci in 1080 samples analysed for 60 accessions were determined both on the basis of individual accessions and on the basis of regions (accessions pooled across the regions). One allele (null) at the Glu-A1 locus, three alleles (17+18, 7+8, 14) at the Glu-B1 locus and, two alleles (2+12 and 2^**+12) at the Glu-D1 locus were found most frequently distributed in the 60 populations. Maximum variation was observed in the Baluchistan and Gilgit regions of Pakistan in terms of distribution of novel Glu-1 alleles. A higher gene diversity was observed between the populations as compared to the gene diversity within the populations while, a reverse pattern of gene diversity was observed when populations were pooled across the regions (higher within the regions than between the regions). A data base has been generated in this study which could be expanded and usefully exploited for cultivar development or management of gene bank accessions.     

The effect of gluten on the retrogradation of wheat starch

The retrogradation of amylopectin in a wheat starch and a wheat starch/gluten (10:1) blend prepared by extrusion and containing 34% water (wet weight basis) was studied using X-ray diffraction, differential scanning calorimetry and NMR relaxometry during storage at constant water content and temperature (25 °C). For both samples, amylopectin ‘fully’ retrograded after 2–3 days storage, i.e. the different parameters monitored with time to follow the retrogradation had reached their maximum value, and crystallised predominantly into the A polymorph. Under the experimental conditions used, there was no evidence of any significant effects of the presence of gluten on the kinetics, extent or polymorphism of amylopectin retrogradation.     

Trait phenotyping and SSR markers characterization of wheat (Triticum aestivum L.) germplasm for breeding early maturing wheat’s for Western-Himalayas

Genetic Resources and Crop Evolution - The study involved evaluation of 96 wheat genotypes for early maturity and related traits and molecular characterization of trait specific candidate genotypes...     

Deep learning-based identification system of weeds and crops in strawberry and pea fields for a precision agriculture sprayer

Precision Agriculture - Controlling weed infestation through chemicals (herbicides & pesticides) is essential for crop yield. However, excessive use of these chemicals has caused severe...     

High-value components and bioactives from sea cucumbers for functional foods--a review

Sea cucumbers, belonging to the class Holothuroidea, are marine invertebrates, habitually found in the benthic areas and deep seas across the world. They have high commercial value coupled with increasing global production and trade. Sea cucumbers, informally named as bêche-de-mer, or gamat, have long been used for food and folk medicine in the communities of Asia and Middle East. Nutritionally, sea cucumbers have an impressive profile of valuable nutrients such as Vitamin A, Vitamin B1 (thiamine), Vitamin B2 (riboflavin), Vitamin B3 (niacin), and minerals, especially calcium, magnesium, iron and zinc. A number of unique biological and pharmacological activities including anti-angiogenic, anticancer, anticoagulant, anti-hypertension, anti-inflammatory, antimicrobial, antioxidant, antithrombotic, antitumor and wound healing have been ascribed to various species of sea cucumbers. Therapeutic properties and medicinal benefits of sea cucumbers can be linked to the presence of a wide array of bioactives especially triterpene glycosides (saponins), chondroitin sulfates, glycosaminoglycan (GAGs), sulfated polysaccharides, sterols (glycosides and sulfates), phenolics, cerberosides, lectins, peptides, glycoprotein, glycosphingolipids and essential fatty acids. This review is mainly designed to cover the high-value components and bioactives as well as the multiple biological and therapeutic properties of sea cucumbers with regard to exploring their potential uses for functional foods and nutraceuticals.     

Genetic algorithms for the sequential irrigation scheduling problem

A sequential irrigation scheduling problem is the problem of preparing a schedule to sequentially service a set of water users. This problem has an analogy with the classical single machine earliness/tardiness scheduling problem in operations research. In previously published work, integer program and heuristics were used to solve sequential irrigation scheduling problems; however, such scheduling problems belong to a class of combinatorial optimization problems known to be computationally demanding (NP-hard). This is widely reported in operations research. Hence, integer program can only be used to solve relatively small problems usually in a research environment where considerable computational resources and time can be allocated to solve a single schedule. For practical applications, metaheuristics such as genetic algorithms (GA), simulated annealing, or tabu search methods need to be used. These need to be formulated carefully and tested thoroughly. The current research is to explore the potential of GA to solve the sequential irrigation scheduling problems. Four GA models are presented that model four different sequential irrigation scenarios. The GA models are tested extensively for a range of problem sizes, and the solution quality is compared against solutions from integer programs and heuristics. The GA is applied to the practical engineering problem of scheduling water scheduling to 94 water users.     

Competitive ability of some cover crop species against Asystasia gangetica and Pennisetum polystachion

Abstract

Asystasia gangetica and Pennisetum polystachion are the most troublesome weeds in oil palm plantations in Malaysia and establishment of cover crops under oil palms is an integral part of sustainable weed management in plantations. Replacement-series experiments were conducted to evaluate the mode and strength of competitiveness of four legume cover crop species, Calopogonium caeruleum, Centrosema pubescens, Mucuna bracteata and Pueraria javanica, and one soft grass species, Axonopus compressus, against Asystasia gangetica and Pennisetum polystachion. Relative yield, relative yield total and relative crowding coefficient were calculated with reference to shoot biomass. Asystasia gangetica was a consistently weaker competitor than Pennisetum polystachion. The legume cover crop species had higher relative yield when grown in mixtures, whereas the yield of Asystasia gangetica was lower in mixtures with legumes than in monoculture. The higher competitiveness of legumes was due to greater canopy height and leaf area index. Centrosema pubescens was a slightly weaker competitor than the other legumes. Although leaf area per plant of Centrosema pubescens did not differ from that of other three legumes, canopy height and blocking photosynthetically active radiation to the soil surface were lower. When grown with a cover crop for 12 weeks, dry weight per plant, leaf area and shoot number of Pennisetum polystachion increased as its proportion decreased in mixtures. Relative yield data indicated that Pennisetum polystachion is a strong competitor. Axonopus compressus was less susceptible to Pennisetum polystachion interference than the legumes. All cover crop species studied proved highly competitive against Asystasia gangetica, but none could compete against Pennisetum polystachion. The study confirms the feasibility of using a cover crop for management of Asystasia gangetica.