Effect of harvest time and drying on supersweet sweet corn seed quality

A supersweet sweet corn hybrid, Pacific H5, was grown under field conditions in South-East Queensland to study the effects of harvest time and drying conditions on seed quality. Cobs were harvested at different times to obtain seed with two moisture percentage ranges (20-30% and 40-50%) and dried to 12% moisture under different combinations of drying temperatures (30 degrees C, 40 degrees C and 50 degrees C) and air velocities (1.25 m/s, 2.75 m/s and 4.30 m/s). Dried seed was stored at 30 degrees C with bimonthly monitoring of seed quality for 12 months. For standard as well as cold test germinations, statistical analysis yielded significant main effects for temperature, air velocity and harvest moisture content and significant interactions for drying temperature by harvest moisture and drying temperature by air velocity. Germination at the beginning of storage was unaffected by drying temperatures up to 40 degrees C regardless of harvest moisture but was lower at 50 degrees C for higher moisture. However, germination at the end of the storage period of 12 months was greatest for seed harvested at higher moisture and dried at temperatures up to 40 degrees C. Germination was not affected by air velocity for drying temperatures up to 40 degrees C but at 50 degrees C it generally decreased with increase in air velocity. To slow down seed deterioration during storage, it is recommended that sweet corn seed should be harvested at a higher moisture range (40-50%) and dried at 40 degrees C and 4.30 m/s air velocity. The drying temperature can be raised to 50 degrees C for seed harvested at a low moisture range (20-30%) provided the air velocity is kept low (1.25 m/s).

Evaluation of eight spring onion genotypes, sulphur nutrition and soil-type effects with an electronic nose

Genotype, sulphur (S) nutrition and soil-type effects on spring onion quality were assessed using a 32-conducting polymer sensor E-nose. Relative changes in sensor resistance ratio (% dR/R) varied among eight spring onion genotypes. The % dR/R was reduced by S application in four of the eight genotypes. For the other four genotypes, S application gave no change in % dR/R in three, and increased % dR/R in the other. E-nose classification of headspace volatiles by a two-dimensional principal component analysis (PCA) plot for spring onion genotypes differed for S fertilisation vs. no S fertilisation. Headspace volatiles data set clusters for cv. 'White Lisbon' grown on clay or on sandy loam overlapped when 2.9 [Mahalanobis distance value (D2) = 1.6], or 5.8-(D2 = 0.3) kg S ha-1 was added. In contrast, clear separation (D2 = 7.5) was recorded for headspace volatile clusters for 0 kg S hd-1 on clay vs. sandy loam. Addition of 5.8 kg S ha-1 increased pyruvic acid content (mmole g-1 fresh weight) by 1.7-fold on average across the eight genotypes. However, increased S from 2.9 to 5.8 kg ha-1 did not significantly (P > 0.05) influence % dR/R, % dry matter (DM) or total soluble solids (TSS) contents, but significantly (P < 0.05) increased pyruvic acid content. TSS was significantly (P < 0.05) reduced by S addition, while % DM was unaffected. In conclusion, the 32-conducting polymer E-nose discerned differences in spring onion quality that were attributable to genotype and to variations in growing conditions as shown by the significant (P < 0.05) interaction effects for % dR/R.

Milling quality and protein properties of autumn-sown Chinese wheats evaluated through multi-location trials

Eight milling quality and protein properties of autumn-sown Chinese wheats were investigated using 59 cultivars and advanced lines grown in 14 locations in China from 1995 to 1998. Wide ranges of variability for all traits were observed across genotypes and locations. Genotype, location, year, and their interactions all significantly influenced most of the quality parameters. Kernel hardness, Zeleny sedimentation value, and mixograph development time were predominantly influenced by the effects of genotype. Genotype, location and genotype x location interaction were all important sources of variation for thousand kernel weight, test weight, protein content, and falling number, whereas genotype x location interaction had the largest effect on flour yield. Most of the genotypes were characterized by weak gluten strength with Zeleny sedimentation values less than 40 ml and mixograph development time shorter than 3 min. Eight groups of genotypes were recognized based on the average quality performance, grain hardness and gluten strength were the two parameters that determined the grouping, with contributions from protein content. Genotypes such as Zhongyou 16 and Annong 8903 displayed good milling quality, high grain hardness, protein content and strong gluten strength with high sedimentation value and long mixograph development time. Genotypes such as Lumai 15 and Yumai 18 were characterized by low grain hardness, protein content and weak gluten strength. Genotypes such as Yannong 15 and Chuanmai 24 were characterized by strong gluten strength with high sedimentation value and long mixograph development time, but low grain hardness and protein content lower than 12.3%. Genotypes such as Jingdong 6 and Xi'an 8 had weak gluten strength, but with high grain hardness and protein content higher than 12.2%. Five groups of locations were identified, and protein content and gluten strength were the two parameters that determined the grouping. Beijing, Shijiazhuang, Nanyang, Zhumadian and Nanjing produced wheats with medium to strong gluten strength and medium protein content, although there was still a large variation for most of the traits investigated between the locations. Wheat produced in Yantai was characterized by strong gluten strength, but with low protein content. Jinan, Anyang and Linfen locations produced wheats with medium to weak gluten strength and medium to high protein content. Wheats produced in Yangling, Zhenzhou, and Chengdu were characterized by weak gluten strength with medium to low protein content, whereas wheats produced in Xuzhou and Wuhan were characterized by weak gluten strength with low protein content. Industrial grain quality could be substantially improved through integrating knowledge of geographic genotype distribution with key location variables that affected end-use quality.

Solid transport in a pyrolysis pilot-scale rotary kiln: Preliminary results?stationary and dynamic results

Experiments for the investigation of the flow of granular solids in a pyrolysis pilot-scale rotary kiln are presented. These experiments consisted first in measuring the volumetric filling ratio (steady-state experiences) for several operating conditions and second in recording the exit flow rates after a positive or negative step in one of the operating parameters (dynamic experiences). A dynamical model computing the evolution of the flow rate of granular solids through the kiln has been developed based on Saeman model [Chem. Eng. Prog. 47 (1951) 508]. The simulations are compared with experimental results; the model gives good results for the rolling mode, but for the slipping mode too. (C) 2004 Elsevier B.V. All rights reserved.

Evaluation by respirometry of the degradability of retort water using a shale ash and overburden packed column

Oil shale processing produces an aqueous wastewater stream known as retort water. The fate of the organic content of retort water from the Stuart oil shale project (Gladstone, Queensland) is examined in a proposed packed bed treatment system consisting of a 1:1 mixture of residual shale from the retorting process and mining overburden. The retort water had a neutral pH and an average unfiltered TOC of 2,900 mg l(-1). The inorganic composition of the retort water was dominated by NH4+. Only 40% of the total organic carbon (TOC) in the retort water was identifiable, and this was dominated by carboxylic acids. In addition to monitoring influent and effluent TOC concentrations, CO2 evolution was monitored on line by continuous measurements of headspace concentrations and air flow rates. The column was run for 64 days before it blocked and was dismantled for analysis. Over 98% of the TOC was removed from the retort water. Respirometry measurements were confounded by CO2 production from inorganic sources. Based on predictions with the chemical equilibrium package PHREEQE, approximately 15% of the total CO2 production arose from the reaction of NH4+ with carbonates. The balance of the CO2 production accounted for at least 80% of the carbon removed from the retort water. Direct measurements of solid organic carbon showed that approximately 20% of the influent carbon was held-up in the top 20cm of the column. Less than 20% of this held-up carbon was present as either biomass or as adsorbed species. Therefore, the column was ultimately blocked by either extracellular polymeric substances or by a sludge that had precipitated out of the retort water.

Towards the preparative and large-scale precision manafacture of virus-like particles

Virus-like particles (VLPs) are of interest in vaccination, gene therapy and drug delivery, but their potential has yet to be fully realized. This is because existing laboratory processes, when scaled, do not easily give a compositionally and architecturally consistent product. Research suggests that new process routes might ultimately be based on chemical processing by self-assembly, involving the precision manufacture of precursor capsomeres followed by in vitro VLP self-assembly and scale-up to required levels. A synergistic interaction of biomolecular design and bioprocess engineering (i.e. biomolecular engineering) is required if these alternative process routes and, thus, the promise of new VLP products, are to be realized.

Biomolecular engineering at interfaces

A broad review of technologically focused work concerning biomolecules at interfaces is presented. The emphasis is on developments in interfacial biomolecular engineering that may have a practical impact in bioanalysis, tissue engineering, emulsion processing or bioseparations. We also review methods for fabrication in an attempt to draw out those approaches that may be useful for product manufacture, and briefly review methods for analysing the resulting interfacial nanostructures. From this review we conclude that the generation of knowledge and-innovation at the nanoscale far exceeds our ability to translate this innovation into practical outcomes addressing a market need, and that significant technological challenges exist. A particular challenge in this translation is to understand how the structural properties of biomolecules control the assembled architecture, which in turn defines product performance, and how this relationship is affected by the chosen manufacturing route. This structure-architecture-process-performance (SAPP) interaction problem is the familiar laboratory scale-up challenge in disguise. A further challenge will be to interpret biomolecular self- and directed-assembly reactions using tools of chemical reaction engineering, enabling rigorous manufacturing optimization of self-assembly laboratory techniques. We conclude that many of the technological problems facing this field are addressable using tools of modem chemical and biomolecular engineering, in conjunction with knowledge and skills from the underpinning sciences. (c) 2005 Elsevier Ltd. All rights reserved.

Life Cycle Assessment (LCA) Applied to the Design of an Innovative Drying Process for Sewage Sludge

Most adverse environmental impacts result from design decisions made long before manufacturing or usage. In order to prevent this situation, several authors have proposed the application of life cycle assessment (LCA) at the very first phases of the design of a process, a product or a service. The study in this paper presents an innovative thermal drying process for sewage sludge called fry-drying, in which dewatered sludge is directly contacted in the dryer with hot recycled cooking oils (RCO) as the heat medium. Considering the practical difficulties for the disposal of these two wastes, fry-drying presents a potentially convenient method for their combined elimination by incineration of the final fry-dried sludge. An analytical comparison between a conventional drying process and the new proposed fry-drying process is reported, with reference to some environmental impact categories. The results of this study, applied at the earliest stages of the design of the process, assist evaluation of the feasibility of such system compared to a current disposal process for the drying and incineration of sewage sludge.

Comparison of gas hold-up distribution measurement in a flotation cell using capturing and conductivity techniques

This paper presents and interprets results of experimental measurements of the spatial gas hold-up distribution in a 3 (3) glass rectangular flotation cell at the JKMRC using two different techniques. The gas hold-up device with the capturing technique was developed at the JKMRC and has been used widely in the P9 project(1) while the one with conductivity technique was developed at the CSIRO Thermal and Fluids Engineering laboratory at Highett, Victoria, Australia. Measurements were conducted at more than 64 locations in the cell to determine the local gas hold-up distribution in the cell. Since the measurements using the two techniques were conducted at the same locations, the results may be compared with each other. The results indicate that the gas hold-up varies widely inside the flotation cell. The gas hold-up distributions measured by the two techniques are relatively similar except in some locations which can be reasonably explained. (c) 2006 Elsevier Ltd. All rights reserved.

Between-tree variation in fruit quality and fruit mineral concentrations of Hass avocados

Inconsistent internal fruit quality in Hass avocados affects consumer confidence. To determine the influence of individual trees on fruit quality, Hass avocado fruit were harvested from adjacent trees of similar external appearance in 3 commercial orchards in 1998 and 1 orchard in 1999. The trees in each orchard were grown with similar commercial practices and in similar soil types. Within each location, there were significant (P < 0.05) differences in the mean ripe fruit quality between trees with respect to fruit body rot severity ( mainly anthracnose) with and without cold storage, internal disorders severity due to diffuse discolouration and vascular browning ( after cold storage), days to ripen, percentage dry matter, and the percentage of the skin area with purple-black colour when ripe. These effects were also noted in the same orchard in 1999. There were significant (P < 0.05) differences in fruit flesh calcium, magnesium, potassium, boron and zinc concentrations between trees. Significant (P < 0.05) correlations were observed between average fruit mineral concentrations in each tree ( particularly calcium, magnesium and potassium) and body rot severity, percentage dry matter and fruit mass. There was little conclusive evidence that characteristics such as the growth of the non-suberised roots or the degree of scion under- or overgrowth was involved in these tree effects; however, differences between trees with respect to other rootstock characteristics may be involved. The inconsistency of the correlations across sites and years suggested that other factors apart from tree influences could also affect the relationship between fruit minerals and fruit quality.