Studies on the processing of New Zealand grapefruit juice : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Food Technology at Massey University

The likely origin of the New Zealand grapefruit (NZGF) is discussed and present and future trends in its production and utilisation presented. Early and late season samples of NZGF juice were analysed for the presence of the enzymes pectinesterase, polygalacturonase and ascorbic acid oxidase, no trace of the latter two being found. Samples of juice from NZGF harvested at regular intervals from July until December 1973 were analysed for yield, total soluble solids, titratable acidity, pH, pectinesterase activity, and ascorbic acid content. The average yield of juice obtained (35.6% w/w) was significantly lower than that reported from overseas for true grapefruit. The level of total soluble solids remained fairly constant in the range 12.0 to 12.6%, while the pH of the juice increased throughout the season from 2.95 to 3.40. The titratable acidity was within the range 1.0 to 2.0 grams of citric acid per 100 ml of juice, while the Brix : acid ratio varied from 5.02 to 10.03. The level of pectinesterase in the juice (which increased as the season progressed) was comparable with that found in overseas citrus juices, while the level of ascorbic acid in the juice declined over the season from 32.4 to 23.2 mg/100 ml, in agreement with overseas trends. With the exception of yield, the compositional characteristics of NZGP juice reported here do not differ markedly from overseas grapefruit juices. The important role which pectinesterase plays in the destabilisation of citrus juice cloud is outlined and possible methods for inactivating the enzyme are described. As the application of heat is the only method in commercial use, factors affecting and methods for studying the thermal inactivation of enzymes are discussed. As the major objection to most of these methods is the way in which the heating and cooling lags are evaluated, a new method which adequately describes these thermal lags has been developed for determining the thermal resistance of pectinesterase in NZGP juice. A digital computer was programmed to determine (using a trial and error technique) the constants in two expressions which relate the equivalent effect of unsteady state heating and cooling of NZGF juice to the inactivation of pectinesterase. One expression assumed that the rate of inactivation was exponentially related to temperature; in this case the constant was the z value. The other expression assumed that the rate was related to temperature according to the Arrhenius equation, in which case the constant was the activation energy. The two constants were evaluated for both low and high pH juice. It was found that the latter expression using the Arrhenius equation described the change in rate of inactivation with temperature more adequately than the former expression. From these expressions the times required at different temperatures to inactivate pectinesterase in NZGP juice of varying pH were calculated. The application of these results to the industrial processing of NZGP juice is discussed

A numerical and experimental investigation of autoignition

This body of research uses numerical and experimental investigative techniques to further the understanding of autoignition. Hydrogen/nitrogen and methane/air fuel configurations of turbulent lifted flames in a vitiated coflow burner are used as model flames for this investigation. Characterisation was undertaken to understand the impact of controlling parameters and the overall behaviour of the flames, and to provide a body of data for modelling comparisons. Modelling of the flames was conducted using the PDF-RANS technique with detailed chemistry incorporated using In-situ Adaptive Tabulation (ISAT) within the commercial CFD package, FLUENT 6.2. From these investigations, two numerical indicators for autoignition were developed: convection-reaction balance in the species transport budget at the mean flame base; and the build-up of ignition precursors prior to key ignition species. These indicators were tested in well defined autoignition and premixed flame cases, and subsequently used with the calculated turbulent lifted flames to identify if these are stabilised through autoignition. Based on learnings from the modelling, a quantitative, high-resolution simultaneous imaging experiment was designed to investigate the correlations of an ignition precursor (formaldehyde: CH2O) with a key flame radical (OH) and temperature. Rayleigh scattering was used to measure temperature, while Laser Induced Fluorescence (LIF) was used to measure OH and CH2O concentrations. The high resolution in the Rayleigh imaging permitted the extraction of temperature gradient data, and the product of the OH and CH2O images was shown to be a valid and useful proxy for peak heat release rate in autoigniting and transient flames. The experimental data confirmed the presence of formaldehyde as a precursor for autoignition in methane flames and led to the identification of other indicators. Sequenced images of CH2O, OH and temperature show clearly that formaldehyde exists before OH and peaks when autoignition occurs, as confirmed by images of heat release. The CH2O peaks decrease later while those of OH remain almost unchanged in the reaction zone

Studies in Natural Product Chemistry

Section 1. The correlation between the infra-red carbonyl frequency and conformation of delta-lactones was based on the study of a limited number of examples. To substantiate the correlation, a pair of epimeric delta-lactones were synthesised by degradation of the sesquiterpene drimenol. One of the pair was forced to adopt a half-chair conformation and had an infrared carbonyl frequency of 1740 cm -1. The other delta-lactone was forced to adopt the half-boat conformation and had an infra-red carbonyl frequency of 1755 cmThe preferred conformation of simple unstrained delta-lactones has not previously been determined. The n. m. r., infra-red and circular dichroism spectra of the lactone of 5-hydroxy-5-t-butyl-pentanoic acid could be best interpreted in terms of it existing as an equilibrium mixture of half-boat and half-chair conformers with the latter predominating. The circular dichroism and optical rotatory dispersion curves of a number of delta-lactones were examined and the signs of their Cotton effects found to be best interpreted in terms of the rule which correlates sign with the chirality of the lactone ring. Investigation of the n. m. r. spectra of columbin, isocolumbin and decarboxy columbin confirmed that the conformation of the first two delta-lactones was the same in solution as in the solid state as determined by X-ray crystallography. Section 2. The conformation of medium ring lactones have not previously been examined. The n. m. r. spectrum of cycloheptanolide at 173 K was consistent with it adopting a boat-chair conformationwith the lactone group occupying one side of the molecule. The n. m. r. spectra of cyclononanolide and derivatives at different temperatures and in different solvents were consistent with cyclononanolide adopting a boat-chair-boat conformation similar to that preferred by cyclodecane. In addition the conformational inversion processes occuring in these two molecules are discussed. The free energy of activationof cycloheptanolide was found to be 8.9+/-2.0 K cal mole -1and for cyclononanolide 9.2+/-1.0 K cal mole -1

A numerical and experimental investigation of autoignition

This body of research uses numerical and experimental investigative techniques to further the understanding of autoignition. Hydrogen/nitrogen and methane/air fuel configurations of turbulent lifted flames in a vitiated coflow burner are used as model flames for this investigation. Characterisation was undertaken to understand the impact of controlling parameters and the overall behaviour of the flames, and to provide a body of data for modelling comparisons. Modelling of the flames was conducted using the PDF-RANS technique with detailed chemistry incorporated using In-situ Adaptive Tabulation (ISAT) within the commercial CFD package, FLUENT 6.2. From these investigations, two numerical indicators for autoignition were developed: convection-reaction balance in the species transport budget at the mean flame base; and the build-up of ignition precursors prior to key ignition species. These indicators were tested in well defined autoignition and premixed flame cases, and subsequently used with the calculated turbulent lifted flames to identify if these are stabilised through autoignition. Based on learnings from the modelling, a quantitative, high-resolution simultaneous imaging experiment was designed to investigate the correlations of an ignition precursor (formaldehyde: CH2O) with a key flame radical (OH) and temperature. Rayleigh scattering was used to measure temperature, while Laser Induced Fluorescence (LIF) was used to measure OH and CH2O concentrations. The high resolution in the Rayleigh imaging permitted the extraction of temperature gradient data, and the product of the OH and CH2O images was shown to be a valid and useful proxy for peak heat release rate in autoigniting and transient flames. The experimental data confirmed the presence of formaldehyde as a precursor for autoignition in methane flames and led to the identification of other indicators. Sequenced images of CH2O, OH and temperature show clearly that formaldehyde exists before OH and peaks when autoignition occurs, as confirmed by images of heat release. The CH2O peaks decrease later while those of OH remain almost unchanged in the reaction zone

The Effects of Continuing Education on Nurse Knowledge of Safe Haven Laws in Illinois

Illegal and often fatal infant abandonment is a pervasive public health crisis. Safe Haven Laws (SHLs) help to prevent illegal infant abandonment by allowing specific professionals, including nurses, to accept unharmed newborns within statutorily defined parameters. SHLs have existed for nearly two decades, yet many healthcare workers are not knowledgeable about these laws: this implies that initial efforts to educate healthcare workers about SHLs have been ineffective. Continuing education supports lifelong learning which is a basic tenet of nursing practice. The purpose of this evidence-based practice (EBP) project was to teach nurses about SHLs through evidence-based continuing education. Literature firmly supported continuing education as an essential modality for dissemination of information. Evidence used to substantiate implementation included level I evidence through level V evidence as defined by the Johns Hopkins Nursing EBP model. Exchange theory, literature related to both continuing education and SHLs, and the Diffusion of Innovation model for EBP implementation all underpinned the clinical question: For nurses at a large Chicago-based medical center, does evidence-based continuing education, as compared to no education, affect knowledge of SHLs over one month? Participants included emergency department nurses at a large medical center in downtown Chicago. A pre-test, a post-test immediately following the intervention, and a post-test given one month after the intervention were used to evaluate the effect of education on nurse knowledge of SHLs. The mean score of the 12-point quiz improved from 6.15 on the pre-test to 11.28 on the post-test immediately following the educational intervention, representing an increase of 84.31%. The mean score of the pre-test was 6.15 and it improved to 10.33 on the post-test given approximately one month after the educational intervention, indicating an increase of 68.80%. Scores between the two post-tests decreased from 11.28 to 10.33, demonstrating a decrease of only 8.42%.The McNemar test was used to compare the scores of the pre-test with the scores of the post-test given immediately following the educational intervention. The results indicated that 75% of questions had a statistically significant improvement in responses. The Cochran’s Q test was applied to compare scores among all three tests. The results indicated that 50% of the questions had a significant improvement in responses. It is recommended that evidence-based continuing education be used to teach healthcare professionals about SHLs. These results will be applied to a statewide initiative aimed at educating healthcare workers in Illinois about SHLs

Defining, profiling and accommodating learning diversity in an international PBL-environment

This paper investigates the wide diversity of learning experience, values and expectations of both students and lecturers in an international PBL environment. The results are based on 24 PBL- related learning parameters (inspired by Hofstede´s cultural dimensions) in the form of two questionnaires – one for students and one for teaching staff. The result quantitatively documents and graphically illustrates the wide diversity of student learning experience, values and expectations and contrasts them with teaching staff. The paper also documents follow-up research into 62% of the same group of students 18 months after the initial survey – to reveal the extent of accommodation and constructive alignment. The authors view the paper as ‘action research’ – the findings being specific to their institution, but could be applied to other PBL teaching and learning situations.Peer Reviewe

The application of phenotypic microarray analysis to anti-fungal drug development

Candida albicans metabolic activity in the presence and absence of acetylcholine was measured using phenotypic microarray analysis. Acetylcholine inhibited C. albicans biofilm formation by slowing metabolism independent of biofilm forming capabilities. Phenotypic microarray analysis can therefore be used for screening compound libraries for novel anti-fungal drugs and measuring antifungal resistance

Law and the Poor in Rural India: The Prospects for Legal Aid

Movements come and go, in society at large no less than in the academy. Theories are refined; they inspire action, engender criticism, and secure successes and failures. Modern programs for social intervention in the contemporary United States, particularly those designed to alleviate poverty or to secure equal treatment for unpopular minorities (the have-nots ), have lately fallen on harder times. An obvious sign of this trend is the federal government\u27s curtailment of financial support. Recent signs from the Supreme Court also indicate a major withdrawal from past judicial activism in favor of the have-nots.\u27 Criticism of pro- grams of social intervention, however, has come not only from conservative politicians, but also from both the left and right of the scholarly community. A crisis of confidence has evolved in the government\u27s ability to help engineer a better society. The subject of this article involves two such movements: free legal aid (and related public interest litigation) and law and development (particularly the application of Western legal experience to the study of developing countries). Both movements have suffered intense criticism. Nevertheless, a new field has emerged-free legal aid in developing countries-which somewhat surprisingly has attracted support from scholars, governments, lawyers, and international institutions. As with other movements, legal aid in developing countries has undergone theoretical refinement. It has engendered action, criticism, some successes, and many failures. This is not to say that criticisms of both left and right have been so devastating as to invalidate these pro- grams for social intervention. Instead, many argue for program improvement and not for elimination. There exists, however, some profound criticisms of public interest litigation, legal aid, and law and development