Immobilized enzyme technology for debittering citrus fruit juices

There has been increased interest in the use of immobilized enzymes in fruit juice industry for debittering of citrus fruit juices due to their high efficiency to remove bitter flavonoids. The structure of naringin, responsible for immediate bitterness, and of limonin, responsible for "delayed bitterness" has been discussed. This chapter also discusses various attempts that have been made to immobilize enzymes on an appropriate support so as to enable their use in debittering of citrus fruit juices. These include physicochemical and enzyme biotechnological approaches which makes the fruit juice more acceptable and cost effective to the consumer. Despite of high volume of production of citrus fruits and fruit juices, suitable processes to produce non-bitter citrus juice by immobilized enzymes technology has not yet commercialized globally.

Diet, nutrition and the prevention of excess weight gain and obesity

Objective: To review the evidence on the diet and nutrition causes of obesity and to recommend strategies to reduce obesity prevalence.
Design: The evidence for potential aetiological factors and strategies to reduce obesity prevalence was reviewed, and recommendations for public health action, population nutrition goals and further research were made.
Results: Protective factors against obesity were considered to be: regular physical activity (convincing); a high intake of dietary non-starch polysaccharides (NSP)/fibre (convincing); supportive home and school environments for children (probable); and breastfeeding (probable). Risk factors for obesity were considered to be sedentary lifestyles (convincing); a high intake of energy-dense, micronutrient-poor foods (convincing); heavy marketing of energy-dense foods and fast food outlets (probable); sugar-sweetened soft drinks and fruit juices (probable); adverse social and economic conditions—developed countries, especially in women (probable).
A broad range of strategies were recommended to reduce obesity prevalence including: influencing the food supply to make healthy choices easier; reducing the marketing of energy dense foods and beverages to children; influencing urban environments and transport systems to promote physical activity; developing community-wide programmes in multiple settings; increased communications about healthy eating and physical activity; and improved health services to promote breastfeeding and manage currently overweight or obese people.
Conclusions: The increasing prevalence of obesity is a major health threat in both low- and high income countries. Comprehensive programmes will be needed to turn the epidemic around.

Longitudinal study of Consumer Price Index (CPI) trends in core and non-core foods in Australia

Objective: This study examined trends in the price of healthy and less-healthy foods from 1989 to 2007 using the Australian Consumer Price Index (CPI).

Methods: CPI food expenditure classes were classified as 'core' or 'non-core'. Trends in the CPI were analysed to examine the rise in prices of core compared with non-core foods.

Results: On average, the CPI for core foods has risen at a slightly higher, though not statistically significant, rate than non-core foods. Furthermore, selected groupings reveal interesting patterns. 'Bread' has risen in price significantly more than 'cakes and biscuits', and 'milk' has risen in price significantly more than 'soft drinks, waters and juices'.

Conclusions and implications: This investigation of food price trends reveals notable differences between core and non-core foods. This should be investigated further to determine the extent to which this contributes to the higher prevalence of diet-related diseases in low socio-economic groups.

Partial purification and characterization of limonoate dehydrogenase from Rhodococcus fascians for the degradation of limonin

An extracellular limonoate dehydrogenase was purified 10-fold from a cell-free extract of Rhodococcus fascians by ammonium sulfate precipitation, dialysis, and ultrafiltration. This purified dehydrogenase catalyzed the
conversion of limonoate to 17-dehydrolimonoate. The enzyme showed optimum activity at pH 8.0 and 40oC, with K_m value of 0.9 µM, and requires Zn ions and sulfhydryl groups for catalytic action. The enzyme activity was inhibited by Hg²⁺ and NaN₃ ions. The degradation of limonin (66%) in Kinnow mandarin juice was successfully demonstrated with partially
purified limonoate dehydrogenase. With scale-up preparation of limonoate dehydrogenase, a successful debittering operation of fruit juices appears feasible.

Does Australia's treatment of non-citizens accord with its international human rights obligations? with specific reference to the treatment of on-shore refugees

The son of immigrants, I was motivated to write a paper addressing the issues of alienation and discrimination which confronts non-citizens upon arriving in Australia. Apart from descendants of Australia's indigenous population, the common bond shared by all citizens and permanent residents of Australia is that they are either themselves immigrants or are descended from immigrants. In this paper I will look at whether Australia's law and practice meets its international human rights treaty and convention obligations vis-a-vis non-citizens. To investigate this issue I trace the history of immigration to Australia and look at the political policies which influenced the treatment of non-citizens from 1788 to present times. In 1958 when my parents stepped upon Australian soil as displaced persons, Australia was a very different place from Australia in the 1990s. At that time Australia was still firmly under the influence of the 'White Australia Policy' which openly encouraged discrimination against non-anglo saxons. Since those times Australia has advanced to become one of the most culturally diverse nations in the world where multiculturalism is encouraged and a non-discriminatory immigration program is supported by both Australia's major political parties. However, notwithstanding the great social advances made in Australia in recent decades the traditional legal sources of law, namely, judicial pronouncements, statutes and the Commonwealth Constitution have not kept pace and it is my submission that Australia's body of law inadequately protects the rights of non-citizens when compared to Australia's international human rights convention and treaty obligations. This paper will consider these major sources of law and will investigate how they have been used in the context of the protection of the rights of non-citizens. It will be asserted that the weaknesses exposed in the Australian legal system can be improved by the adoption of a Bill of Rights1 which encompasses Australia's international human rights treaty and convention obligations. It is envisaged that a Bill of Rights would provide a framework applicable at the State, Territory and Federal levels within which issues pertaining to non-citizens could be resolved. The direction of this thesis owes much to the writings, advice and supervision of Dr. Imtiaz Omar who was always available to discuss the progress of this work. Dr. Omar is a passionate advocate of human rights and has been a tremendous inspiration to me throughout my writing. I owe a debt of thanks to the partners of Coulter Burke who with good nature ignored the sprawl of books and papers on the boardroom table, often for days at a time, thus enabling me to return to my writing from time to time as my inspirational juices ebbed and waned. Thanks also go to my typists Julie Pante, Vesna Dudas and Irene Padula who worked after hours and on weekends always without complaint, on the various versions of this thesis. My final acknowledgement goes to my wife Paula who during the years that I was working on this thesis encouraged me during my darker moments and listened to all my frustrations yet never doubted that I would one day complete the task successfully. I wish to thank her wholeheartedly for her motivation and belief in my abilities. The law relied upon in the thesis is as at the 30th June, 1998. Bill or Charter of Rights 'are taken to be enactments which systematically declare certain fundamental rights and freedoms and require that they be respected'. See Evans, G. 'Prospect and Problems for an Australian Bill of Rights' (1970) 3 Australian Year Book of International Law 1 at 16. Some such notable exception is the New Zealand Bill of Rights Act 1990, contained in an ordinary statute.

Immobilization of bacterial recombinant proteins

Recombinant α-L Rhamnosidase has several potential applications in citrus fruit juice processing industries. Immobilized recombinant α-L Rhamnosidase further provides an added advantage to this industrially important enzyme. Various techniques have been used to immobilize native rhamnosidase from fungal origin and applications were explored in great details by several workers. (Puri et al., 1996, 2000, 2001)

A recombinant rhamnosidase from a bacterial source was expressed in E.coli has been immobilized in calcium alginate beads (entrapment method). A batch bioreactor was created for the hydrolysis of naringin using immobilized recombinant α-L Rhamnosidase under shaking and stationary conditions and it was found to hydrolyze naringin effectively. The system was efficient to hydrolyze narigin under shaking conditions and was operationally stable up to 9 days. A high percent hydrolysis of naringin was achieved at pH 7.5 and 60˚C by immobilized rhamnosidase. Entrapped rhamnosidase was able to hydrolyze naringin content in kinnow juice repeatedly and this feature makes this technique economically suitable for debittering of fruit juices.

Updates on naringinase : structural and biotechnological aspects

Naringinases has attracted a great deal of attention in recent years due to its hydrolytic activities which include the production of rhamnose, and prunin and debittering of citrus fruit juices. While this enzyme is widely distributed in fungi, its production from bacterial sources is less commonly known. Fungal naringinase are very important as they are used industrially in large amounts and have been extensively studied during the past decade. In this article, production of bacterial naringinase and potential biotechnological applications are discussed. Bacterial rhamnosidases are exotype enzymes that hydrolyse terminal non-reducing α-l-rhamnosyl groups from α-l-rhamnose containing polysaccharides and glycosides. Structurally, they are classified into family 78 of glycoside hydrolases and characterized by the presence of Asp567 and Glu841 in their active site. Optimization of fermentation conditions and enzyme engineering will allow the development of improved rhamnosidases for advancing suggested industrial applications.