Peerasak Sanguansri

Impact of Oil Type on Nanoemulsion Formation and Ostwald Ripening Stability

The formation of stable transparent nanoemulsions poses two challenges: the ability to initially create an emulsion where the entire droplet size distribution is below 80 nm, and the subsequent stabilization of this emulsion against Ostwald ripening. The physical properties of the oil phase and the nature of the surfactant layer were found to have a considerable impact on nanoemulsion formation and stabilization. Nanoemulsions made with high viscosity oils, such as long chain triglycerides (LCT), were considerably larger ( D = 120 nm) than nanoemulsions prepared with low viscosity oils such as hexadecane ( D = 80 nm). The optimization of surfactant architecture, and differential viscosity eta D/eta C, has led to the formation of remarkably small nanoemulsions. With average sizes below 40 nm they are some of the smallest homogenized emulsions ever reported. What is more remarkable is that LCT nanoemulsions do not undergo Ostwald ripening and are physically stable for over 3 months. Ostwald ripening is prevented by the large molar volume of long chain triglyceride oils, which makes them insoluble in water thus providing a kinetic barrier to Ostwald ripening. Examination of the Ostwald ripening of mixed oil nanoemulsions found that the entropy gain associated with oil demixing provided a thermodynamic barrier to Ostwald ripening. Not only are the nanoemulsions created in this work some of the smallest reported, but they are also thermodynamically stable to Ostwald ripening when at least 50% of the oil phase is an insoluble triglyceride.

Nanostructured materials in the food industry.

Nanotechnology involves the application, production, and processing of materials at the nanometer scale. Biological- and physical-inspired approaches, using both conventional and innovative food processing technologies to manipulate matter at this scale, provide the food industry with materials with new functionalities. Understanding the assembly behavior of native and modified food components is essential in developing nanostructured materials. Functionalized nanostructured materials are finding applications in many sectors of the food industry, including novel nanosensors, new packaging materials with improved mechanical and barrier properties, and efficient and targeted nutrient delivery systems. An improved understanding of the benefits and the risks of the technology based on sound scientific data will help gain the acceptance of nanotechnology by the food industry. New horizons for nanotechnology in food science may be achieved by further research on nanoscale structures and methods to control interactions between single molecules.

Changes in Food Intake in Australia: Comparing the 1995 and 2011 National Nutrition Survey Results Disaggregated into Basic Foods

As nations seek to address obesity and diet-related chronic disease, understanding shifts in food intake over time is an imperative. However, quantifying intake of basic foods is not straightforward because of the diversity of raw and cooked wholefoods, processed foods and mixed dishes actually consumed. In this study, data from the Australian national nutrition surveys of 1995 and 2011, each involving more than 12,000 individuals and covering more than 4500 separate foods, were coherently disaggregated into basic foods, with cooking and processing factors applied where necessary. Although Australians are generally not eating in a manner consistent with national dietary guidelines, there have been several positive changes. Australians are eating more whole fruit, a greater diversity of vegetables, more beans, peas and pulses, less refined sugar, and they have increased their preference for brown and wholegrain cereals. Adult Australians have also increased their intake of nuts and seeds. Fruit juice consumption markedly declined, especially for younger Australians. Cocoa consumption increased and shifts in dairy product intake were mixed, reflecting one of several important differences between age and gender cohorts. This study sets the context for more detailed research at the level of specific foods to understand individual and household differences.

Progress and issues with the commercialization of cool plasma in food processing: a selection of case studies.

Abstract: The key driver for the commercialization of cool plasma processes in the food industry is the need for alternative, non-thermal and residue-free processes that can replace traditional chemical and thermal treatments with minimal or no impact to the product surface itself. Possible applications include decontamination of powders, egg in shell, meat, fish and fresh vegetables as an alternative to existing chemical disinfection washing or surface hygiene treatments. Case studies from a number of organizations that actively conduct cool plasma research from around the world are presented, including experiences in the developmental pathways, scale-up and commercial implementation of the technology.

Australia’s nutritional food balance: situation, outlook and policy implications

Australia is a food trading nation with a complex food system. Change can have important implications for rural communities, employment, trade, public health nutrition and food security. This study compares Australian food intake scenarios to 2050 with linear projections for Australian agricultural production. The study is distinguished by its nutritional perspective, characterising food balance in terms of basic foods rather than food energy or macronutrients, as well as its systems perspective, taking into account the transformations that occur in food processing and cooking, livestock feed requirements, as well as supply chain and kitchen losses. With Australia’s population projected to increase from around 23 million in 2015 to 37.5 million in 2050, substantial increases in domestic food supply will be required. Although the situation and outlook differ for each commodity, in most respects demand is projected to increase at a greater rate than local production. This suggests that the Australian food system is on a trajectory toward reduced net food exports and increased dependence on imports. This will have implications for Australia’s role in the global food system and presents a change in some of the determinants of national food security. The trajectory of the food system also appears to be at odds with the massive public health challenges associated with diet related disease. These and other implications of an enlarging and increasingly international food system are discussed.

Short communication: a food-systems approach to assessing dairy product waste.

Concern about world population increase, food security, and the environmental burdens of food production have made food-waste reduction a social and environmental priority. In this context, the quantification of dairy product waste is especially difficult due to the varied means of disposal, by solid and liquid waste streams, and due to inclusion as an ingredient in many processed foods. In this study, food intake data from the Australian National Nutrition Survey (>13,000 participants; >4,500 food items) were disaggregated into basic foods and total national dairy product intake was expressed in whole-milk equivalents. This result was compared with total domestic milk supply, indicating a level of waste of 29% for dairy products in the Australian food system. With national food-waste reduction targets becoming increasingly common, reliable estimates of food waste at the national scale are important for goal setting, baseline reporting, and performance monitoring. For this purpose, the systems approach to assessing food waste demonstrated in this project is deemed to have advantages over other common methods of food-waste assessment, such as bin audits, waste diaries, and surveys.

Sequential low and medium frequency ultrasound assists biodegradation of wheat chaff by white rot fungal enzymes.

The consequences of ultrasonic pre-treatment using low (40 kHz) and medium (270 kHz) frequency (40 kHz followed by 270 kHz) on the degradation of wheat chaff (8 g 100ml(-1) acetate buffer, pH 5) were evaluated. In addition, the effects of the ultrasonic pre-treatment on the degradation of the wheat chaff when subsequently exposed to enzyme extracts from two white rot fungi (Phanerochaete chrysosporium and Trametes sp.) were investigated. Pre-treatment by sequential low and medium frequency ultrasound had a disruptive effect on the lignocellulosic matrix. Analysis of the phenolic-derived volatiles after enzymatic hydrolysis showed that biodegradation with the enzyme extract obtained from P. chrysosporium was more pronounced compared to that of the Trametes sp. The efficacy of the ultrasonic pre-treatment was attributed to increased enzyme accessibility of the cellulose fibrils due to sonication-induced disruption of the plant surface structure, as shown by changes in the microstructure.