In vitro digestion model simulating the human upper
gastrointestinal tract.
In vitro digestion models simulating the
human gastrointestinal tract (GIT) are extensively used in accomplishing the
studies of pharmaceutics, pharmacology, nutraceutics, toxicology,
bioaccessibility, bioavailability, micro-ecological and general safety
assessments where the complexities of in
vivo studies have evolved from ethical constraints, costs, accuracy,
reproducibility of data, physiological differences among individuals and
excessive time consumption. The competence and the safety of ingesting
fortified and/or pre-/probiotic incorporated foods and drugs, genetically
modified foods, as well as novel compounds at the pre-clinical (drug discovery)
phase of the FDA approval process, cannot always be assured. Thus creating an in vitro digestion model which dissembles
the human GIT with respect to its anatomy, functions, motility and physiology,
will consent us to observe the dynamic processes as closely as possible.
Innovative
concepts of delivering the gastric secretion and the peristaltic gastric
motility are incorporated with sophisticated compositions of the secretions of
the upper GIT in the artificial stomach reactor in which the generated samples
are comprehensively analyzed and compared to in vivo and clinical data for validation.
Cleaning In Place ‘CIP’ in Dairy Plant
Description:
Cleaning-in-Place (CIP) is employed in Oil Refineries and food
industry so that the processing equipments do not need to be dissembled
when they are cleaned.
A considerable amount of research has been conducted in recent years to seek ways of improving the CIP procedure.
Both the chemical reactions and fluid shear play roles in the removal
of fouling deposit but the effect of chemical reaction is one that is
of the key importance.
The dairy industry in particular suffers from problems associated with cleaning production machinery including heat exchangers.
In the dairy industry, thermal processing is an energy intensive process since every product is heated at least once.
Processing over 13 billion liters of milk every year in New Zealand
(Fonterra 2004) means the efficiency of the heating process is of
paramount importance.
Fouling (Deposits) of heat exchangers is a serious problem as it
reduces heat transfer and increases pressure drop. As a result of
fouling, there is a possibility of deterioration in product quality
since the process fluid cannot be heated up to the required temperature
(say for pasteurization or sterilization). The deposits dislodged by
the flowing fluid can also cause contamination.
Fouling related costs are: additional energy, lost productivity,
additional equipment, manpower, chemicals, and environmental impact.
Generally milk fouling is so rapid that heat exchangers need to be
cleaned every day to maintain production capability and efficiency and
meet strict hygiene standards.
In comparison, the heat exchangers in other major processing plants
like petroleum, petrochemical etc need to be cleaned only once or twice
a year.
In the dairy industry the cost due to the interruption in production
can be dominant compared with the cost due to reduction in performance
efficiency. Along with the cost, quality issues are equally important
and in fact many times a shut down is required due to the concerns of
product quality/contamination instead of performance of the heat
exchanger.
The cleaning involves flushing high levels of caustic cleaning
agents through the machines in order to remove residues build up and
contamination. Once the cleaning is finished the machine must then be
rinsed very thoroughly to remove all traces of these cleaning elements.
Our project aim is to establish the fundamentals processes of fouling
and cleaning in order to develop new technology for minimizing fouling
and improve cleaning.
Transdermal drug delivery - modelling and experiments
Researcher: Saptarshi Kar
Heat production via biological methods
Purpose: Heat can be easily produced through electric heating,
burning fuels, etc. However, it has been noted that heat can also be
generated efficiently via biological means. One example for this will
be in compose heaps where temperature can easily reach 60-70șC through
the action of bacterial decomposition. If we can harness the efficiency
of heat production via biological means, this heat can be used in many
different fields.
Production of high-quality bioactive powders using a hybrid spray drying technique: modeling, experimentation and design
Description:
Manufacturing micro- and nano-particles with specific functionalities
is a popular research area today due to attractive applications of
these sorts of particles in biological, medicine, neutraceutical and
functional food industries. Spray drying is a common, simple and
potentially economical route for making dried particles. One common
problem with the spray drying technology is the existence of the large
particle-size distribution in the final product, which may cause
variation in functionalities during its appliance. In this project, we
are aiming to develop a hybrid lab-scale spray drying technique by
combining spray drying, micro-fluidic and ink-jet technologies to
overcome this common problem. For this purpose an ink-jet device, which
is similar to the ink-jet nozzle from office ink-jet printers, is
introduced as an innovative atomizer to the spray drying technology.
Uniform-size droplets having a well-defined trajectory can be produced
using the new atomization system, which offers great potential for
manufacturing of high-quality bioactive products with uniform
properties. We are also intending to develop detailed mathematical
models for the droplet drying and particle solid structure formation
processes, which are dynamic, simultaneous and fast processes.
Furthermore, a detailed mathematical procedure to design a spray dryer based on a hybrid technique will be worked out.
Developing and utilizing a mini-food powder production facility to produce industrially relevant particles for functionality testing.
The ultimate goal is to build a lab scale spray drier that can run simulations and provide useful data for the dairy industry. In the early stages of the project this entails investigation into atomization techniques, rheological characteristics of fluids to be dried, and both theoretical and empirical droplet size predictions.
Recently, I have been recording dynamic drying kinetics for thin layers of milk concentrate. These will serve as a point of reference for the theoretical drying curves that will be used in the design of the spray drying operation for the proposed lab scale drier.
Shear-less cell culturing
Description:
One of major obstacles in cell culturing is shear. Reasonably high level of shear is necessary in large scale culturing to
ensure sufficient mixing. However, this shear presents a problem to the
cells in the culture, especially when culturing cells in high
concentrations or viscous fluids. Shears can hinder growth, disrupt
cell membrane and cell structures, and even cause cell death. Hence, a method to culture cells in shear-less environment will be beneficial to the industry.
Making high quality microencapsulated bioactive particles through microfluidic device followed by spray drying
Manufacturing designed micron-sized particles with specific functions for medical, food and materials applications is a hot topic today. It is proposed here that uniform microencapsulated particles can be obtained through a spray drying technique. This technique combines the use of a micro-fluidic (for making designed encapsulated phases and particle internal structures and surface characteristics), followed by spray drying. The well-defined droplet/particle path generated using the technology offers great potential for the production of high-quality bioactive products with uniform properties. Vitamin B12 will initially be used for encapsulation and controlled release studies. Enzyme or probiotic bacteria will be attempted to encapsulate. The remaining activity will be examined under microscope and some simulated digestive systems such as artificial stomach juice etc.
Researcher: Nada Hamid
Smart particle production, characterisation and powder forensics
The aim of my project is to characterise the microstructure properties of milk powder produced by spray drying in relation to the process parameters including temperature and rate of drying, in order to improve the properties and functionalities of milk powder. Currently, spray drying operation is mainly based on trial and error, whereby the operating conditions are adjusted according to the product quality, with little understanding of the processes involved. This leads to inefficient operations resulting in unwanted agglomeration and loss of functionality, among others.
In particular for milk powder, the surface composition is very important and can vary from the inner composition of the powder particle. This may be due to how the milk droplets are being dried, causing uneven distribution of proteins through segregation. This difference may cause problems for end-users, such as the formation of “clumps” when dissolving the powder in water. Another way to add value to milk powder is by loading proteins and/or vitamins onto the surface. To do this, analysis of the surface properties for later modifications is also required.
The formation of milk fouling is a major problem in food and dairy industries, where frequent cleaning operations lead to increased operating cost and reduced process efficiencies. Fouling in milk processing also leads to a rise in pressure drop across the exchanger and to possible deterioration in product quality due to decreased heat transfer coefficients. Another serious problem associated with fouling is the cleaning of fouled surfaces by means of costly and time-consuming techniques where environmentally offensive chemicals are employed. Total costs due to fouling were approximately at 0.25% of the gross national produce (GNP) for the industrialized world. Given the economic impact of fouling, it is not surprising that there is a considerable amount of research activities on the fouling process.
Fouling caused by milk constituents is a complex process in which milk protein aggregation and deposition in the bulk fluid restricts the area of the flow passages and the heat transfer, and is therefore of major importance for the process. The milk protein fouling mechanism can be described in the following steps:
1 Straight adsorption of a protein mono-layer even at room temperature
2 When temperature is below 65℃, the protein begin to aggregate and calcium phosphate particles are formed
3 Continuous transports of these foulant particles formed in the bulk to the heat surface
4 Activated molecules deposit on the heat surface by adsorption
Because of the adsorption process plays an important role in the formation of milk fouling, my research is focusing on two points:
(1) The effect of adsorption on milk fouling process under different conditions
(2) The characteristics of the first adsorbed mono-layer of protein and protein-protein reaction in the bulk and liquid-solid interface
The technologies of producing new alternative fuels such as ethanol are driven by the rising concerns over the costs of petroleum and the prospect of global warming. The abundance and relatively low cost of lignocellulosic materials make it attractive as a feedstock for the production of sufficient amounts of bio-ethanol from renewable resources.
Researcher: Zhe Liu (Dylan)
Innova-BFE © 2008 |
