Mathematical modelling and optimisation of the formulation and manufacture of aggregate food products

In this PhD study, mathematical modelling and optimisation of granola production has been carried out. Granola is an aggregated food product used in breakfast cereals and cereal bars. It is a baked crispy food product typically incorporating oats, other cereals and nuts bound together with a binder, such as honey, water and oil, to form a structured unit aggregate. In this work, the design and operation of two parallel processes to produce aggregate granola products were incorporated: i) a high shear mixing granulation stage (in a designated granulator) followed by drying/toasting in an oven. ii) a continuous fluidised bed followed by drying/toasting in an oven. In addition, the particle breakage of granola during pneumatic conveying produced by both a high shear granulator (HSG) and fluidised bed granulator (FBG) process were examined. Products were pneumatically conveyed in a purpose built conveying rig designed to mimic product conveying and packaging. Three different conveying rig configurations were employed; a straight pipe, a rig consisting two 45° bends and one with 90° bend. It was observed that the least amount of breakage occurred in the straight pipe while the most breakage occurred at 90° bend pipe. Moreover, lower levels of breakage were observed in two 45° bend pipe than the 90° bend vi pipe configuration. In general, increasing the impact angle increases the degree of breakage. Additionally for the granules produced in the HSG, those produced at 300 rpm have the lowest breakage rates while the granules produced at 150 rpm have the highest breakage rates. This effect clearly the importance of shear history (during granule production) on breakage rates during subsequent processing. In terms of the FBG there was no single operating parameter that was deemed to have a significant effect on breakage during subsequent conveying. A population balance model was developed to analyse the particle breakage occurring during pneumatic conveying. The population balance equations that govern this breakage process are solved using discretization. The Markov chain method was used for the solution of PBEs for this process. This study found that increasing the air velocity (by increasing the air pressure to the rig), results in increased breakage among granola aggregates. Furthermore, the analysis carried out in this work provides that a greater degree of breakage of granola aggregates occur in line with an increase in bend angle.

Validation and reliability of the Japanese version of the Food Allergy Quality of Life Questionnaire - Parent Form

Background: Food allergy (FA) is a heavy burden for patients and their families and can significantly reduce the quality of life (QoL) of both. To provide adequate support, qualitative and quantitative evaluation of the parents' QoL may be helpful. The objective of this study is to develop and validate a Japanese version of the Food Allergy QoL QuestionnaireeParent Form (FAQLQ-PF-J), an internationally validated disease-specific QoL measurement of the parental burden of having a child with FA. Methods: The FAQLQ-PF and the Food Allergy Independent Measure (FAIM), an instrument to test the construct validity of the FAQLQ-PF-J, were translated into Japanese. After language validation, the questionnaires were administered to parents of FA children aged 0e12 years and those of age-matched healthy (without FA) children. Internal consistency (by Cronbach's a) and test-retest reliability were evaluated. Construct validity and discriminant validity were also examined. Results: One hundred twenty-seven parents of children with FA and 48 parents of healthy children filled out the questionnaire. The FAQLQ-PF-J showed excellent internal consistency (Cronbach's a > 0.77) and test-retest reliability. Good construct validity was demonstrated by significant correlations between the FAQLQ-PF-J and FAIM-J scores. It discriminated parents of children with FA from those without. The scores were significantly higher (lower QoL) for parents of FA children with a history of anaphylaxis than those without, for those with >6 FA-related symptoms experienced than those with less FA-related symptoms. Conclusions: The FAQLQ-PF-J is a reliable and valid measure of the parental burden of FA in children.