3:00pm - 3:20pm
Consolidated Bioprocessing in Brewing and Distilling
McGill University, Canada
Although equipment may have changed, the process of brewing beer has remained relatively the same for centuries. Improvements in energy and water efficiency have occurred, but little of the available modern food processing technologies have grown into regular usage. Flash pasteurization, filter presses, and many more process operations cannot be easily employed due to the simple fact that the brewing wort is required to sit on the grain bed for extended periods of time for the effective enzymatic conversion of starch to fermentable sugars to occur.
Avoiding this step could allow for modern equipment to be introduced into breweries, with strong potential to develop new manufacturing processes and opportunity to develop entirely new product lines. This can be achieved by having necessary yeasts produce extra-cellular enzymes to convert the solubilized starch into sugar which they can subsequently ferment to ethanol in a single step. Consolidation of these two steps occurs rather frequently in biofuel production and several yeasts capable of doing so are currently available. This potential is within arm’s length of the brewing and distilling industries. What remains is a for research into process design, product quality analysis, and finally equipment design to occur.
Experiments to verify the potential for yeasts to perform process consolidation, their impacts on quality such as flavor, aroma, and appearance, as well as areas where more work is necessary will be presented.
3:20pm - 3:40pm
Conversion of Yellow European Plums to Commercial Golden Prunes.
1School of Engineering, University of Guelph, Canada; 2Department of Plant Agriculture, University of Guelph, Canada; 3EARTH University, Limon, 4442-1000 San Jose, Costa Rica
Prunes, which are commercially produced by dehydrating plums are considered to be a prominent source of health promoting nutraceutical compounds including phenolics, flavonoids, and vitamins. Conversion of plums into prunes using dehydration process is a critical part of their postharvest handling. Producers and processors of a novel variety named Yellow skinned European Plums (YEPs) in Ontario, Canada are facing a major problem of browning caused by thermal degradation of sugars during conventional hot-air dehydration process, which results in commercially less appealing brown prunes. However, pre-treating YEPs with chemicals including, ascorbic acid, citric acid and potassium meta-bi-sulphite can reduce browning of YEPs and improve the overall efficiency of the dehydration process. Hence, in this study optimization of conventional hot-air and advance freeze dehydration processes with and without chemical pre-treatment of YEPs was undertaken to produce commercializable dried golden prunes.
3:40pm - 4:00pm
Modification of mass transfer during deep-fat frying
McGill University, Canada
Mass transfers occur during deep-fat frying. In this study, the influence of different centrifugal speeds on oil and moisture content of potato and eggplant during frying and post-frying were investigated. About 25 × 2 mm disc of eggplants (Solanum melongena L. family Solanaceae) and potato (Solanum tuberosum var. Bintje) were fried in canola oil. The frying temperatures used were 130, 150 and 170°C and the frying times were 1, 2, 3, 4 and 5 min. The frying oils were continuously stirred at centrifugal speeds of 100, 200 and 300 rpm during frying, and the products were cooled while spinning at 500, 1000 and 1500 rpm. The results showed that as the speed of rotation increased from 100 to 300 rpm, both moisture loss and oil uptake decreased. Increasing frying time and temperature decreased moisture content while oil content increased. Higher frying temperatures and time significantly (P<0.05) decreased oil efflux in the fried potato samples during the post-frying centrifugation while in the eggplant samples oil efflux was significantly increased (P<0.05). The optimal frying conditions were 150°C, 5 min and 300 rpm, which gave the highest oil efflux of 50 and 80%, respectively in potato and eggplant at 1000 rpm centrifugal force after 5 min. This result showed that integrating oil rotation during frying and use of centrifugal force during cooling of fried products can significantly reduce the amount of oil in fried products.
4:00pm - 4:20pm
Numerical Analysis of Electrohydrodynamic Drying
University of Guelph, Canada
Current drying techniques used in food industries are energy intensive processes that operate at elevated temperatures and are very costly to maintain. Industries are now exploring possible alternatives that can reduce energy consumption for thermally sensitive food products. An innovative process is electrohydrodynamic (EHD) dehydration which enhances heat and mass transfer using electrohdrodynamics. While there are several literatures explaining either heat and mass transfer in porous media or the effects of EHD flow, there are only a few researches that have been done on the combination of both. The purpose of this paper is to develop a numerical model in COMSOL Multiphysics and evaluate electric (electrode gap and electric potential) and porous media (vapor and liquid phase concentration) parameters. The results of model showed that a lower electrode gap would allow for efficient evaporation and that the vortex formation due to presence of air cross-flow can cause the process of evaporation in the opposite direction to the cross flow.
4:20pm - 4:40pm
Numerical modelling of superheated steam drying of a single distillers’ spent grain pellet coated with condensed solubles
University of Manitoba, Canada
The method of drying paste slurry liquids over a dried core which serves as drying nuclei is still under research. This method can be adopted for drying sticky materials like condensed distillers’ solubles(CDS). The current study focuses on the superheated steam (SS) drying of distillers’ spent grain (DSG) pellets and then utilizes those dried pellets as a core material to dry the wet CDS. The drying experiments were conducted with cylindrical DSG pellets at 25% (wet basis) moisture content coated with a thin layer (2.5±0.5mm) of the CDS at different SS temperatures (120, 150, 180°C) and velocities (0.5, 1.0, 1.5 m/s). Separate experiments were done to obtain the drying characteristics and the effective moisture diffusivity of the CDS and the DSG pellets without coating, using a thin layer drying model and diffusion equations for the cylinder. The average effective moisture diffusivity of the CDS and DSG pellets was found to be in the range of 3.3×10-10- 3.7×10-9 and 4.1×10-9 – 4.2×10-8, respectively. A computational fluid dynamics (CFD) model was developed using ANSYS CFX by combining the Reynolds-Average Navier-Stokes (RANS) equations for the SS flow and the diffusion models and transport equations for the DSG pellet with the CDS coating. The comparison of the model with the experimental drying curves gave good agreement. Such models help to predict the SS drying characteristics of liquid materials dried over a porous dry nucleus. This can provide valuable information for the design or optimization steps of an appropriate drying system for such materials.
4:40pm - 5:00pm
Process Intensification of Phenolic Extraction from Plums
1School of Engineering, University of Guelph, 50 Stone Road East, Guelph, Ontario, Canada, N1G 2W1; 2Department of Plant Agriculture, University of Guelph, 4890 Victoria Avenue North, Vineland, Ontario, Canada, L0R 2E0
In Canada, more than $31 billion worth of food waste is generated every year which has potential for significant environmental and social impacts. However, these wastes are rich in health promoting phytochemicals including phenolic compounds, flavonoids etc., which are low molecular weight plant secondary metabolites and are chemically very heterogeneous. Hence, valorization of agricultural and retail food wastes into nutraceutical compounds using conventional and novel extraction methods will generate more revenues for food producers, processors and retailers. But, conventional solid-solvent extraction methods, such as soxhlet and heat reflux, are associated with longer extraction times, high consumption of organic solvents, low energy efficiency and high operational and maintenance cost. Various novel extraction methods including microwave-assisted extraction (MAE), pulsed electric field (PEF), ultrasonication and supercritical fluid extraction (SFE) can be used as an alternative to conventional methods. Of all the aforementioned techniques MAE is a highly viable alternative. MAE utilizes microwave energy for rapid homogeneous heating of low volume of organic solvents and the biomatrix (eg. Organic food waste) to facilitate a synergistic combination of heat and mass transfer. This synergy results in volumetric dissipation of heat and pressure that enhances the overall extraction yield of phytochemicals from biomatrix and also provides selective extraction capabilities that lacks in other novel techniques. In the current study MAE technique is utilized for selective extraction of high value phenolic compounds from various genotypes of Yellow European plums, while reducing extraction time, solvent usage, and energy.