4 Alexandra Smith 1*, Brett Kenney 1, Susan Slider 1, Jacek Jaczynski 1, Litha Sivanandan 2, and Bryce MacAulay 3. 1.Davis College of Agriculture, Natural Resources, and Design; West Virginia University, 2. WVU Extension Service, West Virginia University 2.3. Statler College of Engineering and Mineral Resources. EFFECT OF PROCESSING PARAMETERS ON DRIED BLUEBERRY YIELD D ISCUSSION AND C ONCLUSION Significantly higher yields of final product from: Higher sugar solution concentration (p<0.0001). o These blueberries experienced higher water loss with subsequent sugar gain. Higher temperatures during osmotic dehydration (p=0.0004). o Increasing the temperature increases the diffusion rate because energy is added to the particles. Longer osmotic dehydration durations produces higher yield of the final product (p<0.0001). o Longer times allow for longer sugar transfer, blueberries in the longer duration groups should have a higher sugar concentration, thus increasing the final product yield. Final water activity was lowest when treated with 65°Brix and 25°C: o Suggests that higher yields with higher temperatures may be due to inefficient water loss. o Lower water activity better for product safety. Application of the parameters could improve transfer rates, which may help cut costs and reduce product waste, and cause an increase in yield which will increase profit. A CKNOWLEDGEMENTS Funding: Partial support from National Science Foundation's ADVANCE IT Program under Award HRD Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Partial support from Branch Banking and Trust Company’s CRA / Community Development Donation Fund. Acknowledgements: Ida Holaskova, Tammy Webster, West Virginia University. Air Tank Vacuum Pump Vacuum Chamber Osmotic Dehydration Chamber 1:3g/g Fruit to Solution Schematic of the Pulsed Vacuum Osmotic Dehydration Apparatus. O BJECTIVES o Describe the influence of vacuum, temperature, osmotic solution concentration, and treatment duration on blueberry mass transfer phenomena. R ESULTS A BSTRACT Fruit drying is energy intensive (thermal efficiency 25 ‑ 50%). Improved efficiency is possible if phase change is minimized during the process. To minimize phase change and increase product yield and quality, osmotic dehydration and pulsed-vacuum osmotic dehydration can be applied to maximize water removal before final drying. Objectives of this study were to 1) characterize the effect of vacuum, osmotic solution temperature and concentration, and treatment duration on blueberry mass transfer; and 2) achieve an operating condition that maximizes yield and minimizes processing time. Frozen blueberries were exposed to 2 temperatures (25 or 50°C), 2 sugar solution concentrations (45 or 65°Brix), 2 vacuum treatments (no vacuum or 50 mbar), and 3 duration treatments (180, 240, or 300 minutes). This design generated 24 treatment combinations that were nested in °Brix as a balanced incomplete block design. Following treatments, blueberries were conventionally dehydrated at 57.2°C for 6.5 hours. Higher concentration of osmotic solution increased blueberry sugar gains by 62% compared to sugar gains at the lower concentration. Time affected sugar gain at both concentrations (p<0.0001). Original blueberry °Brix was about 13.0°Brix and increased by 13.03, 17.29, and 17.68°Brix at 180, 240, and 300 minutes, respectively. Solution concentration, temperature, and time affected percent yield after conventional drying (p<0.0001, p=0.0004, p<0.0001, respectively). Higher temperatures increased yield of the final product compared to the lower temperature. Water activity appeared to be affected by an interaction between solution concentration and temperature (p=0.0210). Low temperature processes can be used commercially to reduce water activity of high moisture products and decrease the processing time; thereby, improving yield and producing minimally processed fruit products with marginal changes in color, texture, aroma, and flavor.