Osmotic dehydration of peas: I. Influence of process variables on mass transfer

Osmotic dehydration of uniformly sized peas at 30C was studied using different solutions of sucrose, sodium citrate and sucrose+citrate mixture. The influence of various factors such as solution concentration and composition and the effect of agitation on the mass transfer mechanism was investigated. It was shown that the rate of water loss in the sample was increased by increasing concentration of osmosis solution and agitation. The most effective osmotic dehydration was obtained in sucrose+citrate mixed solutions of 60% total solids level for which a dehydration model was proposed. The apparent diffusion coefficient of water Da, was determined using the dehydration model. The values of Da were found to be in the range 9.10 × 10-11 - 7.63 × 10-10 m2/s

Osmotic dehydration of peas II. Influence of osmosis on drying behavior and product quality

The effect of osmotic dehydration on subsequent air drying behavior and product quality was investigated for peas being osmosed in sucrose and sucrose+citrate mixed solutions. Compared to nonosmosed samples, osmosed samples gave much higher drying rate. It was found that initial osmotic step shortened the air drying time by 55-70%, depending on the osmosis solution and process conditions. It was shown that by initial osmotic dehydration especially in sucrose+citrate solution, a product with higher allowable moisture content and increased solid density can be obtained and rehydration characteristics of osmosed samples are improved. In addition, product thus obtained had a more attractive color and standard level of organoleptic acceptability

Spray drying of yogurt: Optimization of process conditions for improving viability and other quality attributes

Plain yogurt was subjected to spray drying to determine the optimum processing conditions that yield maximum survival ratio of lactic acid bacteria, maximum overall sensory attributes, minimum color change, and acceptable moisture content. The inlet (150-180° C) and outlet air temperatures (60-90° C) and the feed temperature (4-30° C) were the independent factors. A pilot-scale spray dryer was used to conduct a set of drying experiments where the process conditions were selected according to central composite rotatable design (CCRD). The resulting yogurt powder at each condition was also subjected to the measurement of some physical properties (water activity, titratable acidity [lactic acid, %] and pH) to determine the effects of spray-drying conditions. The morphological structure of the powder was inspected by scanning electron microscopy (SEM) analysis. Optimization by the application of the desirability function method resulted in air inlet temperature of 171° C, air outlet temperature of 60.5° C, and feed temperature of 15° C as the optimum processing condition. The mathematical optimum condition was experimentally verified. © 2010 Taylor & Francis Group.Firat University Scientific Research Projects Management Unit 107 O 090 Ege ÜniversitesiThe authors acknowledge the financial support of TUBITAK-TOVAG (Project no. 107 O 090) and Ege University, Council of Scientific Research Projects (Project no. BAP 2006/Muh/043), and Pinar Dairy Products Company, Izmir, Turkey. -

Investigation of drying conditions to valorize 2-phase olive pomace in further processing

Pre-dried 2-phase olive pomace was dried until 8% moisture content of it by tray dryer. The effect of tray dryer’s process conditions in terms of drying temperature (70–90 °C), air velocity (0.5–1.8 m/s), and sample thickness (0.5–1.5) on the quality of olive pomace and system energy efficiency were investigated. Moreover, tray dryer process parameters were optimized considering of minimum drying time, minimum quality loss of olive pomace, and maximum system energy efficiency. The optimum tray dryer conditions were 85.2 °C of drying temperature, 1.72 m/s of air velocity, and 0.5 cm of sample thickness as specified by using the Design Expert packaged software. The effects of drying temperature, air velocity, and sample thickness on the physical and chemical properties of dried 2-phase olive pomace (free fatty acid and specific absorption value [K232, K270]) and the system’s energy efficiency (in terms of the moisture extraction rate and specific energy consumption) were examined. © 2020 Taylor ; Francis Group, LLC.The authors acknowledge Ege University, Council of Scientific Research Projects (Project Number: 16-MUH-024) for financial support.16-MUH-024; Ege Üniversites

Effects of extraction methods and conditions on bioactive compounds extracted from phaeodactylum tricornutum

The effect of homogenization, ultrasound and microwave extraction methods and conditions on fucoxanthin content, total phenolic content and antioxidant activity of extracts obtained from Phaeodactylum tricornutum were investigated in this study. The solvent/biomass ratio was the most effective parameter on fucoxanthin content, total phenolic content and antioxidant activity. The maximum fucoxanthin content (5.60 ± 0.06 mg/g) and antioxidant activity (763.00 ± 15.88 EC50 µg/mL extract) were obtained with the homogenization extraction method whose optimum conditions were 1.93% biomass/solvent ratio, ~5200 rpm homogenization rate and 14.2 min extraction time. Although the ultrasonic extraction method has reached the approximately same level of fucoxanthin content (5.24 ± 0.07 mg/g)), TPC (67.68 ± 1.58 mg gallic acid/L) and antioxidant activity (619.90 ± 17.16 EC50 µg/mL extract) at an amplitude of 55.72%, a higher biomass/ solvent ratio (2.72%) and a longer extraction time (17.37 min) have been required. The lowest fucoxanthin content, total phenolic content and antioxidant activity were determined for the microwave extraction method. © 2020 Slovensko Kemijsko Drustvo. All rights reserved.ES1408; Türkiye Bilimsel ve Teknolojik Araştirma Kurumu, TÜBITAK: TUBITAK-115O578This study was a part of Cost Action ES1408 and the authors would like to thank The Scientific and Technological Research Council of Turkey (TUBITAK-115O578) for financial support