T. Koray Palazoğlu

Effect of Cooking Method (Baking Compared with Frying) on Acrylamide Level of Potato Chips

The effect of cooking method (baking compared with frying) on acrylamide level of potato chips was investigated in this study. Baking and frying experiments were conducted at 170, 180, and 190 degrees C using potato slices with a thickness of 1.4 mm. Raw potatoes were analyzed for reducing sugars and asparagine. Surface and internal temperatures of potato slices were monitored during the experiments to better explain the results. Fried and baked chips were analyzed for acrylamide content using an LC-MS method. The results showed that acrylamide level of potato chips prepared by frying increased with frying temperature (19.6 ng/g at 170 degrees C, 39 ng/g at 180 degrees C, and 95 ng/g at 190 degrees C). In baking, however, the highest acrylamide level was observed in potato chips prepared at 170 degrees C (47.8 ng/g at 170 degrees C, 19.3 ng/g at 180 degrees C, and 29.7 ng/g at 190 degrees C). The results showed that baking at 170 degrees C more than doubled the acrylamide amount that formed upon frying at the same temperature, whereas at 180 and 190 degrees C, the acrylamide levels of chips prepared by baking were lower than their fried counterparts.

Effect of Radio Frequency Postdrying of Partially Baked Cookies on Acrylamide Content, Texture, and Color of the Final Product

Effect of radio frequency (RF) postdrying of partially baked cookies on acrylamide content, texture, and color of the final product was investigated in this study. Control cookies were prepared by baking in a conventional oven at 205 °C for 11 min. Cookies partially baked for 8 and 9 min were postdried in a 27.12 MHz RF tunnel oven until attainment of the moisture content of control cookies. Internal temperature of cookies was monitored during the experiments to better explain the results. Cookies were analyzed for acrylamide content using a liquid chromatography-mass spectrometry (LC-MS) method. Texture measurements were performed using a Texture Analyzer, while digital image analysis was used for color measurement. The results showed that RF postdrying of partially baked cookies resulted in lower acrylamide levels (107.3 ng/g for control cookies, 74.6 ng/g upon RF postdrying of cookies partially baked for 9 min, 51.1 ng/g upon RF postdrying of cookies partially baked for 8 min). Instrumental texture analysis showed no significant difference among the texture of cookies, whereas RF postdried samples had a lower degree of browning. According to sensory evaluation results, control had a more crumbly texture, and RF postdried sample that was conventionally baked for 8 min had a slightly uncooked flavor.

Processing treatments for mitigating acrylamide formation in sweetpotato French fries.

Acrylamide formation in sweetpotato French fries (SPFF) is likely a potential health concern as there is an increasing demand for good-quality fries from carotene-rich sweetpotatoes (SP). This is the first report on acrylamide formation in SPFF as affected by processing methods. Acrylamide levels in SPFF from untreated SP strips fried at 165 °C for 2, 3, and 5 min were 124.9, 255.5, and 452.0 ng/g fresh weight, which were reduced by about 7 times to 16.3, 36.9, and 58.3 ng/g, respectively, when the strips were subjected to processing that included water blanching and soaking in 0.5% sodium acid pyrophosphate before frying. An additional step of strip soaking in 0.4% calcium chloride solution before par-frying increased the calcium content from 0.2 to 0.8 mg/g and decreased the acrylamide levels to 6.3, 17.6, and 35.4 ng/g, respectively. SPFF with acrylamide level of <100 ng/g or several times lower than that of white potato French fries can be obtained by integrating processing treatments commonly used in the food industry.

Effect of tube curvature ratio on the residence time distribution of multiple particles in helical tubes

Abstract The flow of solid–liquid mixtures, containing a heterogeneous mixture of particles, in helical tubes was investigated. The effects of curvature ratio of the helical tube (ratio of tube diameter to coil diameter), flow rate, carrier fluid viscosity, and particle concentration on the residence time (RT) and residence time distribution (RTD) were determined. All of the parameters, except the carrier fluid viscosity, had strong effects on the flow behavior of particles. The RT of acrylic particles decreased slightly upon mixing with the lower-density polystyrene particles. An increase in the flow rate and/or the curvature ratio resulted in a narrower RTD for both particle types.

Effect of combining conventional frying with radio-frequency post-drying on acrylamide level and quality attributes of potato chips.

BACKGROUND In conventional manufacturing of potato chips, achieving an extremely low moisture content (2% by weight) in the final product necessitates prolonged exposure of potato slices to high oil temperatures. This promotes acrylamide formation and causes an exponential increase in acrylamide level toward the end of the frying process. In this regard, frying potato slices partially in hot oil followed by a radio-frequency (RF) drying treatment to selectively heat the remaining moisture appears to be a viable approach in terms of limiting acrylamide formation. RESULTS RF post-drying of partially fried potato slices resulted in lower acrylamide levels (80.4 ng g(-1) for control, 59.4 ng g(-1) for RF post-dried potato slices partially fried for 95 s, 54.8 ng g(-1) for RF post-dried potato slices partially fried for 80 s). This process modification also led a to 12% reduction in oil content in the final product. According to instrumental analysis results, RF post-dried samples had lower hardness and a slightly lower degree of browning in comparison to control. No significant difference (α = 0.05) was found between samples in terms of sensory characteristics. CONCLUSION Results demonstrate that RF post-processing may be an effective strategy for minimising acrylamide levels of potato chips without adversely affecting quality attributes.