Fried Potato Products Research Articles

Static and perfusion culture of adult neocortex

Acrylamide formation during the production of French fries is attributed to Maillard reactions from reducing sugars and asparagine and is dependent on the frying temperature. Low reducing sugars content in potatoes has been recommended to produce fried potato products. However, the influence of the complexity of the potato medium in the chemical reactions that promote the acrylamide formation during deep frying are not well understood. In this study, three potato cultivars (Kennebec, Red Pontiac and Agria) commonly used for fried potato products were evaluated to determine the relationships between the precursors of acrylamide in the fresh potato tubers and the properties of the fried potato strips with the acrylamide content after frying. Frying experiments were conducted at three conditions (time-temperature) to obtain French fries of similar visual colour. Acrylamide formation increased with frying temperature but different behaviour was observed between cultivars. For Red Pontiac, a remarkably increase in acrylamide content was found at 170 °C (∼40%) together with the increase in colour. However, lower oil uptake and higher moisture content was obtained as temperature increase. Significant positive correlations were observed between the acrylamide level and the reducing sugars and sucrose content on fresh potatoes (0.652, 0.699, p ≤ 0.01, respectively). The acrylamide content obtained in Agria cultivar may be obtained from the hydrolysis of sucrose during the frying process. In fried potato strips, positive significant correlation was found between the shear force and acrylamide (0.749, p ≤ 0.01). The significant correlations obtained between colour, and texture, colour and oil uptake and texture and acrylamide content indicate the intrinsic relationship between the properties of the fried potato strips and the acrylamide content.

Sterols and sterol oxides in the potato products, and sterols in the vegetable oils used for industrial frying operations

The objective of this study was to determine the composition of sterols in vegetable oils used in industrial frying operations, and sterols and sterol oxides in the fried potato products. The sterols and sterol oxides were enriched by saponification of oils and by solid phase extraction. Preparative thin layer chromatography, capillary gas chromatography, gas chromatography-mass spectrometry, and nuclear magnetic resonance spectroscopy, were used to give qualitative and quantitative data. The results revealed that the content of desmethylsterols in palm oil, sunflower oil, high oleic sunflower oil, and rapeseed oil/palm oil blend were, 790, 4501, 3550, and 4497 ppm, respectively. Sitosterol was the major desmethylsterol in all samples. Palm oil also contained the lowest levels of total unsaponifiables. The sterols and unsaponifiable contents in sunflower oil were, to some extent, higher than in higholeic sunflower oil. The compositions of sterols after two days of frying were neither markedly different in the oils nor in the potato products fried in these oils compared with the original oils. Isomerised sterols were tentatively quantified to account for 10 ppm, 50 ppm and 20 ppm, in rapeseed oil/palm oil blend, sunflower oil, and high-oleic sunflower oils, respectively. Lipids extracted from French fries prepared in rapeseed oil/palm oil blend contained the highest levels of total sterol oxides, 191 ppm, and epoxides of both sitosterol and campesterol were the major contributors, together at a level of 172 ppm. On the other hand, lipids extracted from French fries prepared in sunflower oil and high-oleic sunflower oil contained 7α-hydroxy-, 7β-hydroxy-, 7-keto- and both epimers of epoxysitosterol, generally in equal amounts. All samples also contained small amounts of different oxidation products of campesterol and stigmasterol.

Deep‐Fat Fried Potato Product Oil Uptake as Affected by Crust Physical Properties

ABSTRACTPhysical properties were determined on the crust region of a restructured potato product undergoing deep‐fat frying. Deformability modulus of the raw material, ranging from 37 to 127 kPa markedly affected moisture content and oil uptake of the restructured product, and its crust. It also affected crust thickness at frying time of 5 min. Lower deformability modulus promoted thicker crust ranging from 327 ± 17 to 650 ± 29 μm. Crust porosity decreased throughout frying, and was markedly affected by lower gel‐strengths. Crust yield strength was affected by trying time and deformability modulus of the raw material. Crust oil uptake stopped when crust yield strength reached a critical value of 210 to 240 kPa. Oil uptake in the crust ranged from ca. 35 to 38% after 1 min and 60 to 85% after 5 min frying.

Color Development in a Model System During Frying: Role of Individual Amino Acids and Sugars

ABSTRACTThe color of fried potato products is limited by reducing sugars, but can be affected by free amino acids. Filter paper discs saturated with solutions of amino acids in combination with glucose, fructose and sucrose were fried in oil to investigate color formation. Four phases of color development were identified; equilibrium, lag, rapid and slow phase, corresponding to the water content of the system. Lysine, 7‐aminobutyric acid and glycine produced most color and glutamic acid least. Fry color of glucose and fructose systems was very similar, but sucrose systems produced less color. Glucose and fructose systems were not affected by pH changes, but there was a slight effect on sucrose systems.

Adipose tissue metabolism

Obesity is a critical risk factor for various diseases including type II diabetes, cerebral infarction, cardiovascular diseases, and various cancers. Acrylamide (ACR) is present in wide range of foods, including fried potato products, root vegetables, bakery products, chips, cakes, cereals, and coffee. In this study, ACR treatment dramatically increased the accumulation of lipid droplets. We also examined expression levels of peroxisome proliferator-activated receptors γ (PPARγ), CCAAT enhancer binding protein α (c/EBPα), and CCAAT enhancer binding protein β (c/EBPβ) as adipogenic transcription factors for adipocyte differentiation. They were dose-dependently increased by treatment of ACR. Moreover, effects of ACR on mitogen-activated protein kinases (MAPKs) and 5′ AMP-activated protein kinase (AMPK)-Acetyl-CoA carboxylase (ACC) activation were investigated. Results also showed that ACR induced phosphorylation of MAPKs and AMPK-ACC. ACR also induced expression of adipocyte fatty acid-binding protein (aP2), lipoprotein lipase (LPL), sterol regulatory element-binding protein (SREBP)-1c, and fatty acid synthase (FAS). Exposure of ACR to high fat diet (HFD)-fed mice significantly increased body weight, organ weight, and fat mass of mice. Collectively, these result showed that ACR can act as an enhancer of adipocyte. Therefore, we suggest that up-regulation of the adipogenesis by ACR may be related to the regulation of the MAPKs and AMPK-ACC pathway.