Mass Transfer and Volume Changes in French Fries During Air Frying

An erratum to this article can be found at http://dx.doi.org/10.1007/s11947-012-0904-8 (The graph located in the left upper corner of Fig. 2 is incorrect)The production of healthier fried foods requires the adaptation of industrial processes. In this context, air frying is an alternative to deep oil frying to obtain French fries with lower fat content. Kinetic analysis of compositional changes and main fluxes involved in air frying were carried out, and the results were compared to those obtained for deep oil frying. The influence of the type of sample (unpretreated, frozen, or blanched potatoes) was also analyzed. The results showed that oil uptake is much lower in air frying although a much longer processing time is required. Also, water loss and thus the loss of volume were much higher in air frying compared to the conventional process.The authors would like to thank the Universitat Politecnica de Valencia (PAID-06-09-2876) for the financial support given to this investigation.Andrés Grau, AM.; Argüelles Foix, AL.; Castelló Gómez, ML.; Heredia Gutiérrez, AB. (2013). Mass Transfer and Volume Changes in French Fries During Air Frying. Food and Bioprocess Technology. 6(8):1917-1924. https://doi.org/10.1007/s11947-012-0861-2S1917192468Aguilar, C. N., Anzaldúa-Morales, R., Talamás, R., & Gastélum, G. (1997). Low-temperature blanch improves textural quality of French-fries. Journal of Food Science, 62, 568–571.AOAC. (1980). Official methods of analysis (12th ed.). Washington, D.C., USA: Association of Official Analytical Chemists.Califano, A. N., & Calvelo, A. (1987). Adjustment of surface concentration of reducing sugars before frying of potato strips. Journal of Food Processing and Preservation, 12, 1–9.Clark, J. P. (2003). Happy birthday, potato chip! And other snack developments. Food Technology, 57(5), 89–92.Debnath, S., Bhat, K. K., & Rastogi, N. K. (2003). Effect of pre-drying on kinetics of moisture loss and oil uptake during deep fat frying of chickpea flour-based snack food. LWT—Food Science and Technology, 36, 91–98.Du Pont, M. S., Kirby, A. B., & Smith, A. C. (1992). Instrumental and sensory tests of cooked frozen French fries. International Journal of Food Science and Technology, 27, 285–295.Dueik, V., Robert, P., & Bouchon, P. (2010). Vacuum frying reduces oil uptake and improves the quality parameters of carrot crisps. Food Chemistry, 119(3), 1143–1149.Hubbard, L. J., & Farkas, B. E. (2000). Influence of oil temperature on convective heat transfer during immersion frying. Journal of Food Processing and Preservation, 24(2), 143–162.Krokida, M. K., Oreopoulou, V., & Maroulis, Z. B. (2000). Water loss and oil uptake as a function of frying time. Journal of Food Engineering, 44, 39–46.Mestdagh, F., De Wilde, T., Fraselle, S., Govaert, Y., Ooghe, W., Degroodt, J. M., Verhé, R., Van Peteghem, C., & De Meulenaer, B. (2008). Optimization of the blanching process to reduce acrylamide in fried potatoes. LWT- Food Science and Technology, 41(9), 1648–1654.Mohsenin, N. M. (1986). Physical properties of plant and animal materials. Nueva York: Gordon and Breach.Moyano, P. C., & Pedreschi, F. (2006). Kinetics of oil uptake during frying of potato slices: effect of pre-treatments. LWT- Food Science and Technology, 39, 285–291.Ngadi, M. O., Wang, Y., Adedeji, A. A., & Raghavan, G. S. V. (2009). Effect of microwave pretreatment on mass transfer during deep-fat frying of chicken nugget. LWT- Food Science and Technology, 42(1), 438–440.Pedreschi, F., & Moyano, P. (2005). Oil uptake and texture development in fried potato slices. Journal of Food Engineering, 70(4), 557–563.Saguy, S., & Dana, D. (2003). Integrated approach to deep fat frying: engineering, nutrition, health and consumer aspects. Journal of Food Engineering, 56, 143–152.Troncoso, E., & Pedreschi, F. (2009). Modeling water loss and oil uptake during vacuum frying of pre-treated potato slices. LWT- Food Science and Technology, 42(6), 1164–1173

Digestion of Raw and Roasted Almonds in Simulated Gastric Environment

Knowledge of digestion kinetics of solid foods in human stomach, as affected by food processing methods, is critical in establishing processing conditions at the manufacturing stage to achieve desirable release of nutrients in the gastrointestinal tract. The objective of this study was to investigate how roasting affected disintegration and solid release properties of almond in simulated gastric environment. In vitro trials were performed for raw and roasted almonds by using static soaking method and a model stomach system. The changes in sample weight, dry mass, and moisture during the trials were determined. Both compression and penetration tests were used to investigate the texture of almonds with a focus on the influence of absorption of gastric juice. Light microscopy and transmission electronic microscopy were used to study the change in microstructure of the raw and roasted almonds after simulated digestion. The results suggested that the slow disintegration rate and the high amount of swelling of the almonds in the stomach may contribute to their high satiety property. Roasting significantly improved the disintegration rates of almonds and increased loss of solids during simulated digestion, which is well correlated with the decrease in the rigidity of almond samples after absorbing gastric juice. Microstructure of digested almonds showed breakage and breach of cell walls due to acid hydrolysis. Intercellular and intracellular channels formed in almonds during roasting are important for penetration of gastric juice that may facilitate an effective digestion

The use of electric fields for edible coatings and films development and production: A review

Edible films and coatings can provide additional protection for food, while being a fully biodegradable, environmentally friendly packaging system. A diversity of raw materials used to produce edible coatings and films are extracted from marine and agricultural sources, including animals and plants. Electric fields processing holds advantage in producing safe, wholesome and nutritious food. Recently, the presence of a moderate electric field during the preparation of edible coatings and films was shown to influence their main properties, demonstrating its usefulness to tailor edible films and coatings for specific applications. This manuscript reviews the main aspects of the use of electric fields in the production of edible films and coatings, including the effect in their transport and mechanical properties, solubility and microstructure.Fundação para a Ciência e a Tecnologia (FCT), Portugal.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brasil

Characteristics of Different Systems for the Solar Drying of Crops

Solar dryers are used to enable the preservation of agricultural crops, food processing industries for dehydration of fruits and vegetables, fish and meat drying, dairy industries for production of milk powder, seasoning of wood and timber, textile industries for drying of textile materials. The fundamental concepts and contexts of their use to dry crops is discussed in the chapter. It is shown that solar drying is the outcome of complex interactions particular between the intensity and duration of solar energy, the prevailing ambient relative humidity and temperature, the characteristics of the particular crop and its pre-preparation and the design and operation of the solar dryer