Effect of soy protein/starch edible coatings on drying kinetics of french fries

Abstract

The potato (Solanum tuberosum) is an annual herbaceous, growing up to 100 cm in height and produces a tuber that ranks as the fourth world food crop, after maize, wheat and rice. Although the United States is the fifth largest potato producer in the world, only a third of the potatoes is consumed fresh and 60% of annual output is processed into frozen products such as frozen French fries and wedges, crisps, dehydrated potato and starch. In Brazil, the annual consumption is around 14 kg per inhabitant, but this market is changing, particularly for processed potato snacks. The development of chronic non-communicable diseases is associated with several factors such as inadequate physical activity, excess intake of calories and fat, inadequate intake of vitamins and minerals, excessive alcohol consumption and genetics. The increase in the consumption of fried foods is critical, requiring alternatives to reduce the absorption of fats from fried foods. It is known that some edible coatings are able to reduce the oil absorption during the frying process (e.g., coatings based on hydroxypropyl methylcellulose and whey; guar gum; carboxymethylcellulose and pectin; Basil seed gum and salep; whey protein and pectin in the presence of transglutaminase; methylcellulose). One of the limitations of the implementation of this technological innovation in the industry is that few studies focusing on the effect of different drying parameters on covered foods may be found in literature and, in most studies, the foods are dried at room temperature, which would require longer processing time. In this context, this book chapter aimed to study the role of edible coatings based on natural polymers (soy protein-SPI and potato starch) on process variables such as drying temperature and time. Kinetic modeling was used to study the drying behavior of potatoes after applying the coating. The Fick equation was considered to calculate the mass diffusivity