ABSTRACT
Typically, most snacks contain large quantities of oil that impact sensory properties, oxidative stability, shelf-life, caloric density, and nutritional value. The most common way to include oils in snacks is through deep-fat frying. There are a wide array of commercial oils in the market and the proper selection is of utmost importance in terms of product quality. Most commercial oils are first mechanically and/or chemically extracted from soybeans, palm, cottonseed, canola, corn germ, peanuts, sunflower, safflower, sesame, and coconut followed by chemical or physical refining which removes phospholipids, free fatty acids, pigments, mono and diglycerides, aldehydes, ketones, and other impurities. New frying oils are emerging with different fatty acid (FA) profiles that favor stability, especially when used in deep-fat frying operations. The most relevant are high-oleic oils extracted from new varieties of soybeans, cottonseed, canola, corn, sunflower and safflower. Refined oils differ in their FA composition, iodine value, saponification value, and amounts of omega 9, 6, and 3 FA, which have different implications in human health. These oils can undergo partial or total hydrogenation, fractionation, and intra- or interesterification in order to modify their physical, chemical, and oxidative stability properties. Partially hydrogenated oils are being discontinued in many parts of the globe because they contain significant amounts of trans FA that are related to a higher incidence of chronic diseases and cancer. Palm oil is commonly fractionated into olearin and stearin with contrasting FA profiles and iodine values. Stearins alone or blended with other vegetable oils are commonly used for frying purposes to generate trans-free snacks. Recently, the technology to produce trans-free oleogels from liquid oils high in unsaturated fatty acids blended with oleogelators (waxes, emulsifiers, hardfat) has gained attention because they can substitute vegetable shortenings and animal fats in many applications.
