44 Biscuit, cookie and cracker manufacturing manuals 6.8 Spray oil fats Many cracker biscuits are sprayed with oil immediately after baking This improves the appearance of the biscuits and modifies the eating The fat used for spraying must be selected with care. On the surface of biscuits the fat is exposed to the air and hence to xidation. The technique of spraying also is conducive to oxidation changes as the oil is hot and the droplets are small and have a great ce area Fats which are resistant to oxidative change should be used. The cheapest and among the best are the same fats that are used for sandwich creams, coconut oil and palm kernel oil. The fats are sprayed warm and the fact that they are solid at ambient temperature is not important as the film on the biscuit surface does not set to an obvious crust. However, if higher melting types are used there is a tendency for the fat to set and cause adhesion to touching biscuits when packed in columns. The adhesion may result in damage to the thin surface of the biscuits as they are separated before eating 6.9 Use of emulsifiers and antioxidants Before leaving the complex and important subject of fats and oils, mention should be made of the additives that are commonly associated with fats Fats and water are not miscible. Thus when doughs are made it is necessary for vigorous action to ensure that the fat is present as very small globules in a flour and sugar system that has an aqueous phase. It is possible to improve the dispersion of the fat in the aqueous phase by using a chemical that has both water and oil solubility characters. Chemicals with these properties are called surface active agents and range from those that promote the dissolution of fats in water, known to us as detergents, and those that promote the dispersion of water in fat, commonly called emulsifiers Fats in a biscuit recipe contribute to the soft eating nature of the baked biscuit. They make the dough shorter, less extensible and the biscuit softer because less water is needed to make the dough. For this reason dough fats are sometimes referred to as shortenings. By using a small quantity of an emulsifier the fat is dispersed in the dough better and the shortening effect is significantly improved It is common to find that using an emulsifier can reduce the quantity of44 Biscuit, cookie and cracker manufacturing manuals 6.8 Spray oil fats Many cracker biscuits are sprayed with oil immediately after baking. This improves the appearance of the biscuits and modifies the eating quality. The fat used for spraying must be selected with care. On the surface of biscuits the fat is exposed to the air and hence to oxidation. The technique of spraying also is conducive to oxidation changes as the oil is hot and the droplets are small and have a great surface area. Fats which are resistant to oxidative change should be used. The cheapest and among the best are the same fats that are used for sandwich creams, coconut oil and palm kernel oil. The fats are sprayed warm and the fact that they are solid at ambient temperature is not important as the film on the biscuit surface does not set to an obvious crust. However, if higher melting types are used there is a tendency for the fat to set and cause adhesion to touching biscuits when packed in columns. The adhesion may result in damage to the thin surface of the biscuits as they are separated before eating. 6.9 Use of emulsifiers and antioxidants Before leaving the complex and important subject of fats and oils, mention should be made of the additives that are commonly associated with fats. Fats and water are not miscible. Thus when doughs are made it is necessary for vigorous action to ensure that the fat is present as very small globules in a flour and sugar system that has an aqueous phase. It is possible to improve the dispersion of the fat in the aqueous phase by using a chemical that has both water and oil solubility characters. Chemicals with these properties are called surface active agents and range from those that promote the dissolution of fats in water, known to us as detergents, and those that promote the dispersion of water in fat, commonly called emulsifiers. Fats in a biscuit recipe contribute to the soft eating nature of the baked biscuit. They make the dough shorter, less extensible and the biscuit softer because less water is needed to make the dough. For this reason dough fats are sometimes referred to as shortenings. By using a small quantity of an emulsifier the fat is dispersed in the dough better and the shortening effect is significantly improved. It is common to find that using an emulsifier can reduce the quantity of