The effects of new ingredient strategies to slow down starch retrogradation rate in cakes were investigated. In this study, devil's fudge cakes were formulated using gum, modified starch and enzyme technology. Cake samples that were prepared with combinations of gums, bacterial amylases and pregelatinized starch were found to have slower starch retrogradation rates. An accelerated shelf life protocol was followed to observe the effect of predescribed ingredients on slowing the starch retrogradation rate. The samples were evaluated for moisture content, water activity, texture and thermal properties, as well as morphological characteristics. The staling rate was found to be accelerated by the fluctuations in temperature from high to low temperatures. Modified starches, enzymes and gums were found to decrease the rate of staling and improve product quality. The formulated cakes were found to have 25% lower toughness and hardness values as compared with the control product. It was found that for all the cake formulations, there was a significant decrease in both hardness and toughness values, whereas springiness values did not change much. The basic differences within formulations were created by incorporation of gums, enzymes, soluble fibers, emulsifiers and modified flours in the cake. PRACTICAL APPLICATIONSNutritional balance is quite important for each individual. For certain groups of people, based on their activity levels, high energy supplies are required to help them to achieve their optimal performance. Cakes, waffles and pancakes are in the group of breakfast bakery items that provide high energy for these groups of people. In bakery food products, staling reactions start before microbial deteriorations; as a result, they are the major factor in determining shelf life. Cakes that are acceptable to the consumers should be moist and soft in texture. Starch retrogradation is the primary mechanism determining the shelf life of the product. Although the product is microbiologically safe, the adverse affects of starch crystals on textural properties is the main cause of product rejection by the consumer, which leads to huge economical losses. The current methods of controlling starch retrogradation lean on technologies of the 1980s. Despite several studies on bread staling, there is hardly any study on the staling mechanism of cakes and other bakery food items. This study provides information on how to retard staling in cakes by the use of an in-house developed accelerated shelf life protocol.

Numerical simulation was carried out to predict the effect of external temperature conditions on thermal behavior of frozen US military rations, during storage and transportation. An army breakfast menu box containing beefsteaks, concentrated orange juice, peppers & onions, French toast, and Danishes, was selected for conducting this study. Thermo-physical properties of each food item were characterized using their composition and differential scanning calorimeter (DSC). Apparent heat capacity method was used to account for the latent heat of phase change during simulation of thawing and freezing. Numerically simulated results were experimentally validated using a gel-based model food system and the food items in the menu box. The average deviation between numerically predicted temperature and experimentally measured temperature for the model food system was approximately 1°C and for the targeted food items the deviation ranged from 2°C to 5°C, depending on the food item.

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Pears in syrup in flexible pouches are part of the U.S. Army's Meals Ready-to-Eat rations, which are expected to have a shelf life of 3 years at 26.7C. However, browning during storage was reducing the shelf life. Pear pouches were subjected to complete headspace removal and rotation during retorting for extended shelf life of 45 days at 48.9C. The pears were tested for browning, ascorbic acid and headspace composition during storage. A combination of complete headspace removal and rotation of pouches during retorting increased the acceptability of pear by decreasing ascorbic acid degradation and browning. Aerobic and anaerobic ascorbic acid degradation reactions took place in the pears, with most of the aerobic degradation beginning during retorting. A lag period of several days between different stages of ascorbic acid degradation was detected. Finally, the ascorbic acid loss followed zero-order kinetics, with a reaction rate dependent on the initial concentration. PRACTICAL APPLICATIONSThis paper highlights the importance of minimizing the headspace volume during vacuum packaging and enhancing the application of heat transfer during retorting to improve the preservation of color of thermally processed pears in flexible pouches. This process also serves to reduce the ascorbic acid degradation during storage.

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