Manufacture of Frozen Peas from USA Dry Peas
The unit operations employed in the manufacture of frozen peas from USA dry peas, though similar in nature to those used in the manufacture of canned processed peas, include a number of essential differences.
If artificially colored peas are required, an appropriate coloring agent can be added to the pre-soaking water and to the water used for cooking the peas.
During canning, the texture of the peas is softened by the sterilization process. There is no equivalent to this during the preparation of frozen peas. Consequently, it is necessary to introduce a cooking stage.
This is achieved by extending the blanching to provide a total time of about 25 to 30 minutes at 203 degrees F (95 degrees C). Otherwise, a separate cooking process is introduced. At the end of cooking, using cold water, the peas should be cooled as rapidly as possible to a temperature not higher than 86 degrees F (30 degrees C) prior to the commencement of freezing.
The method used for freezing will inevitably depend upon the equipment available. Ideally, a ow freezer will be used so that the end product will be free owing in nature. Packing, in this case, will take place after the completion of freezing.
Alternatively, cooked and cooled peas may be packed into retail containers and then frozen in a plate freezer or blast freezer. Such aggregation of the peas can, however, impact quality.
Frozen foods should be stored at temperatures no warmer than -0.4 degrees F (-18 degrees C) to inhibit microbial growth. Provided due care is taken with regard to all the aspects of hygienic manufacture, the product will remain safe for the consumer during the storage period. Prolonged storage can lead to deterioration due to chemical rather than microbial reasons.
Frozen foods require a frozen distribution system able to help ensure that the products remain safe and meet the desired sensory quality requirements. It is the responsibility of the food manufacturer to guarantee that the distribution system used is adequate for the intended purpose.
Chemical, Physical, and Structural Changes
During leblebi processing, carbohydrates and proteins are modified as a consequence of the heat treatment, including the carmelization of polysaccharides on the surface of the chickpeas. In addition, some acids are partially decomposed during roasting, while volatile acids are partially lost due to evaporation. Chickpea volume increases during processing at the same time the density and kernel weight decrease. The flavor can also change, especially as a result of the heating processes.
During the resting stage other changes can occur, some positive (e.g., ripening) and some negative (e.g., off flavor). The original raw chickpea is dense and contains no air spaces. But during roasting, the water inside the chickpea changes from liquid to vapor. Given the compact structure of chickpeas, this can cause an increase in the vapor pressure of water so that the steam that is generated triggers expansion during roasting. This can lead to development in the chickpea of a large number of air spaces in the cotyledons and give roasted chickpeas a porous structure and an opaque, chalky appearance.
The Growing Role of Legumes
Food legumes are important components in a healthy diet and make major contributions to good health around the world. Whether canned, roasted, fried, or used as an ingredient in soup, pulses offer a welcome alternative to the fast foods that have come to de ne the diets of so many.
The more we learn about the benefits of pulses and how best to process and prepare them, the greater the number of options will develop for their use. To promote their increased consumption, new and ever-more appealing products are required in the market. Food researchers are employed in just such a pursuit, attempting every day to find new uses beyond regional and ethnic preferences in an effort to introduce consumers around the globe to these delicious, versatile, healthful foods.See Appendix C for a collection of sample formulations.